Why didn't animals evolve wheels?

[Seth]

But evolution created human beings and everything we are today, and yet sharks haven't changed substantially in 40 million years. Why not?

You are making assumptions, based on very little knowledge of evolution. You still seem to have this feeling that evolution has some sort of goal, to produce some super being. It's not like that at all.

And yet it did. Why only once? Why aren't there other creatures as intelligent as we are?

Evolution is a random, haphazard process.

So science would have us believe. But what if evolution gets a bit of a nudge from intelligent design from time to time?

It doesn't matter if it produces change, or no change. The majority of species went extinct. Do you question that? Those that exist now were basically the lucky ones, which had just enough of an edge to survive. Not always by constantly changing. Sometimes a design reaches a point where it doesn't get any better. Like the bicycle.

A motorcycle is better than a bicycle.

While computers have changed out of all recognition, the bicycle is still pretty much what it was sixty years ago.

Only in basic form. In detail it's highly advanced.

Having said all that, the shark has produced the closely related rays. Manta rays and sharks. Not changed substantially?

Did it? Or was it the other way around? Or are they two entirely different lines, each of which was created by intelligent manipulation of DNA?

Just because one branch develops in a different way, it doesn't mean that others can't stay the same. If it works, it will reproduce.

And yet so many species have gone extinct, or have evolved into something quite different from what they began as, and yet sharks haven't changed substantially in 40 million years. Why is that?

So why aren't dolphins like sharks. Or sharks like dolphins? Why are there elk and deer, wolves and coyotes? Why is there 40 million year old species differentiation? Why haven't all creatures evolved towards an organism that is in all ways superior to all other forms of life in all environments?

You really do need to do some reading. No form of life is superior to other forms.

We disagree.

If it's alive, after four and a half billion years, it's incredibly successful, as were all of it's ancestors.
A human isn't superior to an ant in evolutionary terms.

Sure it is because it has the capacity to both change and protect it's own DNA through direct manipulation which therefore circumvents evolution, which is inherently superior to an organism that cannot manipulate its own DNA to achieve specific results.

A lion isn't superior to a wildebeest, or a hyena. They all get by, just about.

The lion might disagree.

Why don't you read up on it a bit, instead of wasting your breath on everlasting gun posts? Evolution is the most interesting thing I've ever discovered, and you never stop learning, there is so much to it.

Trust me, I have. But my education is hardly the point here, as you ought to know by now.

You'll find better answers than I can give, and all the evidence you could wish for.

Well, that's a true statement.

And if you want the above questions answered fully, read up on how and why evolution is geared to produce variety. It's a subject all on it's own, and well worth reading. You can't answer it in one post on a forum.

You just said evolution isn't geared to do anything, it just happens.

[Seth]

Just in case you're not being rhetorical,

I'm being Socratic.

the shark is perfectly adapted for its niche - it doesn't have to be any smarter than it is to be the consummate lone apex predator that it is.

So why did humans evolve a complex brain? They were well adapted to their ecological niche too.

Orcas and dolphins on the other hand are social mammals which hunt through communication and cooperation, so it seems reasonable to suppose that animals like this probably benefit from enough smarts to develop a theory of mind and a communication schema by which they can relate to other pod members and pool information, and where developing more smarts significantly enhances survivability over time within a particular niche. Cali's the one to ask really. Him and the fishes go back a long way.

And sharks wouldn't be a better apex predator if they were social animals with cognitive and communications abilities? I shudder to think what the course of ocean navigation by humans would have been like if sharks banded together and worked in concert. Sharknado my ass...Didn't somebody make a movie about genetically enhanced sharks escaping a research facility and wreaking havoc?

It seems to me that random mutation over 40 million years would have produced a strain of more intelligent sharks. It did so to humans in what, 4 million years?

[mistermack]

A motorcycle is better than a bicycle.

Yeh? So why are there still bicycles then?

( that's the sort of moronic answer you christian trolls like to give. You have some of it. )

[Clinton Huxley]

Brontosauruses with caterpillar tracks? Where are they? They SHOULD be anywhere they bloody well like.

[JimC]

Jet powered pterodactyls! You know it makes sense!

[Clinton Huxley]

Hovercraftus rex, at home on land and sea.

[Clinton Huxley]

The precocious Segwaysaurus.

[Seth]

A motorcycle is better than a bicycle.

Yeh? So why are there still bicycles then?

Because there are unevolved idiots who still think mixing with superior forms of transportation by riding them on the streets is a good idea. Eventually they will all get run over by cement trucks and then bicycles will again be what they really are: children's toys never to be ridden anywhere but in the 'hood.

[Brian Peacock]

Just in case you're not being rhetorical,

I'm being Socratic.

the shark is perfectly adapted for its niche - it doesn't have to be any smarter than it is to be the consummate lone apex predator that it is.

So why did humans evolve a complex brain? They were well adapted to their ecological niche too.

You've already had an answer to that: we are evolved beings. Now you only need to understand what evolution is in order to understand how redundant that question is.

Orcas and dolphins on the other hand are social mammals which hunt through communication and cooperation, so it seems reasonable to suppose that animals like this probably benefit from enough smarts to develop a theory of mind and a communication schema by which they can relate to other pod members and pool information, and where developing more smarts significantly enhances survivability over time within a particular niche. Cali's the one to ask really. Him and the fishes go back a long way.

And sharks wouldn't be a better apex predator if they were social animals with cognitive and communications abilities?

Now you only need to understand what adaptation to an ecological niche means to understand why this question is also redundant.

I shudder to think what the course of ocean navigation by humans would have been like if sharks banded together and worked in concert. Sharknado my ass...Didn't somebody make a movie about genetically enhanced sharks escaping a research facility and wreaking havoc?

It seems to me that random mutation over 40 million years would have produced a strain of more intelligent sharks. It did so to humans in what, 4 million years?

Hmm. The so-called Socratic thrust of your point belies some basic misunderstandings about evolution. I'd recommend 'What Evolution Is' in the Science Masters series for a comprehensive overview.

[Seth]

Just in case you're not being rhetorical,

I'm being Socratic.

the shark is perfectly adapted for its niche - it doesn't have to be any smarter than it is to be the consummate lone apex predator that it is.

So why did humans evolve a complex brain? They were well adapted to their ecological niche too.

You've already had an answer to that: we are evolved beings. Now you only need to understand what evolution is in order to understand how redundant that question is.

So why haven't all other creatures evolved towards the same superior pattern?

Orcas and dolphins on the other hand are social mammals which hunt through communication and cooperation, so it seems reasonable to suppose that animals like this probably benefit from enough smarts to develop a theory of mind and a communication schema by which they can relate to other pod members and pool information, and where developing more smarts significantly enhances survivability over time within a particular niche. Cali's the one to ask really. Him and the fishes go back a long way.

And sharks wouldn't be a better apex predator if they were social animals with cognitive and communications abilities?

Now you only need to understand what adaptation to an ecological niche means to understand why this question is also redundant.

I'm asking you to explain how it is that almost all other creatures on the planet have evolved from something else in 40 million years, but sharks have not. Random mutational chance would suggest that there would be lesser-evolved and more-evolved sharks around in the continuum of shark evolution. But there aren't, are there?

I shudder to think what the course of ocean navigation by humans would have been like if sharks banded together and worked in concert. Sharknado my ass...Didn't somebody make a movie about genetically enhanced sharks escaping a research facility and wreaking havoc?

It seems to me that random mutation over 40 million years would have produced a strain of more intelligent sharks. It did so to humans in what, 4 million years?

Hmm. The so-called Socratic thrust of your point belies some basic misunderstandings about evolution. I'd recommend 'What Evolution Is' in the Science Masters series for a comprehensive overview.

If I wanted to read a book, I'd read a book. I'm interested in having you explain.

[JimC]

Seth wrote:

I'm asking you to explain how it is that almost all other creatures on the planet have evolved from something else in 40 million years, but sharks have not. Random mutational chance would suggest that there would be lesser-evolved and more-evolved sharks around in the continuum of shark evolution. But there aren't, are there?

This alone betrays a layman's ignorance of the mechanisms of evolution. "Random mutational chance" has of course continued in the gene pool of sharks, as it has in all gene pools. In fact, the relative constancy of the rate of such mutations, when examined in stretches of DNA with no phenotypic effect, is one of our best tools in determining exactly when various branchings in the tree of life occurred.

Before I return to the key player in the evolutionary theatre, natural selection, I'll just mention that sharks are not alone in maintaining a relatively fixed form (albeit with significant radiation into specialised niches such as plankton eating). Many other plant and animal lineages have retained their ancient forms, some for considerably longer time periods than sharks. If there is a fairly isolated peak in the adaptive landscape, and if the environment of that peak does not alter significantly, then a peak it shall remain...

Natural selection is the key driver in the development of adaptations over time, using your "Random mutational chance" as its feedstock. But in constant environments, it frequently acts to prune back change, and maintain the very form that does so well in a given context. The contrast to sharks is best seen in the lobe-finned fish that were the ancestors of all tetrapods. In the challenging environment of the edge between two worlds, the coastal littoral, natural selection indeed made significant change after significant change - an adaptive radiation of immense size, one that opened up a vast array of further ecological niches. When some of the members of that surge to the land returned in the form of cetaceans, they had a long history of evolutionary change driven by a highly variable environment; their relatively sophisticated neural apparatus would have been highly unlikely to develop without such a history, compared to the stay-at-home sharks...

[jamest]

There's no point in having wheels in a rugged terrain devoid of roads and extensive regions of smooth hard surfaces. You're better off with legs or wings which enable you to traverse almost any terrain, including mountains and jungle. So, [/thread].

[Seth]

Seth wrote:

I'm asking you to explain how it is that almost all other creatures on the planet have evolved from something else in 40 million years, but sharks have not. Random mutational chance would suggest that there would be lesser-evolved and more-evolved sharks around in the continuum of shark evolution. But there aren't, are there?

This alone betrays a layman's ignorance of the mechanisms of evolution.

How so? What is this mechanism you speak of?

"Random mutational chance" has of course continued in the gene pool of sharks, as it has in all gene pools. In fact, the relative constancy of the rate of such mutations, when examined in stretches of DNA with no phenotypic effect, is one of our best tools in determining exactly when various branchings in the tree of life occurred.

And do what degree do sharks have this mutation?

Before I return to the key player in the evolutionary theatre, natural selection, I'll just mention that sharks are not alone in maintaining a relatively fixed form (albeit with significant radiation into specialised niches such as plankton eating). Many other plant and animal lineages have retained their ancient forms, some for considerably longer time periods than sharks. If there is a fairly isolated peak in the adaptive landscape, and if the environment of that peak does not alter significantly, then a peak it shall remain...

Such as...?

Natural selection is the key driver in the development of adaptations over time, using your "Random mutational chance" as its feedstock. But in constant environments, it frequently acts to prune back change, and maintain the very form that does so well in a given context. The contrast to sharks is best seen in the lobe-finned fish that were the ancestors of all tetrapods. In the challenging environment of the edge between two worlds, the coastal littoral, natural selection indeed made significant change after significant change - an adaptive radiation of immense size, one that opened up a vast array of further ecological niches. When some of the members of that surge to the land returned in the form of cetaceans, they had a long history of evolutionary change driven by a highly variable environment; their relatively sophisticated neural apparatus would have been highly unlikely to develop without such a history, compared to the stay-at-home sharks...

Which doesn't explain why sharks didn't also evolve such characteristics.

[JimC]

Seth wrote:

And do what degree do sharks have this mutation?

It's not "this mutation", it is mutations occurring at a steady rate in the DNA of all living things, sharks and humans alike. In those stretches of DNA where there are genes affecting phenotype, natural selection ruthlessly prunes the majority of such changes, which of course mostly produce a non-functional organism. In those stretches of DNA where genes are not expressed, the mutations are neutral in selective effect, and accumulate at a steady rate over time. Careful analysis of these sections of DNA sheds light on branchings of evolutionary clades.

Seth wrote:

Such as...?

Ever heard of the coelacanth?

Many other invertebrate groups are morphologically indistinguishable from their relatives hundreds of millions of years ago, including many groups of shellfish. Cycads look the same now as they did when being munched on by dinosaurs. The list could be as long as you want...

Seth wrote:

JimC wrote:

Natural selection is the key driver in the development of adaptations over time, using your "Random mutational chance" as its feedstock. But in constant environments, it frequently acts to prune back change, and maintain the very form that does so well in a given context. The contrast to sharks is best seen in the lobe-finned fish that were the ancestors of all tetrapods. In the challenging environment of the edge between two worlds, the coastal littoral, natural selection indeed made significant change after significant change - an adaptive radiation of immense size, one that opened up a vast array of further ecological niches. When some of the members of that surge to the land returned in the form of cetaceans, they had a long history of evolutionary change driven by a highly variable environment; their relatively sophisticated neural apparatus would have been highly unlikely to develop without such a history, compared to the stay-at-home sharks...

Which doesn't explain why sharks didn't also evolve such characteristics.

It does, if you actually understood what I was saying. You have a mistaken impression that major evolutionary change to any given group is inevitable, and thus its absence needs to be explained. Modern day sharks will have real genetic differences to their remote ancestors, but those differences do not have to include genes causing major structural change, if there is no selective advantage to such change. The relatively unchanging nature of the oceanic environment meant that the well adapted sharks had their morphologies maintained by selection. Dolphins, on the other hand, have an evolutionary history dominated by major changes in their environment, as their path went from sea to land and back again.

[mistermack]

If I wanted to read a book, I'd read a book. I'm interested in having you explain.

The incentive isn't there, is it?
Explaining to someone who doesn't want to know is like trying to get a baby to eat cabbage when it doesn't like it.
You demonstrate every day that you enjoy your ignorance, like all the rest of the religious fundies.

There are 12 year old kids in school who easily understand the logical principles of evolution. That's the difference in having an open mind.