Re: Speed of human evolution

John Sankey said:

"A recent look at mutations that show up in the human genes are
most often related to response to disease and there are a number
of these with recent histories."

Quoted message said:

Agreed, and I'll add smallpox, where the difference in survival
of unexposed North Americans compared to the European invaders
makes it obvious that substantial preselection had taken place in
Europe.

Quoted message said:

But, I'm not sure why you feel that invalidates my point. Good
adaptation to indigenous diet (nutrition) is the best promoter of
disease resistance I know of. By contrast, the gene cluster ASMP
has no known connection to disease resistance. Its demonstrable
speed of selection should be exceeded by nutritional genes
conferring additional resistance against disease.

Quoted message said:

There are several on this group who have argued for a diet that
reflects a million years or more of evolution. The ASMP research
is but one more indication that the human evolutionary timescale
is much, much shorter, perhaps as short as 10k years.

It's also not a one-sided thing. Animals eat other livings things,
which themselves will evolve defences against being eaten. One good
and well-exploited defense is to make whatever eats you ill. The
things animals eat don't just stand still, they fight back. A lot of
the useful medical chemicals we find in plants are the results of such
evolution, such as the hormone mimics in plants which evolved as ways
of upsetting the metabolism of insects which ate them.

Big-brained omnivores which can adapt to a wide variety of food
sources are a relatively recent evolutionary invention. In the last
few million years there must be a few plants and animals which
suddenly started suffering heavy losses because some big-brained
omnivore had started eating them. I wonder if anyone has spotted
recent adaptations by these prey species to make themselves more toxic
to their predators?

--
Chris Malcolm [email hidden] +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]

"Chris Malcolm" <[email hidden]> schrieb im Newsbeitrag
news:[email hidden]...

Quoted message said:

John Sankey said:

"A recent look at mutations that show up in the human genes are
most often related to response to disease and there are a number
of these with recent histories."

Quoted message said:

Agreed, and I'll add smallpox, where the difference in survival
of unexposed North Americans compared to the European invaders
makes it obvious that substantial preselection had taken place in
Europe.

Quoted message said:

But, I'm not sure why you feel that invalidates my point. Good
adaptation to indigenous diet (nutrition) is the best promoter of
disease resistance I know of. By contrast, the gene cluster ASMP
has no known connection to disease resistance. Its demonstrable
speed of selection should be exceeded by nutritional genes
conferring additional resistance against disease.

Quoted message said:

There are several on this group who have argued for a diet that
reflects a million years or more of evolution. The ASMP research
is but one more indication that the human evolutionary timescale
is much, much shorter, perhaps as short as 10k years.

It's also not a one-sided thing. Animals eat other livings things,
which themselves will evolve defences against being eaten. One good
and well-exploited defense is to make whatever eats you ill. The
things animals eat don't just stand still, they fight back. A lot of
the useful medical chemicals we find in plants are the results of such
evolution, such as the hormone mimics in plants which evolved as ways
of upsetting the metabolism of insects which ate them.

Big-brained omnivores which can adapt to a wide variety of food
sources are a relatively recent evolutionary invention. In the last
few million years there must be a few plants and animals which
suddenly started suffering heavy losses because some big-brained
omnivore had started eating them. I wonder if anyone has spotted
recent adaptations by these prey species to make themselves more toxic
to their predators?

"recent" developments in evolution happen over thousands of generations to
be noticeable..
you can actually see evolution happening (and adaption mechanisms as well)
when you go to very short lived species like bacteria or viruses however
(the flu virus being a very prominent example).

one thing that is often overlooked when talking about adaption and
evolution:
it is not a cognitive process of any kind, evolution is made up by two
pieces 1) random mutation 2) selection of specific mutants.

if a species has developed a "new" effective defense mechanism that means:

1) there once was a mutant with that defense mechanism (random mutation)
2) the mutant survived and could reproduce more effective than the "wild
type".
3) the mutant eventually became the new "wild type", the old one was ousted
and became extinct.

[note that this is a rather dramatic example, of course things are not so
simple in real life]

Chris Malcolm <[email hidden]> wrote in part:

Quoted message said:

Big-brained omnivores which can adapt to a wide variety of food
sources are a relatively recent evolutionary invention. In the last
few million years there must be a few plants and animals which
suddenly started suffering heavy losses because some big-brained
omnivore had started eating them. I wonder if anyone has spotted
recent adaptations by these prey species to make themselves more toxic
to their predators?

Many plants have a developed thin coatings of carbaryl and other toxic
chemicals. And many animals have replaced their small amounts of healthy
fats with large amounts of fats that cause disease in big-brained omnivores.
;-)
--
Jim Chinnis Warrenton, Virginia, USA [email hidden]

x-no-archive: yes

Jim Chinnis said:

Many plants have a developed thin coatings of carbaryl and other toxic
chemicals. And many animals have replaced their small amounts of healthy
fats with large amounts of fats that cause disease in big-brained omnivores.
;-)
--

Non feedlot animals? I wouldn't exactly call garbage and grain fed
critters evolved. :-)

Susan

x-no-archive: yes

Jim Chinnis said:

Non-feedlot animals have also changed drastically and rapidly in terms of
their genes. As an example, they produce more marbling of fat in the muscle
tissue than they used to, even when pastured.

That's genetic change in a short time period.

Isn't it due to being supplied with abundantly grass filled pasture, as
opposed to having to search for food?

Susan