Behavior May Influence Evolution

eldavojohn writes "Pending your beliefs about evolution, National Geographic is running an interesting article on the influences of behavior on evolution. The study supports the controversial idea that an animal's behavior in response to environmental change can spur evolutionary adaptations. By adding a predator to an island where a species of lizards lived with no predators, they witnessed a quick shift in the average length of legs on the lizards. Long legs meant to escape were useless against the new larger predators while short legs became the dominant feature since they increased climbing ability (to trees the predators could not reach). For the finer details on the research, visit the Losos Lab Research Page."

Comments

Why is this controversial?

[the_skywise]

It only makes sense. If the "animal" is intelligent to overcome its primal instincts it can avoid "evolutionary" dangers.

Are we not doing seeing this now in humans with antibiotics? Genetic manipulation?

How many people on Slashdot have said that the gene pool has become watered down due to the protections of civilization?

Re:Why is this controversial?

[Daniel_Staal]

I've read good arguments that many of these are actually adaptations that will help the species survive.

Think about it: who is more likely to say 'fuck civilization': A person with perfect eyesight, or someone who needs that civilization to buy their next pair of contact lenses?

Re:Why is this controversial?

[marcello_dl]

Right wingers can't be religious people. They can only assert they are (and they probably know it since they kill religion the same way fascism kills nationalism) but reading the ABC of most religions proves the opposite.

This discovery seems to me more "dangerous" for current science theories than current religions. It implies that will could have a different meaning than the mere transition of electrons in some areas of the brain. Down with Darwin, go Lamarck :D

It disproves the higher power Direct intervention in reality, sure. But didn't the predominance of an OS like windows have the same effect, or stronger? Anyway I didn't believe in it already, even if I believe in the possibility of a higher power being responsible for reality. If you think about it, imperfect creatures created by the higher power are much more problematic for theology than a higher power creating the universe, giving freedom to everything inside.

Why I Used the Word 'Controversial'

[eldavojohn]

Why is this controversial?

Well, as I am the poster of this story and enjoy many things about evolution (book recommendation), I'll give you the best answer I can though I am not an evolutionary biologist. First off, anything about evolution is controversial. Second, it's controversial because if these animals didn't become tree-born, this quick evolution of short legs never would have happened. A lot of evolutionary theory revolves around evolution not by choice (example of the brown moths becoming dominant over white moths during the industrial revolution when smoke and carbon on trees and buildings hid them). But this almost suggests that the decision to take to the trees is in and of itself a factor in evolution. So it appears that there is evolution by way of behavior in addition to random mutations. I guess what I'm saying is that a lot of people consider evolution to be purely random ... but this study suggests that behavioral choices influence that.

Maybe you can argue that it was only natural for them to seek safety in the trees but I think that this study addresses something we must face. If you believe in evolution, you have to acknowledge that it's not only random genetics but also influenced by the behaviors of the animals granted those random mutations. If the lizards had behaved differently and not gone to the trees, perhaps longer and longer legs would have been developed until they were fast enough to outrun their predators. Or perhaps the species just would have been eradicated on the island.

Controversial because it implies that species may be able to subconsciously choose which feature is 'evolved' to be the dominant factor.

If you want to apply this to human evolution (as one is naturally only concerned with their own species), then I suggest you read Guns, Germs & Steel by Jared Diamond. What I found interesting is that in some places, humans began a farming lifestyle earlier than other hunter-gatherers. It was this decision by way of discovery that led some civilizations to outpace others. In fact, the choice or 'discovery' of planting seeds and harvesting them periodically eventually led to some regions invading and 'colonizing' other regions. Can we call this evolution? Can we say that some evolution hinges on behavioral choices? I think we can, but that's why it's controversial because it has traditionally been thought that the dominant feature was only influenced by the environment--not by a choice made by the animal.

Re:Why I Used the Word 'Controversial'

[Angostura]

First off, anything about evolution is controversial.

No. Really, it's not. It;s directly observable - you can see this from the experiment.

Second, it's controversial because if these animals didn't become tree-born, this quick evolution of short legs never would have happened.

.

Nothing controversial about that. If peahens didn't prefer to mate with showy males as a measure of fitness, presumably we wouldn't have peacocks.

 

A lot of evolutionary theory revolves around evolution not by choice (example of the brown moths becoming dominant over white moths during the industrial revolution when smoke and carbon on trees and buildings hid them). But this almost suggests that the decision to take to the trees is in and of itself a factor in evolution. So it appears that there is evolution by way of behavior in addition to random mutations. I guess what I'm saying is that a lot of people consider evolution to be purely random ... but this study suggests that behavioral choices influence that.

No. This almost suggests nothing of the kind. The lizards tried to escape by climbing. Those with shorter legs were better climbers and were therefore "fitter" the lizards didn't sit around stroking their chins and devising a cunning new survival strategy.

Maybe you can argue that it was only natural for them to seek safety in the trees

.

Precisely. This was clearly a behaviour used by the ancestral lizards when there were predators.

but I think that this study addresses something we must face. If you believe in evolution, you have to acknowledge that it's not only random genetics but also influenced by the behaviors of the animals granted those random mutations. If the lizards had behaved differently and not gone to the trees, perhaps longer and longer legs would have been developed until they were fast enough to outrun their predators. Or perhaps the species just would have been eradicated on the island.

Uh - yeh, OK. So what's the problem? No controversy there.

Controversial because it implies that species may be able to subconsciously choose which feature is 'evolved' to be the dominant factor.

What? That's just silly. Short legged lizards are better at climbing trees and survived It's as simple as that. Long legged ones could neither climb very well, nor run fast enough to escape. They were shit out of luck.

If you want to apply this to human evolution (as one is naturally only concerned with their own species), then I suggest you read Guns, Germs & Steel by Jared Diamond. What I found interesting is that in some places, humans began a farming lifestyle earlier than other hunter-gatherers. It was this decision by way of discovery that led some civilizations to outpace others. In fact, the choice or 'discovery' of planting seeds and harvesting them periodically eventually led to some regions invading and 'colonizing' other regions.

It's been a long time since I read it, but he makes a persuasive case that farming took off in certain regions because the natural wildlife were well adapted to being used as crops (large grain size etc.)

Can we call this evolution?

Nope. You can call it the predominance of a successful meme, if you want.

Can we say that some evolution hinges on behavioral choices? I think we can, but that's why it's controversial because it has traditionally been thought that the dominant feature was only influenced by the environment--not by a choice made by the animal.

You're seeing controversy where none exists. Really. Behaviour effects evolution and vice versa all the time and it has nothing to do with conscious decision. A classic case. In the UK hedgehog behaviour has changed dramatically over the last 40 years. They no longer curl up in a spikey ball when threatened by cars on roads - they run for it?

Why? Because the ones that curled up didn't have many offspring.

Re:Article is wrong - Study misinterpreted.

[Esteanil]

Interesting thought, but no.
Phenotypic plasticity can only select between states already present in the genome. Activating a certain subset of genes, but not altering the genome as is required in Lamarckian evolution.
(Lamarckian evolution in a nutshell is generations of giraffes stretching their necks to reach the higher leaves, passing the added length they train through life on to their decendants)

What could (as far as I understand) be theoretically possible, is for males to "select" the sperm to produce from a set of phenotypes. Perhaps dependent on hormonal activity, etc. (Producing "warrior children" if they had been stressed, angry and afraid over a long period of time?)
Don't really know if it's possible, but it would give a distinct survivability advantage to be able to "devolve" the next generation back to an earlier phenotype if conditions were too harsh...

Re:Article is wrong - Study misinterpreted.

[callistra.moonshadow]

I've mentioned this before in a similar article months ago. There are studies of twins separated at birth, either raised at sea level or high in the Andes. Even though the two individuals are genetically identical the ones raised in the mountains are barrel chested and stout whereas the siblings raised at sea-level are average. Plasticity due to behavior (needing to breath deeply in a thin atmosphere - perhaps not voluntary but still a behavior), caused a person to develop differently.
Link to one article:
http://jeb.biologists.org/cgi/reprint/204/18/3151. pdf
It often makes me wonder if we will begin seeing people naturally born more darkly pigmented given the current state of the ozone.
Just some food for thought.


Cally