Within the context of mammalian reproduction, the pineal gland depends on a complete photo period of light and darkness. So if the comet that caused a mass extinction blocked out the sunlight. How where mammals able to reproduce and lead the way for future mammals? Does that mean that there was primitive estrous cycle not present in mammals today?
2007-03-23 11:35:50 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Zoology
"It has been estimated that after the collision there was so much dust in the atmosphere that the entire planet was completely dark for 1-3 months. The lack of sunlight would have caused the extinction of many plants and animals. Among the animals, cold-blooded forms like dinosaurs would have been affected more than the warm-blooded mammals."
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2007-03-23 12:34:26 · answer #1 · answered by tagi_65 5 · 1⤊ 0⤋
Actually there is a lot of evidence that it WAS a comet that caused the extinction of dinosaurs. And I don't think that's your point.
Well, I guess not all sunlight was blocked. The hit caused a coating of dust to cover the planer, but this doesn't mean that earth didn't receive any light. If that was true, ALL creatures would be extinct.
Probably, those who survived were small ones without much need for light, they managed to get through with a little bit of it.
2007-03-23 11:52:12 · answer #2 · answered by Lilly26 3 · 1⤊ 0⤋
Evolution would probably suggest that those mammals that had an easier time regulating their hormones without the sun would survive while those who didn't died out. Pretty crappy answer, but that's that.
On a side note, it should be noted that mammals were nocturnal creatures at that time.
On yet another side note, and somewhat unrelated: Mammals, when they evolved from reptiles, lost the ability to process the ultraviolet range as well as a series of colors due to this nocturnal behavior. Primates managed to recover some of that series of colors, but not the ability to see into the ultraviolet range. Birds, on the other hand, kept all the abilities from their reptilian (therapod dinosaur) ancestors.
2007-03-23 20:14:10 · answer #3 · answered by Gabe 2 · 0⤊ 0⤋
Comets strike Earth on a daily basis (tiny ones, of direction). in actuality, there is one satellite tv for pc that has, as its considerable activity, the diagnosis of comets hitting the top environment. Comets are extra loosely sure than asteroids, so they have a tendency to break aside lots bigger than asteroids while they do enter the ambience. of direction, all "predictions" for 2012 are suspect. Over ninety 9% of the predictions bearing directly to 2012 are fake, with those for December being even faker. Apophis isn't a comet and there is not any hypothesis: it won't hit us in 2036, no longer in 2037 and not in 2069 (the three closest bypass for this asteroid's destiny). The Mayan calendar would not even end. That lie became invented in the previous due Eighteen Eighties for a e book that became offered in the early Nineteen 1890s. the author (J.A.) became giving HIS understanding of old correct-American calendars. His understanding became, how would properly be say this courteously... faulty. Even the story related to the Mayans believing in a clean Age (their gods reviewing their introduction at that element) became written 5 centuries after the decline of the Mayan empire... by using a Spanish priest. That makes it below one hundred% good (even with the undeniable fact that, it would not make it at once incorrect). of direction, you could believe in Mayan gods, nevertheless. --- fairly some the questions approximately 2012 in this internet site are truthfully for the purpose of artificially conserving a point of hype earlier than the launch of a action picture referred to as "2012" (later q4).
2016-12-15 07:27:12 · answer #4 · answered by motato 4 · 0⤊ 0⤋
The mammals that survived may have been subterranean or underground living. Those mammals likely evolved to not need light to regulate breeding??
2007-03-23 11:41:02 · answer #5 · answered by bravozulu 7 · 1⤊ 0⤋
There is no evidence that the comet blocked out all light. There is no evidence that all mammalian life was extinct. There is no evidence that a comet caused the extinction of the dinosaurs. Any more questions??
2007-03-23 11:45:40 · answer #6 · answered by dtwladyhawk 6 · 1⤊ 2⤋
they used their sense of smell. most terrestrial mammals are nocturnal to decrease their likelihood of being killed by predators. if it's sufficiently dark during daylight hours, there's no reason for mammals to be inactive.
2007-03-23 17:30:39 · answer #7 · answered by ophus 1 · 0⤊ 0⤋
As the saying goes "love will find a way". We tend to have back-up systems that will kick in.
2007-03-23 11:46:45 · answer #8 · answered by Anonymous · 1⤊ 0⤋
I have sex in the dark all the time...don't you?
2007-03-23 12:25:43 · answer #9 · answered by Anonymous · 0⤊ 0⤋