Devolution of Humans

[Kane Jiang]

Why do humans think we are at the top of the evolution pyramid?

In terms of lifespan, there are many animals that live as long as us such as crocodiles, turtles, and even the dinosaurs.
In terms of science, we haven't proven there is enough fuel for us to escape if the sun goes supernova. (I also do not think science can explain everything and if there is not enough fuel, I do not think that is a coincidence)
In terms of survival of the fittest, plants automatically win because animals depend on them for survival.

And then there are the major examples of devolution:
1. A starfish can regenerate its arms; our regenerative abilities pale in comparison
2. Many animals have magnetoreception, can you imagine humans losing a whole sense, a whole way to experience the world? That should be really big.
3. Many animals have electroreception.
4. Reptiles have better metabolism by being cold-blooded. By spending less energy producing warmth, they could use their metabolism in other areas. That's how dinosaurs got so big, and modern day reptiles don't usually get fat from not moving a lot. Compare this with mammals, like hippos, and elephants, they get VERY fat.
5. Reptiles and birds' feces smell less than mammals in my opinion.
6. Going from laying eggs to bearing young should be an example of devolution, right? Also, just because an animal lays eggs doesn't mean he or she can't raise their young. This is devolution in my eyes in terms of ability because of the pain and length of being pregnant compared to a chicken laying eggs everyday...


I also don't think power is an example of evolutionary finesse because of what I said above about survival of the fittest and I think all forms of power are unethical. Having ability is more ethical and makes you more independent than being powerful IMO.
There are many reasons why I think mammals are a step down in the evolutionary pyramid compared to reptiles. BUT, I do believe humans to be more evolved than most, if not all mammals and some reptiles.

[LuckyR]

Why do humans think we are at the top of the evolution pyramid?

In terms of lifespan, there are many animals that live as long as us such as crocodiles, turtles, and even the dinosaurs.
In terms of science, we haven't proven there is enough fuel for us to escape if the sun goes supernova. (I also do not think science can explain everything and if there is not enough fuel, I do not think that is a coincidence)
In terms of survival of the fittest, plants automatically win because animals depend on them for survival.

And then there are the major examples of devolution:
1. A starfish can regenerate its arms; our regenerative abilities pale in comparison
2. Many animals have magnetoreception, can you imagine humans losing a whole sense, a whole way to experience the world? That should be really big.
3. Many animals have electroreception.
4. Reptiles have better metabolism by being cold-blooded. By spending less energy producing warmth, they could use their metabolism in other areas. That's how dinosaurs got so big, and modern day reptiles don't usually get fat from not moving a lot. Compare this with mammals, like hippos, and elephants, they get VERY fat.
5. Reptiles and birds' feces smell less than mammals in my opinion.
6. Going from laying eggs to bearing young should be an example of devolution, right? Also, just because an animal lays eggs doesn't mean he or she can't raise their young. This is devolution in my eyes in terms of ability because of the pain and length of being pregnant compared to a chicken laying eggs everyday...


I also don't think power is an example of evolutionary finesse because of what I said above about survival of the fittest and I think all forms of power are unethical. Having ability is more ethical and makes you more independent than being powerful IMO.
There are many reasons why I think mammals are a step down in the evolutionary pyramid compared to reptiles. BUT, I do believe humans to be more evolved than most, if not all mammals and some reptiles.

You're kind of asking the wrong question. Modern organisms are farther along the evolutionary branch than those earlier on the same branch. But you are trying to compare those on separate branches, who are not direct genetic competitors. In addition, as environmental forces change, adaptations that were previously advantageous can become an evolutionary disadvantage.

Thus any species can become disadvantaged at any time, this is a dynamic system.

[Kane Jiang]

Yes, I should change the title from "devolution" to something else.

I guess some of the points wouldn't apply to humans' ancestors, but 6, 3, and 2 might. Did human ancestors have electroreception or magnetoreception? If they did (presumably as marine animals, our ancestors had electroreception?), what is the rationale for losing an entire sense, and is it lost forever from a natural perspective?

[Steve3007]

There are many reasons why I think mammals are a step down in the evolutionary pyramid compared to reptiles. BUT, I do believe humans to be more evolved than most, if not all mammals and some reptiles.

It's not really clear to me what you mean by the concept of being a "step up" or a "step down" in an evolutionary pyramid or by the concept of being "more evolved".

In reality, Evolution doesn't work that way. It doesn't have an end point towards which species are striving and against which their progress can be measured. There are certainly some species that are more complex than others and over large periods of time, as species diffuse outwards into the space of all possible forms the complexity of the most complex species has increased. But I think it's a mistake (albeit a very natural one for a human mind to make) to see that in terms progress.

[Kane Jiang]

It's not really clear to me what you mean by the concept of being a "step up" or a "step down" in an evolutionary pyramid or by the concept of being "more evolved".

Yes, my bad. I didn't really believe in an endpoint to evolution along which progress could be measured; I just wanted to see what the prevailing opinion on the matter is.

I'm aware that animals have their own niches, but I do think there are some traits that can be measured via progress. For example, I believe, the more senses you have, the better. I don't see how losing a sense, a way to experience the world, could ever be beneficial considering experiencing the world through a sense is pretty much involuntary and doesn't take effort (and there may not be more than a few possible senses to experience the world). I also think any progress made through traits such as ability, flexibility, or sustainability is a step up. For example, it's better to have the ability to fly and use your hands than just use your hands. Yes, more isn't always better but I think in terms of senses, and ability more Is always better. There can be examples of devolution of losing the ability to fly so that your hands wouldn't be affected by the burden of having wings, but I think retaining the ability to do both would be an example of a step up in the evolutionary pyramid (not necessarily having 2 physical traits, but just having the ability to do both somehow).

So maybe it's not really a line that I refer to when I'm saying a "step up" or "step down" in an evolutionary pyramid and maybe it's not with every trait that I'm referring to.

[h_k_s]

Why do humans think we are at the top of the evolution pyramid?

In terms of lifespan, there are many animals that live as long as us such as crocodiles, turtles, and even the dinosaurs.
In terms of science, we haven't proven there is enough fuel for us to escape if the sun goes supernova. (I also do not think science can explain everything and if there is not enough fuel, I do not think that is a coincidence)
In terms of survival of the fittest, plants automatically win because animals depend on them for survival.

And then there are the major examples of devolution:
1. A starfish can regenerate its arms; our regenerative abilities pale in comparison
2. Many animals have magnetoreception, can you imagine humans losing a whole sense, a whole way to experience the world? That should be really big.
3. Many animals have electroreception.
4. Reptiles have better metabolism by being cold-blooded. By spending less energy producing warmth, they could use their metabolism in other areas. That's how dinosaurs got so big, and modern day reptiles don't usually get fat from not moving a lot. Compare this with mammals, like hippos, and elephants, they get VERY fat.
5. Reptiles and birds' feces smell less than mammals in my opinion.
6. Going from laying eggs to bearing young should be an example of devolution, right? Also, just because an animal lays eggs doesn't mean he or she can't raise their young. This is devolution in my eyes in terms of ability because of the pain and length of being pregnant compared to a chicken laying eggs everyday...


I also don't think power is an example of evolutionary finesse because of what I said above about survival of the fittest and I think all forms of power are unethical. Having ability is more ethical and makes you more independent than being powerful IMO.
There are many reasons why I think mammals are a step down in the evolutionary pyramid compared to reptiles. BUT, I do believe humans to be more evolved than most, if not all mammals and some reptiles.

We are at the top because we are the most recent to have evolved -- less than 2 million years ago.

The whole process went something like this:

Single cell life without nuclei.

Single cell life with nuclei.

Single cell moving organisms.

Invertebrates.

Fishes.

Amphibians.

Reptiles.

Dimetrodon.

Mammals.

Miacids.

Monkeys.

Apes.

Hominids.

This is the current state of the theory of human evolution.

[h_k_s]

Why do humans think we are at the top of the evolution pyramid?

In terms of lifespan, there are many animals that live as long as us such as crocodiles, turtles, and even the dinosaurs.
In terms of science, we haven't proven there is enough fuel for us to escape if the sun goes supernova. (I also do not think science can explain everything and if there is not enough fuel, I do not think that is a coincidence)
In terms of survival of the fittest, plants automatically win because animals depend on them for survival.

And then there are the major examples of devolution:
1. A starfish can regenerate its arms; our regenerative abilities pale in comparison
2. Many animals have magnetoreception, can you imagine humans losing a whole sense, a whole way to experience the world? That should be really big.
3. Many animals have electroreception.
4. Reptiles have better metabolism by being cold-blooded. By spending less energy producing warmth, they could use their metabolism in other areas. That's how dinosaurs got so big, and modern day reptiles don't usually get fat from not moving a lot. Compare this with mammals, like hippos, and elephants, they get VERY fat.
5. Reptiles and birds' feces smell less than mammals in my opinion.
6. Going from laying eggs to bearing young should be an example of devolution, right? Also, just because an animal lays eggs doesn't mean he or she can't raise their young. This is devolution in my eyes in terms of ability because of the pain and length of being pregnant compared to a chicken laying eggs everyday...


I also don't think power is an example of evolutionary finesse because of what I said above about survival of the fittest and I think all forms of power are unethical. Having ability is more ethical and makes you more independent than being powerful IMO.
There are many reasons why I think mammals are a step down in the evolutionary pyramid compared to reptiles. BUT, I do believe humans to be more evolved than most, if not all mammals and some reptiles.

You're kind of asking the wrong question. Modern organisms are farther along the evolutionary branch than those earlier on the same branch. But you are trying to compare those on separate branches, who are not direct genetic competitors. In addition, as environmental forces change, adaptations that were previously advantageous can become an evolutionary disadvantage.

Thus any species can become disadvantaged at any time, this is a dynamic system.

I agree.

[Steve3007]

For example, I believe, the more senses you have, the better. I don't see how losing a sense, a way to experience the world, could ever be beneficial considering experiencing the world through a sense is pretty much involuntary and doesn't take effort (and there may not be more than a few possible senses to experience the world). I also think any progress made through traits such as ability, flexibility, or sustainability is a step up.

That's an interesting point. It implies that the acquisition of any new ability or sense always confers an evolutionary advantage and that their loss always confers a disadvantage. But there do seem to be numerous examples in nature of species losing such a thing. Creatures who live in the perpetual darkness at the bottoms of the oceans, for example, sometimes seem to have lost the sense of sight. Losses like this generally seem to happen because if the sense (or other physical trait) in question is not used to help survival there is no evolutionary pressure to keep it. Mutations of the genes that code for that particular piece of physical anatomy will not be selected out because they will have no effect on the ability to survive and produce offspring.

Since any sense takes energy and effort to maintain and use, I presume there would be an evolutionary advantage to not having that sense if it's not needed (the advantage of efficiency), so presumably the individuals in which the genes which code for the creation of that sense have mutated in such a way as to stop the sense from working would have a slight advantage in an environment where the sense has no use.

Another classic example of this happening is the gene which codes for the production of vitamin C in the body which exists in all mammals but is mutated in primates (including us) in such a way that primates cannot create vitamin C and have to have it in our diet. It looks as though this mutation occurred at some point in the distant past, after primates split from other mammals, because we primates had ample supplies of vitamin C in our diets and so there was no selective advantage to making it in the body. So individuals who by a genetic mutation couldn't make it were no less likely to survive and produce offspring than those who could. But I don't know whether removing the effort required to create vitamin C in the body actually conferred any positive advantage.

We are at the top because we are the most recent to have evolved -- less than 2 million years ago.

If the measure of which species is "at the top" was based on how recently that species diverged from the common ancestor with a different species (i.e. how recently it "evolved") then there is apparently a species of Galapogos finch that has a much greater claim than us. Also, if we regard ourselves as being at the top because our common ancestor with chimpanzees (our nearest extant relatives) lived only a few million years ago then surely, using this measure of topness, the chimpanzee can rightly be regarded as at the same level as us since, by definition, they "evolved" (i.e. the species came into existence by a process of speciation) at the same time as us.

[Kane Jiang]

Since any sense takes energy and effort to maintain and use, I presume there would be an evolutionary advantage to not having that sense if it's not needed (the advantage of efficiency), so presumably the individuals in which the genes which code for the creation of that sense have mutated in such a way as to stop the sense from working would have a slight advantage in an environment where the sense has no use.

Except is there any example of regaining a sense in evolution? I think about all the examples of marine mammals that have returned to being aquatic and only the monotremes (who look like our reptilian ancestors) still have electroreception. Did their ancestors ever lose electroreception?

Almost all fish seem to have electroreception so what is the reason for whales, dolphins, and sea cows not having them (regaining the sense)?

In vertebrates, electroreception is an ancestral trait, that is to say that it was present in the last common ancestor of all vertebrates.

New evidence from 100-million-year-old jawbones found in Australia suggests that egg-laying mammals such as the platypus may have evolved more slowly than other mammals,

Other vertebrates that have electroreception such as [...] monotremes, and at least one species of cetacean all have different secondarily derived forms of electroreception

It says its form of electroreception is derived from the ancestral one. I can't put my finger on this if it means monotremes' ancestors ever lost electroreception or they just evolved a different form and replaced the original one. Ok, never mind, it says one species of dolphin (cetacean) has electroreception.

I'm assuming bees have a different form of electroreception not derived from that ancestral one. If the ancestors of platypuses and that one species of dolphin evolved electroreception after losing it, the chances of having a form of electroreception derived from the ancestral one is slim or 0? So I'm inclined to believe that no mammal that lost it has ever regained electroreception?

But if regaining a sense is impossible or near impossible, wouldn't that put the theory of losing a sense as being evolutionary advantageous under some circumstances on its face?
Also, we don't know if animals that lost a sense had their sense inhibited of if the sense was completely lost. I used electroreception as an example because there are different types of electroreception (scientists can compare the different organs responsible, and a regaining of electroreception after completely losing it should likely mean a completely different form).

[h_k_s]

For example, I believe, the more senses you have, the better. I don't see how losing a sense, a way to experience the world, could ever be beneficial considering experiencing the world through a sense is pretty much involuntary and doesn't take effort (and there may not be more than a few possible senses to experience the world). I also think any progress made through traits such as ability, flexibility, or sustainability is a step up.

That's an interesting point. It implies that the acquisition of any new ability or sense always confers an evolutionary advantage and that their loss always confers a disadvantage. But there do seem to be numerous examples in nature of species losing such a thing. Creatures who live in the perpetual darkness at the bottoms of the oceans, for example, sometimes seem to have lost the sense of sight. Losses like this generally seem to happen because if the sense (or other physical trait) in question is not used to help survival there is no evolutionary pressure to keep it. Mutations of the genes that code for that particular piece of physical anatomy will not be selected out because they will have no effect on the ability to survive and produce offspring.

Since any sense takes energy and effort to maintain and use, I presume there would be an evolutionary advantage to not having that sense if it's not needed (the advantage of efficiency), so presumably the individuals in which the genes which code for the creation of that sense have mutated in such a way as to stop the sense from working would have a slight advantage in an environment where the sense has no use.

Another classic example of this happening is the gene which codes for the production of vitamin C in the body which exists in all mammals but is mutated in primates (including us) in such a way that primates cannot create vitamin C and have to have it in our diet. It looks as though this mutation occurred at some point in the distant past, after primates split from other mammals, because we primates had ample supplies of vitamin C in our diets and so there was no selective advantage to making it in the body. So individuals who by a genetic mutation couldn't make it were no less likely to survive and produce offspring than those who could. But I don't know whether removing the effort required to create vitamin C in the body actually conferred any positive advantage.

We are at the top because we are the most recent to have evolved -- less than 2 million years ago.

If the measure of which species is "at the top" was based on how recently that species diverged from the common ancestor with a different species (i.e. how recently it "evolved") then there is apparently a species of Galapogos finch that has a much greater claim than us. Also, if we regard ourselves as being at the top because our common ancestor with chimpanzees (our nearest extant relatives) lived only a few million years ago then surely, using this measure of topness, the chimpanzee can rightly be regarded as at the same level as us since, by definition, they "evolved" (i.e. the species came into existence by a process of speciation) at the same time as us.

Due to humans' most recent evolution over other species, we are more intellectual, make the best tools, and are the top of the food chain on land and on the surface of the seas.

[Pantagruel]

Why do humans think we are at the top of the evolution pyramid?

Because the vast majority of people think anthropocentrically. It is one of our many, many cognitive biases. One of the worst, since it drives our destruction of our own habitat.

[Sy Borg]

Why do humans think we are at the top of the evolution pyramid?

Because the vast majority of people think anthropocentrically. It is one of our many, many cognitive biases. One of the worst, since it drives our destruction of our own habitat.

Spot on. I could not agree more.

Re: the thread. I don't think humans are devolving, they are overcrowding and the upper and lower classes are stratifying. There's many more brilliant people as well as many more ignorant ones. The latter make more noise, though.

[Pantagruel]

Because the vast majority of people think anthropocentrically. It is one of our many, many cognitive biases. One of the worst, since it drives our destruction of our own habitat.

Spot on. I could not agree more.

Re: the thread. I don't think humans are devolving, they are overcrowding and the upper and lower classes are stratifying. There's many more brilliant people as well as many more ignorant ones. The latter make more noise, though.

Yes, probably speciation rather than devolution...

[Jklint]

Why do humans think we are at the top of the evolution pyramid?

Because we obviously are in terms of intelligence and our ability to change the world. This should not lead to even the slightest hubris but to its opposite.

Intelligence invariably evolves as a twin entity co-existent with the other half called stupidity which so-called less intelligent creatures are able to avoid. The only way to make intelligence less dangerous to itself is by noticing the risk. If not then stupidity will take the reins which leads to catastrophe and possibly to consequences which can't be recovered from. Spiraling downward is a much more sudden event than applying the torque of intelligence to escape our limitations...aside from never landing where we started from as though it were a new beginning.

[Felix]

Spiraling downward is a much more sudden event than applying the torque of intelligence to escape our limitations... aside from never landing where we started from as though it were a new beginning.

Dude, you are not quoting song lyrics, are you?!