Bjørn Østman

71 posts · 98,146 views

Pleiotropy
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  • June 29, 2014
  • 12:05 PM
  • 202 views

Vertebrate sexual systems

by Bjørn Østman in Pleiotropy

Awesome figure of the sexual systems used by 2,145 vertebrates species (705 fish, 173 amphibian, 593 non-avian reptilian, 195 avian, 479 mammalian).... Read more »

Ashman, T., Bachtrog, D., Blackmon, H., Goldberg, E., Hahn, M., Kirkpatrick, M., Kitano, J., Mank, J., Mayrose, I., Ming, R.... (2014) Tree of Sex: A database of sexual systems. Scientific Data. DOI: 10.1038/sdata.2014.15  

  • March 4, 2014
  • 05:03 PM
  • 242 views

Evolutionary dynamics in holey fitness landscapes

by Bjørn Østman in Pleiotropy

What do real fitness landscapes look like? Do they look more like the image on the left, a nearly-neutral holey fitness landscape, or the one on the right, a rugged fitness landscape with many distinct peaks? - See more at: http://pleiotropy.fieldofscience.com/2014/03/evolutionary-dynamics-in-holey-fitness.html#sthash.eTuURlc7.dpuf... Read more »

Østman B, & Adami C. (2013) Predicting evolution and visualizing high-dimensional fitness landscapes. Recent Advances in the Theory and Application of Fitness Landscapes" (A. Engelbrecht and H. Richter, eds.). Springer Series in Emergence, Complexity, and Computation. DOI: 10.1007/978-3-642-41888-4_18  

  • January 27, 2014
  • 04:12 PM
  • 264 views

Sewall Wright's last paper

by Bjørn Østman in Pleiotropy

Sewall Wright lived to be 98. Two months before he died he published a paper in The American Naturalist titled Surfaces of Selective Value Revisited (Wright, 1988).... Read more »

Sewall Wright. (1988) Surfaces of Selective Value Revisited. The American Naturalist. DOI: 10.1086/284777  

Bjørn Østman, Arend Hintze, & Christoph Adami. (2010) Critical properties of complex fitness landscapes. Proc. 12th Intern. Conf. on Artificial Life, H. Fellerman et al., eds. (MIT Press, 2010), pp. 126-132. arXiv: 1006.2908v1

Østman B, Hintze A, & Adami C. (2012) Impact of epistasis and pleiotropy on evolutionary adaptation. Proceedings. Biological sciences / The Royal Society, 279(1727), 247-56. PMID: 21697174  

  • November 13, 2013
  • 09:28 AM
  • 330 views

Smooth and rugged fitness landscapes

by Bjørn Østman in Pleiotropy

In evolutionary theory, a fitness landscape is a map where fitness is a function of either the genotype or the phenotype. The genotype is some description of the genetic make-up of an organism. This can be the DNA or a list of the mutations/alleles, and are discrete variables. ... Read more »

Jasper Franke, Alexander Klözer, J. Arjan G. M. de Visser, & Joachim Krug. (2011) Evolutionary accessibility of mutational pathways. PLoS Computational Biology 7 (8) e1002134 (2011). arXiv: 1103.2479v2

Weissman DB, Desai MM, Fisher DS, & Feldman MW. (2009) The rate at which asexual populations cross fitness valleys. Theoretical population biology, 75(4), 286-300. PMID: 19285994  

Østman B, Hintze A, & Adami C. (2012) Impact of epistasis and pleiotropy on evolutionary adaptation. Proceedings. Biological sciences / The Royal Society, 279(1727), 247-56. PMID: 21697174  

  • April 13, 2013
  • 04:26 PM
  • 489 views

Can we predict evolution?

by Bjørn Østman in Pleiotropy

Evolution is predictable if we know population size, mutation rate, and the fitness landscape.... Read more »

Szendro IG, Franke J, de Visser JA, & Krug J. (2013) Predictability of evolution depends nonmonotonically on population size. Proceedings of the National Academy of Sciences of the United States of America, 110(2), 571-6. PMID: 23267075  

Ostman B, Hintze A, & Adami C. (2012) Impact of epistasis and pleiotropy on evolutionary adaptation. Proceedings. Biological sciences / The Royal Society, 279(1727), 247-56. PMID: 21697174  

  • October 10, 2012
  • 09:52 AM
  • 793 views

Ochman on bacterial evolution

by Bjørn Østman in Pleiotropy

Yesterday I went to the annual Thomas S Whittam Memorial Lecture here at MSU. Howard Ochman talked about "Evolutionary Forces Affecting Bacterial Genomes", though he had changed the title to "Determinants of Genome Size and complexity.... Read more »

Raghavan R, Kelkar YD, & Ochman H. (2012) A selective force favoring increased G C content in bacterial genes. Proceedings of the National Academy of Sciences of the United States of America, 109(36), 14504-7. PMID: 22908296  

  • September 28, 2012
  • 08:45 AM
  • 670 views

Genotype-phenotype maps and mathy biology

by Bjørn Østman in Pleiotropy

... Read more »

Peter F. Stadler, & Christopher R. Stephens. (2003) Landscapes and Effective Fitness. Comm. Theor. Biol. DOI: 10.1080/08948550302439  

  • September 5, 2012
  • 05:31 PM
  • 587 views

ENCODE: What defines genomic function?

by Bjørn Østman in Pleiotropy

A new wealth of articles by the ENCODE (the ENCyclopedia Of DNA Elements) consortium suggest that far more of the human genome carries out some function or other, and one might conclude that very little DNA is junk.... Read more »

Joseph R. Ecker, Wendy A. Bickmore, Inês Barroso, Jonathan K. Pritchard, Yoav Gilad . (2012) Genomics: ENCODE explained. Nature. DOI: 10.1038/489052a  

  • July 23, 2012
  • 04:41 PM
  • 782 views

Crossing valleys in fitness landscapes

by Bjørn Østman in Pleiotropy

With his "holey adaptive landscapes", Sergey Gavrilets (e.g. 1997) solved the problem of crossing valleys of low fitness in the fitness landscape* by positing that for high-dimensional landscapes (which is realistic - typiwrightcally the genotype consists of thousands of genes and many more DNA nucleotides) there is always a ridge between fitness "peaks" (which are then not really peaks). ... Read more »

Weissman DB, Desai MM, Fisher DS, & Feldman MW. (2009) The rate at which asexual populations cross fitness valleys. Theoretical population biology, 75(4), 286-300. PMID: 19285994  

Bjørn Østman, Arend Hintze, & Christoph Adami. (2010) Critical properties of complex fitness landscapes. Proc. 12th Intern. Conf. on Artificial Life, H. Fellerman et al., eds. (MIT Press, 2010), pp. 126-132. arXiv: 1006.2908v1

Østman B, Hintze A, & Adami C. (2012) Impact of epistasis and pleiotropy on evolutionary adaptation. Proceedings. Biological sciences / The Royal Society, 279(1727), 247-56. PMID: 21697174  

  • May 31, 2012
  • 02:42 PM
  • 840 views

The Black Queen Hypothesis

by Bjørn Østman in Pleiotropy

In the game of Hearts, the object is to not get certain cards. The most vile of them all is the dreaded black queen of spades, which is as bad as all the other bad cards put together.... Read more »

  • March 27, 2012
  • 12:17 PM
  • 1,044 views

Carnivores have bad taste

by Bjørn Østman in Pleiotropy

Pseudogenes are genes that used to have a function, but no longer do. If a gene contributes to an important function for the organism, offspring with deleterious mutations that ruin the gene will have lower fitness, and as a result won't have as many offspring, if any at all. That mutated gene will likely not go to fixation (become prominent in the population). On the other hand, if the gene used to have a function, but no longer don't, then mutations affecting the gene won't be deleterious. Mut........ Read more »

Jiang P, Josue J, Li X, Glaser D, Li W, Brand JG, Margolskee RF, Reed DR, & Beauchamp GK. (2012) Major taste loss in carnivorous mammals. Proceedings of the National Academy of Sciences of the United States of America. PMID: 22411809  

  • January 26, 2012
  • 02:38 PM
  • 897 views

Link between political views and physiology

by Bjørn Østman in Pleiotropy

It is becoming more and more clear that political views are in fact not completely decided by rational considerations, as common sense would have us believe. Rather, previous studies have shown a link between emotional (i.e., largely uncontrollable) responses and position on the left/right spectrum: "those on the right are ‘distrustful of differences … fear change, dread disorder, are intolerant of nonconformity, and derogate reason’."*... Read more »

Dodd MD, Balzer A, Jacobs CM, Gruszczynski MW, Smith KB, & Hibbing JR. (2012) The political left rolls with the good and the political right confronts the bad: connecting physiology and cognition to preferences. Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 367(1589), 640-9. PMID: 22271780  

  • January 11, 2012
  • 07:08 PM
  • 1,082 views

What determines rates of ecological speciation?

by Bjørn Østman in Pleiotropy

Speciation models are the most beautiful thing in evolutionary biology. This is widely known, and those who disagree are the crazies. Other models have their place, and empirical evidence for speciation, and insights from there into how speciation takes place are crucial for progress. But real understanding of this question of questions in evolutionary biology only comes once a model is constructed and validated. It is the ultimate goal of scientific work to condense knowledge in terms we can sh........ Read more »

Birand A, Vose A, & Gavrilets S. (2012) Patterns of species ranges, speciation, and extinction. The American naturalist, 179(1), 1-21. PMID: 22173457  

  • November 22, 2011
  • 10:45 AM
  • 1,279 views

Reproductive species vs. ecological species

by Bjørn Østman in Pleiotropy

Why are two breeds of dogs who can't mate without human assistance the same species, while two fish species, which can and do have fertile offspring, but which are intermediate in size and therefore not as good at obtaining resources as the parents, are different species?... Read more »

  • November 14, 2011
  • 12:07 AM
  • 415 views

Speciation in the virtual social world: Facebook vs. G

by Bjørn Østman in Pleiotropy

It may just be me and the people I follow, but isn't Google+ used more for serious stuff that people want others to see, while Facebook is for whatever friends do to each other. That would make sense, I suppose, given that you can't control who follows you on G+. But does it mean that G+ and Facebook are not really competing for the same niche? Even if there are overlapping functions, as there clearly are, are the two so diverged from each other in function that they will continue to coexist sid........ Read more »

Barrick, J., Yu, D., Yoon, S., Jeong, H., Oh, T., Schneider, D., Lenski, R., & Kim, J. (2009) Genome evolution and adaptation in a long-term experiment with Escherichia coli. Nature, 461(7268), 1243-1247. DOI: 10.1038/nature08480  

Østman, B., Hintze, A., & Adami, C. (2011) Impact of epistasis and pleiotropy on evolutionary adaptation. Proceedings of the Royal Society B: Biological Sciences. DOI: 10.1098/rspb.2011.0870  

  • November 13, 2011
  • 11:50 PM
  • 722 views

Speciation in the virtual social world: Facebook vs. G+

by Bjørn Østman in Pleiotropy

It may just be me and the people I follow, but isn't Google used more for serious stuff that people want others to see, while Facebook is for whatever friends do to each other. That would make sense, I suppose, given that you can't control who follows you on G . But does it mean that G and Facebook are not really competing for the same niche? Even if there are overlapping functions, as there clearly are, are the two so diverged from each other in function that they will continue to coexist sid........ Read more »

Barrick, J., Yu, D., Yoon, S., Jeong, H., Oh, T., Schneider, D., Lenski, R., & Kim, J. (2009) Genome evolution and adaptation in a long-term experiment with Escherichia coli. Nature, 461(7268), 1243-1247. DOI: 10.1038/nature08480  

Østman, B., Hintze, A., & Adami, C. (2011) Impact of epistasis and pleiotropy on evolutionary adaptation. Proceedings of the Royal Society B: Biological Sciences. DOI: 10.1098/rspb.2011.0870  

  • August 13, 2011
  • 09:46 PM
  • 1,387 views

Scandinavians have bigger brains for better vision

by Bjørn Østman in Pleiotropy

No matter that this study proposes that people of the north have bigger brains than those at the equator merely to cope with lower levels of sunlight - it would still cause an uproar if the rather large group of people (including scientists) who regularly commit the moralistic fallacy should ever hear about it.We demonstrate a significant positive relationship between absolute latitude and human orbital volume, an index of eyeball size. Owing to tight scaling between visual system components, th........ Read more »

  • June 30, 2011
  • 03:29 PM
  • 1,478 views

Using deleterious mutations to cross fitness valleys - as misunderstood by ID creationists

by Bjørn Østman in Pleiotropy

It is fitting that an article I just got published in Proceedings of the Royal Society B [1] has been blogged about on the ID lover's Uncommon Descent: Are Fitness Valleys Too Deep?
... Read more »

  • June 15, 2011
  • 04:37 PM
  • 1,675 views

Homophobes are turned on by homosexuality

by Bjørn Østman in Pleiotropy

Unfortunately I can't access the full length article of this one: Is homophobia associated with homosexual arousal?But it is obviously too good to miss. The abstract reads:The authors investigated the role of homosexual arousal in exclusively heterosexual men who admitted negative affect toward homosexual individuals. Participants consisted of a group of homophobic men (n = 35 ) and a group of nonhomophobic men (n = 29); they were assigned to groups on the basis of their scores on the In........ Read more »

Adams, H., Wright, L., & Lohr, B. (1996) Is homophobia associated with homosexual arousal?. Journal of Abnormal Psychology, 105(3), 440-445. DOI: 10.1037/0021-843X.105.3.440  

  • May 13, 2011
  • 01:14 PM
  • 1,574 views

Keller shows robots evolving altruism - Nowak dismisses simulations

by Bjørn Østman in Pleiotropy

As also reported on Panda's Thumb, Laurent Keller's group have evolved robot behavior in a computer (report in Science). The robots were given the ability to share food with each other, and more related groups quickly evolved altruism, sharing food with other robots they were related to. Classical and unsurprising, at least given our theoretical understanding of the evolution of altruism.However, Martin Nowak, champion of the anti-kin-selection view, in a stunning feat of denial, dismisses the r........ Read more »

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