Re: Is the complexity of evolutionary change explainable?


hrvoje-d wrote:
These articles did *not suggest otherwise. They clarify that the
mutations are random, and natural selection "chooses" from the
currently available variety. They certainly *did evolve immunity to the
antibiotics. What they did not do is either of two things:
1. They did not have a greater than normal mutation rate.
2. They were not predisposed to have mutations which would be useful
under the circumstances.

I don't count selection of exsisting information under "evolution" if
an chromosome contained a gene for green eyes for example and green
eyes became an imperaty of survival - then green eyes will be selected.
But how do you get new information for purple eyes? If you could only
change 1-2 nucleotides by mutation of an 250 million of them.

You do not understand the experiment described. For micro organisms
the population tested arises from a single non resistant bateria. They
are all clones. They should be genetically identical except for new
mutations that occur during growth of the population. The existing
variation in this population occurred during the propagation of the
bacteria into a large enough population to screen from a single cell.
They were screening for new mutations that had occurred within a very
few generations. Luria and Delbruck did an experiment to determine
when such mutations occurred in the growth of a population and found
the incidence to be "random." In some populations the mutation
occurred early, but as you might guess in most others the mutation
occurred later when there were more dividing cells and more chance for
mutations to occur.

The addition of the antibiotics did not affect the mutation rate or the
chance of any particular bacteria having the needed mutation. The new
mutations were arbitrary with respect to their potential function.

Real populations do have existing variation that is the results of
mutations that may have occurred a very long time ago. If a population
exists for a long enough time you reach a mutation selection balance.
In reality this is probably never reached due to changing environmental
conditions, but the prediction is that a lot of genetic variation will
accumulate in any population whether this variation has a selective use
or not. All evidence suggests that the new mutations are arbitrary or
"random" with respect to function.

What we are finding when we compare fish genomes with other vertebrate
genomes like humans is that novel genes are very rare if ever present.
You have to ask what you consider a novel gene. There are gene fusions
(parts of two existing genes getting stuck together), but mostly it
looks like existing genes get duplicated and their function is altered
slightly to do different things. You do not have to create an entire
gene from scratch. It looks like you just have to take existing
information and change it slightly. Gene duplications are very common
even between closely related species like chimps and humans. Genome
comparisons tell us that this is a major source of what you seem to be
calling new information.

Ron Okimoto


I can show you the algorithm it is a classical genetic algorithm that
IS close to the natural processes. And you certanly must agree that in
theese 250 million genes there are specific groups of genes that
control features that humans had to change to addapt (loose the tail,
change the complexity of the brain, loose hair, cahange the
construction so they can stand straight") and all that in a 1-2 million
generations. And the algorithm has to set 200 bits to approach the
maximum and fails. Randomness is randomness it doesn't matter is it
simulated or natural.


I am aware of benefits of genetic algorithms in genetics but, as I have
seen they don't deal with mutation, only with selection:

http://evolution.berkeley.edu/evolibrary/article/0_0_0/bergstrom_01

If you found one that simulates evolution (or a simple model of it)
using natural mutation rates, please show it to me.

.

Relevant Pages

  • Re: Humans did not have gill slits
    ... Natural selection: ... Mutations provide new information however. ... It's not evolution until they become turkeys or some other bird? ... J. Genetics, 55:511-24.] ...
    (talk.origins)
  • Re: Humans did not have gill slits
    ... Natural selection: ... Mutations provide new information however. ... It's not evolution until they become turkeys or some other bird? ... J. Genetics, 55:511-24.] ...
    (talk.origins)
  • Re: Does anybody want to proofread and criticize a 7000 plus word
    ... Statistical Probability in the Evolution of Mendelian Populations ... selection of slightly advantageous mutations that frequently recur, ... biased gene conversion, and some elements of neutral molecular ...
    (talk.origins)
  • Re: Humans did not have gill slits
    ... How do they "go against" biolgical evolution, ... Natural selection: ... which comes from mutations, and recombination of traits. ... There are no genetics textbooks which claim this. ...
    (talk.origins)
  • Re: Can any old earther refute common genetic ancestry?
    ... And mutations include point substitutions, ... As there are billions of such observations this is powerful support for the factuality of common descent with modification through the agency of natural science and other processes. ... The same holds for DNA sequences of homologous genes, or for the gene contents of organisms. ... In the past genetics assumed that a gene expressed for single well defined trait or function. ...
    (talk.origins)