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I find Dawkins's approach to all this incredibly implausible. Think about it. How does a population of creatures split into multiple different reproductively in

by it 6y ago

I find Dawkins's approach to all this incredibly implausible. Think about it. How does a population of creatures split into multiple different reproductively incompatible species via chance mutations? A much more believable mechanism for speciation would be something repeatable like genes being spliced in by a virus, or a new symbiosis like what Lynn Margulis describes in her book Symbiotic Planet. Edit: Nice demo though. And maybe it could be fun to do one based on viruses or symbioses.

batmanthehorse 6y ago
It happens when populations are isolated from each other for a long time. It's a fact.
- it 6y ago
  Sure, but that doesn't imply that the means by which it happens is what Dawkins says.
  - it 6y ago
    Hey downvoters, I invite you to express your disagreement with actual arguments.
    - deleted 6y ago
      [deleted]
jmcgough 6y ago
Most genetic modification by viruses is deleterious, as are most random genetic mutations. Part of endosymbiotic theory is pretty well accepted now (I remember being told in school that mitochondria may have come from prokaryotic cells), but it's a bit optimistic to think that symbiosis causes all speciation. It's very conceivable that most speciation is caused through many generations of reproduction, environmental stressors and separation.
- yters 6y ago
  Then what is the engine of evolution? This is a point that I see repeatedly glossed over. First it's random mutation. Then random mutation is mostly bad. So, then the secret is natural selection. But what is natural selection? Is it merely survival and reproduction? Finally, when the author gets around to giving an example of 'natural selection' that actually works, they always give an example of human (livestock breeding, biomorphs, etc.) or animal driven selection (Koonin's lamarckianism or Shapiro's natural genetic engineering). This is always directed and purposeful, the very thing that evolution is not supposed to be. It seems the authors cannot get their story straight for whatever reason.
  - c1ccccc1 6y ago
    Yes, the engine of selection is just survival and reproduction. This, combined with random mutations is pretty much all you need for evolution to happen. In an artificial environment, survival and reproduction can be affected by humans, but selection happens in natural environments too. In the applet, the user plays the role of the environment, since that makes things interesting for you as the user. But one can imagine a (perhaps more boring) applet where the computer makes the choice for you. Maybe the computer always selects the biggest critter to reproduce. Then, even though there is no intelligent overseer, the critters will tend to get larger and larger. Or one can imagine a more complicated selection process involving a physics simulation where a bunch of copies of the critter are dropped on top of one another in a pile. The tallest pile is selected to reproduce. Over time, one would tend to see critters that were good at stacking on top of one another, maybe they would be rectangular like bricks, or maybe they would have lots of spines so they could stick together like burrs. Or maybe evolution would hit upon something else. But there is no need for the selection process to be intelligent. Of course, in those examples, you might say that whoever wrote the objective, like "grow big", or "stack in tall piles" is still directing the process from behind the computer program. That's why in the natural world, we don't have objectives like that. Instead, the only "objective" in the natural world is "survive and reproduce", since that is tautologically what determines reproductive success. There is a freely available software application called "biogenesis" that shows evolution using that objective function in a world with greatly simplified physics, if you are curious. There are certainly plenty of examples of evolution being driven by the natural environment, even if the books tend to focus on things like evolutionary arms races, symbiosis, and sexual selection. Here is one: An organism that can convert a molecule of glucose to more molecules of ATP than its neighbours can will be able to use its food more efficiently than them. This will give it an edge in survival and reproduction, since it needs less food to do the same amount of stuff. So the genes that enable this more efficient metabolism will tend to spread throughout the population, because the organisms that bear them will be less likely to die of starvation.

by it 6y ago

batmanthehorse 6y ago

It happens when populations are isolated from each other for a long time. It's a fact.

it 6y ago
Sure, but that doesn't imply that the means by which it happens is what Dawkins says.
- it 6y ago
  Hey downvoters, I invite you to express your disagreement with actual arguments.
  - deleted 6y ago
    [deleted]

jmcgough 6y ago

Most genetic modification by viruses is deleterious, as are most random genetic mutations. Part of endosymbiotic theory is pretty well accepted now (I remember being told in school that mitochondria may have come from prokaryotic cells), but it's a bit optimistic to think that symbiosis causes all speciation. It's very conceivable that most speciation is caused through many generations of reproduction, environmental stressors and separation.

yters 6y ago
Then what is the engine of evolution? This is a point that I see repeatedly glossed over. First it's random mutation. Then random mutation is mostly bad. So, then the secret is natural selection. But what is natural selection? Is it merely survival and reproduction? Finally, when the author gets around to giving an example of 'natural selection' that actually works, they always give an example of human (livestock breeding, biomorphs, etc.) or animal driven selection (Koonin's lamarckianism or Shapiro's natural genetic engineering). This is always directed and purposeful, the very thing that evolution is not supposed to be. It seems the authors cannot get their story straight for whatever reason.
- c1ccccc1 6y ago
  Yes, the engine of selection is just survival and reproduction. This, combined with random mutations is pretty much all you need for evolution to happen. In an artificial environment, survival and reproduction can be affected by humans, but selection happens in natural environments too. In the applet, the user plays the role of the environment, since that makes things interesting for you as the user. But one can imagine a (perhaps more boring) applet where the computer makes the choice for you. Maybe the computer always selects the biggest critter to reproduce. Then, even though there is no intelligent overseer, the critters will tend to get larger and larger. Or one can imagine a more complicated selection process involving a physics simulation where a bunch of copies of the critter are dropped on top of one another in a pile. The tallest pile is selected to reproduce. Over time, one would tend to see critters that were good at stacking on top of one another, maybe they would be rectangular like bricks, or maybe they would have lots of spines so they could stick together like burrs. Or maybe evolution would hit upon something else. But there is no need for the selection process to be intelligent. Of course, in those examples, you might say that whoever wrote the objective, like "grow big", or "stack in tall piles" is still directing the process from behind the computer program. That's why in the natural world, we don't have objectives like that. Instead, the only "objective" in the natural world is "survive and reproduce", since that is tautologically what determines reproductive success. There is a freely available software application called "biogenesis" that shows evolution using that objective function in a world with greatly simplified physics, if you are curious. There are certainly plenty of examples of evolution being driven by the natural environment, even if the books tend to focus on things like evolutionary arms races, symbiosis, and sexual selection. Here is one: An organism that can convert a molecule of glucose to more molecules of ATP than its neighbours can will be able to use its food more efficiently than them. This will give it an edge in survival and reproduction, since it needs less food to do the same amount of stuff. So the genes that enable this more efficient metabolism will tend to spread throughout the population, because the organisms that bear them will be less likely to die of starvation.