Do you agree with these statements?

[Speedwell]

Someone's wrong here.

The prefix, 'tetra', is Greek for four.

Yes and all those creatures have--or had at some point--four limbs.

 

[Shemjaza]

Ducks, snakes, bats, ducks, water dragons, e.t.c. Are not tetrapods!

What on Earth do you think a tetrapod is?

 

[klutedavid]

Yes and all those creatures have--or had at some point--four limbs.

I think your referring to 'tetrapoda' and that is a biological definition. What happens if you believe that there is a lack of evidence for speciation. Does that mean that I have to accept that broader definition?

 

[klutedavid]

What on Earth do you think a tetrapod is?

A four legged species. I have never imagined that a snake is a tetrapod.

 

[Shemjaza]

They can still breed and I have seen a picture of a very large dog mating, with a small dog breed.

Dogs are separated all over the world and so are wolves. I have yet to see a new canine species develop.

You can see how diverse the breeds of dogs are. It was mutations that created that variety, and mutations, built on mutations is how speciation works. If mutation can create that level of variation in recorded history, the vast history of the world has all the time in the world for larger scale evolutionary change.

Have you heard of ring species? Sometimes separate, but related species are unable to breed... but can breed with species in a chain.

ie:
Population A can breed with population B can breed with population C can breed with population D can breed with population E
...but population A can't breed with population E

That's just an example of how variation can lead to speciation.

 

[klutedavid]

Some questions...

1. Do you agree that if you have a group of animals - say a herd of zebra - then each individual will be slightly different to the others?
2. Do you agree that some of those differences can make it easier for that individual to survive - say, better eyesight so it has a better chance of spotting an approaching predator?
3. Do you agree that these differences are due to the genes that the animals have?
   
4. Do you agree that the genes that are responsible for these differences can be passed on to the offspring when that animal reproduces?
5. Do you agree that if an animal has some genes that mean it has a difference that helps it survive, this animal is more likely to have more offspring precisely because these differences help it live longer (living longer means more chances to reproduce)?
6. Do you agree that if animals with these helpful differences produce more offspring, then the number of animals in the herd that have this helpful difference will tend to increase over the generations?
7. Do you agree that if we wait for enough generations to pass, most if not all animals in the herd will have this difference, and what was once different is now normal?

If you think it's wrong, can you tell me which one exactly do you think is incorrect?

With herd animals if one or more see very well due to breeding, the whole herd benefits. I think one of the caveats of speciation is a population is split by geography. Then through mutations the separated populations diverge into differing species.

Hard to believe and I struggle to believe this occurs.

You may do better to choose a different species.

 

[Shemjaza]

A four legged species. I have never imagined that a snake is a tetrapod.

It has the remnant genes for four legs... even if it has lost them.

Some species of snakes have little nubs at their vestigial bone.

Some individual snakes have a mutation that activates the legs genes and they develop little useless legs.

 

[klutedavid]

It has the remnant genes for four legs... even if it has lost them.

Some species of snakes have little nubs at their vestigial bone.

Some individual snakes have a mutation that activates the legs genes and they develop little useless legs.

Not a very good word usage, 'tetrapod', that is used to describe species without legs.

 

[klutedavid]

It has the remnant genes for four legs... even if it has lost them.

Some species of snakes have little nubs at their vestigial bone.

Some individual snakes have a mutation that activates the legs genes and they develop little useless legs.

I have seen snakes with two heads. Now that is a distinct advantage. Problem is the next time that two headed snake breeds, the offspring will more than likely have a single head.

 

[Speedwell]

I think your referring to 'tetrapoda' and that is a biological definition. What happens if you believe that there is a lack of evidence for speciation. Does that mean that I have to accept that broader definition?

What difference would it make?
I'm beginning to wonder what your point is. You're working very hard to show that there is no speciation, as if it was somehow important that there not be; or that you require more certainty than science generally provides that there is.

 

[klutedavid]

You can see how diverse the breeds of dogs are. It was mutations that created that variety, and mutations, built on mutations is how speciation works. If mutation can create that level of variation in recorded history, the vast history of the world has all the time in the world for larger scale evolutionary change.

Have you heard of ring species? Sometimes separate, but related species are unable to breed... but can breed with species in a chain.

ie:
Population A can breed with population B can breed with population C can breed with population D can breed with population E
...but population A can't breed with population E

That's just an example of how variation can lead to speciation.

The odd thing is, if you released all those breeds into the wild, eventually you end up with. Something akin to a wolf.

 

[klutedavid]

What difference would it make?
I'm beginning to wonder what your point is. You're working very hard to show that there is no speciation, as if it was somehow important that there not be; or that you require more certainty than science generally provides that there is.

Because speciation is the heart of the Evolutionary theory. Species must diverge into other species.

As I have repeated, sudden abrupt explosions of species in the fossil record. Not a gradual transition of speciation over hundreds of millions of years.

 

[Shemjaza]

I have seen snakes with two heads. Now that is a distinct advantage. Problem is the next time that two headed snake breeds, the offspring will more than likely have a single head.

Having two heads (more accurately sharing one body) is a developmental issue of twin snakes fusing in the egg. It's not a genetic condition, so it won't be passed onto offspring.

The odd thing is, if you released all those breeds into the wild, eventually you end up with. Something akin to a wolf.

Like a wolf, certainly, but not exactly the same.

Different form means different advantages and different pressures.

A leopard is like a lion... but it is not the same.

A dog is like a wolf, but it is also no longer the same.

 

[klutedavid]

Having two heads (more accurately sharing one body) is a developmental issue of twin snakes fusing in the egg. It's not a genetic condition, so it won't be passed onto offspring.


Like a wolf, certainly, but not exactly the same.

Different form means different advantages and different pressures.

A leopard is like a lion... but it is not the same.

A dog is like a wolf, but it is also no longer the same.

I see dogs and wolves as one species on the basis of morphology. Give all these breeds enough time in the wild and the basic genetic code, for the wolf will be re-established.

Trust me on this.

 

[klutedavid]

Having two heads (more accurately sharing one body) is a developmental issue of twin snakes fusing in the egg. It's not a genetic condition, so it won't be passed onto offspring.


Like a wolf, certainly, but not exactly the same.

Different form means different advantages and different pressures.

A leopard is like a lion... but it is not the same.

A dog is like a wolf, but it is also no longer the same.

Still there is not one dog breed out there that differs in it's basic genetic code. They are all dogs, all exactly the same species. In fact, pure breeds carry damage in the genetic code and have inherent problems. The mongrel is superior to the pure breed and a wolf is superior to the mongrel.

 

[Speedwell]

Because speciation is the heart of the Evolutionary theory. Species must diverge into other species.

And if they do, so what?

As I have repeated, sudden abrupt explosions of species in the fossil record. Not a gradual transition of speciation over hundreds of millions of years.

Why should we accept your interpretation of the fossil record over that of serious experts in the field? After all, you haven't actually wowed us with your knowledge of zoology so far.

 

[klutedavid]

And if they do, so what?

Why should we accept your interpretation of the fossil record over that of serious experts in the field? After all, you haven't actually wowed us with your knowledge of zoology so far.

Never run with the pack as they are always wrong about everything.

Species are genetically hard wired to reproduce that exact species, over and over, again. The dragonfly is virtually an exact copy today of it's ancestor, it's ancestor existed hundreds of millions of years ago.

If a species is not sustainable due to, let's say, an environmental change, then that species will become extinct. The fossil record is the record of mass extinction, how many millions of species are extinct is impossible to know.

Changes that cause extinction are not slow and not gradual, they are usually sudden, abrupt changes. That is why we see so many extinction events in the fossil record.

We have seen the extinction of so many species during the anthropocene era, and this may well be the last era for all species. At present, it certainly appears to be one of the biggest extinction events in the earth's history.

Come back to the trees my offspring and bring the bananas with you.

 

[klutedavid]

It has the remnant genes for four legs... even if it has lost them.

Some species of snakes have little nubs at their vestigial bone.

Some individual snakes have a mutation that activates the legs genes and they develop little useless legs.

Interesting point you raised.

Has anyone tried to cross breed snakes given that they may possibly be but one species?

 

[Speedwell]

Never run with the pack as they are always wrong about everything.

Sometimes. But in the case of whether there is speciation (and evolution) or not, there is no downside to accepting it provisionally--as all scientific theories are accepted.

Species are genetically hard wired to reproduce that exact species, over and over, again. The dragonfly is virtually an exact copy today of it's ancestor, it's ancestor existed hundreds of millions of years ago.

I wonder if you know as much about evolution as you think. That stasis is actually, in its way, a demonstration of the evolutionary mechanism.

If a species is not sustainable due to, let's say, an environmental change, then that species will become extinct. The fossil record is the record of mass extinction, how many millions of species are extinct is impossible to know.

Changes that cause extinction are not slow and not gradual, they are usually sudden, abrupt changes. That is why we see so many extinction events in the fossil record.

Quite right. A rapid change in selection criteria depletes the information content of the gene pool faster than it can be replenished by natural means and so the randomly distributed variation on which evolutionary change depends is much reduced. Consequently, the species is unable to adapt to any further change and becomes extinct. Something similar happens during selective breeding, which is why it can only be taken so far.

 

[Shemjaza]

I see dogs and wolves as one species on the basis of morphology. Give all these breeds enough time in the wild and the basic genetic code, for the wolf will be re-established.

Trust me on this.

Why?

Those traits are gone. Something similar may well develop, as it is still probably a viable niche, but recreating the exact structure is so unlikely that it verges on impossible.

Still there is not one dog breed out there that differs in it's basic genetic code. They are all dogs, all exactly the same species. In fact, pure breeds carry damage in the genetic code and have inherent problems. The mongrel is superior to the pure breed and a wolf is superior to the mongrel.

They are different because they have different genetic code.

Wolves developed over millions of years of adaptation. Dogs have thousands of years of human acting as extreme selective pressures... that leads to a loss of genetic diversity, and the kind of problems we see in pure breeds.

Dogs have been bred to live with and for humans, in that environment they are far superior. On global scale the species Canis lupus is far more dog then it is wolf.

Interesting point you raised.

Has anyone tried to cross breed snakes given that they may possibly be but one species?

Some snakes are close enough to hybridise, may wouldn't be. (In fact many see each other as a tasty snack).

Here's an article about hybrid snakes that appear to breed true.

I can't find the article unfortunately, but I once read about a area where sterile hybrids formed a permanent population due to being superior to either parent species... but since they couldn't breed they never took over the entire region.