Current Events > Could we reverse evolution?

(+) Yeah! (+)

Notti posted...

Let's take an actual example of my explanation for losing fur.

Cave animals that lose their site.

That very example disproves your idea.

https://phys.org/news/2017-04-cave-animals.html

tl;dr

the idea of disuse or a trait not being useful and thus lost was proposed by Darwin as why this happens and it is proven...
WRONG

instead the population of fish that are blind like the cave and the population that are not just leave the cave

that is, this same fish has relatives that can still see not very far away

Cartwright's team turned to a hypothesis going all the way back to a letter to the editor of Nature in 1925 by E. Ray Lankester, that essentially stated that the reason you have blindness in caves is because the fish that can see simply leave.

"If sighted fish swim towards the light, the only fish that stay in the cave are blind fish. They aren't trying to get to the light anymore because they can't see it. Which actually is a form of selection, and thus, Darwinian evolution in action," Cartwright said.

Now, here is the big problem with your fur example.
Humans in cold weather still NEED the fur.
They literally kill furred animals and wear their skin, yet you suggest that they lost the fur because it wasn't useful or needed any longer (not directly, but indirectly in that it saves so much energy to not grow it; of course you forget the energy spent hunting coats of prey).

Consider these fish or other blind cave animals. Are they hunting for working eyes to attach to their skulls? no
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darkphoenix181 posted...

Notti posted...

Let's take an actual example of my explanation for losing fur.

Cave animals that lose their site.

That very example disproves your idea.

https://phys.org/news/2017-04-cave-animals.html

tl;dr

the idea of disuse or a trait not being useful and thus lost was proposed by Darwin as why this happens and it is proven...
WRONG

instead the population of fish that are blind like the cave and the population that are not just leave the cave

that is, this same fish has relatives that can still see not very far away

Cartwright's team turned to a hypothesis going all the way back to a letter to the editor of Nature in 1925 by E. Ray Lankester, that essentially stated that the reason you have blindness in caves is because the fish that can see simply leave.

"If sighted fish swim towards the light, the only fish that stay in the cave are blind fish. They aren't trying to get to the light anymore because they can't see it. Which actually is a form of selection, and thus, Darwinian evolution in action," Cartwright said.

I'm sure that's a minor partial contributor.

But there are many blind creatures in caves. And many are not just slightly blind, but totally eyeless.



So here's the better explanation.

https://news.nationalgeographic.com/2015/09/150911-blind-cavefish-animals-science-vision-evolution/

Few animals have ignored the warning use it or lose it as spectacularly as the Mexican blind cavefish (Astyanax mexicanus), which no longer has eyes.

Now scientists may have solved the riddle of why the fish lost their eyes in the dark.

With food so scarce in caves, the animals have to save their energyand being sightless gives them a major boost

For the study, the team acquired captive cavefish and measured the energy cost of their sight. They did this by calculating the oxygen consumption of their eyes and vision-related parts of their brain.

The results, published September 11 in the journal Science Advances, showed that for young, developing fish, the energy cost of sight is 15 percent greater than if they were blind.

vision is costly because of energy-hungry photoreceptive cells and neurons.

As underground caves are often poor in food and oxygen, natural selection would favor individuals with reduced visual capacity, he says.

Any animal that lives in permanent darkness and doesnt need vision to find food or avoid predators wont really need their eyes or visual centers in the brain,

Moran doesnt disagree. Evolution is often a mixture of many processes happening simultaneously, he says.

One such process in Mexican blind cavefish is a phenomenon called pleiotropy, in which genes usually involved in eye development are reassigned to features more useful to life in caves, such as increased numbers of taste cells for finding food in the dark.

In fact, Moran says, the evidence suggests both pleiotrophy and energy savings are major drivers in the cavefish eye loss.

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darkphoenix181 posted...

Now, here is the big problem with your fur example.
Humans in cold weather still NEED the fur.

But humans didn't need the fur before. But that's not the example we were talking about. We were talking about monkeys, not humans. And it was your example, not mine. In other words, I wasn't explaining why humans lost fur. I was explaining why our hypothetical monkeys (that we give free coats to) would lose fur.

In addition I said earlier in the topic that humans move at the speed of technology, not at the speed of evolution.

Once we lost our fur, and LAAAATER started moving north to push into new territories, it's much faster to get fur from other animals. (making coats = technology)

They literally kill furred animals and wear their skin, yet you suggest that they lost the fur because it wasn't useful or needed any longer (not directly, but indirectly in that it saves so much energy to not grow it;

Saved energy, yes.

of course you forget the energy spent hunting coats of prey).

Of course I didn't forget that. I carefully worded my reply as such "Group B gets stretching cleaning safe fur coats put on by us humans for life."

For this exact reason. :)

Consider these fish or other blind cave animals. Are they hunting for working eyes to attach to their skulls? no

???

Saved. Energy.

But, you could say they ARE "hunting for working eyes to attach to their skull", in a manner of speaking.

What do I mean?

The animals often substitute other better senses to deal with their new environment. Such as longer whiskers and better smelling. Their old eyes are the old useless fur. Their other senses are the new fur skin coat. If you want to see what they are trading
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Everything is devolving as it also evolves at the same time if you take a long view of things. Our own sun will burn out one way or the other in 4 billions years. We most likely won't see the kind of space travel that might get us to another habitable planet anywhere. So, eventually, this whole planet and it's solar system will be consumed by the sun's radiation, and I don't know about other galaxies, but life on Earth be totally gone. So in a way, it all devolves.

Cocytus posted...

Everything is devolving as it also evolves at the same time if you take a long view of things. Our own sun will burn out one way or the other in 4 billions years. We most likely won't see the kind of space travel that might get us to another habitable planet anywhere. So, eventually, this whole planet and it's solar system will be consumed by the sun's radiation, and I don't know about other galaxies, but life on Earth be totally gone. So in a way, it all devolves.

Part of the earlier debate in this topic is on what "devolving" means.

As if fish, that evolve into land mammals, and then back into say whales or dolphins, are devolving. (sea -> land -> sea again)

Strictly speaking, thats not devolving.

Neither is fish losing their eyes in dark caves known as devolving. It's all evolving. They are all fitting better in their new niches. (better fit in the niche = survival of the fittest)
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