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Author Topic: Are we still evolving?  (Read 13709 times)

Offline valley

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Re: Are we still evolving?
« Reply #25 on: 11/06/2004 20:45:12 »
Hello to you all, just got here, thought I'd jump straight in with a controversial one...

Does anyone else worry that, with the increasing use of reproductive techniques such as IVF, we may get to the point (admittedly this'd be way off in the future) where we cannot breed naturally? I heard that French bulldogs can't give birth naturally due to their large heads and therefore all need Caesarian sections, not nice. Oops, sorry, digression (is it true, anyone know..?)... Anyway, if people are infertile due to genetic reasons, isn't it rather selfish to use such techniques with the knowledge that the problem is likely just being passed down to the next generation, so that your own child has the same heartache when coming to try to reproduce? If we should have any worries about losing envionmental constraints that would normally keep up evolutionarily topped-up then surely this is the biggie.

By the way, yes I realise that infertility is horrible and can lead to great despair and psychological trauma; I lived with someone through their failed round of IVF and the time when her sister had to abort a very damaged IVF baby :(
 

Offline chris

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Re: Are we still evolving?
« Reply #26 on: 15/06/2004 10:01:27 »
Yes, I think you are probably right. We are indeed storing up trouble for ourselves by helping genes, which would historically have been eliminated from the pool, to slip through the net into successive generations.

I sincerely hope we don't end up with a world where everyone is born by caesarian section - in my experience most people view caesarian as an easy option. The fact is it consitutes major abdominal surgery with many risks by immediately and in the longer term.

I'm also not sure we've got evidence on the long-term effects of birth by caesarian in children either. There may be a physiological benefit to being squeezed out the normal way...

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Offline concordsonata

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Re: Are we still evolving?
« Reply #27 on: 17/06/2004 05:06:16 »
Valley: "French bulldogs can't give birth naturally"

Dogs are an excellent example of selective breeding gone crazy. Many of the most popular breeds have been damaged to the point where they are plagued with indigenous conditions due to inbreeding and overbreeding. (And the big ones are way too big. The dogs that flourish in the wild -- gray wolves, coyotes, red foxes -- are smaller than Labs and Golden Retrievers, never mind guys like Bernese Mountain Dogs!)  Dog shows that give medals for "best of kind" are perversely rewarding genetic nondiversity!

I believe that many of the concerns discussed throughout this thread are legitimate, and most of the posters know a lot more than I do! Just thought I'd toss this out as, ummm, a bone of contention.
 

Offline chris

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Re: Are we still evolving?
« Reply #28 on: 17/06/2004 08:18:11 »
I completely agree with your point about dogs - the clear advantage that a mongrel has over a 'pedigree' dog speaks for itself.

However, the dog breeds we see represent extreme selective pressure in which animals are bred to 'concentrate' specific traits within the breed. This has the disadvantage of simultaneously concentrating many maladaptive (harmful) alleles (genes).

You do see this kind of phenomenon amongst groups of humans who tend towards consanguinity (being incestuous). It is particularly prevalent where small (religious) groups are isolated within a larger community and so only tend to marry each other. As a result certain disadvantageous traits may become increasingly common within the population. The Amish, Hutterites, and Ashkenazi Jews have all been affected in this way.

Chris

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Offline qazibasit

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Re: Are we still evolving?
« Reply #29 on: 25/06/2004 16:43:26 »
Ya we are still evolving and there are two types of changes
1. short term
2. long term
Short Term
   The short term changes is the acccimitization at high altitude in which the body produce more number of RBCs coz at high altitude the oxygen is deficient.

Long Term
 You see the arabs have long nose just to cope with the environment of desert to filter the air.

 

Offline neilep

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Re: Are we still evolving?
« Reply #30 on: 25/06/2004 20:04:56 »
Why don't we all just agree to meet here again in one hundred thousand years and see what (if any) changes there are in us ?....I'll set my alarm:D

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Offline qazibasit

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Re: Are we still evolving?
« Reply #31 on: 26/06/2004 16:27:03 »
cross fetilization marrying different ppls of different races also cause evolution.
 

Offline roberth

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Re: Are we still evolving?
« Reply #32 on: 27/06/2004 08:41:53 »
I also think that "cross fertilisation" will enable us to take advantage of the positive evolutionary traits from both races to create a more superior species. It also has the advantage of making us a bit more the same and reducing the racism that has existed for many generations.
 

Offline qazibasit

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Re: Are we still evolving?
« Reply #33 on: 01/07/2004 18:02:54 »
but now as the genetic engineering is going common the scientists are able to add or remove the different characters form the fetus.
 

Offline daveshorts

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Re: Are we still evolving?
« Reply #34 on: 24/03/2005 22:02:35 »
As, to a fairly close approximation, all children survive to adulthood, isn't the only selection pressure how many children people have?

 So isn't the major selection pressure at the moment an inability to use contraception properly, a tendancy to sleep around irresposibly, or possibly belonging to a religious sect that emphasises prolific breeding? I am not sure I like the long term implications of this, or any conceivable solution to them.
 

Offline Ultima

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Re: Are we still evolving?
« Reply #35 on: 26/03/2005 12:59:33 »
Wow loads of peeps talking and I missed it :(

quote:
Does anyone else worry that, with the increasing use of reproductive techniques such as IVF, we may get to the point (admittedly this'd be way off in the future) where we cannot breed naturally?


This is exactly the argument for allowing people under going IVF to have a greater freedom in "selecting" the child they want, to prevent negative traits continuing.


Someone mentioned that we will probably evolve to avoid obesity, diabetes etc. I don't know about this, as is there any study to show any genetic trait leading to people becoming obese?? Plus obese people (up until a certain point) don't have much of a problem "breeding", the same with people with diabetes it is perfectly manageable with insulin.


The only major thing I can see in the future of our evolution is a separation in our species with possible super intelligent (enfeebled) peeps and brawny average intelligence peeps. With the clever people having to sacrifice yet more physical presence to allow oxygen to their massive pulsating brains :D and then relying on everyone else to provide for them… Similar to how colonies of insects have specific roles, such as queens, guards and workers. We already have this in our society now with many family generations continuing a particular role such as with the Army or being a Doctor. Taking the insect model further, isn’t there more women being born now than men, and more men being infertile than before?? Or is this an urban legend.


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Offline akuba

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Re: Are we still evolving?
« Reply #36 on: 28/04/2005 02:53:47 »
quote:
Originally posted by chris


The other point you make John is that people are mixing their genes so widely these days as to rule out in-breeding. This is certainly untrue, largely thanks to our old friend religion. There are many examples of well-known and well studied genetic diseases that crop up in people of certain religions, such as Islam, because individuals from that faith insist on marrying their cousins and other close relatives. Other groups include the Amish, and Jewish faiths.

Chris



Actually, I read it is OK to marry your first cousin.  The precenatge of possible birth defects from it is only 2%  and I read Darwin himself was married to his first cousin.
« Last Edit: 28/04/2005 02:54:24 by akuba »
 

Offline realmswalker

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Re: Are we still evolving?
« Reply #37 on: 28/04/2005 23:42:25 »
For evolution to work one trait needs to provide that organism with the ability to reproduce more or cause it to reproduce less.
In our current society it seems anyone can have children, they just need to find someone else who wants to.
Yes obesity might be gross and definatly doesnt aid someone in reproducing more, but it doesnt prevent them from having kids either, as an obese couple and a skinny couple will probably have around 2-3 kids.
 

Offline Andrew K Fletcher

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Re: Are we still evolving?
« Reply #38 on: 29/04/2005 10:47:08 »
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Re: Are we still evolving?
« Reply #38 on: 29/04/2005 10:47:08 »

 

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