Wednesday, April 30, 2008

red in tooth and claw...

... and a good way for you to start thinking about the evolution of cooperation and kin selection!


Pritha Singh found this astonishing video to share with the class:









While the above is mostly raw footage posted to YouTube acclaim, here's a higher-resolution version edited and with commentary, as broadcast on the National Geographic Channel .








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Tuesday, April 29, 2008

A breath of reason after a week full of truthiness

After the week we've had in these parts with assorted god-botherers turning up to sell snake-oil throughout town, it was so refreshing to catch this interview with the author of "The Age of American Unreason":



I'm impressed with how well she kept pace with Colbert! Must have something to do with that elitist reason thing she touts...



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The trouble with eating things with claws

... is that they can get you even after you've killed them! If you need another reason to stay away from eating chicken-feet, check out this photo: they might be kinda hard to swallow!


080424-hawk-claw-02.jpg


Note, however, that this is not a case of a bird trying to fight its way out of they hawk's gullet - more an accident when you try to swallow sharp objects that can rupture your crop and burst through your skin! This poor little Sharp-shinned Hawk had properly killed the small bird it was trying to eat, but appears to have bitten off more than it could swallow, resulting in a rather bizarre death. Can we nominate this hawk for a Darwin Award?


[From Dead Hawk's Last Meal Claws Partway Out]




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Monday, April 28, 2008

More on the flamenco-dance of the male jumping spider





This is from the recent episode of Nature on PBS:



With a high-speed camera and vibrometer in his toolkit, researcher Damian Elias, featured in Part Two of "What Females Want and Males Will Do," is able to pick up on a courtship ritual few have ever seen before. He's discovered that male jumping spiders actually perform an elaborate dance — with coordinated vibrations, no less — to woo potential partners. Part of the 26th season of the Peabody and Emmy award-winning series produced by Thirteen/WNET New York for PBS, "What Females Want and Males Will Do" premiered over two Sundays, April 6 and 13, at 8 p.m. (check local listings). For more information, visit http://www.pbs.org/nature.

And while there, browse the archives for more cool animal behavior footage from this series on sexual selection. Given that we are discussing sexual selection in class this week, I may post more of these videos here as well.



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A summary of Ted Peter's talk on the ethics of stem cell research

Student post submitted by Stephanie Chow.


Ted Peters discussed the topic of stem cell controversy at Wednesday’s ethics lecture. He brought a surprising amount of information about both sides of the debate. [I felt he was a little heavy on the pro-stem cell usage side, but he admitted that he was personally still on the fence for the issue.] A summary of what he discussed:


Regenerative medicine has the potential to offset diseases such as Parkinson’s disease, Alzheimer’s, and multiple sclerosis. This can be achieved using undifferentiated stem cells. These cells are obtained as blastocysts from fertilized eggs are broken apart. Most of the stem cells used in research come from fertility clinics. When women undergo fertility treatments, they fertilize several of their eggs at once. They use one or two at a time, and the rest are frozen. If that single treatment becomes a successful pregnancy, the woman often decides that they do not need the other eggs. Rather than be discarded, these fertilized eggs are used in research.


There are several ethical arguments against the use of stem cells. One is the embryo protection reason. Roman Catholics have taken the stance that scientists should not take apart the blastocyst to get stem cells. They feel that once an egg is fertilized (and is a zygote at that point), it has dignity because it has a soul. In other words, each unique genome correlates with a unique soul. The “14-day position” is another argument used within embryo protection. After 14 days, the fertilized egg adheres to the uterine wall and develops the primitive streak (the first stage of backbone development). Other religious groups used the 14-day position to explain their feelings towards stem cell usage.


Proponents for stem cell research contend that every fertilized egg should not automatically be considered a person. They give the statistic that 60-80% of all fertilized eggs are flushed from the woman’s body, known as fetal wastage. There is also the circumstance of chimerism, when two fertilized eggs join and a person will end up with extra genome. Stem cell advocates say that situations like these demonstrate that not every fertilized egg is a unique, soul-bearing being.



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Regenerative medicine inspired by a Newt

Student post submitted by Sheena Edmonds


ResearchBlogging.orgResearchers in the field of regenerative medicine are turning their attention to a potentially new source of stem cells. This new source is generated directly from ones own cells that were previously thought to be terminally differentiated. If scientists are correct they will be able to take any cell in the body and dedifferentiate it so that it goes from a more differentiated state to a less differentiated state. This phenomenon is most frequently seen in invertebrates like earthworms and amphibians. When an earthworm is cut in two it has the ability to regenerate into two identical worms. Newts have been reported to have the ability to regenerate entire limbs, tail and even their spinal cord. Unfortunately, mammals are a little more restricted in their ability to regenerate parts of their body due to irreversible differentiation in certain tissues. Aside from this, researchers believe that by studying the mechanism by which newts restore their tissues by dedifferentiation they might discover a molecular signal that can be incorporated into humans that would allow them to rejuvenate damaged tissue through dedifferentiation. This is thought to be more beneficial than organ transplants, tissue engineering, and even stem cell therapy because the cells involved in dedifferentiation come from the patient going through treatment. By using ones own cells there is no risk of initiating an immune response and no chance of rejection. In addition, ethicists might be more favorable to this type of regenerative medicine as opposed to embryonic stem cells. (continues below...)


fig13_12.jpgMore studies are being done to determine how exactly this process works. At the genetic level the cells gene activation is repressed and genes that keep the cell in an undifferentiated state are turned on. Once these genes are turned on the cell can reenter the cell cycle (Cai, 2007). The most familiar example of this process is the ability of a newt to grow back its tail after having it amputated. By studying the unique behavior of newts and examining this adaptation they have, researchers believe they can uncover the exact signaling that initiates a phenotypic reversion of fully differentiated cells. Studies indicated that once the tail is amputated the epithelial cells migrate and form a mature epithelium cap at the end of the wound. The internal cells underlying the cap lose their tissue characteristics and dedifferentiate in response to an unknown signal. The dedifferentiated cells proliferate and form a mass of pluripotent cells that are capable of redifferentiating. These pluripotent cells then build a replica of the missing tail (Cai, 2007). It is clear that this event does happen, however, the goal is to discover what molecular signals make it occur.


An experiment was done that utilized immature muscle cells of newts and mice. The two types of myoblasts were grown together and induced to differentiate into skeletal muscle fibers. Some of the newt myoblasts fused with the mouse myoblasts and created a hybrid. The hybrid cells were isolated and stimulated with serum (Cai, 2007). The serum was expected to cause the newt myotube to synthesize DNA but they did not expect the mouse myotube to do the same. Shockingly, the mouse myotube also began to synthesize DNA which indicated that there was something in the newt myotube nuclei that made the mouse myotube nuclei able to respond to the serum (Cai, 2007). In yet another experiment, the mouse myotube dedifferentiated when it was treated with extract derived form the regenerating limb of the newt implying the signal that initiates dedifferentiation was in the extract. Researchers subjected the extract to chemical and physical treatment including lipid removal, boiling, and trypsin digestion. The results proved the signal within the extract was a protein (Cai, 2007). Moreover, these two experiments confirm that mammalian cells can dedifferentiate when stimulated with the right factors. Identification of the exact molecules would aid in studying the mechanism for dedifferentiation which could eventually be used to regenerate tissue in vivo.


Researchers have now directed their attention to studying the dedifferentiation process that occurs in human myoblasts. They found that ciliary neurotrophic factor (CNTF) plays an important role in regulating many processes with in the nervous system. They also found that there are an abundance of CNTF receptors in human skeletal muscles (Cai, 2007). More excitingly they tested the affects of CNTF and found that it induced committed myoblasts to dedifferentiate into mulitpotent cells. Not only could these cells restore skeletal muscles, they also have the ability to differentiate into new tissues such as neurons, glial cells, and smooth muscle cells (Cai, 2007).


By investigating the way invertebrates adapt to the stresses and strains of their environment researchers have come closer to discovering the mechanism by which cells that were previously thought to be permanently differentiated can work backwards to their original pluripotent cells. This new method for regenerative medicine is one of the many breakthroughs in modern science. Dedifferentiation of one’s own cells offers many advantages over other researched treatments. It poses little threat of initiating an immune response and it is morally more correct then utilizing human embryonic stem cells.


Reference:



CAI, S., FU, X., SHENG, Z. (2007). Dedifferentiation: A New Approach in Stem Cell Research. BioScience, 57(8), 655. DOI: 10.1641/B570805

Additional related articles:



Cells That Go Back In Time


Mammalian myotube dedifferentiation induced by newt regeneration extract




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The mating dance of the jumping spider

As seen in lecture on friday!

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human sexual attraction and stinky t-shirts

Hat-tip: Lisa Anderson for pointing to this video in a comment on Stephanie Chow's post on weird ways to pick mates

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Benefits of invading exotic organisms in a marine environment

Student post submitted by Darin Alexander.


ResearchBlogging.orgWhen we think of invading exotic species you already have a negitive view in your mind. There is a high rate of negative publicity on exotic species. They are thought to be destructive, and can cause large amounts of stress and possible extinction of native species. This is a true statement when it comes to terrestrial or aquatic species, but what about marine? In this article John Briggs discusses the benefits, yes benefits, invasive species can have on marine environments. (Continues below...)


Briggs discusses the ongoing situation taking place in the Mediterranean. Since the opening of the Suez Canal in 1869 there has been a steady stream of invading species to the Mediterranean from the red sea. 300 of these organisms are now established in the area. The organisms documented are 59 fish species, 129 mollusk species and 49 crustacean species. You would think with all these new entering species they must be pushing out native ones. This is a surprisingly wrong assumption. From the data collected there have been no extinctions due to the newly invading species. They have actually increases the community’s biodiversity and has been beneficial. Introduced primary consumers have increased consumption of producers and allowed more access to energy. This helps increase the community’s productivity. People commonly lump the problem of aquatic and terrestrial invaded species with marine but this is a mistake.


It has been shown that there is no obvious detrimental effect invading species have on marine environment. In most instances marine invaders are needed to help keep up the populations biodiversity. This article also talks about the migration of mollusks 5.4 billion years ago across the Bering Strait. The mollusks came from the pacific region of the U.S and settled on the coast of Europe and Eastern America. A statistic given is now 47% of the original pacific species established on the east coast has diverged into a separate species. This is Evolution and species divergence at hand. Also with fossil records they were able to prove that the invading species caused no extinction of the original native species and in some cases the populations assimilated together.


This was a very interesting article and it shows different aspects of things we have leaned in class this year. We go from migration, to competition, to nitch differentiation, to species divergence, then to assimilation and eventually evolution. It also sheds some light on the benefits of exotic organism invasion and shows us that it is not always bad.


Reference:


Briggs, J.C. (2007). Marine biogeography and ecology: invasions and introductions. Journal of Biogeography, 34(2), 193-198. DOI: 10.1111/j.1365-2699.2006.01632.x


Abstract:


Although biogeography and ecology had previously been considered distinct disciplines, this outlook began to change in the early 1990s. Several people expressed interest in creating a link that would help ecologists become more aware of external influences on communities and help biogeography’s realize that distribution patterns had their genesis at the community level. They proposed an interdisciplinary approach called macroecology. This concept has been aided by the advent of phylogeography, for a better knowledge of genetic relationships has had great interdisciplinary value. Two areas of research that should obviously benefit from a macroecological approach are: (1) the question of local vs. regional diversity and (2) the question of whether invader species pose a threat to biodiversity. The two questions are related, because both deal with the vulnerability of ecosystems to penetration by invading species. Biogeographers, who have studied the broad oceanic patterns of dispersal and colonization, tend to regard isolated communities as being open to invasion from areas with greater biodiversity. It became evident that many wide-ranging species were produced in centres of origin, and that the location of communities with respect to such centres had a direct effect on the level of species diversity. Ecologists, in earlier years, thought that a community could become saturated with species and would thereafter be self-sustaining. But recent research has shown that saturation is probably never achieved and that the assembly of communities and their maintenance is more or less dependent on the invasion of species from elsewhere. The study of invasions that take place in coastal areas, usually the result of ship traffic and/or aquaculture imports, has special importance due to numerous opinions expressed by scientists and policy-makers that such invasions are a major threat to biodiversity. However, none of the studies so far conducted has identified the extinction of a single, native marine species due to the influence of an exotic invader. Furthermore, fossil evidence of historical invasions does not indicate that invasive species have caused native extinctions or reductions in biodiversity.



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Are facial expressions hereditary within a family?

ResearchBlogging.org[Student post submitted by Swapna Medichetti]


A group of researchers from Israel conducted an interesting study on human subjects and tried to provide evidence for a signature of facial expressions that is supposedly unique within a family. Before this, many studies relating to this have been done on humans. These studies show proof of facial expressions being heritable in an individual while some focus on how different facial expressions are among individuals. But there have been no reports of studies that throw light on different emotional states of people belonging to the same family. (continue reading below the fold)


They did this by studying the ‘gestalt’ of facial expressions in different emotional states that include thinking, sadness, happiness, anger, surprise and disgust. The most interesting thing about this study is that half the human subjects that they used in the study are blind, by birth. The other half consisted of relatives of the blind individuals, who had a normal vision. Basically, by using various tests and individual interviews, they tried to compare the facial expressions of the blind person in all five emotional states to that of his or her relative who had a normal vision.


zpq0420638250004.jpegI am assuming the reason behind them using blind individuals as their subjects is to control for the expressions that could have been developed in an individual by learning from people around them, over time. They have also removed the factors in the study that could account for false results. For example, they made sure that the blind subjects did not learn these expressions by touching the face of their relatives. They also made sure that the subjects with normal vision did not imitate the blind subjects.


The study has 21 blind people, and 30 normal vision people who are related to them. The researchers induced expressions in the subjects by asking them questions that would allow them to feel all the five emotions. For example, if they had to study anger, they asked them to talk about something that they are not very happy about. They documented what they observed in the form of writing and recorded videos while interviewing the subjects.


The study made use of a few computational methods like the in-out family test and the classification test. In the first method, they calculated the frequency at which the blind subject’s facial expression occurred in relation to that of his or her relatives’. In-family represents a positive result where the blind subjects and their relatives show the same face expression. On the other hand, the out-family represents a negative result where the blind subjects do not show the same facial expressions as their relatives. This was done for all the five different emotional states.


In the second method, based on the facial expressions, the blind subjects are classified to his or her family. This was apparently done to differentiate between two different sets of data. They also calculated the heritability in terms of high or low. Both the tests showed a positive correlation between the occurrence of facial expressions of blind subjects and their relatives. Future study can include work on genes that account for these expressions on the face.


Charles Darwin wrote a book called ‘The expression of the emotions in man and animals’, which talks in great details about the heritability of emotions and expressions. The book is available online on the Darwin online website.


Reference:


Peleg, G., Katzir, G., Peleg, O., Kamara, M., Brodsky, L., Hel-Or, H., Keren, D., Nevo, E. (2006). From the Cover: Hereditary family signature of facial expression. Proceedings of the National Academy of Sciences, 103(43), 15921-15926. DOI: 10.1073/pnas.0607551103



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Evolution by Song

ResearchBlogging.org[Student post submitted by Darin Alexander]


plumbeitarsus singing.jpgThis is a well written and studied article. This article was about the evolutionary divergence of the Siberian green warbler. The evidence they gather for their thesis is overwhelmingly convincing and they seemed to cover all questions that may come up. They believed and tested that the divergence of song may be the main cause of speciation. This is a highly feasible theory because if you can’t understand someone it is hard to breed with them. (Continues below...)


Background Information: The warbler formed a ring species of interbreeding populations. These populations differed slightly in size, habitat, and calls/songs they use for communication and mating. When we reach the western and eastern Siberian warblers there song was so different that they don’t interbreed causing two separate species. “Molecular genetic data and consideration of preistolene climatological history indicate that the west Siberian and east Siberian forms of green warbler each result from northward expansions of southern forms along separate routes. (Irwin et al 2008)” The article takes a look at the evolution of calls and songs and what possible scenarios might have caused the variation.


The main hypothesis for song variation came from the size of the warbler, the environmental influence of sound, and genetic variation. As the species traveled northward the habitats would have been similar on their parallel routes. With this you would assume that the songs of the two groups migrating would be identical if habitat was the cause of evolution. This was not the case because the eastern and western form varied in song still. As they moved north the land was lusher so warblers grew larger in size. The two groups although similar in size also varied in song so that hypothesis also had to be thrown out.GW map with songs.jpg


Due to genetic testing it shows as the warblers migrated around small genetic changes caused a simultaneous change in their songs and calls. This was indeed the cause of the speciation of the two migrating warblers. When the two reached Siberia there vocal communication was so altered that they had completely different mating songs. You can’t really court a mate if she can’t understand you. So these small genetic changes that occurred while the warbler groups were separated cased the species to separate into two groups.


I believe there is sufficient evidence to conclude that song is the main cause for speciation in the warbler. The tests they conducted took all questions into account. The environment and landscape and there effects on sound was the main question on variation. The Warbler evolution is a fascinating event and it shows us firsthand how a related species can diverge into separate groups.


Reference:


IRWIN, D.E., THIMGAN, M.P., IRWIN, J.H. (2008). Call divergence is correlated with geographic and genetic distance in greenish warblers (Phylloscopus trochiloides): a strong role for stochasticity in signal evolution?. Journal of Evolutionary Biology, 21(2), 435-448. DOI: 10.1111/j.1420-9101.2007.01499.x


Abstract


Abstract
Divergence in signaling systems might play a central role in speciation. To assess the importance of possible causes of signal divergence, we examine two types of vocalizations within a geographically variable species complex, the greenish warblers (Phylloscopus trochiloides Sundevall). Calls, which are used by both sexes throughout the year, and songs, which are sung primarily by breeding males, differ distinctly between two distinct Siberian forms. Through
a ring of southern populations that connect the northern forms, signal divergence is correlated with both geographic distance and genetic divergence. Calls and songs differ in their particular patterns of geographic variation, probably because of the larger influence of sexual selection on songs than on calls. These patterns are supportive of neither acoustic adaptation nor morphology being major drivers of divergence in vocalizations. Rather, these results support the importance of stochastic evolution of communication systems in the evolution of new species.



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More from the other side: the origin of life

[Student post submitted by Sukh Kang]


Taken aback from the discussion we had in class about how to this day, after so much biological evidence, both on the micro and the macro level, there are people who still believe that evolution is a myth, and it simply does not exist! While searching for an interesting evolutionary article to write about, I came across this brief video clip, which argues that the organisms in this world did not descend from one common ancestor, but were rather created by an intelligent being for a purpose, and that there is a design to the universe! (Continues below...)


This video clip starts off by quoting Charles Darwin, the father of evolution, “The universe is precisely the properties we should expect. If there is at the bottom no design, no purpose, nothing but blind pitiless indifferences.” This is followed by a commentary from the general public on how they feel about evolution. After that begins the argument that Evolution simply did not occur and that there is far too much diversity and variation in organisms to tie them all back to one common ancestor.


What is interesting about this video is that most of the people or the speakers arguing against evolution are scientists, including a molecular biologist, a biochemist, and a microbiologist. To think that these people who have deeply studied biology and still don’t believe in evolution makes a great case for the con side. Other speakers include scientific Philosophers, a science author as well as an astronomer.


Some of the interesting points from the video include the Microbiologist mentioning that the more we get to learn about biology and life, the more problems Darwinism has. Another main point was that there is not the slightest chance of chemical evolutionary origin for even the simplest of cells in out bodies. The third main biological argument made is that the discovery of information bearing properties of DNA and RNA fundamentally challenges all of the existing materialistic theories to the origin of life. There is a mention that the theories of evolution and others alike will not be able to survive the biology of the 21st century, because they’re inconsistent.


The video was really catchy and made some bold claims to void the theory of evolution which was first presented by Charles Darwin. While it is very persuasive and has strong references, none of them really explain what the problem is with the Darwinian Theory and why it is becoming outdated in the 21st century. It is their personal educational experiences mixed with their beliefs and their assumptions. While it is in no way challenging to the accepted theory of evolution, I thought it was still very interesting to hear the other side, and contribute to the topic brought up in class today!



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Wednesday, April 23, 2008

Patton is Awesome!

Or so says one student - Biology major Steven Miller (yes, he's a Steve who may not be on the list yet) who attended Monday night's lecture by Don Patton on campus. Miller wants to share his thoughts on the talk, so read on below:


I had a chance to go to this wonderful event and there were numerous problems with this man's presentation. One of the main topics of the lecture was to promote creation science teaching in schools as an alternative scientific approach to evolution, as opposed to a religious pursuit. The supposed basis for this field is that it is based on the observation of things in the universe that are apparently designed and must have a creator. I find his examples to be preposterous and I believe I can list quite a number of ordered things that occur in nature, and that are not created by people in our world or by any intelligence that is known. He amusingly used the bacterial flagellum as a proof for his point. This is something that appears to have been created and is de facto, created by intelligence. Not by random chance, and although he didn't use the really cool phrase 'irreducible complexity,' (and for the anonymous person who claims text cannot express implied tone - I am being sarcastic) he alluded to the flagella working with its complex 30 working parts and would not be able to do so without them but he is most likely referring to the eubacterial flagella that was mentioned by William Dembski and Michael Behe. There are numerous examples in eubacteria and archebacteria that function in motility and work by very different mechanisms, without the 30 parts, that he would claim are required for the proper function of that complex machine (the flagella is NOT a machine, his definition of a machine is from a human perspective and does not entirely apply to the flagella, which by the way does not only function in motility!). Also, numerous studies have actually produced bacteria with flagella that have been significantly pruned but still function properly in motility, along with the other numerous functions that were not mentioned.


But... I digress, I was a little distracted by the 'evidence.' Why is it not okay to allow this guy into our colleges, into our high schools? Is this truly a scientific alternative to the teaching of evolution that does not have to do with evolution? No! It is not!


The very idea of creation - is a religious idea. He did not say outright if he thought the world was 10,000 years old or not but he did put it on a slide, so I can guess he disagrees with the age of the world/universe according to natural science. That specific age of the world/universe is a Christian concept. But, since he very carefully did not say what his belief was (at any point in the lecture), I cannot rightfully say that I KNOW that he believes this, even though, I think it is likely. What I can say however, is that the theory there is a creator, is a religious perspective. He even mentioned 'Adam' being the first man (a Christian idea!).


There were numerous problems with his proposing this 'creation science' be taught in schools. Ignoring that for a little bit, let's proceed onto other topics that were discussed.


There were quite a few scientists that were quoted out of context. Including, one of my favorites - Richard Dawkins - on many occasions. He quoted the first page of Richard Dawkin's book, The Blind Watchmaker, that says:



Biology is the study of complicated things that give the appearance for having been designed for a purpose.



Not only does he fail to mention the subtitle of this book, "Why the Evidence of Evolution Reveals a Universe Without Design" he provides this quote as if biologists might have some doubt that evolutionists like Dawkins' may even have doubt themselves that evolution can explain the whole picture. Nor does he finish explaining what was on the rest of the page in Dawkins’ book! He also quotes Richard Dawkins' during an interview with Bill O’Reilly, here Dawkin’s says that evolutionary biologists can observe evolution, and in order to secure a point, Dawkins’ says that large changes in evolution are like coming upon a murder scene with blood, fingerprints, etc. Bill O’Reilly believed he proved Dawkins’ and evolutionary biologists alike – are morons when he says, “But did you see the murder?” Did Dawkins, Mayr, Darwin, or anyone else see the transitional species like Tiktaalik Roseae, Dinosaurs, Neanderthals, etc? NO! No biologist said that he has seen these organisms alive, or that we have seen the life history of the planet in its entirety. Although, I could deal with this terrible logic more, it is irrelevant because I must mention, why was he talking about this?


Don Patton, PhD (Education), was saying that using the strict definition of the scientific method, we cannot study evolution, we cannot study creation science. But according to him if we use ‘science,’ we can! Whaaaat? To do science we use the scientific method! We have conducted experiments on evolution (change in allele frequencies in a population) and we’ve witnessed the results. He claims to refute this point by discussing his term horizontal variation, that quantitative trait differences, like beak depth (which he mentioned) always exist in a spectrum with averages and shift around, but they’ll always exist, and if for some reason some variable trait is no longer present, populations can revert back to these traits. No traits appear or disappear. He also mentions that evolution is the building up of information, and thinks that evolution says that new traits simply appear.


Once again, what is his example for the appearance of traits that supposedly confirm evolution according to biologists? Antibiotic resistance!! And I’m so glad he discussed this. He goes on to say, genes for antibiotic resistance didn’t simply appear in populations and that they are always present at some percentage in a population (he shows a picture that has 20% of individuals in the image are resistant to antibiotics). Once antibiotics are applied to this population, now 80% of the individuals die, and the remaining members (now 100%) of the population are resistant to antibiotics. He thinks this is a proof because this was a trait that was present all along, and that all of us biologists are morons for stating antibiotic resistance appeared, which he uses synonymously with evolved. Which is an incorrect usage of the word, AND no biologist would say that.


Why is this actually a proof FOR evolution? As we should know from our class, evolution is a change in allele frequency over time. Over the time where antibiotics are applied to this population, the bacteria who are resistant, survive and the gene for antibiotic resistance goes from an allele frequency of perhaps 0.2 to 1. This IS evolution!!! He said that this is an example of ‘horizontal variation’ but his definition for horizontal variation says that there is a trait in a population that varies (i.e. antibiotic resistance, antibiotic susceptibility). How can antibiotic resistance vary in this population when 100% of the individuals possess the gene for antibiotic resistance?! I actually asked this question to Don Patton and his reply to me was:



Well… ha ha.. when you use strict definitions like that, then yes that makes sense to the mind of a biologist.



What?! I used his definition of horizontal variation!!!!! Also, that is an example of a loss of information!!! Evolution does not suggest there will be a gain of information in population over time. If he did possess any information or knowledge regarding the genetic aspect of the Modern Synthesis, he might’ve had more interesting arguments, he might have been able to discuss that perhaps the bacteria in his example were heterozygous for this gene of resistance, and some of the population will horizontally vary back to susceptible, but he did no such thing, and it would be easy to eviscerate that line or thinking (since that would be a change in allele frequency!!!). Oh I forgot to mention, he thinks a lot of evolution education is a conspiracy amongst scientists and the media. An example of what he believes – regarding this statement – is that Darwin plagiarized most of his work.


Although, I was rightfully upset by the time I left that room, I was comfortable knowing this logic was rather pathetic and fails to carry any weight. I can only think of what Dr. Muller said the next morning after the lecture (which I hope she does not mind me quoting) If this is the best that they can bring on, I am not too worried. I could not agree more.




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A more substantial discussion about biology and theology on campus today

At least I expect it to be more substantial than the other stuff that's been going on around here lately. The last lecture of the Ethics Center's spring seminar series will be by Ted Peters, a theologian who has published extensively on the connections between science and religion and ethics.


In today's lecture "The Stem Cell Controversy: Who is Fighting Whom About What?" Peters will discuss religious and ethical issues that arise in the context of debates about stem cell research and biotechnology. This talk will be based in part on Peters’ recent book, The Stem Cell Debate.


The lecture will be at noon in the Alice Peters Auditorium at the University Business Center.


Ted Peters is Professor of Systematic Theology at Pacific Lutheran Theological Seminary and the Graduate Theological Union in Berkeley, California. His recent books include: Science, Theology, and Ethics, Playing God? Genetic Determinism and Human Freedom and the forthcoming Sacred Cells?: Why Christians Should Support Stem Cell Research. Peters also serves on the Scientific and Medical Accountability Standards Working Group for the California Institute for Regenerative Medicine (CIRM).


Andrew Fiala reminds me to add that Peters will also be meeting with students in the philosophy club from 2-3 in USU 311, where he will lead an informal and general discussion of religious studies, theology, science, free will and determinism, and whatever else students want to talk about. Faculty and students are welcome to attend.


And students, if you attend, consider submitting your impressions/reflections on the talk and the general topic of stem cell ethics for this class blog.



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Tuesday, April 22, 2008

A Bird's Way Up

ResearchBlogging.org


Student post submitted by Emily Felts.

In an article published in Bioscience two years ago entitled “What Use Is Half a Wing in the Ecology and Evolution of Birds?”, authors Kenneth Dial and colleagues suggest the answer is climbing. The authors reject the traditional view of wing evolution in birds as either ground-up, or tree-down, and suggest a third, up-a-rock model. They used the chukar partridge as a model because it is a ground bird that prefers to use wing-assisted incline running or WAIR to flying in gaining higher ground, and has precocial development(a trait that is thought to be shared with birds' dinosaur ancestors. They then record various activities of chukar chicks and adults.


The authors criticize the tree-down and ground-up models as both limited and unsupported. The tree-down model, they argue, is not a clear and logical explanation for how wings for gliding could have evolved for flying. They suggest the current examples of gliding by vertebrates, such as squirrels with extra skin who glide form limb to limb and to avoid injury during falls, are sufficient for an arboreal environment and show no inclination to need or that they would gain an advantage by the adaptation of flight. The ground-up hypothesis is even less likely say the authors, the idea that proto-wings were used to accelerate running seems unlikely when no bipedal organism currently uses that strategy.


I think their point on the flaws with the tree-down hypothesis demonstrates how hypotheses for the evolution of characters are weakened when they lack a way to support them through observation, experimental, or correlative methods. An explanation for how and why a feature came to evolve needs more than just an intuitive guess. I think they made an even better argument with the weakness of ground-up because if using wings or proto-wings to increase speed was advantageous, it would seem that some of the extant fast running, bipedal birds like the ostrich would employ it, rather than tucking its wings out of the way. Also, flapping arms\proto-wings\wings to gain speed would be energetically costly and would only be advantageous in that it allowed the organism to run faster than its prey/predator, thus I think the use of arms\proto-wings\wings for acceleration is overkill.dialnaturecover1_001.jpg


Fairly recently, certain ground birds have been discovered to use their wings to run up steep inclines, even at ninety degree angles. This is called wing-assisted incline running (WAIR) and is preferentially used to flying when the terrain makes it possible. Because chukars are ground dwelling, they have powerful leg muscles that are capable of sustained work. Though chukars are fully capable of flight, their wings are dependent on anaerobic energy and they tire easily. WAIR is thought to be an energy efficient means of escape for the ground birds that exhibit it. The authors argue (as a few have before them) that WAIR is a good model for the transient stages of flight and that it shows a gradient of adaptation that gives a possible explanation to how wings capable of full flight arose.


The authors tested the wing stroke and the force generated during WAIR with adult chukars. They found that the wing stroke was similar to a flying stroke, but rotated so the force pulls the bird toward the substrate and slightly upwards, increasing traction and adding some propulsion. They also showed that the majority of the ascension was powered by the legs. Then, they used day old to adult chukars to simulate the use of WAIR with less developed wings to those that can fly. Chukar chicks are incapable of true flight until they are seven or eight days old, though they can run soon after hatching. They reach their full flight capabilities by seventy days. The authors tested WAIR ability as the chukars were growing up. In some of the chicks, they plucked out the wing flight feathers, in others, they trimmed the feathers to half their size, and some they left intact. Though the intact birds did WAIR best and the plucked birds worst, all used WAIR to get to elevated areas. They authors also found that chukars start with symmetrical flight feathers before later developing their asymmetrical flight feathers usually seen in adult birds. Though symmetrical feathers are often thought to have no aerodynamic value and not meant for flight, birds in this stage are capable of creating aerodynamic force to ascend steeper inclines then they could otherwise do.


Because the developing feathers and bodies of young birds can give insight into transitional forms of flight, this experiment did well in using developing birds. Also, by using modified wings, they showed that even a proto-wing with the less derived symmetrical feathers could be useful in WAIR for escaping predators. By showing that the wing stroke during WAIR could be modified for flight by simply rotating it, they support their clam that WAIR could represent a transitional step. Though the wing stroke during WAIR may be a precursor to flight, the authors didn’t mention that the similarity might exist because WAIR may have come after fully flight, rotating the wing stroke from that of propulsion through the air, to up a cliff.


The experiments done by the authors furthered the understanding of WAIR and made a decent argument for it being the transitional step to flight. That WAIR can be used by modified wings, useless for flight, as well as wings capable of flight demonstrates a possible transition from a flightless ground bird, to one that is capable of powered flight. That the authors demonstrated that a symmetrical feather can be aerodynamically useful might also lead to a reinterpretation of the fossil record, where birds with symmetrical feathers were often assumed to be flightless. The article is also a call to base ideas on possible functions of transitional forms on evidence from many disciplines such as life history, and development to achieve a more holistic and complete model rather than one based on some evidence but with guesswork filling in the blanks.


[Editor's note: Ken Dial and colleagues have recently published another paper in Nature (which Emily must've have missed) where they tested their theory further, by focusing specifically on wing-stroke kinematics. You can download the article and read more about this work from Dial's website - Madhu Katti]

Reference:


Dial, K.P., Randall, R.J., Dial, T.R. (2006). What Use Is Half a Wing in the Ecology and Evolution of Birds?. BioScience, 56(5), 437. DOI: 10.1641/0006-3568(2006)056[0437:WUIHAW]2.0.CO;2


Dial, K.P., Jackson, B.E., Segre, P. (2008). A fundamental avian wing-stroke provides a new perspective on the evolution of flight. Nature, 451(7181), 985-989. DOI: 10.1038/nature06517



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Those disorganized cellular filing cabinets we call chromosomes


Dear readers who were subjected to last night's dumb version of science, your reeducation must begin now, starting with the basics! And, by an amazing coincidence, there happens to be an excellent new post on Pharyngula today, addressing a basic question: how can chromosome numbers change? Go read it, and bookmark it for future reference. If you haven't yet had someone throw that question at you as a "gotcha" about how new species couldn't possibly evolve, you will likely find it flying at you one of these days - and if you read this post, you'll be ready!


PZ makes the nucleus sound rather like my office: lots of disorganized information stashed in bundles everywhere... I need a linkage map to find stuff; or perhaps I could just induce some mutations to make chunks of it go away or something! You better hope I don't end up with rearrangements of your term papers, eh? Might be entertaining, though... :-)





[From Pharyngula: Basics: How can chromosome numbers change?]




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Monday, April 21, 2008

But how many Steves are on your list, Dr. Patton?

That was one of the questions I was going to ask Dr. Don Patton at the much ballyhooed lecture today on "what is creation science" which turned out to be something of a damp squib. And I'm not just saying that because I didn't get to ask it or any of my other questions - there were so many students' hands up that I didn't get my turn, which was great to see! I was promised at the end by one of the mike-wranglers that I would get the first question at tomorrow's lecture - but, meh, I didn't see much today to draw me back for more. I hope some of you students who did ask those great questions chime in here so we can talk about it, because you sure didn't get much of an answer from Patton, did you? I'll try to address some things more specifically in detail soon - am too tired to deal with it right now and I have a field trip early tomorrow morning, so let me just give a quick summary of the lecture for now. Those of you who attended the lecture, and can't wait to get some real answers, go play here and see if you can find all the main arguments on display today. And read why John Wilkins thinks such talks can, on the whole, be good for evolution education... I hope he is right!


Despite all the promise of a dialog on science made to us (in public and private) by the promoters of this event, what we saw was a typical presentation (from what I've read of such talks) with the following not-unexpected ingredients:



  • repeated mischaracterizations of science and of evolution


  • plenty of arguments-by-analogy


  • a great big pile of selectively mined quotes from eminent evolutionary biologists


  • arguments from popularity including results from public opinion polls to show how creationism is "winning" despite the efforts of us evilutionists


  • lists of "hundreds of scientists" who support creationism (which raised the question I never got the chance to ask, about how many Steves)


  • a defense of Patton's academic credentials (which is an irrelevant issue if you ask me, but more on this later; and Scott Hatfield has more on that and on his talk radio appearance during the first half of this lecture)


  • when questioned by students, a fine display of slipperiness to smoothly evade probing questions, including rapid re-definition of terms just used, "not-blaming" the poor student because "this is what you've been told", complete refusal to address any alternative creationist hypotheses, yet declaring the unspecified creationism as the winner because Gould at some point somewhere said some argument about evolution was dead, etc., etc...!!


  • And, of course, absolutely no actual data on anything other than the polls despite repeated proclamations that we were gathered to examine evidence!!


Like I said - meh! - I have better things to do tomorrow evening, including a choice of two other presentations that should be much more educational: on Earth Day by Dr. Chris Pluhar of our EES Dept., and on the ethics of stem cells and genetics by Dr. Andy Fiala, Director of the Ethics Center here @ CSUF. I don't have the links handy, so I will add them tomorrow sometime - or look out for flyers in the Science building.


And speaking of flyers, there was a miraculous appearance of the Great FSM in the lecture hall, and even a "ramen" was heard from a questioner! Unfortunately, I got there just seconds before the talk started, and the FSM disapparated sometime during the second segment of the lecture (leaving me in agony wondering why I had been left behind!) so I couldn't take a picture. I hope someone else did, and if so I will try obtain a copy for posting here!



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Friday, April 18, 2008

Evolution of MRSA

ResearchBlogging.orgStudent post submitted by Trevor Clark.


The article, Evolution and pathogenesis of Staphylococcus aureus: lessons learned from genotyping and comparative genomics, is well written and also well diagramed. The article is looking to obtain an understanding of what the exact biologic role of methicillin resistant S. aureus (MRSA) is. The authors want to understand the existence and the mechanism of evolution for the genesis of C-MRSA. The paper gives a clear background of MRSA but it does not go into depth about the history of how it has evolved to what it is now. It is clearly stated by the authors that, not much is known about how MRSA is able to evolve as quickly as it does to medications.


The body of the paper dives right into the evolution of the core genome of MRSA. My focus is more towards how MRSA has evolved in the hospital and medial setting and the effects that it has had on humans. The research conducted for the paper was vital for them to understand the clonal structure so they could compare it to the strains that common today. They were able to obtain an understanding of what genes it had by running it through a multilocus sequence typing (MLST). “MLST is currently the most popular typing method through the sequencing of seven housekeeping genes (arcC, aroE, glpF, gmk, pta, tpi, and yqiL). For each gene, the different sequences are assigned as alleles and the alleles at the seven loci provide an allelic profile, which unambiguously define the sequence type (ST) of each isolate.” From the data collected from the MLST they were able to analyze and conclude that point mutations have given rise to new alleles more frequently than recombination. Their data shown in figure 1 is good, but I still do not have a clear understanding on how their calculations came about. I would have liked to see a side-by-side comparison of the genes from each individual strains that they were able to sequence successfully. Anyone can talk about what they have found, but I need to see proof through more data.



fmr_086_f1.jpg


Fig. 1. Protein homology between nine sequenced Staphylococcus aureus genomes. In each box is the number of orthologues shared by the corresponding strains and median nucleotide divergence that reflects divergence between the two strains. The orthologue was constructed by the orthomcl program (Li et al., 2003). Nucleotide divergence is defined as the number of mismatch bases divided by the number of comparable bases. The color intensity in each box is in inverse proportion to the nucleotide divergence. The accession numbers of the S. aureus genomes are: NC_002745 (N315), NC_002758 (Mu50), NC_003923 (MW2), NC_002953 (MSSA476), NC_002951 (COL), NC_007795 (NCTC8325), NC_007793 (USA300), NC_002952 (MRSA252), NC_007622 (RF122).



The second half of the paper was geared more towards what I was interested in. They talked about how MRSA enters a host and clearly explained the life cycle of MRSA on what they gathered from their studies. Community-acquired MRSA (C-MRSA) has become a problem and is considered to be a super bug since doctors and scientist have not yet found a cure or a drug to fight it. The evolution of MRSA to become what it has become today has interested the medical community and also has sparked an interest in me. This paper does a good job in bringing some light towards possible ways to fight MRSA; “staphylococcal species are one of the most important topics in the research of the evolution and pathogenesis of S. aureus”.



fmr_086_f4.jpg



Fig. 4. Illustration of the hypothetical Staphylococcus aureus evolutionary history. The whole S. aureus species can be divided into two putative subspecies (Robinson et al., 2005a). The circles with different colors represent different agr groups, and the circles with numbers inside represent the corresponding clonal complexes. The arrows on the right side indicate the important phases during the S. aureus evolution.


The table and figures that were used were well done overall. They were clearly explained and could be understood. The way the paper was written and put together made is so those who have taken an entry-level genetic course would be able to understand and follow what was being said.


References:



Feng, Y., Chen, C., Su, L., Hu, S., Yu, J., Chiu, C. (2007). Evolution and pathogenesis of Staphylococcus aureus: lessons learned from genotyping and comparative genomics. FEMS Microbiology Reviews DOI: 10.1111/j.1574-6976.2007.00086.x



Robinson, D.A. (2005). Evolutionary Genetics of the Accessory Gene Regulator (agr) Locus in Staphylococcus aureus. Journal of Bacteriology, 187(24), 8312-8321. DOI: 10.1128/JB.187.24.8312-8321.2005




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Weird Ways to Pick Your Mate

ResearchBlogging.orgsniff.jpgStudent post submitted by Stephanie Chow.


Can you imagine picking your soul mate merely by their scent? It has been shown that people can show a preference to certain people of the opposite sex based on how they smell (Wedekind et al 1995; click on photo for another such study). In the experiment, participants were asked to wear a t-shirt for two consecutive nights, and remain as odor-neutral as possible during this period (use fragrance-free detergent and soap, refrain from exercising and eating smelly foods). Participants also had their MHC (major histocompatibility complex) typed. The shirts were then collected and given to members of the opposite sex to sniff and rate how pleasant the odors were to them. The more pleasant the odor, the “sexier” that person was considered. These results were compared to the degree of closeness of the male’s and female’s MHC. The males and females that had more difference between their MHCs found each other’s scents more attractive than those who had similar MHCs. Essentially, people’s preference towards different MHCs ensures a greater chance for variation in this important factor of the immune system. This is an important selection aid to avoid inbreeding. By nature, people tend to show preferences towards people that are more like them. If there were not selection guides, like the scent preference linked to MHCs, there would be a much higher incidence of inbreeding. As a result, there would be less genetic variation and a higher incidence of accumulation of deleterious mutations or rare genetic diseases in the inbred population.


A more recent study showed human males’ innate ability to detect higher probability for mating success at strip clubs (Miller et al 2007).


Lap dancers were asked to report their tip earning for each shift they worked, and to also record their ovulatory cycle for 60 days. The results showed that men were most responsive to women approximately one week after their menstruation had ceased. This implies that the men found the women most attractive (indicated by a higher tip amount) when they were the most fertile—just before ovulation. Part of this study also asked men to rate the attractiveness of each woman’s body (the faces were covered) in photographs of women during their peak fertile period compared to other times during their cycle. The picture taken during ovulation was deemed the most attractive. This is due to the slight physical changes in women during ovulation: increased facial attractiveness, decreased hip-to-waist ratio, and increased body symmetry—all traits that men perceive as more attractive in a woman. This heightened sensitivity to women’s ovulatory cycle is comparable to other animals—such as dogs—being in estrous or “heat”.


References:



Wedekind, C., Seebeck, T., Bettens, F., Paepke, A.J. (1995). MHC-Dependent Mate Preferences in Humans. Proceedings of the Royal Society B: Biological Sciences, 260(1359), 245-249. DOI: 10.1098/rspb.1995.0087


Miller, G., Tybur, J., Jordan, B. (2007). Ovulatory cycle effects on tip earnings by lap dancers: economic evidence for human estrus? Evolution and Human Behavior, 28(6), 375-381. DOI: 10.1016/j.evolhumbehav.2007.06.002




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Teach the controversy? Not Ben Stein's way

So concludes this LA Times feature which actually tries to get two alternative perspectives on Ben Stein's movie Expelled (opening today at least according to all the previews on the telly, although I'm not sure even this turkey will open in Fresno at the same time as elsewhere) but fails! Not surprisingly, both Michael Shermer (well known skeptic) and Greg Lukianoff (lawyer on a mission to defend individual rights in education) end up panning the movie, although Lukianoff feels compelled to end his piece by appealing to Ben Stein for help:


We could use some high-profile help here, Ben. With your power and influence you really could help bring a missing dose of liberty back to campuses. But if you only care about ID education, I suspect that you will only be preaching to people who already agree with you.


Really? Why would Lukianoff want to seek help from someone who failed to convince even him (a champion of other students' rights cases) that there is any there there when it comes to intelligent design? A has-been "celebrity" whose latest film, though marketed as this big controversial challenge to the scientific establishment, fails to raise the dust even in the middle of this dust-up involving someone as sympathetic as Lukianoff? Given the spate of bad reviews this documentary is getting, the prospects don't look too good for Ben's profile, nor his "power and influence". So one has to wonder how things are going to turn out for Lukianoff if he still wants to appeal for Ben's help! Just seems odd... but what do I know?


BTW, Michael Shermer is coming to Fresno this evening for another dustup on our campus - a debate with that towering intellect among religious conservatives, Dinesh D'souza, on the little matter of "Does God Exist?". Should be fun, and I hope Shermer is up to the task of maintaining the bar on D'Souza as high as this guy set it last year:



and in part 2:



If he wants to pick up that gauntlet (in addition to the debate), Shermer surely has a big task on his hands, no?



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Thursday, April 17, 2008

Oh how I hate storks...

... and even more, those who would expose the scientific conspiracy that I thought had successfully Expelled the Stork Theorists from the ranks of reproductive academia! Now what? Do I have to start digging up the old Storkology books buried behind the Biology dept. greenhouse? I guess I better start rewriting the syllabus for my upcoming fall Birds and Reptiles course too while I'm at it. Gimme a break with all this academic freedom, would you now?


Sigh!! Watch and weep, my fellow Astorkist conspirators...









And once you're done wiping your tears, go read the comments thread on this video on YouTube (just click on the above video to get to it). Seriously!



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Obligatory reading of the day: Phylogenetic Fallacies

Go read Genomicron on: Phylogenetic fallacies: "early branching equals primitive". It should clarify your thinking and might even help you on the finals! And don't complain that I only serve up links and commentary on non-evolutionary fluff like the brouhaha over next week's events on campus!



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Darwin Online: Browse Darwin's Papers

The Darwin Online project has now made all of Darwin's papers from the Cambridge University Library, including drafts of chapters from "On the Origin of Species" available to the public online! They have images of the original writing including all his scribbling in margins, and transcriptions to make them readable. For example, it has this page from one of his notebooks, which induced shivers in my spine when I was able to actually see it (in the cellulose, so to speak) a couple of years ago when we visited the Darwin Exhibit at AMNH:


DarwinArchive_1837_NotebookB_CUL-DAR121.-_038.jpg

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Get bigger brains to live (and make babies) longer

ResearchBlogging.orgHere's another interesting paper waiting in the publication pipeline at the Journal of Human Evolution on brain size and life history in primates. Should be fun to chew on following on the heels of Heidi Rivera's post about cellular scaling rules which has generated some interesting discussion. Look below the fold for the abstract of the paper, and my own first impressions (and email me if you want the pdf):


Life history costs and benefits of encephalization: a comparative test using data from long-term studies of primates in the wild


Nancy L. Barrickman, Meredith L. Bastian, Karin Isler, and Carel P. van Schaik


Abstract


The correlation between brain size and life history has been investigated in many previous studies, and several viable explanations have been proposed. However, the results of these studies are often at odds, causing uncertainties about whether these two character complexes underwent correlated evolution. These disparities could arise from the mixture of wild and captive values in the datasets, potentially obscuring real relationships, and from differences in the methods of controlling for phylogenetic non independence of species values. This paper seeks to resolve these difficulties by (1) proposing an overarching hypothesis that encompasses many of the previously proposed hypotheses, and (2) testing the predictions of this hypothesis using rigorously compiled data and utilizing multiple methods of analysis. We hypothesize that the adaptive benefit of increased encephalization is an increase in reproductive lifespan or efficiency, which must be sufficient to outweigh the costs due to growing and maturing the larger brain. These costs and benefits are directly reflected in the length of life history stages. We tested this hypothesis on a wide range of primate species. Our results demonstrate that encephalization is significantly correlated with prolongation of all stages of developmental life history except the lactational period, and is significantly correlated with an extension of the reproductive lifespan. These results support the contention that the link between brain size and life history is caused by a balance between the costs of growing a brain and the survival benefits the brain provides. Thus, our results suggest that the evolution of prolonged life history during human evolution is caused by increased encephalization.


Here's the key figure demonstrating the main correlations between brain growth (x-axis) and (a) lactational period, (b) juvenile period, and (c) Age @ First Reproduction, all after controlling for the effects of body growth:


primate_brain_life-history_Fig3.jpg


This leads the authors to argue that the high cost of growing all that brain tissue is offset by prolonging juvenile and reproductive phases. The juvenile phase is when the brain apparently grows faster than the body in most primates (which is why there is no correlation in panel (a) of the figure). In turn, species with larger brains have better survival over longer juvenile and reproductive phases in their life history. In other words, species that have bigger brains pay the cost of growing more of the most expensive tissue in the body, but benefit by being smarter at foraging, avoiding predators, and generally living and fornicating over longer periods than their smaller-brained counterparts. Note that having a bigger brain is not correlated with an increase in reproductive output at any given time, just the prolongation of the reproductive phase oveall - which, I suspect, may leave you with greater lifetime reproductive success (=fitness) in any case.


The argument of the paper is strengthened by the fact that they draw mostly upon datasets from wild populations that have been studied for long enough to document a boat-load of life history parameters (including gestation length; interbirth interval between surviving offspring; lactational period; juvenile/adolescent period; age at first reproduction for females; life expectancy at AFR, or the inverse of mortality rate; adult lifespan) - so they are analyzing real-life situations faced by these primates in the wild, and not more benign or stressful conditions in captivity. They also used a phylogenetic comparative method in analyzing correlations such as shown in the above figure - i.e., they removed or controlled for effects of phylogeny.


So, do you buy the causal argument (at the end of the abstract) that increased brain size is what caused the life-history phases to lengthen? Or is it the other way around? What does the correlation tell us about causation in this case? Myself - I'd have to say I like the correlations, but have to digest the paper some more before I completely buy the causal argument.


So what else are we doing as the primate with the most brains, and longest active sex lives? Well, cutting down on our reproduction (or trying to anyway), for one thing. And also, apparently trying to decouple brain growth from body growth entirely - in other domesticated animals - even thinking about producing animals with more meat and much less brain! Why? So we can have more meat to eat, of course, without having to worry about animal rights issues, presumably! Now that's an interesting direction to go in, opposite from the self-sacrificing talking cow imagined by Douglas Adams in "The Restaurant at the End of the Universe"!


[Hat-tip to Afarensis]

Reference:


BARRICKMAN, N., BASTIAN, M., ISLER, K., VANSCHAIK, C. (2007). Life history costs and benefits of encephalization: a comparative test using data from long-term studies of primates in the wild. Journal of Human Evolution DOI: 10.1016/j.jhevol.2007.08.012


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Wednesday, April 16, 2008

Tangled Bank #103 is online

tbbadge.gifFor your reading pleasure, the latest edition of this traveling carnival of evolutionary and medical blog writings is now up at Nature Network. Enjoy!


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Why can't we get this guy instead?

He even starts with a prayer and a blessing!







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Tuesday, April 15, 2008

Ages of Rocks or Rocks of Ages


Hat-tip to Pharyngula for this wonderful video. As I pondered what those sage rocks would think of our ephemeral evolution-creation culture wars, and scratched my head (and keyboard) for a title for this blog post, I stumbled upon this. Some added context to the show coming into town next week, I suppose!



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I feel so left out...

... almost like I too have been pre-emptively Expelled - being the only biology faculty member (as far as I know) not to receive a personal invitation to the lecture series by "Don Patton, Ph.D." in my campus mail today!! Where have I gone wrong (or right?) to not get on their mailing list? (And how can I keep it that way?). I'm putting the text of the invitation letters below the fold (and hope the organizers don't mind that because they are encouraging recipients to spread the word), so read on if you are interested. Note that these letters, addressed individually to tenured and tenure-track faculty alike, all of whom have a well-earned Ph.D., invariably address the recipient as "Mr." or Ms." even as they tout "Dr. Don Patton, Ph.D."! Now why would someone do that?


Perhaps the answer lies in the email response my colleague Paul Crosbie received from an elder of the Sun Garden CoC (a different elder from the one who signed those invitation letters) upon asking, politely, why they were associating themselves with someone with dubious academic credentials. I won't quote the whole arrogant email response here, although I can't help but note something. Here's the gist: the elder first invites Paul to challenge Patton with his "obvious vast knowledge of truth", and bring his class along, before predicting that Paul will do neither because "aren't closed academic elitist minds convenient and wonderful?". He then berates Paul for questioning Patton's credentials because "it is a way not to have to listen to anything different than you already believe".


Huh-whaaaa?? Seriously?! Do these people ever read their own writing or look in the mirror? Who is the party claiming to have the "truth" on their side? Who has the closed minds? And who, above all, relies on a single ancient text as a way to not to have to listen to anything different? Really now!! Pot-kettle-black?


As for that invitation letter which came via campus mail (possibly in violation of campus regulations about use of official intra-campus mail channels for promoting private religious functions) read for yourself:

Dear Mr. [or Ms.] not-Madhu-Katti,


Please consider this letter your personal invitation to attend a free series of lectures with question and answer sessions on the broad subject of "Does Planet Earth Reveal a Creator?" The dates for these lectures are April 21-22, 2008, in the Satellite Student Union on the Fresno State University campus, and April 22-25, 2008, in the Rotary Theater on the Bullard High School campus. Each evening's program will begin at 7:00 p.m., include two 30 minute presentations with 15 minute question and answer periods following each, and conclude by 9:00 p.m.


As a person of both science and academe, we believe you will be vitally interested in what the speaker, Dr. Don Patton, of Dallas, Tx, has to say. Dr. Patton has devoted his life to finding and evaluating geologic and archaeological evidences of human history and finds the evidence to present a compelling argument for special creation in contrast to the popular hypothesis that we are a result of evolutionary forces.


We believe you will find this program to be extremely interesting, informative, and conforming to rigorous scientific scrutiny. So, please mark your calendar to join us for as many evenings of this program as you can and add to the program by addressing your comments and questions to Dr. Patton during the question and answer periods.


Sincerely,


Jack Flad


P.S. Feel free to bring other colleagues and your students to these presentations. All are Welcome.


Now how can one turn down an invitation like that? Even if one is not on the list of people getting this official invitation letter? So I'll show up, and ask my class to show up - and hope I don't get Expelled like a more illustrious evilutionist



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Monday, April 14, 2008

A creationist in our midst

I was surprised to see a little advert in our campus newspaper, the Collegian, last friday for an upcoming event on campus - part of a lecture series titled "Does Planet Earth Reveal A Creator? There IS Compelling Evidence" to be given by a Dr. Don Patton, Ph.D.! How can a scientist, especially one who teaches evolution, not be intrigued by that? So I followed the link on the advert and discovered that Patton is in Fresno all week, hosted by the Sun Garden Church of Christ around the corner from campus. He will speak first at the church, but they are advertising a series of free "science" themed talks for Fresno State (2 nights) and Bullard High School (3 nights) - aren't we blessed?! So I shared the news with colleagues on campus and my friend Scott Hatfield, a biology teacher at Bullard High, who was really alarmed and sent out a call for help. PZ Myers then picked up Scott's distress call over the weekend, weighing in with much advice on strategy to deal with such an incursion of religion into the public school space.


Scott has just posted an update indicating that Bullard High School will not be a venue for these lectures [UPDATE to the update: Scott's frustration is back because apparently the talks will still be held at Bullard High], and that Patton's local handlers have known this for two weeks - yet they continue to advertise the event as occurring at the school! As far as I know, the Fresno State lectures are still on - but I will find out how much truth there is to that as well. Given the other evidence I see from video snippets of Patton's talks posted on their website, it is hard to believe anything they say. I am curious also to learn more about how our campus came to be chosen as a venue in the first place. After all, its not every day that such blatant "challenges" to science are brought to the Satellite Student Union, right next to the Science building that is my academic home! Is it simply a case of the university happily taking the money from whomever wants to rent our space, without regard to what they will use it for? Or is some campus organization / entity actively hosting this event? Given that the advertising mentions no such CSUF entity, I hope the former is the case, although I wouldn't be surprised to learn that there are people/groups sympathetic to Patton's anti-science agenda on campus. But, odd as it may seem, for once I do hope Fresno State is being merely a money-grubber in this case - and that some campus entity is not giving these people a free ride because they are a religious organization!


Bear in mind that I'm not really worried about any "challenge" to evolution from this "geologist" who, among other things, is known to claim that humans and dinosaurs coexisted (although I haven't been able to ascertain whether he also believes that T. rex was a vegetarian before Eve bit the apple). Evolutionary biology thrives on plenty of real challenges and unanswered questions, and new critical questions and perspectives are always welcomed, not Expelled. So bring it on, if you have any real alternative hypotheses that we can test - but I doubt Patton has any such to offer. His goal seems to be merely to exploit the lack of knowledge on the part of naive religious people, and to sow further confusion about - not to mention potential hostility against - good scientific evidence by filtering it through his own particular interpretation based on a particularly literal reading of the bible. (And I emphasize "particular" because not even many other creationists, let alone intelligent design proponents buy into Patton's twisted version of the geological/fossil evidence.) Moreover, being a university open to free exchange of ideas, we need not worry as Scott does about violating any state education standards. In principle I shouldn't have to worry about this kind of thing corrupting any young minds either, given that we are at a university with mostly adult students - but I'm not entirely convinced of that around here; I'm not that confident that we are reaching our critical thinking goals in our education here, having seen enough uncritical students, and being aware of the strongly religious / conservative culture of the Central Valley. As such, I would encourage my students to attend, but with their critical faculties turned on (and they better be turned on this late in the semester if you are taking my class!), and to ask good questions. Especially those of you who have engaged me in some thoughtful discussion of religion/science issues on the class blog or via email.


I do have a different concern where I do question the university however, and that has to do with whether we want to be used by charlatans to promote their own agendas that are blatantly against everything we are supposed to stand for. The promotional materials for the lecture series already proclaims that Patton is a "popular" speaker at colleges and universities, on top of highlighting his geoscience "expertise" and touting his "Ph.D.". I most certainly do not want him using the fact that he merely had access to our lecture hall to bolster his "academic" credentials among the uncritical believers victim to his deceptions. And on that ground alone, I do seriously question the appropriateness of Fresno State playing host (even if unwitting) to this event.


In response to my own "advertising" of these lectures, several of my colleagues have responded with ideas on how we might counter this propaganda / proselytization. I will post updates here when I've learnt more, so stay tuned!


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