This answer only deals with evolution and no meteorites. Just delete it
and you will not have missed any meteoritic information.
Steve Dunklee, I'm not jumping in the discussion about the existence of
aliens but you are making a few mistakes.
- A change every 10 minutes for one billion years doesn't add up to 53
billion changes, that would be only 53 per year. The real number is
53000 billions.
That is only for one cell. You have to add in the diversification that a
planet teeming with life adds to the numbers. How many microbes inhabit
this planet?
Every cell division gives two new cells and after 1 billion years there
should be 2^53000000000000 cells, more than enough that some should give
rise to humans with a merely 3000000000 base pairs in the DNA strain.
When life got more complex it invented sex to speed up development by
mixing and fusing different DNA strains. (That humans have turned sex
into an amusement park is just an abomination of it's true purpose!)
:-)
Ok, that is a looong stretch that a cell should give rise to complex
multi cellular life. I just threw out some big numbers like you did.
Your argument only dealt with one strain of microbe while my numbers
puts no upper limit to the numbers of microbes (biomass). The truth lies
somewhere in between but I leave that for the biologists to work on.
- The other mistake you are doing is to say that there is 4^3000000000
combinations of the human genome. If you change too much of the genome
it isn't a human any longer. Just change 5% percent and you could end up
with a chimpanzee. A bit further and you have a mice. Even yeast shares
a lot of genes with humans.
More than half of the human DNA seems to be made up of junk. Repeated
expressions, inactive parts left overs from evolution and remains of
viruses.
Whenever a complex being is reproducing it will change a lot of
different base pair, not only one. As a proof, look at the divergence
between chimpanzee and humans. 5 million years created a 5% difference
between our species. If we take a simplistic view and translate that
into base pairs even though it isn't that easy to compare. (It is moved
parts, added sequences, removed sequences and changed parts.) we have an
approximately difference of 5% of 3 billion, or 150 million base pairs
over 5 million years, or 30 base pairs per year (15 per specie). Not
that big a number at all.
So I don't find any problems with the reproduction rates compared to the
complexity of our DNA.
Btw I believe there is life in other places of the universe but that is
only a belief. I have no proof of existence or absence. The only thing I
know is that we soon have the tools to detect traces of life if it
exists in our stellar vicinity.... and that the scientific debate
following a possible find will make the meteorite list seem dull.
:-)
/Göran
Steve Dunklee wrote:
the fastest reproducing micro organism has a reproduction rate of once every
ten minutes.
http://en.wikipedia.org/wiki/Microbe
this reproduction rate if there was one change in dna every ten minutes would
result in just shy of 53 billion different combinations in a billion years.
different combinations of dna.
the oldest life on earth is 3.5 billion years ago but the change to multi
cellular organisms was only about 1 billion years ago with stromatolites.
the human genome has 4 to the 3 billionth power of genetic combinations in
its dna and a reproduction rate of once every 9 months. as species become more
complex the reproduction rate decreases.
http://www.madsci.org/posts/archives/1998-12/912824618.Ge.r.html
4 to the 3 billionth power is way over the possible 52 billion combinitations
assuming one change every ten minutes which we all know is impossible.
the only possible explaination of the complexity of the human genome and other
forms of life on earth is that life could not possibly have formed on earth.
there has not been enough time! even at one surviable change every ten minutes.
at one change every ten minutes it would still take over 2 billion years.
http://www.madsci.org/posts/archives/1998-12/912824618.Ge.r.html
http://en.wikipedia.org/wiki/Microbe
http://www.abc.net.au/news/newsitems/200606/s1658283.htm
I know I don't have all the answeres but it's hard to ignore real science of
reproduction rates as compared to our dna. and the amount of time it takes for
reproduction to occure.
In short we are the aliens!
eve a great day!
Steve
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