Harvard Scientists Discover Origin of Male Genitalia

Harvard Scientists Discover Origin of Male Genitalia

Human Fetus 310x 2

Our reproductive system comes from cells that stem from the embryonic tail.

New research out of academia shows the origin of human male genitalia, and how it's tied to the reproductive system in, oddly enough, snakes.

The findings, published in the science journal Nature, demonstrate where the external genitalia in both snakes and humans originate.

In snakes, genitalia is tied to limb production, or the "limb buds," as snakes once had limbs before evolution gave them the old heave-ho. While a snake no longer possesses arms and legs, this reptile family's external genitalia is made from the same tissue that would make up hind limbs if they existed. During the formation process, the process that would turn these buds into limbs is interrupted, leaving the snake leg-free (no leg day at the gym, I'm afraid).

In humans (all mammals, actually), genitalia is tied to the "tail bud," or the cell cluster that forms the embryonic tail. The same applies to birds as well. And while mammals and birds share a reproductive origin story, bird's systems (cloaca) are totally internal, while male mammals are external.

These new findings also explains the location of our genitalia. In humans, it's close to the tail bone, and in snakes, it's located where legs would form on most reptiles.

And if you prefer more scientific terminology?

In squamates, the genitalia develop directly from the budding hindlimbs, or the remnants thereof, whereas in mice the genital tubercle originates from the ventral and tail bud mesenchyme. The recruitment of different cell populations for genital outgrowth follows a change in the relative position of the cloaca, the genitalia organizing centre. Ectopic grafting of the cloaca demonstrates the conserved ability of different mesenchymal cells to respond to these genitalia-inducing signals.

The word genitalia was used 13 times in this post, title included.

Sources: Forbes | Nature

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Hey babe.. Wanna see me 'Wag my Tail'?

So calling it the 'one-eyed snake' is probably not as gross an exaggeration as first thought..

*Insert Beavis and Butt-Head chuckle here

Devin Connors:

The word genitalia was used 13 times in this post, title included.

Thanks for the info! Actually this whole article is quite interesting... so in essence it is a limb, and thus calling it a third leg isn't necessarily wrong just inaccurate?

lol... dickbutt was correct all along
image

Imperioratorex Caprae:

Devin Connors:

The word genitalia was used 13 times in this post, title included.

Thanks for the info! Actually this whole article is quite interesting... so in essence it is a limb, and thus calling it a third leg isn't necessarily wrong just inaccurate?

Yeah, if what the article says is verified, it'd be more proper to call male genitals the frontal tail instead of the third leg. Oh ho ho~ Someone shoot me.

Makabriel:
*Insert Beavis and Butt-Head chuckle here

hah reminds me of this part:

OT: this is interesting...time to figure out more sexual names for my penis

Imperioratorex Caprae:

Devin Connors:

The word genitalia was used 13 times in this post, title included.

Thanks for the info! Actually this whole article is quite interesting... so in essence it is a limb, and thus calling it a third leg isn't necessarily wrong just inaccurate?

That pun has a whole new level of awesomeness now.

To everyone making jokes your all terrible and I love you all for it.

OT: Quite a intristing turn of events and puts a new meaning in the term chasing tail.

So all dudes are interrupted tripods?

https://www.youtube.com/watch?v=3Rbz777_glw

Well well well, looks like when i called it wrestling the python in the masturbation thread, i was closer to the mark than i though.

Snakes eh? I guess you could call your dick a..

Trouser Snake.

...Don't kill me. XD

So it looks like I actually have two tail bones! Or would it be more like 1.5?

So my cock really is like a babies arm...

josemlopes:
lol... dickbutt was correct all along
image

Comment Winner

Svarr:
Snakes eh? I guess you could call your dick a..

Trouser Snake.

...Don't kill me. XD

Too late.

OT: Now, speaking frankly, if this is the embryonic tail, the important part of a developing child in the womb, what ummm...what exactly causes a difference in women there? Is it a chemical? Just genetic?

FalloutJack:

OT: Now, speaking frankly, if this is the embryonic tail, the important part of a developing child in the womb, what ummm...what exactly causes a difference in women there? Is it a chemical? Just genetic?

The difference in women doesn't actually occur until after 6 weeks, so specifying male genitalia is incorrect. The original article from nature does not actually say anything about the male genitalia except that in males the structures develop into a penis.

If you really want to know the difference in female and male development in humans this is determined by a gene on the Y chromosome called sex determining region Y (SRY). This gene transcribes a peptide hormone called testis determining factor (TDF) which in turn activates several genes including SOX9. One of the products is a hormone called anti-Müllerian hormone (AMH). AMH causes the structure found in any human embryo called Müllerian tube to degenerate, while dihydrotestosterone cause the Wolffian tube to develop into the penis accessory structures and the medulla (or the core) of the early gonads will become testicles while the cortex (the outer part).

Female development is basically the absence of the SRY gene's gene products, so anyone born with XX or with an inactivation of this portion of the Y chromosome will become female. In the absence of SRY there won't be any AMH to degenerate the Müllerian tube, and this will develop into the upper part of the vagina and the fallopian tubes. In absence of dihydrotestosterone the wolffian tube will degenerate. The cortex of the early gonads will develop into the uterus while the medulla will degenerate.

Now this is a simplified model since it turns out that female development is a little more complicated and I don't know all the details by heart, but this is a rough sketch of the development of sex. Does this answer your question?

OT: This article is misrepresenting the article it cites. Rule of the thumb, never take information that comes from secondary or tertiary sources without looking it up. The article in Nature does not mention male or female differentiation as fundamentally different and they are actually not determined before after the body axises and overall embryonic structures are determined. The hind legs or tail structures doesn't develop in males and not in females, they develop in both and they become the internal and external sex organs in both, but I guess if we had pointed that out from the start we couldn't make jokes about the penis being our third leg or our tail.

I....I'M A LEGENDARY SUPER SAYIAN!!! Just don't grab my tail, or I get all weak.

 

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