

Ask HN: Are we undermining our own evolution? - ryanwaggoner

We've all seen numerous documentaries and stories about the marvels of modern medicine available to us, and on a personal level, I think almost everyone would agree that these are positive developments.  But by short-circuiting the natural mechanism of evolution that helps weed out these weaknesses, are we undermining our own future evolution?<p>A simple example: infertility treatments.
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tokenadult
A lot of people talk about dysgenic trends that they imagine must be happening
because the weak are being protected from having their genes eliminated from
the human gene pool. But few notice that the data show improvements in
phenotype that are so large in effect size that they can't even be explained
by ENORMOUS favorable changes in gene frequencies.

<http://books.apa.org/books.cfm?id=431712A>

[http://www.springer.com/statistics/social/book/978-0-387-949...](http://www.springer.com/statistics/social/book/978-0-387-94986-4?detailsPage=toc)

The simple empirical fact is that human ingenuity and shared cultural
knowledge is improving the human condition faster than any process of natural
selection of genes could, and we can all join in on that, whatever genes we
have. And it won't be too long before we can start manipulating the genes of
our descendants, if we so choose.

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biohacker42
We are long past the point of evolution as it applies to all other life.

And I don't mean that in some crazy pseudo science way.

Consider the human brain. Did you know human infants fall intellectually
behind chimpanzees of the same age.

Eventually humans overtake but it's several years late, how come?

It's because our brains are so huge that we can be born without them getting
all mashed up. Our skull plates are flexible and they do to a newborn's brain
what would instantly kill an adult.

But our brains are adapted to deal with that, we survive and fully recover,
catch up to and surpass other great apes.

But birth is STILL problematic for us humans, so we invented cesarean section.

A medical procedure which was already common by the time Cesar was born.

And ever since all the knowledge society can come up with influences who
survives.

This kind of group level evolution is not unique to us, a lot of social
animals have aspects of that But we're unique in just how much our
intellectual innovation matters.

Short answer, we're selecting for brains and not much else. And that's a good
thing.

Chimpanzee's have a much better immune system then us, but they're endangered.

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russell
I think not. Darwin had a second theory of evolution by sexual selection, and
it may be the more important. It's selection, not by the jungle, tooth and
claw, but intraspecies mate selection. I think a lot of human activity is
driven, directly or indirectly, by mate selection: Wall Street Money,
superstars, Nobel prizes, boring jobs in IT. I have read reports that human
evolution has its afterburners on. Curing disease and helping the less able is
irrelevant, because it's overshadowed by all the other competition going on. A
century ago, the pool of potential mates was limited by your home town or
county. Now you have college, world wide travel, and the internet.

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bprater
I guess it depends on what "good" evolution looks like. Should evolution be
humans that can procreate most efficiently?

In general, I think the question is 'yes'. Because all humans can "connect"
with all other humans in society, it doesn't leave pockets of evolution to
take hold.

I suspect that in the next few hundred years, as real space journeys become
normal, that we may see evolution start to do it's thing again.

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ericwaller
It's not possible (by definition) to "short-circuit" or undermine evolution.
Modern medicine is our species acting within the process of evolution. Just as
we consider early humans to have "evolved" the ability to use crude tools, we
have "evolved" the ability to use penicillin, brain surgery, etc.

"Survival of the fittest" is a useless tautology. An organism's evolutionary
fitness, if there were such a thing, would be its ability to survive to
reproductive age. So of course the fittest survive, we've defined fitness to
mean survival.

In reality it's the species that has an evolutionary fitness; and the
distinction is important. Take a bee colony for example, a huge number of the
bees are infertile.

To address your example: infertility treatments may catalyze an evolutionary
process of selecting against those who are disinterested in child rearing. Or,
like the bee colony, infertility in some members of the species may be
evolutionarily advantageous; hard to imagine, but not without precedent.

~~~
Allocator2008
"In reality it's the species that has an evolutionary fitness".

Sorry but no. Read "The Selfish Gene" by Richard Dawkins. Selection does NOT
act on the level of a bee colony, it acts on the level of the individual genes
to be found within that colony. So sure some bees are infertile, but they are
in service of the genes of the fertile bees. They are in effect enslaved by
the genes of the Queen bee for instance.

Some types of ants will raid the colonies of other ants, and kidnap their
children, bring them back, and the kidnapped children were grow up in
service/servitude to the colony which had kidnapped them, and join in on
future raids of what was once their home nest. The kidnapped ants are in
service to their captors, to the genes of their captors. Say for instance the
kidnapped ants were black, and their captors were red(or the other way
around), so, even though the kidnapped ants do not have the "red" gene, they
are helping to promote the selective advantage of the "red" gene by joining in
the hunt for the colony of their captors. It is not a matter of "colony a"
being selected for over and above "colony b". It is rather the genes of either
colony getting selected for over other genes. All life, from viral to the
naked apes like us, are subject to "the tyranny of the selfish gene".

~~~
ericwaller
Strictly, the evolutionary fitness of an individual is the ratio of that
individual's genes to all of the genes in the subsequent generation.

What Dawkins is likely saying (I haven't read the book), is that we can (or
even should) forget about individuals and just look at relative gene
frequencies (b/w generations); we'll see that some are selected for and some
are selected against. And that this is actually the level at which evolution
occurs.

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conanite
Evolution often occurs when due to changes in the environment (climate change,
new diseases, new predators) vast numbers of the species die off. The marvels
of modern medicine are a less traumatic alternative.

For example, if evolution were to have its way, HIV should kill off those
humans who lack the CCR5 gene. This would be bad news for most Africans and
Asians, as well as up to 95% of people of European descent.

The deletion mutation of CCR5 in Europeans is possibly an evolutionary
adaptation to mediaeval European plagues - the Black Death and smallpox. (see
<http://en.wikipedia.org/wiki/CCR5> )

We don't have a moral obligation to evolve. I'll stick with medicine,
personally. As well as clothes, houses, electricity, supermarkets, central
heating and air conditioning.

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noodle
just want to point out that this would be the plot to the movie "idiocracy"

<http://video.google.com/videoplay?docid=1597642154209383351> (naughty
language warning).

~~~
ryanwaggoner
Added to my list :)

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arram
It's irrelevant. We'll have perfect control over our bodies and genes within
500 years, which in evolutionary terms is a very short time. We don't need
natural selection anymore.

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raquo
Not only medicine undermines biological evolution. Evolution works in such a
way that those who make more children become dominant. 'Many children' is not
one of the values of our society, so people whom our society values most do
not drive the evolution.

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triplefox
We are cyborgs. Our technology is not orthogonal to our biology.

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pasbesoin
I'd just point out that it depends in part on the time scale you apply. If
things get "dumber" for a while, a compensating circumstance is likely to
arise. Whether you view it as positive or negative is subjective; it will
occur.

I don't take that on faith. Rather, it's my prediction based on all the
historical and scientific data and analysis we've accumulated.

What gives me some hope for our current circumstances and our own species, is
that so far, as education and affluence rise, birth rates drop. If we can use
this to mitigate the pressure of increasing population against dwindling
resources (including the health of ecosystems), perhaps we can reach a
sustainable existence with regard to the earth and its ecosystems. Our
species' evolution will continue, but hopefully in a sustainable fashion.

Life has shown itself to be very pervasive, at least on this planet. If we
fill the world up with radiation, heavy metals, organic toxins, and whatnot,
some forms of life will adapt to cope. But I'd prefer that there not be such a
large set back. Not another "great extinction". Life on the planet has reached
an interesting level of complexity. I'd rather see that continue on without
interruption. But then again, that is merely my subjective preference.

