Evolutionary Origin of Toenails

[MRaverz]

Simple enough query, what is the evolutionary history concerning toenails and fingernails?

 

[nasher168]

Simple enough query, what is the evolutionary history concerning toenails and fingernails?

Claws. They're found in reptiles, birds and mammals. Ours just aren't as thick.
I think, anyway.

 

[Eidolon]

Nails in general may have once been claws, but I would imagine that toe nails are probably just left over from a time when our feet were more hand like. Similar to chimps today.

 

[nemesiss]

Simple enough query, what is the evolutionary history concerning toenails and fingernails?

Claws. They're found in reptiles, birds and mammals. Ours just aren't as thick.
I think, anyway.

The fingernail is an important structure made of keratin that has 2 purposes. The fingernail acts as a protective plate and enhances sensation of the fingertip. The protection function of the fingernail is commonly known, but the sensation function is equally important. The fingertip has many nerve endings in it allowing us to receive volumes of information about objects we touch. The nail acts as a counterforce to the fingertip providing even more sensory input when an object is touched.

http://dermatology.about.com/cs/nailanatomy/a/nailanatomy.htm

could have said in my on words, but this is more clear.


additionally, "CLAW" is a hand!

 

[MRaverz]

Simple enough query, what is the evolutionary history concerning toenails and fingernails?

Claws. They're found in reptiles, birds and mammals. Ours just aren't as thick.
I think, anyway.

Ahh yes, of course!

I was thinking of nails as being introduced for a purpose rather than being the remnants of something else.

Thanks to everyone.

 

[GenesForLife]

Actually, the strict adaptationist model (that everything has to be conserved for a purpose) went out of the window long ago, late 1960s to be accurate, Kimura's work highlighted the possibility of drift alone being able to fix traits in a gene pool, especially when neutral mutations (a majority of mutations are neutral) are involved.

These seem to be variations in the activity and development of keratogenic cells, that is all.

 

[MRaverz]

Actually, the strict adaptationist model (that everything has to be conserved for a purpose) went out of the window long ago, late 1960s to be accurate, Kimura's work highlighted the possibility of drift alone being able to fix traits in a gene pool, especially when neutral mutations (a majority of mutations are neutral) are involved.

These seem to be variations in the activity and development of keratogenic cells, that is all.

So, toenails could have sprung up out of nowhere?

 

[GenesForLife]

Actually, the strict adaptationist model (that everything has to be conserved for a purpose) went out of the window long ago, late 1960s to be accurate, Kimura's work highlighted the possibility of drift alone being able to fix traits in a gene pool, especially when neutral mutations (a majority of mutations are neutral) are involved.

These seem to be variations in the activity and development of keratogenic cells, that is all.

So, toenails could have sprung up out of nowhere?

Not sure modified regulatory pathways that govern keratogenesis would qualify as nowhere, the pathways could be ancestral, but a modification of those pathways could have had a drastically different phenotypic output.