Freethought & Rationalism Archive

Mountainbike Racer · 05-13-2002, 07:49 AM

One thing that has always interested me about the TOE is what is the end result. If we all had a common background, and we are all in competition with one another, then the processes that drive evolution are the same, wouldn't we end up with one, perfectly evolved animal? Isn't that the endgame of natural selection by definition? And if it isn't, what forces would prevent this?

I remember a biology term from Biology 101, convergant evolution. Where unrelated and distant animals evolved the same characteristics because their environments were similar. I can't remember any examples of this, but if true, it would seem to support this idea.

dangin · 05-13-2002, 08:01 AM

We have a common background. A billion some years ago. Since then our backgrounds are quite varied, as affected by different biomes, ecologies, and competitions.

We aren't all in competition. I do not compete with lemurs. North American Bison do not compete with zebra. Guppies do not compete with hammer head sharks. It goes on and on.

There is no "final perfect animal". What works in one environment for a brief time does not work in others. Any "perfect" animal would have to have genetic redundancies, and unused genetic potential so that it could evolve to survive against changes in environment, parasites, or predators. There is no final step, just like there is no static environment.

One thing that has always interested me about people that don't understand evolution is they still like to argue about it. And I don't even understand evolution as well as most of the science professionals who post here. (I am not one of them but at least I know enough to see through silliness like your post)

Godless Dave · 05-13-2002, 08:19 AM

No because most organisms need other organisms to survive. Animals get energy from eating plants and other animals. Many plants rely on animals to enable fertilization or the spread seeds. Animals need the bacteria that live in their stomach to digest food. Even plants that get all their energy from the sun depend on the microorganisms that live in the ground to eat the dead plants and turn them into soil. And the bacteria need the plants and the animals to provide food.

It's an oversimplification to say that all organisms are in competition with one another.

An example of convergent evolution would be the Thylacoleo, or marsupial lion. It was a marsupial that lived in Australia until the last ice age. It was physically very similar to the great cats of other continents - but a marsupial, not a placental mammal, so much more closely related to koalas and kangaroos than to tigers and lions. It filled the same niche as the great cats (large predator) and evolved similar characteristics, including big meat-eating teeth. But it could never mate with a lion or a tiger, because it wasn't anywhere close to being the same species. It had only evolved to look (sort of) like a cat, because it was doing the same thing in Australia that cats were doing in the other continents. More information on Thylacoleo can be found <a href="http://www.naturalworlds.org/thylacoleo/index.htm" target="_blank">here</a>.

nogods4me · 05-13-2002, 08:23 AM

this sounds like the Astrology Theory of Evolution. Well you were all born under the sign of Virgo, so you all are high strung, self-starters that are fiercely independant.

5 billion years since we all shared a common background, different environments, mutations, luck, etc.

there will be no "end" result, so long as life continues evolution shall as well. It is inevitable. A simple look at the grand outline of the theory shows us how marvelously simple a theory it really is, and yet how amazingly powerful.

[ May 13, 2002: Message edited by: nogods4me ]</p>

Machiavelli · 05-13-2002, 08:24 AM

Dangin, you seem to lack the ability to extrapolate out the process of evolution over time. You aren't competing with lemurs because recources are plentiful, and at this point in time, you don't have to.

Is it silly that natural selection is one of the driving forces of evolution?

Do you think it is silly that Natural Selection implies a single winner?

How do you reconcile the two?

Autonemesis · 05-13-2002, 08:33 AM

Some features or traits only need to be "good enough" to lend support to the animal's survival. Other features neither help nor hinder survival, in comparison to competitors, and are thus superfluous. The end result is that the species continues, that the genome is replicated into the next generation. Superfluous features or traits can come along for the ride, so long as they don't interfere (too much) with survival. But are humans "less perfect" because they still have an appendix, that serves no purpose but sometimes can become fatally infected? That remains to be seen. So far, we have survived in spite of it. And that is all that counts "in the end" when considered in light of natural selection.

I'm reminded by a PBS series that has been showing recently that echinoderms - sea stars, urchins, sand dollars, etc. - have survived practically unchanged for 500 million years. Most other species live 10-20 million years before dying off. The echinoderms have seen the rise and fall of the dinosaurs, and the rise of the mammals in their wake. They appear not to age. Except for predation, injury, disease, they don't seem to grow old and die. A piece of one's body can regenerate the whole animal. They lack anything like a vertebrate central nervous system or a brain, yet they show complex "higher" animal social behavior - aggressive displays, territoriality, ritual combat. They just do it in a slower timeframe compared to other animals. They live throughout the world's oceans, along the sea floor but especially in warmer waters near land and in tidal pools. They have no relatives that live on land or in fresh water, but having conquered the other 3/4 of the earth's surface, they can perhaps be forgiven that "failure."

Are echinoderms "less perfect" than humans? Than dolphins? Are they inferior to any multi-cellular animal? Aside from microbes, there are few lifeforms that can match the objective record of the echinoderms, from the standpoint of natural selection.

[ May 13, 2002: Message edited by: Kind Bud ]</p>

dangin · 05-13-2002, 08:36 AM

No. I'm not competing with lemurs, because lemurs are not native to my area. North american Bison are not competing with zebra because they are on different continents. I understand fully, that were I competing within the same biome with lemurs, for a limited supply of the same foodstuff and shelter that we would be competing to a limited extent. But until a lemur steals the food from my shopping cart, I think it is safe to say that we are not in competition. Maybe you live in a lemur heavy area . . .

Late_Cretaceous · 05-13-2002, 08:43 AM

Godless Dave,

South America also had a marsupial "big cat" called Thylacosmilus. It was strikingly similar to the smilodon saber toothed cats which replaced it when the continent connected to N. America.
This is also a good example of convergent evolution, plus competition of indroduced species.

Godless Dave · 05-13-2002, 08:50 AM

If I lived in Madagascar I would be competing with lemurs - but I wouldn't be competing with the fleas that live on lemurs.

Yellow3 · 05-13-2002, 09:46 AM

Quote:

Originally posted by Kind Bud:
<strong>Some features or traits only need to be "good enough" to lend support to the animal's survival. Other features neither help nor hinder survival, in comparison to competitors, and are thus superfluous. The end result is that the species continues, that the genome is replicated into the next generation. Superfluous features or traits can come along for the ride, so long as they don't interfere (too much) with survival. But are humans "less perfect" because they still have an appendix, that serves no purpose but sometimes can become fatally infected? That remains to be seen. So far, we have survived in spite of it. And that is all that counts "in the end" when considered in light of natural selection.[ May 13, 2002: Message edited by: Kind Bud ]</strong>

The appendix is not purposeless. If you look at the tissue itself you notice multiple aggregations of B-lymphocyte nodules (they show up all down the gut but they're particularly diagnostic for areas like the appendix); as such, it plays a role in the nonencapsulated lymphoid system, the GALT (gut-associated lymphoid tissue). Interestingly enough, between the appendix and the introns present in all eukaryotic genes, we're finding that a lot of things we had thought redundant are actually pretty darn important. Some eukaryotic genes (e.g. blood clotting factor 2, I think) will not work if the cDNA with introns removed is cloned into bacteria. Those noncoding, "useless" introns do something, but damned if we know what.

For truly superfluous traits, you usually have to go down to levels like isozymes (multiple forms of the same enzyme that all work exactly the same). These are good traits to track for the presence of genetic drift and mutational rates, since they are neither selected for or against, and thus their presence in the population depends purely on the actions of mutation and drift.

And maybe wisdom teeth. But at the rate we're going, hell, maybe there's a reason for those too that we don't know yet.

- Jen

05-13-2002, 07:49 AM	#1
Mountainbike Racer Junior Member Join Date: Feb 2002 Posts: 29	Endgame of evolution One thing that has always interested me about the TOE is what is the end result. If we all had a common background, and we are all in competition with one another, then the processes that drive evolution are the same, wouldn't we end up with one, perfectly evolved animal? Isn't that the endgame of natural selection by definition? And if it isn't, what forces would prevent this? I remember a biology term from Biology 101, convergant evolution. Where unrelated and distant animals evolved the same characteristics because their environments were similar. I can't remember any examples of this, but if true, it would seem to support this idea.

Thread Tools	Search this Thread
Show Printable Version	Search this Thread: Advanced Search

05-13-2002, 08:01 AM	#2
dangin Veteran Member Join Date: Dec 2000 Location: The Middle, Kansas Posts: 2,637	We have a common background. A billion some years ago. Since then our backgrounds are quite varied, as affected by different biomes, ecologies, and competitions. We aren't all in competition. I do not compete with lemurs. North American Bison do not compete with zebra. Guppies do not compete with hammer head sharks. It goes on and on. There is no "final perfect animal". What works in one environment for a brief time does not work in others. Any "perfect" animal would have to have genetic redundancies, and unused genetic potential so that it could evolve to survive against changes in environment, parasites, or predators. There is no final step, just like there is no static environment. One thing that has always interested me about people that don't understand evolution is they still like to argue about it. And I don't even understand evolution as well as most of the science professionals who post here. (I am not one of them but at least I know enough to see through silliness like your post)

05-13-2002, 08:19 AM	#3
Godless Dave Contributor Join Date: Feb 2002 Location: With 10,000 lakes who needs a coast? Posts: 10,762	No because most organisms need other organisms to survive. Animals get energy from eating plants and other animals. Many plants rely on animals to enable fertilization or the spread seeds. Animals need the bacteria that live in their stomach to digest food. Even plants that get all their energy from the sun depend on the microorganisms that live in the ground to eat the dead plants and turn them into soil. And the bacteria need the plants and the animals to provide food. It's an oversimplification to say that all organisms are in competition with one another. An example of convergent evolution would be the Thylacoleo, or marsupial lion. It was a marsupial that lived in Australia until the last ice age. It was physically very similar to the great cats of other continents - but a marsupial, not a placental mammal, so much more closely related to koalas and kangaroos than to tigers and lions. It filled the same niche as the great cats (large predator) and evolved similar characteristics, including big meat-eating teeth. But it could never mate with a lion or a tiger, because it wasn't anywhere close to being the same species. It had only evolved to look (sort of) like a cat, because it was doing the same thing in Australia that cats were doing in the other continents. More information on Thylacoleo can be found <a href="http://www.naturalworlds.org/thylacoleo/index.htm" target="_blank">here</a>.

05-13-2002, 08:23 AM	#4
nogods4me Contributor Join Date: Jun 2001 Location: Baltimore, MD USA Posts: 17,432	this sounds like the Astrology Theory of Evolution. Well you were all born under the sign of Virgo, so you all are high strung, self-starters that are fiercely independant. 5 billion years since we all shared a common background, different environments, mutations, luck, etc. there will be no "end" result, so long as life continues evolution shall as well. It is inevitable. A simple look at the grand outline of the theory shows us how marvelously simple a theory it really is, and yet how amazingly powerful. [ May 13, 2002: Message edited by: nogods4me ]</p>

05-13-2002, 08:24 AM	#5
Machiavelli Veteran Member Join Date: Sep 2001 Location: South Georgia Posts: 1,676	Dangin, you seem to lack the ability to extrapolate out the process of evolution over time. You aren't competing with lemurs because recources are plentiful, and at this point in time, you don't have to. Is it silly that natural selection is one of the driving forces of evolution? Do you think it is silly that Natural Selection implies a single winner? How do you reconcile the two?

05-13-2002, 08:33 AM	#6
Autonemesis Contributor Join Date: Feb 2002 Location: I've left FRDB for good, due to new WI&P policy Posts: 12,048	Some features or traits only need to be "good enough" to lend support to the animal's survival. Other features neither help nor hinder survival, in comparison to competitors, and are thus superfluous. The end result is that the species continues, that the genome is replicated into the next generation. Superfluous features or traits can come along for the ride, so long as they don't interfere (too much) with survival. But are humans "less perfect" because they still have an appendix, that serves no purpose but sometimes can become fatally infected? That remains to be seen. So far, we have survived in spite of it. And that is all that counts "in the end" when considered in light of natural selection. I'm reminded by a PBS series that has been showing recently that echinoderms - sea stars, urchins, sand dollars, etc. - have survived practically unchanged for 500 million years. Most other species live 10-20 million years before dying off. The echinoderms have seen the rise and fall of the dinosaurs, and the rise of the mammals in their wake. They appear not to age. Except for predation, injury, disease, they don't seem to grow old and die. A piece of one's body can regenerate the whole animal. They lack anything like a vertebrate central nervous system or a brain, yet they show complex "higher" animal social behavior - aggressive displays, territoriality, ritual combat. They just do it in a slower timeframe compared to other animals. They live throughout the world's oceans, along the sea floor but especially in warmer waters near land and in tidal pools. They have no relatives that live on land or in fresh water, but having conquered the other 3/4 of the earth's surface, they can perhaps be forgiven that "failure." Are echinoderms "less perfect" than humans? Than dolphins? Are they inferior to any multi-cellular animal? Aside from microbes, there are few lifeforms that can match the objective record of the echinoderms, from the standpoint of natural selection. [ May 13, 2002: Message edited by: Kind Bud ]</p>

05-13-2002, 08:36 AM	#7
dangin Veteran Member Join Date: Dec 2000 Location: The Middle, Kansas Posts: 2,637	No. I'm not competing with lemurs, because lemurs are not native to my area. North american Bison are not competing with zebra because they are on different continents. I understand fully, that were I competing within the same biome with lemurs, for a limited supply of the same foodstuff and shelter that we would be competing to a limited extent. But until a lemur steals the food from my shopping cart, I think it is safe to say that we are not in competition. Maybe you live in a lemur heavy area . . .

05-13-2002, 08:43 AM	#8
Late_Cretaceous Veteran Member Join Date: Oct 2001 Location: Alberta Posts: 1,049	Godless Dave, South America also had a marsupial "big cat" called Thylacosmilus. It was strikingly similar to the smilodon saber toothed cats which replaced it when the continent connected to N. America. This is also a good example of convergent evolution, plus competition of indroduced species.

05-13-2002, 08:50 AM	#9
Godless Dave Contributor Join Date: Feb 2002 Location: With 10,000 lakes who needs a coast? Posts: 10,762	If I lived in Madagascar I would be competing with lemurs - but I wouldn't be competing with the fleas that live on lemurs.

Freethought & Rationalism Archive

The archives are read only.