Posted on 12/07/2005 10:17:23 AM PST by blam
Big brain means small testes, finds bat study
12:16 07 December 2005
NewScientist.com news service
Gaia Vince
Proceedings of the Royal Society B: Biological Sciences The brainier male bats are, the smaller their testicles, according to a new study. Researchers suggest the correlation exists because both organs require a lot of energy to grow and maintain, leading individual species to find the optimum balance.
The analysis of 334 species of bat found that in species where the females were promiscuous, the males had evolved larger testes but had relatively small brains. In species, where the females were monogamous, the situation was reversed. Male fidelity appeared to have no influence over testes or brain size.
Both brain tissue and sperm cells require a lot of metabolic energy to produce and maintain. The different species appear to have evolved a preference for developing one organ more than the other, presumably determined by which will help them produce more offspring.
“An extraordinary range of testes mass was documented across bat species - from 0.12% to 8.4% of body mass. That exceeds the range of any other mammalian order,” says Scott Pitnick, from Syracuse University in New York, US, one of the research team. Primate testes vary between species from 0.02% and 0.75% of body mass.
Energy knife-edge
Efficient use of energy is crucial for bats, says Pitnick: “Bats really exist on an energy knife-edge: they are small with a large surface area, and they need to fly around, particularly during the mating season.”
Pitnick and his colleagues had predicted that, in species with promiscuous females, males would require bigger brains in order avoid being cuckolded. So they were surprised to find the opposite: “Perhaps monogamy is more neurologically demanding.”
Harry Moore, a sperm researcher at the University of Sheffield, UK, says that testis size is normally related the amount of sperm produced.
“In species with promiscuous females, the males are competing to fertilise her eggs and so need to produce a lot of sperm," he told New Scientist. “And this may be especially true in some species of bats where the females store sperm for several months.”
Journal reference: Proceedings of the Royal Society B: Biological Sciences (DOI: 10.1098/rspb.2005.3367)
Don't worry... the bigger the bat, the smaller the testes.
Ping to #51.
ROTFLOL! I think the odds are pretty doggone good that you*ll get a few protesting replies on this one. It*s not often that we get a chance to scientifically prove what we already knew. ;o)
>> "This would explain why aliens are abducting humans for reproduction experiments." <<
There was a VERY funny skit on Kids in the Hall, where two aliens are worried about WHY they are instructed to administer anal probes. One comments about how it's really cruel, and the other says, "actually, it's the ten percent who seem to enjoy it who really creep me out."
LMBO!!
Glad to know MIT is still turning out such fine students. By the way, you are AN MIT grad. *eyeroll*
Ey donn unnustand whut that meens.
(Adjusts self in chair to relieve groin discomfort)
>>There is a joke about Pinky and The Brain in there, but I won't do it. <<
Good. The USENET oracle had a specific rule about bannishment for making references to mouse balls. :^D
ROFLMAO!
No, I am A Massachusetts Institute of Technology grad. ;)
Yeah, I'm looking for a study of brain size and "bat" size.
Nice piece of ash.
I was in the POOL!
A wife?
OMG!! My wife is cheating on me!!
She's just waxing and polishing!
Ok. let's see here:
If smarter bats have smaller balls, but I am smarter than a a bat and more energetic bats have bigger balls but I do not have the energy of a bat, and I am more monogamous than your run of the mill flit around the yard show off bat, then....
Suffering Succotash! And I thought it was just a Wisconsin winter.
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