Endosymbiosis --- A challenge to Dawkins' Universal Darwinism

by hamilcarr 46 Replies latest jw friends

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  Midget-Sasquatch

  Endosymbiosis doesn't nullify the fact that all evolutionary change occurs by selective pressures changing the frequency of alleles (gene variants). More times than not, these genes aren't mobile, so aren't shared across organisms.

  However, Margulis' insight has expanded our understanding the way life forms can diversify. Its a beautiful addition to the initial simple view of evolution. Lateral gene transfer has probably contributed greatly to the earliest stages of evolution of life on earth.

  How our own evolution has been altered by incorporating genes from other organisms is interesting to explore. There's some papers I read once discussing how the mammalian placenta owed some of its development to viral genes.

  I'd have to agree with one thing FD said:endosymbiosis doesn't seem to have been the key driving mechanism for our speciation from other earlier hominds.

  That said, Auld Soul may find it interesting that there was a paper I came across once on how parasites may have contributed to furthering bipedalism in Austrolopithecus. That's not endosymbiosis or symbiosis, really, but more generally how the interactions of two organisms can affect the evolution of both. Alot of us have been taught about the "arms race" of predator and prey but not too much is made of other types of ecological relationships and its impact of evolution.

  While endosymbiosis isn't likely to be the most predominant form of evolution thats occuring at any one time (or maybe not even the most prevalent overall), I'd have to say that it has the most potential for radical change - so its a very important factor.
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  hamilcarr

  Thanks for all your input.

  I'd recommend anyone interested to consider that recent genome mapping has revealed that the major taxa are extensively cross-linked, refuting the assumption that endosymbioses can't be responsible for the majority of evolutionary change, even in eukaryotes.
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  BurnTheShips

  Thanks for all your input.

  Thank you for this thread. It was intriguing. Another world!
• 

  AuldSoul

  While endosymbiosis isn't likely to be the most predominant form of evolution thats occuring at any one time (or maybe not even the most prevalent overall), I'd have to say that it has the most potential for radical change - so its a very important factor.

  I think Margulis' point is exactly this, slightly modified.

  While endosymbiosis isn't likely to be the most predominant form of evolution thats occuring at any one time (or maybe not even the most prevalent overall), I'd have to say that it has the most potential for radical beneficial change - so its a very important factor.

  Evolution defined as "genetic change" sets random mutation well apart as much more frequent in occurrence than endosymbiosis, but which is more frequently the cause of a beneficial change to a species?
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  seattleniceguy

  I also don't see the point of the original post. I don't see how endosymbiosis is a challenge to anything except creationism. It's a fascinating fact of the physical world, and one that fits perfectly with the rest of modern evolutionary theory.

  SNG
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  Midget-Sasquatch

  Evolution defined as "genetic change" sets random mutation well apart as much more frequent in occurrence than endosymbiosis, but which is more frequently the cause of a beneficial change to a species?

  The hippie in me has got to agree with the point being made. We'd see much more with endosymbiosis, but I want to say that you could expect this to be the case. What else but positive selective pressure would drive the formation of the endosymbiotic relationship in the first place?

  Endosymbiosis is a beautiful phenomenon and while it doesn't discount the neo-darwinian view, it certainly takes a good bite out of a completely cold hearted view of nature that was touted by social darwinists. Maybe its that misperception of the neo-darwinian view that the original poster had in mind? In any case, I would be just as against that view if I were strong, tall, blond, and super-intelligent. Its got nuttin' to do with my subpar genetic makeup...honest.
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  MissingLink

  funkyderek

  it doesn't require much thought to realise that mergers like this can only take place at the level of single-celled or at least very small and simple organisms. Nobody could seriously be proposing that the differences between humans and apes (for example) are the result of such a merger.

  You mean a mouse didn't climb up a monkey's butt and turn it human?

  Seriously though - this seems like a manufactured "fight" by yer woman to get herself some press.

  Nobody would seriously argue that nature isn't full of symbiotic relationships. Our own bodies are full of bacteria (separate life forms) that we could not survive without. How did this come about is arguable. Perhaps at one point we primates didn't have these and were fully capable of digesting our own food, introduce some bacteria and spin the dice a few million times and wham - the creatures in the symbiotic relationship had a survival advantage. Was this a hostile or peaceful takeover which resulted in the loss of a function of the larger creature? Or perhaps these paired creatures evolved together. I don't see why both can't be true at the same time.
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  Satanus

  Not sure if i'm a darwinist, but anyway. I'm certainly not a dawkinsian;) (dawkinsist?) Evolution is a balance between competition and cooperation. The organism that best balances those two succeeds the best. That is true on the biological level, the lower animal level, and on the human social level.
  
  S
• 

  hooberus

  On a related note,one of the passages I found interesting in "The God D elusion" was Dawkins statement that:

  "Nevertheless, it may be that the origin of life is not the only major gap in the evolutionary story that is bridged by sheer luck, anthropically justified. For example, my collegue Mark Ridley in Mendel's Demon . . .has suggested that the origin of the eucaryotic cell (our kind or cell, with a nucleus and various other complicated features such as mitochondria, which are not present in bacteria) was an even more monumentous, difficult and statisally improbable step than the origin of life." The God De lusion page 168.

  (see also http://www.answersingenesis.org/docs2/4341_endosymbiont.asp)
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  Mincan

  A simple sentence to disprove survival of the fittest in it's usually taken fashion: Any organism that removes more from its environment than it puts back in is by definition unsustainable and would never have evolved in the first place.