Naked Science Forum
Life Sciences => Plant Sciences, Zoology & Evolution => Topic started by: Eric A. Taylor on 26/05/2010 15:07:36
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Why do we think life on Earth started just once? Isn't it much, much more likely it started is several places and/or times?
Before you start going off on my about transspermia let me say I disagree with this theory on the grounds it does not answer HOW life got started. It simply takes that event and moves it to another location. Personally I think life started in the most likely place, Earth. If life got going on Mars first, it's just as likely to start here as well.
I think it's much more likely that life started on Earth AND Mars separately than that life started on Mars, somehow survived an impact large enough to propel it into space, where it had to survive millions of years in inter-planetary space then survive entry of the atmosphere and impact with the water. Then it had to somehow get OUT of the rock it was in, then had to find some way to survive in a completely lifeless ocean long enough to evolve into something that would be comfortable here.
Perhaps life got going, then died out contemplate several times before what became us got going.
Perhaps life got started in many many places, expanded it's range until it met other life forms then had a war or perhaps simply absorbed it, both life forms becoming something new.
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Perhaps life got going, then died out contemplate several times before what became us got going.
Perhaps life got started in many many places, expanded it's range until it met other life forms then had a war or perhaps simply absorbed it, both life forms becoming something new.
Sounds quite plausible, if not probable, to me.
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I've heard it argued that looking at the genome of all life it seems to be all related. But if I made 5 cakes with the same ingredients and in the way there would be no way to tell if the cakes were made in one batch or 5.
There has never been a life form discovered that appears alien. However this question has not been looked into very deeply. It's a little like saying elephants don't exist if you have only looked in North America. (I know there are elephants in North America but I'm assuming wild, non captive animals only.)
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I've heard it argued that looking at the genome of all life it seems to be all related. But if I made 5 cakes with the same ingredients and in the way there would be no way to tell if the cakes were made in one batch or 5.
There has never been a life form discovered that appears alien. However this question has not been looked into very deeply. It's a little like saying elephants don't exist if you have only looked in North America. (I know there are elephants in North America but I'm assuming wild, non captive animals only.)
Possibly life on earth did have a few goes and will after we destroy it making it unable for present life to live here, possibly the mechanism for life will change, not requiring protines any longer. Maybe DNA will not require RNA in the future, who knows! who knows what really existied here on earth prior to DNA.
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I believe that the initial life forms on earth were predators. They consumed the materials around them and did not create new materials such as plants do. The ones that survived this initial feeding period may have eliminated other less aggressive feeders. Had there been multiple starts in life, the ones to survive were the ones not eaten.