Posted on 12/12/2005 11:36:30 AM PST by Sopater
For male bats, intelligence comes at a steep price. A new study found that bat species with large brains have smaller testicles.
The correlation is likely an evolutionary tradeoff between having to maintain a large brain and producing lots of sperm, said Scott Pitnick, a biologist at Syracuse University in New York who conducted the research.
"The male who ejaculates the greatest number of sperm may win at this game, and hence many bats have evolved outrageously big testes," Pitnick said. "Because they live on an energetic knife-edge, bats may not be able to evolutionarily afford both big testes and big brains."
Female bats in many species mate with more than just one male, and sperm can survive in the female's body for long periods of time; this leads to fierce competition between sperm to fertilize the egg.
Pitnick suspects that the males with relatively large testes and small brains leave more offspring than larger-brained and less fertile competitors.
In the study, Pitnick and colleagues analyzed 334 species of bats and found that in species with promiscuous females, the males had evolved larger testes but had relatively small brains.
In species where the females were faithful to their mates, the correlation was reversed. The study also showed that male fidelity appeared to have no influence over testes or brain size.
In some bat species, the male's testes can make up as much as 8.5 percent of body mass. Of all mammals, bats have the widest range of testes mass: between 0.12 percent and 8.5 percent of body mass.
As a comparison, testes mass in primates (including humans) varies between 0.02 and 0.75 percent.
The research was detailed in a recent issue of the journal Proceedings B of London, a biology journal of the United Kingdom's Royal Society.
(Excerpt) Read more at foxnews.com ...
The voting patterns show that states with higher average IQs tend to vote democrat, and everyone knows that Republicans have more... uhm... "guts".
Therefore, this proves the theory of evolution. Right?
Even Moonbats?
I'm NOT going to post the squirrel with the big nuts.
LOL! Even moonbats!
It's hard catching insects in midair
with your gear snaggin brush
Republicans are smart and should take a leadership role in Congress (where they have the majority) but they haven't got the balls.
But maybe the people with the highest IQs in the highest IQ states vote GOP. After all, I vote GOP and my mommy says I'm the smartest boy in all of Monmouth county.
how could they get the bats to hold still while they measured?
Our tax dollars at work, yee hah.
How can they be sure it just wasn't shrinkage?
oh BALLS!
Hung like a dumb bat ping?
Anyone for baseball and or softball? We have bats and balls.
That's why I'm so sm... Oh,.... wait,... nevermind.
Does this mean that steroids might make me smarter???
How do they know that they weren't "grow-ers" and not "show-ers"?....:)
They put 'em in mothballs.
But perhaps having a bigger brain allows cleverer placement.
So I guess Robin's sidekcik has NO COJONES!!
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