Re: How many ways are there to make a human species?

"r norman" <r_s_norman@xxxxxxxxxxx> wrote:
On Tue, 09 Jun 2009 22:43:33 +0100, rossum <rossum48@xxxxxxxxxxxx>
wrote:

Every one of us has different DNA, that is why DNA forensics and
paternity testing work. Even identical twins have slightly different
DNA because of individual mutations. So I thought it might be
interesting to make an estimate of how many different ways there were
to put together human DNA to make a human being. I look at three
elements:
1. We each have a different combination of chromosomes from our
parents.
2. We each have some neutral mutations.
3. We could have had a different set of parents.

<snip all the details>

4 The Answer
------------

<snip>

3.43 x 10 ^ 1018.


5 The Point
-----------

Partly for fun, partly to show that evolution does not have to hit
single target rather any one of many many similar targets but mainly
so that when a creationist waves a REALLY BIG NUMBER at you, now you
have your very own REALLY BIG NUMBER to wave back at them. :)


Sorry, your calculation isn't even as convincing as the bogus ones
used by IDers. Besides, with a diploid genome of 6 billion base
pairs, there are more than 10 to the 8 billion possible genomes so
that the probability of random mutations producing one of your humans
still is less than 10 to the negative 8 million.

Their REALLY BIG numbers are an awful lot biggerthan yours!

The moral: Don't try to answer bull*** with bull***. They are an
awful lot better at it than you are.

Of course you can always answer a bull*** question with another
bull*** question. So I will ask, in how many ways could the Designer
produce a human species? Our species has roughly 18,000 genes
arranged in a particular order on 23 chromosomes (+1 for Y and
+1 for the mitochondrion). But the order seems to be more or
less arbitrary, as is the number 23 for chromosome count. As far
as we know, the Designer could have created humans with 16
chromosomes or 37. The genes could be in a completely different
order. And still the creatures would still be in the Designer's image -
two arms, two legs, hair on the head, no hair on the palms, social
but bossy, taste for red meat, reaching puberty in 12-15 years, etc.

Only thing is, one of those 16 chromosome humans probably wouldn't
be able to breed successfully with our kind of 23 chromosome humans.
Inability to do the crossing-over thing during meiosis. So these variant
human species really would be different species.

So how many such species could there be? Same genes as us, but arranged
into a different genome. Lots. But to simplify the calculation, lets just
count the number of species with the same number of chromosomes as
us and the same number of genes per chromosome. But the genes are
just in a different order. Ah! That calculation is easy. How many different
orders can you find to arrange 18,000 genes? The answer is 18000
factorial. I think you will find that the number is considerably larger
than the 10^1018 that the OP calculated.

The point? The Designer could have created man with his 18,000 genes
arranged in any of 18000! different ways. Yet She chose to create us
with our genes in an order which just screams out to us, "Hey, you idiots!
You are cousins to chimpanzees."

.