Friday, January 30, 2009

Randolph Nesse on Darwinism

 
Randolph Nesse is the co-author of "Why We Get Sick: The New Science of Darwinian Medicine" (along with George C. Williams). This is the uncut version of an interview with Richard Dawkins. Thanks to RichardDawkins.net for posting the video.

The subject is evolutionary medicine.

It's interesting how one's perspective can be distorted by only thinking about animals. Nesse wonders how large multicellular species can survive when bacterial pathogens can evolve so rapidly. Part of his answer is the immune system but he also talks about pain and vomiting as adaptive responses to disease.

If you think about trees and tulips, you might come up with very different answers to the same questions. Plants survive very well without an immune system or pain. It makes you realize that there are different ways of solving a problem.




3 comments :

  1. "Plants survive without an immune system." Yikes! You must mean that they lack an "adaptive immune system" They certainly have an innate immune system, one that is very adept at identifying pathogen-associated molecular patterns. See, for instance, Thorsten Nürnberger, Frédéric Brunner, Birgit Kemmerling, Lizelle Piater, TI: Innate immunity in plants and animals: striking similarities and obvious differences. Immunological Reviews 198(1), 249-266, 2004.

    However, you are probably referring to the remarkable additional ways that plants protect themselves. Many plants also ramp up their chemical defenses in response to cues of injury, even cues in other nearby plants. For evidence and important controversies, see Volatile signaling in plant–plant–herbivore interactions: what is real? Current Opinion in Plant Biology, Volume 5, Issue 4, 1 August 2002, Pages 351-354 by Ian T. Baldwin, André Kessler and Rayko Halitschke for current evidence and controversies.

    Some plants even use pheromone imitations to bring in predators who prey on the plant herbivores. For instance, see Defensive Function of Herbivore-Induced Plant Volatile Emissions in Nature, André Kessler and Ian T. Baldwin (16 March 2001)
    Science 291 (5511), 2141. [DOI: 10.1126/science.291.5511.2141]

    I do not by any means think only about animals. In fact, when teaching animal behavior, I usually start with whole days on plant behavior. Anytime you want to spend time looking at flora, and their adaptive and maladaptive characteristics, just let me know!

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  2. Randolph Hesse says,

    "Plants survive without an immune system." Yikes! You must mean that they lack an "adaptive immune system" They certainly have an innate immune system, one that is very adept at identifying pathogen-associated molecular patterns. See, for instance, Thorsten Nürnberger, Frédéric Brunner, Birgit Kemmerling, Lizelle Piater, TI: Innate immunity in plants and animals: striking similarities and obvious differences. Immunological Reviews 198(1), 249-266, 2004.

    This is a situation where the "striking" similarities don't seem all that striking but the "obvious" differences are truly obvious.

    I do not by any means think only about animals. In fact, when teaching animal behavior, I usually start with whole days on plant behavior. Anytime you want to spend time looking at flora, and their adaptive and maladaptive characteristics, just let me know!

    It would have been wonderful if you could have incorporated some of that into the video when you talked about how large multicellular organisms resist bacteria. Then everyone watching the video would have learned to think about species other than humans and their close relatives.

    BTW, do you still think that there are alleles for menopause, picky eating, and morning sickness and that these alleles have been selected during human evolution?

    What about dyslexia? Do you still think there might have been a selective advantage to be dyslexic before reading became popular?

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  3. Hi there,

    Enjoy your blog.

    About morning sickness, Marjorie Profet wrote me 10 single spaced pages objecting because we left the hypothesis as possible, not accepted. I sure hope someone is doing the research to find out. Plausible, but by no means confirmed.

    About menopause, I get dizzy from trying to assess the relative importance of mathematical models, human data and comparative data. See Shanley, D., R. Sear, et al. (2007). "Testing evolutionary theories of menopause." Proceedings of the Royal Society B: Biological Sciences 274(1628): 2943-2949. for a nice review. My guess is that it is an epiphenomenon, perhaps related to oocyte competition or constraints related to all oocytes being formed by birth. What do you think/

    About dyslexia, very unlikely. For some simple reasons why, see see my attempt to encourage rigor in considering evolutionary hypotheses about disease: How to Test an Evolutionary Hypothesis About Disease on the front page of my website. A cookbook, but simple is good for such things.

    Now, how about if you write about the evolution of biochemical systems. for instance, bilirubin is synthesized at some cost, while biliverdin is more water soluble. There seems to me to be considerable evidence that this is because it is a fine anxioxidant, including Snyder's nice paper. Do you know a biochemist who has systematically considered the issue? It should not be left to a psychiatrist to figure this out!

    Likewise, how about uric acid. The comparative data suggests that human levels are high to prevent oxidative damage in a long lived species. Do you agree? How would a biochemically sophisticated evolutionary biologist assess the evidence?

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