And that is but a taste of what we will get this afternoon in our department colloquium here at Fresno State, for Dr. Full is on campus and will be speaking shortly. I will try to record audio for potential podcast.
Here's the flyer for the event:
This week, the CSU-Fresno Consortium for Evolutionary Studies brings you another public lecture in our Evolutionary Biology Lecture Series. On the evening of Thursday, March 25, 2010, join us at the Satellite Student Union on campus to hear Prof. Trevor Price of the University of Chicago tell us about his work on the origin, distribution, and maintenance of high bird species diversity in the Himalaya. The public talk starts at 7:30 PM, and you can download the flyer for the talk below. On the following afternoon, Dr. Price will give us another talk in the Biology department colloquium series.
Why yes, we have a Jellyfish mass occurrence... well... occurring on the campus of Fresno State this friday afternoon! Well, ok - I'm not talking about some biblical flood in the valley (its been a wet winter, sure, but not that wet!) or that long anticipated Big One, the earthquake that cleaves coastal California off and converts all our homes here in the valley into beachfront property! No not that - that's not happening this friday (as far as I know). But the jellies will be here in spirit and data form rather than physically present, as we get a seminar from Dr. Michael Dawson of UC Merced just up the road from us. Should be a fun, fascinating talk - here's the relevant info, and you can click on the title below to read the abstract and get further details:
Phylogeny and Ecology of Jellyfish (Scyphozoa) Mass Occurrences
Friday, March 12, 2010
3:00-4:00 PM
Science II, Room 109
CSU-Fresno
And afterwards, you might ask Dr. Dawson what a marine biologist like him is doing in the Central Valley of California... do they know something we don't?
Life is in peril. A mass extinction threatens to take more than 90% of the world's species. Evolution will not be able to replace these species, neither in kind nor in number. Our religious and ethical responsibilty to protect our world is challenged as never before.
But there is good news: we can prevent this mass extinction with a method called Reconciliation Ecology. Reconciliation Ecology means working out ways for us to have our land and share it too.
Reconciliation Ecology is not a pipe dream. It is widely practiced all over the world. And it is successful. Reconciliation ecology puts nature back into the everyday lives of people, surrounding us with living wonders we usually associate with a vacation in a National Park. It is not expensive and it redesigns our own habitats so that we can keep them, keep living in them, keep using them for our needs, keep earning profits in them... while at the very same time making them havens for wild species of plants and animals.
The new habitats we engineer to satisfy both our desires and the needs of nature will not resemble those of a thousand years ago. This will surely put new evolutionary pressures on the species we harbor. They will change in ways we are only beginning to study. But surely it is better to meet them halfway, better to give them a chance to adapt to us, than to let them vanish utterly and leave our grandchildren with an impoverished world that bears evidence that we did not choose to fulfill our responsibilities.
Friday, January 29, 2010
3:00-4:00 PM in Science II, Room 109
Professor,
Dept. of Chemistry & Biochemistry and Molecular Biology
University of California, San Diego
La Jolla, CA
The availability of whole genome sequences for a variety of vertebrates is making it possible to reconstruct the step-by-step evolution of complex phenomena like blood coagulation, an event that in mammals involves the interplay of more than two dozen genetically encoded factors. Gene inventories for different organisms are revealing when during vertebrate evolution certain factors first made their appearance or, on occasion, disappeared from some lineages. The whole genome sequence databases of two protochordates and seven non-mammalian vertebrates were examined in search of some 20 genes known to be associated with blood clotting in mammals. No genuine orthologs were found in the protochordate genomes (sea squirt and amphioxus). As for vertebrates, although the jawless fish have genes for generating the thrombin-catalyzed conversion of fibrinogen to fibrin, they lack several clotting factors, including two thought to be essential for the activation of thrombin in mammals. Fish in general lack genes for the “contact factor” proteases, the predecessor forms of which make their first appearance in tetrapods. The full complement of factors known to be operating in humans doesn’t occur until pouched marsupials (opossum), at least one key factor still being absent in egg-laying mammals like the platypus.
I am really excited to invite you to an evening with Dr. Eugenie Scott on the Fresno State campus next Wednesday, Dec 2, 2009! An evolutionary biologist by trade, Dr. Scott is the Executive Director of the National Center for Science Education, and as such, has been at the forefront of the culture war around the teaching of evolution in the US for over a quarter century. Along the way she has testified on behalf of evolution and science at numerous venues, most famously at the Dover trial a couple of years ago, and has authored several valuable books on the subject, including Evolution vs. Creationism and Not in Our Classrooms: Why Intelligent Design Is Wrong for Our Schools (with Glenn Branch). I am therefore thrilled that she accepted my invitation to come down into the valley to talk to us because here, as you may know, we happen to be in something of a hotbed for that culture war as well, although not nearly as hot as some other parts of the country (no attempts to mess with public school science curricula at least).
Dr. Scott will give a public lecture on "Why the fuss about Darwin and Evolution" at the campus' Satellite Student Union (maps) at 7:30 PM on Dec 2, 2009, as part of a new Evolutionary Biology lecture series hosted by the campus Consortium for Evolutionary Studies (see poster below for the various sponsors of this particular talk). We are bracing for a good turnout since this will be one of the most prominent speakers to come here and speak on behalf of teaching evolution and science in the classrooms - and we plan to bring some more over the coming year.
I know we got off to a bit of a late start in the Darwin Bicentennial celebrations this year, but we hope to keep the momentum going into the future as we try to light a few more candles in the dark in this lovely valley.
Click below the fold for the poster announcing this lecture - feel free to download and share it as widely as you like! And if you are on Facebook, check out the event page to rsvp and invite others, and become a fan of the Biology Department page while you are at it. I hope you will join us for this talk next week.
We resume the Central Valley Café Scientifique tonight after a prolonged summer hiatus - and at a new venue too! My colleague Dr. Alejandro Calderón-Urrea will start the new season with a talk about GMOs and suicidal worms! You know where to find the details, don't you? The Café's website, of course! And you've always had our Google Group to get email updates. But now there are a couple of new ways for you to keep up with the Café: join us on our new Facebook page, and follow us on twitter too! And soon, if we manage to master the technology, we may start podcasting the talks afterwards! So watch this space (and all the above spaces too) for that development.
Most importantly, of course, I hope to see you in person tonight!
As the semester winds down, we have a special treat on campus this Monday, when the Biology colloquium series winds down for the semester with a lecture by paleoanthropologist Dr. Kaye Reed, of the Institute of Human Origin at Arizona State University, on "The Life and Times of Australopithecus" . This lecture is co-sponsored by the Tri-Beta Biological Honors Society and the Consortium for Evolutionary Studies at CSU-Fresno, and is part of our ongoing series celebrating Darwin Bicentennial year. Dr. Reed has been working in Ethiopia and other parts of Africa, places where some of the most important and exciting hominin fossils (such as the famous Australopithecine, Lucy seen in the reconstructed portrait here) have been discovered. Her specialization is paleoecology with a focus on reconstructing the ecological communities within which our own lineage evolved. So it should be a very exciting lecture - I hope to see you there (especially if you are taking one of my classes!)!
Spatiotemporal coordinates: Monday, May 4, 2009 @3:00PM in Room 109 of Science II building, CSU-Fresno (of course!).
Website for additional details: Darwin's Bulldogs.
Its time for another Café Scientifique tonight here in Fresno. And this time we have Robin Vijayan, a Fulbright scholar visiting my lab for his graduate research (he actually roped me in as a coadviser for his Ph.D. for some odd reason!) telling us about "Islands in the Sky: Science and conservation in the montane forests of India" - well, southern India, to be exact.
We meet, as usual, at the wonderful Lucy's Lair Ethiopian restaurant in north Fresno, from 6:30 - 8:30 PM. Perhaps I'll see you there!
Andrew Mora review's Christy Strand's seminar on neuroplasticity.
Nueroplasticity is an interesting concept that deals with changes in the brain due to experiences. In order to study neuroplasticity better, Dr. Christy Strand used hormonal and environmental cues to see how they would affect the brain. The specific region of the brain that Strand was interested in was called HVC (high vocal center in birds) and the size of this region of the brain was recorded before and after experiments. According to Strand, this region in birds is important in motoring song output, and is also involved in song learning. She asserted that testosterone, an important steroid that affects the brain, did in fact increase HVC volume, but was uncertain as to how the region got bigger. Did individual neurons get bigger? Was the density decreased? Or were there simply more neurons from new cells?
In order to test for the size of the HVC, Strand used bromodeoxyuridine (BrdU) which is a cell birth marker. She used house finches because they are very common throughout the US and they are great song birds to test for the HVC region. Besides using testosterone treatment for the birds, she also wanted to know the role of the photoperiod in increasing HVC growth. Her results indicated that testosterone treatment does affect HVC growth, that photoperiod alone might affect HVC growth, and that testosterone treatment does not affect the number of new HVC neurons, despite an increase in total neuron number. Her reasoning for this might be because of a natural turnover; that is, there is no new neurons being created, but there is a decrease in cell death. Corticosterone (a stress hormone) had no affect on HVC growth.
In another related experiment, Strand used rufus-winged sparrows to test environmental cues on HVC. She used these birds because they have a unique characteristic of beginning their breeding season after the first monsoon in southern Arizona and northern Mexico. Breeding season is important for HVC size because the birds are singing frequently when they are looking for a mate. According to strand, the testes of these birds are big in March, but only used in July when the first rain falls. Her results found that during breeding of these sparrows, HVC neuron number does not increase, and testosterone levels were not different on sampling dates. She did find that singing behavior increases during the breeding season, but was still unsure whether or not HVC affects singing behavior or if the reverse was true.
I particularly enjoyed the area of future research being done by Dr. Strand. She discussed that she will be experimenting with hormonal factors affecting neurogenesis and neuroplasticity in adult snakes and lizards. She will look at the affects of captivity on neurogenesis and affects of sex on neurogenesis. Instead of the HVC region she will look at the size of the medial cortex in adult rattlesnakes. I like this integration because it attempts to compare research done on birds with similar research done on reptiles. Hopefully we will see this work published soon.
Well, you will at least learn about neuroplasticity in species that do have more plastic brains then humans. As usual, the seminar will be in Science II, Room 109, starting at 3:00 PM. Be there!
Hormonal and environmental control of neuroplasticity
Dr. Christy Strand
Department of Biological Sciences
California Polytechnic State University
Abstract
Many people have the incorrect notion that the brain is a relatively static organ or that it can degenerate, but not grow. The study of neuroplasticity encompasses changes in the brain from the cellular and molecular level to the gross anatomical level (e.g. changes in the sizes of brain regions). In adult male songbirds, the brain regions that control singing behavior grow seasonally, providing a means to investigate the regulatory mechanisms and the functional consequences of adult neuroplasticity. Specifically, during the breeding season, these regions are larger than at other times of the year due to increases in neuron number and size or decreases in density. Numerous factors that change during the breeding season have been implicated in regulating the growth of these brain regions, most notably, testosterone (T), photoperiod and singing behavior. I use a comparative approach to investigate the effects of T, photoperiod, singing and other social or environmental factors on song control region growth and new neuron incorporation in the adult male songbird brain. I also investigate how environmental, physiological and hormonal factors affect neurogenesis and neuroplasticity in adult snakes and lizards. This integrative approach provides a more complete analysis of the contributions of various factors to the regulation of neuroplasticity in vertebrate animals.
Andrew Mora offers a review of the Biology department seminar by Rachel Mazur.
The American Black Bear, Ursus americanus, is currently the only species of bear in the state of California. In a fascinating presentation by Rachel Mazur, pictures and videos were used to depict the beauty of these bears in their natural and not so natural environments; the latter being bears foraging for food in developed areas of the national parks including getting food out of trash cans, cars, etc.
According to Mazur, these bears are especially hungry during the months of March and April. During this time, a bear is either termed by Mazur to be a wild foraging bear, which consists of eating grasses, roots, insects from shredding logs etc., or they can be food conditioned bears, which consist of getting their nutrition from developed areas, or humans.
Research by Mazur finds that bears have traits for social learning and the most critical times of a bears learning process is during the first year when they are in constant contact with their mother (Mazur, 2008). Three separate hypotheses were compared to describe how these bears are learning to become food-conditioned to developed areas. The first is that bears inherit these behaviors from their mothers and can be predicted (Mazur, 2008). The others include bears learning individually (that is, without the help of the mother) and transmitted learning from sow to cub (Mazur, 2008).
The methods used for this experiment were efficient in that homogeneity was taken into consideration. Therefore five variables were taken into consideration including park, sow identity, sow behavior, rearing method and cub outcome (Mazur, 2008). The two national parks which Mazur encouraged everyone to visit include Sequoia National Park and Yosemite National Park. From showing clips of a movie on this research, it was evident that many years of hard work by numerous staff was done to work with these bears and monitor their statuses.
Mazur stated that she was very pleased with the results that they came across. An easy to read table of her results shows the number of sows that they started with (23 food conditioned and 9 wild), the rearing methods of these sows (rearing in wild or food-conditioned rearing), and the outcome of the cubs once separated from their mothers (Mazur, 2008).
Conclusions made by Mazur asserted that rearing method had a highly significant effect on the cub outcome (Mazur, 2008). If a cub was reared food-conditioned, it was much more likely to be food-conditioned once separate from its mother. That being said, the last hypothesis stated by Mazur was seen to be the most accurate: that bears become food-conditioned through social learning.
In both seminar and paper, Mazur stated that there are numerous implications for the work that has been done. She posed a question to the room regarding the bear’s possibility of creating culture and even tradition in our national forests with these new food-conditioned characteristics (Mazur, 2008). What I found beneficial in this work is the implication that food-conditioning in developed areas in our national forests do not necessarily imply adaptive strategies of these Ursus americanus, but may very well be falling into an ecological trap (Mazur, 2008). I also found it interesting for her to note that science and management have recently become less taboo as a pair in the scientific world.
Reference:
R MAZUR, V SEHER (2008). Socially learned foraging behaviour in wild black bears, Ursus americanus Animal Behaviour, 75 (4), 1503-1508 DOI: 10.1016/j.anbehav.2007.10.027
Its my own turn at bat in our departmental colloquium today. Here's the blurb on what I'll talk about:
Becoming urban: behavioral and evolutionary implications of living in the city
Dr. Madhusudan Katti, Department of Biology, California State University, Fresno
Abstract
The city may be the ultimate expression of the human effort to control our environment: in evolutionary ecological terms, it represents a strategy to minimize the risks of starvation and predation by creating habitats which dampen natural variability in climate and food availability, and provide shelter from predators. Simultaneously, humans also generate a considerable surplus of food, making cities attractive habitats to many other wild species. Recent theoretical work by myself and colleagues shows that typical changes in spatio-temporal patterns of food availability (higher and more predictable) and predation regimes (may be lower) accompanying urbanization can alter competitive dynamics such that weak competitors survive better in urban than in more natural habitats. This has several implications for species that are able to invade the novel urban habitat: higher population densities, potentially reduced selection pressures, and in turn, greater vulnerability to sudden environmental changes. In this presentation, I explore consequences for the evolution of commensalism and the continued coexistence of other species with humans, using recent work on house sparrows (the ultimate commensal now at risk in urban habitats), corvids (suburban Scrub Jays), and south Asian primates (urban Macaques and Langurs). I will also present an overview of several projects currently ongoing in my laboratory focusing on different effects of urban environments on bird behavior, ecology, and diversity, and describe opportunities for students to get involved!
On: Friday, October 3, 2008, At: 3:00-4:00 PM, In: Science II, Room 109
Yes, I am one of the group of faculty members invited to a reception with James Randi tomorrow night, before he gives his public lecture on campus. Here's the announcement:
The University Lecture Series
Proudly Presents
James Randi
“Pseudo-Technology in the New Millennium”
Thursday, October 2, 2008
7:30 p.m. ~ Satellite Student Union
James Randi has an international reputation as a magician and escape artist, but today he is best known as the world’s most tireless investigator and demystifier of paranormal and pseudoscientific claims. He has pursued “psychic” spoonbenders and exposed the dirty tricks of faith healers. He appears frequently on US television shows and in the late 1960’s was host of “The Randi Show” on WOR-Radio.
For Ticket Information: please call the University Student Union Information Center at 278-2078 or visit them in the University Student Union.
Tonight, the Central Valley Café Scientifique presents a talk by yours truly! Here's the announcement:
Of junk food, city jive, & homelessness: the evolutionary ecology of city life
Dr. Madhusudan Katti, Dept. of Biology, California State University, Fresno
Monday, Sep 8, 2008, 6:30-8:30 PM
North India Grill
80 W Shaw Ave.,Clovis, CA 93612 ☎ (559) 325-7788 In the Village Square Shopping Center, S/W of Shaw at Minnewawa.
Go fishing in the bay for dinner, or fish KFC out of the dump - what’s an urban gull to eat? Scarf up the human handouts and you can start breeding early - but can a suburban scrub jay parent raise a family on that kind of food? What’s with the high-pitch songs of the Dutch urban tits? Why are there, often, more birds of fewer kinds in cities than outside them? And why might rich neighborhoods have more bird species than poorer neighborhoods?
As it turns out, recent research on these questions suggests that birds flock to cities (as do monkeys, raccoons and other of our urban commensals) for reasons not all that different from our own. I will draw upon research from my laboratory and elsewhere to explore the evolutionary ecology of how some species may become habitual urban dwellers, and what we might do to allow others to coexist with us amid sprawling cities.
And remember that the Central Valley Café Scientifique meets on the first Monday of every month (except this one because we had labor day last week!).
For more information, visit the website, and/or sign up to the Google Group.
Just a quick reminder that tonight we have another meeting of the Central Valley Café Scientifique:
How the News Media Frame Global Warming: A Harbinger of Human Extinction or Endless Summer Fun?
Dr. Andrew Jones, Assistant Professor, Department of Sociology, CSU-Fresno
Monday, May 5, 2008, 6:30-8:30 PM @ Lucy’s Lair.
Read more about it on the cafe website, and please join us for another fun evening!
Kara Ward shares her experience attending the 29th Annual Central California Research Symposium held recently on campus.
Overall Impression:
The 29th annual CCRS symposium, held at Cal State-Fresno, was without doubt an experience to remember. Although I cannot say that it was my preferred activity for the afternoon, I can definitely say that when I left the symposium I had acquired a greater knowledge of how many undergraduate and graduate science talks and public presentations progress. I myself have not attended many of the weekly Friday Biology seminars they have here at Fresno State so it was definitely a treat to attend this symposium and I was actually very interested in seeing work produced by my peers.
Out of the six presentations that were actually presented to us, it was apparent that each presenter had a different angle and strategy in the planning and preparation of his or her presentation. Of the six presentations, a few presenters actually did an excellent job in presenting their topic thoroughly in the sparse time allotted to them. These few presenters stood out because of their ability to utilize all of their skills to present a complete presentation. Others, however, failed in many areas such as utilizing their allotted time efficiently, in using the correct grammar and speech necessary to give a public presentation, and most importantly, in presenting the material and data in a manner that we the audience could understand. It is my opinion that these presenters would defiantly [sic] benefit from more practice and possible lessons in how to give public presentations. I can definitely understand that they had to present a lot of information and data in a very short time, but more practice on the presentation itself may have produced much smoother delivery and pace. It was apparent that many of the presenters were nervous and a public speaking course could and would serve them well. Overall my assessment of this symposium is fair, and based on my experience attending this symposium, I would positively attend next year should I be afforded the opportunity and recommend that all science majors do the same.
Critique 1: The Identification of Brachyuran Megalopae of the San Francisco Bay Estuary
Presented by: Vanessa Gonzales
I chose this presentation to critique because I had heard a few things about the Chinese mitten crab in prior classes; however I had never actually been presented with such detailed facts about the crab’s lifecycle and I was extremely intrigued by it. I liked the flow of the presentation and appreciated how she began her talk explaining the problem before going into the details of the experiment. I thought Gonzales did and great job of explaining how the presence of the crabs negatively affected the habitat by competition with and predation of some of the native species; however, I would have liked her to speak a little more about some of the native species which were affected. I also thought that the presenter did an excellent job of providing graphs, charts and tables which illustrated the facts and stressed the points that she was trying to make. As I stated earlier, I feel that the presenter did a great job of going through all of the important stages in the life cycle of the crab. This background information would be vital to know prior to being able to understand the full extent of the problem at hand as well as understanding how the experiment was set up and I feel that she was wise to include it. As the presentation continued and Gonzales entered the research portion of the presentation, I felt that she entered into somewhat of a read and speak mode. By read and speak mode I mean that it almost seemed like she was just reading lines from her note cards and it was apparent that she may have gotten lost in her notes, because between every sentence she would say phrases akin to “um” and “like”. Aside from these minor areas, I felt that the presenter did a good job of presenting the information in an organized manor. The presentation flowed and each section was explained well by Gonzales who utilized her time well.
Critique 2: Potential Impacts of Selenium on California Red-Legged Frog (Rana draytonii)
Presented by: Foung Vang
I chose this presentation to critique because I had never heard of the primary organism of this study, the Red-Legged Frog, and just the name was enough to warrant my interest. After reading the abstract, provided by the presenter, my initial thoughts went to the Zebrafish experiment we conducted in our Developmental Biology lab in which we treated the fish with varying amounts of ethanol. Based on my experiences with the Zebrafish lab, I knew that most experiments monitoring early development are quite interesting and could really go either way so I was definitely interested in seeing the outcome of this experiment. Overall I felt that there were some strong areas of the presentation as well as some weak areas. The weak areas in the presentation for me, was the lack of background information on the frogs as well as the lack of graphics and illustrations. Where the presenter did a great job of providing us with a background of selenium and the issues presented by selenium in the environment, he hardly spoke at all about the history and life cycle of the frogs. It almost seemed as if the presenter was too eager to begin the discussion of the hypothesis and results section of the experiment, but in doing so, the presentation came off as being unbalanced and dry. Although this lecture presented a lot of facts and data, I still felt as if something was lacking in the overall presentation. Perhaps the problem for this presenter was merely a time management issue, trying to put too much information in a twelve minute presentation; however, this should not be an excuse. My overall assessment of this talk was that it was very informative and the presenter was well spoken, however, I still would have preferred a little more background information on the target organism as well as a little more visual stimulation.
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.
We have the following seminar in systems computational biology this afternoon - try to attend if you can!
When & where: April 1, 2008, @ 3:00 PM in Alice Peters Auditorium.
What: Open Reading Frame Composition and Organization as Indicators of Phenotypic Diversity in Bacteria and Archaea.
Who: Scott Harrison, Ph.D., NIH Postdoctoral Fellow, Indiana University Purdue University Indianapolis.
Abstract:
Phenotypically, intragenomic recombination enables prokaryotic organisms to respond to dramatic changes in environmental conditions by restructuring the genome. The relationship between adaptation and alterations to genome structure over time impacts phylogeny and relates to factors regarding the optimal physiological configuration of genome structure. This study provides a quantitative treatment of open reading frame (ORF) organization based on aspects of functional conservation and DNA mobility. An analytical software system was built to facilitate randomizations, subsamplings, and comparative treatments of calculated and organized measures of open reading frame (ORF) attributes encompassing 447,551 annotated ORFs from 155 fully sequenced prokaryotic genomes. An operational subset of ORFs (O-ORFs) of putative phenotypic importance was selected based on a simple heuristic of similar length and content in comparison to five or more other ORFs. The proportion of total, annotated ORFs represented by O-ORFs strongly correlated with a predicted 3:1 signal-to-noise ratio of O-ORFs, likely associated with some phenotype, to putatively silent ORFs (S-ORFs) of unknown and undefined phenotype. The O-ORF subset had a significant degree of clustered chromosomal organization across a broad phylogenetic range. Additional study of ORF organization was conducted by developing quantitative measures of ORF clustering based on segmentation of the chromosomal sequence into consecutive regions of specified scalings. Properties associated with performance of non-parametric measures were partly characterized by simulation using an extended model of an abstract expansion modification system. Measures of ORF organization were evaluated as potential signatures of the recombinational history of an organism. As predicted by a postulated relationship between genomic organization and phylogenetic relatedness, the measurements had significant correspondence with times of divergence from last common ancestors. The presence of mobile elements predictably correlated with greater deviations from organizational symmetries of ORFs.
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