9th February 08:56
Can current environment effect "natural selection"? (diabetes)
Hopefully. Some of these diseases, like cancer, are an inevitable
result of our biology. So people will always get them, but we'll
hopefully be able to cure or treat the disease. In the case of
diabetes, one day we may be able to vaccinate against it. Others, like
hypertension, need not exist today. Exercise and proper diet could wipe
that out today...
Some people have evolved resistance to malaria. Sycle-cell anemia
represents one such advance. If you have one copy of the sycle-cell
gene you're as close to immune to malaria as you can get. However, if
you get two copies of that gene you get sycle-cell disease. There are
many other mutations which have induced resistance to malaria; some are
totally harmless to humans if they get it in 2 copies.
As for how we know if a gene provides resistance, it's simple. You look
for people who are resistant to a disease (say people who make it
through a large outbreak without getting disease) and then use
conventional genetic mapping techniques to identify genes which are
associated with surviving the disease. Given enough time, and enough
people getting sick, you can identify the resistance gene(s).
Yes. If you are not exposed to a pathogen we've evolved resistance to
can lead, over many generations, to a loss of that gene. The reason
being that there is no longer disease selecting for the gene, so there
is nothing to keep in in the population. If the gene also has
deleterious effects, the gene may even be "forced" out of the population
by natural selection.
They're not expressed, ever. Junk DNA just sites around, and doesn't
encode for any genes.
Not really. At times genes or chunks of DNA will get duplicated during
cell division. This can make copies of a gene which can then evolve
into something else. But we do not receive "new" DNA from outside our
bodies - all we get is what mom & dad give to us.
Bacteria are an example of the opposite. Many bacteria can import new
DNA from other bacteria, thus giving themselves "new" genes which come
from other species.
A lot of the diseases we suffer from now (diabetes being a good example)
have existed for a long time. They simply were very rare until recently
as people did not live long enough for them to form, and didn't have the
lifestyle to increase the risk to the levels we have now. So our longer
lives are one of the reasons these diseases are more common, and the
other half of the equation is they way we live now (notably diet). But
the underlying genetics have been around for thousands, if not hundreds
of thousands or millions, of years.
In our lifetimes, not much. It takes hundreds or more generations to
see significant genetic change, so modern technology isn't likely to
have genetic consequences for a long time yet.
The obvious exception being genetic engineering. That allows for
No for genetic material, yes for natural selection. Exception to the
'no' being genetic engineering.
Highly unlikely. Also, there is no such thing as "reverse evolution".
Evolution only goes forward, and if our current technology is driving
evolution "backwards" - meaning that we're loosing previous adaption,
then we're loosing those adaptations as it is an advantage to us.
9th February 08:57
Can current environment effect "natural selection"? (malaria)
Yes, can it be thought that diabetes2 is a predisposition or greed to
overeating and living sed. lifestyle? Till we actually lose normal
production of insulin, or till we become alike type1 or till we start
losing weight, we may control BG levels by diet and excercise. But it
may not be in our normal control. Why then we don't give such medicines
which resist us to overeat or encourage us to do physical activities?
Is it at the cost of getting bigger disease? I think it is not normally
evolved resistance or due natural selection?
Btw malaria or few other regular infections can also be due to some
biochemic imbalances/ac***ulations and may be meant to balance
those..as NaCl? Can we get these balances and feel better after restore
Getting resistances on natural selection due to exposure of these, may
be other favour to our offsprings.
How we will get such resistances if we shall be immediately and
regularily treated midway of getting natural selection prepared for it?
Why many generations? Can't it happen in next genaration by "natural selection" route?
Means all of our genetic material already become polluted to current
and past environmental effects?
How reversal of past and present environmental effects mutated in our
genes can take place on reversal of environment?
Can it reverse evolved resistances gained by them? Whether resistances
of bacterais can be reversible considering their shrt life? Why we don't try it?
We may need greed of food so been evolved previously. It can be a
normal evolution. But current environment can be responsible to use
such evolved property excessively? When we go to some remote natural
area even for short period, sometime such greed or excessive cravings
or effect of overeating don't truble to diabetes. How?
Can't it be possible via "natural selection" route?
Ok, can modern introductions make our offspring resistance to their
adverse effects via "natural selection" route? Will natural selection
recognize and process such adversities in view of that these
introductions are not very old?
Natural selection process behave according to exposed environment to
people. If there is no impression of diseases due to modern
introductions because instantly and regularily treated by modern
interventions, how natural selection can process modern introductions?
Does it not make our offsprings to lose such possible resistances to
survive naturally under modern environment?
Thanks and regards.
10th February 00:15
Can current environment effect "natural selection"?
Some of it. Not necessarily all of it.
-- David Wright :: alphabeta at prodigy.net
These are my opinions only, but they're almost always correct.
"If you can't say something nice, then sit next to me."
-- Alice Roosevelt Longworth