Evolutionists: How did legs evolve?

[Clete]

I'm hoping that there is an evolutionist here on TOL who would be willing to give a reasonably brief while still conceptually detailed explanation of how legs evolved.
That might sound like a weirdly specific request but I have a reason for asking it. It isn't a trick question. I really do want to focus on legs - any legs! Where did they come? What preceded them? What was the incremental genetic mutation that became legs? Note that legs almost always come in pairs and that there is all kind of various sizes, lengths, and configurations of legs. Did all these different types of legs show up separately or did they evolve from each other? Etc, etc, etc.
My question is not necessarily only about the first appearance of legs but also the current incarnations of legs in general. Where did legs come from and how did we get to the current state of legs. Why, for example, do dogs have four legs while ants have six and spiders eight. Why do some legs have three joints while other have more or less? Just whatever you can think of about legs and how does the theory of evolution explain what we see?

And I don't intend to try to pick apart whatever explanation is offered. It isn't about that. I'm simply curious to know what evolution has to say about legs and why they exist and how they got here. Feel free to just offer whatever it is you understand to be what evolutionary theory has to say on the topic.


Thanks,
Clete

 

[Right Divider]

You'll probably get a lot of posts about the benefits of legs.

 

[jamie]

Evolution doesn't have a leg to stand on.

 

[Eeset]

I need at least 2 legs to walk easily,

 

[The Barbarian]

Since genetic, anatomical, and fossil data show that legs evolved from fins, you really are asking how fins evolved. In fact, the first known functional legs are on a fish that could not have walked on land.

More recently, limbs in fish have evolved at least twice in fish for walking and/or climbing.

I'm assuming you mean vertebrate legs, Arthropod legs are much older and evolved from a different source.

Would you like to focus on vertebrate legs?

 

[Clete]

Since genetic, anatomical, and fossil data show that legs evolved from fins, you really are asking how fins evolved. In fact, the first known functional legs are on a fish that could not have walked on land.

More recently, limbs in fish have evolved at least twice in fish for walking and/or climbing.

I'm assuming you mean vertebrate legs, Arthropod legs are much older and evolved from a different source.

Would you like to focus on vertebrate legs?

Nope, it doesn't matter whether it's vertebrate legs or whatever other sort of leg. Just tell me what evolution says about how they showed up.

If it's different for one species than another then I'm fine with that, give me both. In fact, I'd prefer to have both.

In fact, any conceptual explanation you care to offer will be acceptable. It doesn't even have to be an accepted theory or have any application to a real species. Just guess if you have to. Give me anything you can think of that has to do with the evolution of legs. What had to come before them and what came before that and whatever else you can think of.

Clete

 

[Clete]

Since genetic, anatomical, and fossil data show that legs evolved from fins, you really are asking how fins evolved.

I read your post too fast and looked right over this!

This is PRECISELY the sort of thing I'm look for.

What data?

I don't need detailed specifics just in general, what do you mean by "genetic, anatomical and fossil data" and what does it tells us about where legs come from?

 

[User Name]

I'm hoping that there is an evolutionist here on TOL who would be willing to give a reasonably brief while still conceptually detailed explanation of how legs evolved.

https://en.wikipedia.org/wiki/Evolution_of_tetrapods#From_fins_to_feet

 

[Clete]

https://en.wikipedia.org/wiki/Evolution_of_tetrapods#From_fins_to_feet

Okay, so from fins to legs to feet, all to get access to food and or to escape predators or drying out or otherwise dying. Fine and dandy.

How about other legs like those of crabs, insects, spiders, centipedes, etc? Any idea how they came about and what preceded them?

And just for good measure, how about those fins anyway. Those are sort of a form of leg, right? Anything out there that came before fins that wasn't quite a fin yet?

 

[User Name]

How about other legs like those of crabs, insects, spiders, centipedes, etc? Any idea how they came about and what preceded them?

And just for good measure, how about those fins anyway. Those are sort of a form of leg, right? Anything out there that came before fins that wasn't quite a fin yet?

I would suggest searching reliable sources on the net or elsewhere for information specifically on the evolution of crabs and the other animals you mentioned.

Here are links to a few informative videos:

Which Fish Did We Evolve From?

The Evolution of Limbs from Fins

Wings, Legs, and Fins: How Do New Organs Arise in Evolution?

 

[6days]

Evolutionists generally due to confirmation bias 'logic' claim something like "genetic, anatomical, and fossil data show that legs evolved from fins... In fact, the first known functional legs are on a fish that could not have walked on land."

Fossil evidence?? Nope!
This has lead evolutionists to many faulty conclusions, and often resulted on egg on the face of believers (Those who believe fish grew legs). One of their most embarassing involves a mistake of 65 million years...

Evolutionists believed the coelacanth fossils represented a fish that swam in shallow seas, developed stubby limbs and primitive lungs to breath air. This fish was claimed as evidence of evolution... a transitional fossil. Those were the claims until it was found these fish still survive today. They do not have lungs... it is a swim bladder. They don't live in shallow seas, but in ocean depths. And they don't have limbs for crawling onto shore...they have fins.

Fossil evidence?? Nope... coelacanth, tiktaalik, and other fish have made into 'just so stories'.

Anatomical evidence?? Nope!
Arranging antatomical features to fit belief systems is nothing more than pseudoscience. If the evolutionist thinks a feature / structure can be arranged into a pattern consistent with their beliefs, they call it a homologous feature. (They believe it was inherited). If however the structure / feature can't be made to fit into the evolutionary story, then it is called analogous. (They believe it evolved indepentently...not inherited)

Genetic evidence?? Nope!. .
There is no chance a cold blooded fish can evolve into warm blooded, 2 legged philosopher.... it's simply a fairy tale. Science shows us 'evolution' / natural selection is a process of elimination. Organisms may adapt and speciate, but it results in less genetic variation than parent populations. Highly adapted organisms, such as coral populations are often endangered... unable to survive environmental change. Science shows us finned populations sometimes go extinct... they don't evolve legs.

 

[Clete]

I would suggest searching reliable sources on the net or elsewhere for information specifically on the evolution of crabs and the other animals you mentioned.

Here are links to a few informative videos:

Which Fish Did We Evolve From?

The Evolution of Limbs from Fins

Wings, Legs, and Fins: How Do New Organs Arise in Evolution?

Any chance of getting you to just sort of give me the gist?

So far we've got legs coming from fins in order to gain access to food or escape from predators or whatever. Is there anything else that legs come from for any other reason?

Would you say that it necessary for legs to evolve slowly from simple and less functional forms to more and more complex and useful forms or could it happen that something just has a set of legs that are perfectly suited to their life cycle and always has had them in that form?

And no one has yet said a word about insect and spider legs. Surely evolution has some theory about what forms of life came before a spider with some guess as to how spiders came to have four pairs of six jointed legs. Why eight legs? Why always six joints in each leg? Is there a spider like creature that doesn't have eight legs with six joints?

These are all real questions. I'm not making fun. I'm actually curious to know just what it is that evolution says about the origin of legs. There is a specific reason why I want to know that I'll get to in due time. Just for now tell me what evolution's best guesses are in relation to the origin of functioning legs with joints and feet and ankles and the ability to step over obstacles and whatever else you can think of that has anything to do with legs.

Clete

 

[Clete]

Evolutionists generally due to confirmation bias 'logic' claim something like "genetic, anatomical, and fossil data show that legs evolved from fins... In fact, the first known functional legs are on a fish that could not have walked on land."

Fossil evidence?? Nope!
This has lead evolutionists to many faulty conclusions, and often resulted on egg on the face of believers (Those who believe fish grew legs). One of their most embarassing involves a mistake of 65 million years...

Evolutionists believed the coelacanth fossils represented a fish that swam in shallow seas, developed stubby limbs and primitive lungs to breath air. This fish was claimed as evidence of evolution... a transitional fossil. Those were the claims until it was found these fish still survive today. They do not have lungs... it is a swim bladder. They don't live in shallow seas, but in ocean depths. And they don't have limbs for crawling onto shore...they have fins.

Fossil evidence?? Nope... coelacanth, tiktaalik, and other fish have made into 'just so stories'.

Anatomical evidence?? Nope!
Arranging antatomical features to fit belief systems is nothing more than pseudoscience. If the evolutionist thinks a feature / structure can be arranged into a pattern consistent with their beliefs, they call it a homologous feature. (They believe it was inherited). If however the structure / feature can't be made to fit into the evolutionary story, then it is called analogous. (They believe it evolved indepentently...not inherited)

Genetic evidence?? Nope!. .
There is no chance a cold blooded fish can evolve into warm blooded, 2 legged philosopher.... it's simply a fairy tale. Science shows us 'evolution' / natural selection is a process of elimination. Organisms may adapt and speciate, but it results in less genetic variation than parent populations. Highly adapted organisms, such as coral populations are often endangered... unable to survive environmental change. Science shows us finned populations sometimes go extinct... they don't evolve legs.

Clear some room out of your private message in box!

 

[6days]

Clear some room out of your private message in box!

Done

 

[glorydaz]

Did anyone mention escaping? Running. I'd want legs for that.

 

[iouae]

 

[iouae]

Paleontological ages go Pre-Cambrian, Cambrian, Ordovician, Silurian, Devonian, Carboniferous...

The Devonian is the Age of Fish, and towards the end there are supposed fish with limbs (supposed aquatic/amphibian tetrapods).
Then there is a mass extinction, a gap of 15 million years with virtually no tetrapod fossils called Romer's gap, and land tetrapods EXPLODE onto the scene walking on 4 legs.

You can read about tetrapod or 4-legged animal leg evolution, but from my research, walking land animals appear as if by an act of creation, after Romer's gap, in the early Carboniferous era.

Evolutionists call a sudden appearances of many new animals, "adaptive radiation". I call it Jesus creating (John 1:3). I personally find these explosions such as the Cambrian explosion, the land tetrapod explosion, the mammal explosion in the Eocene very faith affirming. In each case, thousands of new animals seemingly spring from nowhere. Evolutionists fill these gaps in the fossil record with dashed lines or "ghost lineages", meaning we guess this happened.

There is a ghost lineage between aquatic tetrapods, and land ones. Along with land living came egg laying, requiring a little "ocean" enclosed in a shell (amniotes). Land tetrapods as a rule were amniotes (eggs with water enclosed, laying).

 

[6days]

walking land animals appear as if by an act of creation, after Romer's gap, in the early Carboniferous era.

Walking land animals appear about 24 hours after the sea creatures were created; this was after the 'gap' of an evening and morning on the 5th day.

 

[iouae]

It is a bit of a holy grail among evolutionists to find the missing links which gave rise to tetrapods. So far, none have been found. This gap in fossils is called the Romen gap.

Another holy grail is to find the missing link between wingless insects and winged insects. So far, none have been found. This gap in fossils is called the Hexapoda gap.

Finding these missing links would make one famous.

 

[Right Divider]

It is a bit of a holy grail among evolutionists to find the missing links which gave rise to tetrapods. So far, none have been found. This gap in fossils is called the Romen gap.

Another holy grail is to find the missing link between wingless insects and winged insects. So far, none have been found. This gap in fossils is called the Hexapoda gap.

Finding these missing links would make one famous.

Which is another thing that keeps the "theory" going strong.