Vestigial structures in the Human Body

[beaglelady]

Here’s a short, very interesting video about vestigial structures in the human body. The title is “Proof of Evolution that you can find on your own body,” but I think that “Evidence” would be a better word than “Proof.”

[jpm (Phil McCurdy)]

Thanks for posting. I remember back in comparative anatomy and embryology following the changes that happen, but it is fun to see the surface effects of vestigial structures. In medicine, there are some pathologic conditions related to retained vestigial structures (brachial cleft cysts, supernumerary nipples etc.)

[beaglelady]

And the most common one is wisdom teeth!

[dcscccc]

see also this counter list:

Vestigial organs revisited

its not a scientific argument.

[jpm (Phil McCurdy)]

Some of the arguments listed on that link are nonsense and I am sure have been addressed elsewhere. Still, it would be hard to argue the usefulness of an extra nipple. Also, I would also say that there is no such thing as “devolution” as loss of complexity as an adaptive response is also evolution, such as blind cave salamanders etc.

[beaglelady]

So what do you do with your nipples, d? Are they for piercing and jewelry? And what about chestnuts, ergots, and splint bones on horses?

[dcscccc]

@jpm

Still, it would be hard to argue the usefulness of an extra nipple.

there is also cases when human born with extra finger. so according to this its mean humans shared a commondescent with an animal that had 6 fingers?

[jpm (Phil McCurdy)]

Supernumerary nipples are usually in the “milk line” that developmentally lead to the line of teats in other animals, so have a vestigial explanation both in function and location. An extra finger is…well… an extra finger. Not a big difference I guess.

[gbrooks9 (George Brooks)]

HEY!!! That video is pretty impressive…

I was worried that it would over-state or exaggerate the material at hand … but I think it avoided that trap well. And it provided material that I hadn’t really seen presented so clearly at any time before.

This video needs to be stored somewhere so that newcomers can find it quickly and easily … Any ideas?

Thanks @beaglelady

[gbrooks9 (George Brooks)]

@dcscccc

there is also cases when human born with extra finger. so according to this its mean humans shared a commondescent with an animal that had 6 fingers

Sometimes EXTRA stuff is just EXTRA … it doesn’t mean anything about a common ancestor.

So being born with ONE tail is probably a lot more meaningful in a species that has no tail than being born with TWO tails in a species that normally only has one.

Follow what I mean @dcscccc ??

[gbrooks9 (George Brooks)]

@jpm

Some of the arguments listed on that link are nonsense and I am sure have been addressed elsewhere.

@jpm, I am eager to read your comments about the example you think is the WORST one …

[dcscccc]

@jpm

Supernumerary nipples are usually in the “milk line” that developmentally lead to the line of teats in other animals, so have a vestigial explanation both in function and location

what do you mean by that?

by the way- we also have cases when sharks mutation make it look like legs:

Shark with webbed feet

so again- does it mean that sharks evolved from land animal?

[beaglelady]

That’s a good idea, George. Maybe it belongs in resources.

[jpm (Phil McCurdy)]

The first thing that stands out is the section on extrinsic ear muscles ( the kind that let some people wiggle their ears,) where they they go into talking about function of the tensor tympani muscle inside of the ear as though they were the same. Someone who didn’t know basic anatomy might think they were the same and not notice the misdirection. Then, suggesting that the ability to wiggle ones’s ears is has significant functional significance. Most people cannot wiggle their ears, and suffer no disability.

[jpm (Phil McCurdy)]

Here is a link to one article discussing them, though they may well be related to imperfect embryologic development.

Supernumerary nipple

[jpm (Phil McCurdy)]

Did you actually read the article and follow up some of the comments? What the poster claimed as feet was actually it’s dissected penis, though thought to possibly malformed.

[dcscccc]

@jpm

Here is a link to one article discussing them, though they may well be related to imperfect embryologic development.

so again- how it have any conection to evolution? its just an extra nipple. like extra finger.

@jpm

Did you actually read the article and follow up some of the comments? What the poster claimed as feet was actually it’s dissected penis, though thought to possibly malformed.

true. but its show how an organ can be similar to another organ in another species that is very different. its not prove any commondescent.

[jpm (Phil McCurdy)]

I think what I see as the difference, is that the extra nipple is a structural anomaly that is directly related to development of different mammary glands in other animals, showing interrelatedness. As to the extra fingers, I looked a little further, and that trait is related to a genetic mutation, and thus reinforces the mechanism of evolution, though in this case, it is not a trait that is deemed beneficial, as most are not.
As to the shark feet/penis, it shows that looks can be deceiving, and that the big hands/big feet comments made in the presidential campaign is based on faulty science.

[beaglelady]

@jpm

As to the shark feet/penis, it shows that looks can be deceiving, and that the big hands/big feet comments made in the presidential campaign is based on faulty science.

LOL LOL LOL!