how come evolution selected for testicles that hang on the outside?

[boochi]

Balls need to swing to get the jizz flowing.

 

[lozina]

Balls need to swing to get the jizz flowing.

after a good shaking it comes out frothy

 

[SolMiester]

Because women need something else for their hands to play with while giving fellatio. Any man here who has been in a relationship knows what it is like when they think that giving your shaft indian burn is somehow sexy.

LOL....haha, so true!

 

[HamburgerBoy]

I wonder why there are so many land-based animals (some mammals included) with internal testicles then. Elephants don't have a big ole sac dangling down, after all.

 

[OverVolt]

Temperature

 

[OCGuy]

I wonder why there are so many land-based animals (some mammals included) with internal testicles then. Elephants don't have a big ole sac dangling down, after all.

They have a body temp that is 1-2 degrees lower than average, and they may have one time been aquatic animals:


"Elephant's testes do not descend into a scrotum during embryonic development and remain intra-abdominal after birth. This feature is characteristic to aquatic mammals, whose testes need to be protected from the cold. Elephants and dugongs are primary testicond mammals (their testes never have been scrotal), whereas seals and whales are secondary testiconda (their testes once have been scrotal, but were subsequently withdrawn back into abdominal cavity in the course of the evolution)."

http://www.geochembio.com/biology/organisms/elephant/

 

[Angry Irishman]

For the slapping noise during sex....simple.

 

[dawp]

they're external just so these guys would have food source:

http://news.yahoo.com/men-worried-testicle-eating-pacu-fish-205100506.html

Unlike the piranha, pacu are vegetarians. They feed mainly on fruits and nuts that have fallen into the water, using their powerful jaws to crack the shells and get at the meat inside.

Perhaps that explains why the fish have such a terrifying reputation, since their diet lends itself so easily to double entendre. They're even sometimes referred to as the "nutcracker fish."

 

[Aikouka]

We need them to be kept cooler than body temp.

This is what I recall as being the reason. I also remember reading an article where they found that simply heating up the testicles actually serves as a viable method of male-based birth control. I don't remember much of the specifics though.

 

[surfsatwerk]

This is what I recall as being the reason. I also remember reading an article where they found that simply heating up the testicles actually serves as a viable method of male-based birth control. I don't remember much of the specifics though.

My preferred method of birth control is a hummer prior to intercourse.

 

[z1ggy]

My preferred method of birth control is a hummer prior to intercourse.

Mine is a solid flight of stairs and a well timed round house kick.

 

[momeNt]

This is what I recall as being the reason. I also remember reading an article where they found that simply heating up the testicles actually serves as a viable method of male-based birth control. I don't remember much of the specifics though.

Well either that, or you watched Nip/Tuck and took it as gospel.

The only thing viable about it is sperm and the future squalling baby you'll end up with. You make sperm way too fast.


From Yahoo Answers - sounds like a researched answer.

In theory (where there are not variants and all's perfectly planned) it works. Optimal sperm production (spermatogenesis) requires temperatures several degrees Celsius below average body temperature. The testes are located outside the body in the scrotum, which has several mechanisms to keep the testes cooler than the rest of the body. Warming the testes to or above body temperature temporarily disrupts spermatogenesis.

Multiple researchers in the 1950s and 60s did proof of concept studies of external heat as a male contraceptive (Robinson 1968, Steinberger 1959, Watanabe 1959). These studies universally showed decreased sperm counts of their human and animal participants, but none tested the methods’ effectiveness as a contraceptive.

The main evidence for effective use of external heat as a male contraceptive comes from the unpublished works of a Swiss doctor working in India between 1930 and 1950. Dr. Martha Vogeli advised 100s of men on the use of hot sitz baths, and claims that her patients attained 100% effective contraception using this method (1956).


Dr. Vogeli tested baths in a range of temperatures with 9 volunteers to determine the most effective regimen. She determined that 21 consecutive days of 46.5 ºC (116 ºF) sitz baths lasting 45 minutes typically provided 6 months of contraception. However, there was a range of duration of the contraceptive effect from 4 to 8 months just among these 9 men. Dr. Vogeli ’s volunteers did not continuously monitor the temperature of the bath, but presumably it decreased over the course of the 45 minute treatment (Vogeli 1956).

In the accounts of her work, Dr. Vogeli did not mention a delay in the start of effectiveness. However, heating as a contraceptive method would likely require at least 2 months to become effective. The onset of effectiveness depends on the individual.

Because this method of contraception has had few clinical trials, safety issues are relatively unexplored. Trial participants have reported no effects on libido, mood or physical health. Although no data have been collected for humans, rats in external heat trials experienced a one-third reduction in the volume of their testes 6 weeks after treatment (Steinberger 1959).

And then, there'sthe reversal time and all that. Isn't it easier and safer to buy and use a condom?

So.... to me this sounds like to make this treatment effective, you literally need to cook your balls and potentially cause irreversible damage to them in order to consider it a contraceptive. I wonder what cooking your balls does to your testosterone levels?

 

[Aikouka]

Well either that, or you watched Nip/Tuck and took it as gospel.

Nah, I've never seen Nip/Tuck. I just didn't want to start Googling testicles or other genitalia on this computer! However, I just whipped out my phone and found the article on it instead.

http://abcnews.go.com/Health/testicle-zap-future-birth-control/story?id=15472917

Although, talk of zapping your balls reminds me of the South Park medicinal marijuana episode.

 

[sdifox]

Cuz Pacus have to eat too.

 

[SlowSpyder]

regulate temp. Closer to body when cold, hang like a fruit basket when hot.

Also, it is a sign of manliness when you are in your 70s. You get yourself a gym-pass, pretend to workout for 10 minutes, then spend the rest of your time in the locker room with no towel on and one leg up on the bench, talking to whoever will listen.

The lower, the more manly you are.

I always thought this was just a myth... then I went to the local YMCA to work out.

 

[Zodiark1593]

They hang to make it easier for the other gender to kick, or at least, that's been my experience. :|

I've dealt with far worse pain though, so a kick down there does relatively little to me, much to the shock of the offending female. The joys of school.

 

[epidemis]

Why did evolution require testicles to be kept cooler?

Because evolution is constrained by physics