Discussion on answer by TCAT117: How do you "devolve" a species?

Feeds

03:18

76

Devolution doesn't really ever occur, organisms simply adapt to best suit their environment over time. A good example is cave dwelling Troglodyte type species that have lost the ability to see. They haven't actually devolved to not have eyes, they simply did not need them and evolved to save valu...

Henry Taylor

+1 Excellent Answer! I especially like the irony of our returning to Eden and going extinct because we are not "the fittest" for life there. 1 minute after you, I posted an answer which agrees strongly with your first paragraph, but I'm going to delete it now because your supporting second paragraph is much better than mine. Thanks for a great read!

Arkhaine

Very interesting and if I may ask for more information with regards to this idea, by asking a follow up question. What would determine the pinnacle of evolution? Would it be the situation you described above or what if for example the ideal evolution would be to have the highest intelligence or the strongest physical form? Does the environment dictate the evolution progress or do the species living inside it have any say? Let me know if this is too broad but I hope you get my gist.

TCAT117

The problem with reaching a "pinnacle" in evolution is overspecialization. A good example is the panda. It has no natural predators and a plentiful food supply it has to do very very little work to get. so why adapt aggressive breeding strategies when it will just waste energy? It is the apex of its environment. Environments change, often more rapidly than can be adapted to. Becoming the pinnacle of something means a dead end when the environment that supports that adaptation set changes.

Headcrab

In an environment so "perfect", wouldn't they just over-populate to a degree where plentiful resources become scarce resources, for which they would then fiercely compete?

Real Subtle

Put them into the Matrix. There the clever ones always die or get out and remove themselves from the gene pool that way. (Only, the machines would not bother making sure that if a couple has a baby in the matrix, the real life equivalent of it carries their DNA, they would just impregnate the woman with whatever's available locally.)

Lightness Races in Orbit

03:18

"become stuck in an environment for a few hundred thousand years that heavily discourages intellect, sociability, communication skills,culture, and inventiveness. That's a tough one to come up with" Higher brain function is a huge energy drain (we can't go without respiration for more than a handful of seconds because we are right on the precipice of what is possible at our mass level) so just make resources scarce

@TCAT117: And, ironically, that's arguably why they're dying out because they just cba to have kids

called2voyage

You hit the nail on the head with childbirth. Big brains and walking upright make childbirth incredibly dangerous, not just for the mother but also the offspring! In an environment where all that extra intelligence wasn't helpful, a subgroup of humans that developed to reduce this problem would potentially be more successful at population growth.

John

one of the major places brains come in handy is competing with other humans, available calories is one of the major limits, a more plentiful environment will encourage intelligence no discourage it.

Konrad Rudolph

@Arkhaine The concept of a “pinnacle” is simply not meaningful in the theory of evolution. There is no conceivable “optimum” that could be reached. Evolution (biological, but also theoretically other kinds, such as memetic, or artificial evolution) doesn’t work like this. I realise that this may be unsatisfactory but that’s just the way things are. Sasha’s and JAD’s answers hit the nail on the head.

Mooing Duck

@Arkhaine: Every species is the "pinnacle" of evolution for the environment they're in. Orrorin tugenensis and Paranthropus included. And earthworms.

Arkhaine

Thank you for the insight. Yeah I'm thinking its a big circle altogether, where in one world the pinnacle of evolution might be physical strength, and another, intellect and in another, a different attribute and even if these worlds meet and somehow interacted for a very long time to have evolution the result would be different again.

Cephalopod

03:18

"They haven't actually devolved to not have eyes, they simply did not need them and evolved to save valuable energy" Do you know of evidence for this? Eyes could have devolved via genetic drift combined with lack of evolutionary pressure (ie mutations that damage the eye are not selected against).

Cows quack

Reminds me of The Time Machine, where humans have evolved into two separate species, one of which is composed pale, weak, dumb, helpless creatures.

AlbeyAmakiir

@Cephalopod: Mutations are exactly what causes evolution. There isn't an inherent difference in whether something is "damaged" or "improved" by a mutation. Instead, it's just different, and has a higher or lower likelihood of being propagated.

Cephalopod

@AlbeyAmakiir Answer claimed eyes devolved to "save energy". I doubt that.

collapsar

@Cephalopod (genetic drift) Wouldn't that imply that the physical realization of the visual apparatus should remain basically intact in specimens, just being hampered to work properly ? To drive the reasoning further, shouldn't one even see ( pun intended ;) ) lots of different incarnations of the visual apparatus ? Does this apply to any of Earth's cave-dwelling creatures? Has it been observed in beings populating any other environment?

AlbeyAmakiir

@Cephalopod More like creatures that had the eye mutations that happened to use less energy were more likely to survive in that particular environment than other eye mutations that used more energy. And again, that's not devolving, but evolving.

Cephalopod

03:18

@collapsar Yes, this is basically what we find (with various stages of degradation) but this alone does not tell us much about the reason (drift or economical). Sometimes yes, also depends on how long this is going on. This fish is a good example. Yes, eg color blindness in mammals, many vestigial organs, but it's hard to tell bc you can't see the "reason" why something evolved

@AlbeyAmakiir Do you have evidence for that claim? That's what I'm asking.

AlbeyAmakiir

@Cephalopod Not on me right now, but it's fairly basic and well-understood. I'm sure google will be your friend in finding the proof you are after. :)

Cephalopod

@AlbeyAmakiir Maybe you should have tried Google as this is neither basic nor well-understood but actually a topic of ongoing debate. Turns out evolution is not as simple and straightforward as laypeople often think it is

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Discussion on answer by TCAT117: How …