Re: [asa] Finding Your Inner Fish

Hi Randy,

"The title of his book reflects his perspective that humans contain the essence of 3.5 billion years worth of life. Our genetic structure reflects elements of all the other organic structures. He noted that in the past 15-17 years, many of the Nobel prizes in medicine and related biological fields have been for studies on worms and parasites and other small species. He inferred that many of the critical processes in our own bodies were reflected in the "lower" life forms and could be more easily studied there. He also spoke of the comparison of human and shark embryos and he showed the early similarities of analogous structures in these embryos. As a fish paleontologist, he has been teaching a first-year anatomy course to the U of Chicago medical school. He tells them that all the major human structures were all first seen in fish."

Yes, this is all very cool. But it's better than this. If anyone would like to see single-celled amoeba form a multicellular life form before your very eyes, check out this:

http://designmatrix.wordpress.com/2009/04/17/dictyostelium/

The amoeba coalesce into a multicellular life as a response to stress. What's makes this so super cool is that they use the same circuitry the human body uses to respond to extreme stress: G protein receptor, G proteins, adenylyl cyclase, cAMP, and protein kinases. Humans use this circuit as part of their "fight and flight" response, where it is triggered by the hormone epinephrine (adrenalin). I don't know if these amoeba make or use epinephrine, but others do:

http://designmatrix.wordpress.com/2009/02/02/the-neurotransmitter-toolkit/

Someday I may write a book entitled, "Our Inner Amoeba" as these continual findings of deep homology enhance the plausibility of my particular front-loading hypothesis.

BTW, I should also mention that such deep homology was not predicted to exist by the Modern Synthesis. On the contrary, it was predicted to not exist. Again, from Koonin's paper, "Darwinian evolution in the light of genomics":

"Moreover, the adaptationist paradigm of evolutionary biology seemed to imply that genes, whatever their molecular nature, would not be well conserved between distant organisms, given the major phenotypic differences between them, as emphasized in particular by Mayr, one of the chief architects of the Modern Synthesis (21)."

Or, as Mike Levine explained:

"And so to see that genes that are doing such profound things in the fruit fly - making head from tail, stomach from back, thorax from abdomen - are conserved, related in other animals . this was just not predicted by anybody. At least nobody that I ever read. So this was very profound. It meant that there could be a common blueprint for all animal life on this planet.

In the case of the discovery of common homeotic genes among all animals, there was a strong sense in the '70s and the '80s that embryonic development among different animals involved completely different molecules, completely unrelated. This was such a strongly held view. And so, yes, it came as a huge surprise not only to people like my mother who says, "My God, an earthworm and a mouse? An earthworm and me, sharing things in common?" But it came as a surprise to other scientists that there was this profound conservation of mechanism of building embryos among all these different kinds of animals."

http://designmatrix.wordpress.com/2009/02/14/evo-devo-fits-comfortably-with-front-loading/

- Mike

  ----- Original Message -----
  From: Randy Isaac
  To: asa@calvin.edu
  Sent: Thursday, April 16, 2009 10:21 PM
  Subject: [asa] Finding Your Inner Fish

  After less than 3 weeks away from this list, it is rather daunting to find over 200 unread notes. This is where a peer reviewer is needed--to help identify the ones to read!

  I just returned from the Harvard Museum of Natural History where Neil Shubin gave a public lecture tonight to an SRO crowd. His book, "Finding Your Inner Fish" has been discussed on this list before and was highly recommended. I thought he was also an excellent speaker and gave a very good talk. I haven't read the book but I presume most of what he said is also in the book.

  Most of the talk was about the discovery of Tiktaalik Roseae, a fossil of the Devonian period. It really is a classic story of scientific discovery. Years of intense search for the missing link between fish and tetrapods in the wrong place followed by a serendipitous discovery of a promising site in the arctic. Then many more years of difficult fossil hunting until the prize was found. More years of arduous work followed until the discovery was announced in 2006.

  The description of the fossils (about 3 or 4 specimens have been found) was very interesting. It's not too hard to see the intermediate features between fish and tetrapods, notably in the neck and the limbs but also in the jaw. The most important bone that has not yet been found is a femur and they continue to return each year to hunt for one. It seems that the hip socket is peculiarly deep and they want to see how the femur connects to it.

  The title of his book reflects his perspective that humans contain the essence of 3.5 billion years worth of life. Our genetic structure reflects elements of all the other organic structures. He noted that in the past 15-17 years, many of the Nobel prizes in medicine and related biological fields have been for studies on worms and parasites and other small species. He inferred that many of the critical processes in our own bodies were reflected in the "lower" life forms and could be more easily studied there. He also spoke of the comparison of human and shark embryos and he showed the early similarities of analogous structures in these embryos. As a fish paleontologist, he has been teaching a first-year anatomy course to the U of Chicago medical school. He tells them that all the major human structures were all first seen in fish.

  Some of you have read the book and can probably recount this more accurately. I thought it was a remarkable story. The evolutionary paradigm led to a prediction of the kind of rocks and geologic time frame where fossils such as this could be found. The prediction was borne out in a most dramatic fashion. It really is a storybook case.

  Randy

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Received on Fri Apr 17 22:08:19 2009