Thread: Natural Selection

First of all I dont wantr this to become religous or a questioning of Natural Selection.

If your answering this thread you consider Darwinian Evolution to be correct

Now
Human beings
Natural Slection works because of selection pressures
99% of which come from the environment, we have effecitvely taken ourseleves out of the environment
Thereby reducing the number of selection presures greatly
not only that, for those who become burdened by selection pressures, like genetic diseases, we have created medicines,
Science can either keep them alive or at least keep them alive longer enoguh to reproduce and pass on those genes.
Someone with a smaller brain is just as likely to reproduce as sum1 with a larger one.
therefore, we can see that the brai nsize is not going to increase due to natural selection
So the question I am asking is this.
Have we as humans effectively ended our evolution?
Discuss
Imran

For one, we have not "removed ourself" from the environment. We are still bombarded with viruses and bacteria every day and our immune system works to fight it. Sure, medicine helps us. But people who cannot survive against these things are being "weeded out." Also, our technology has in fact not stopped evolution, but it is increasing it I think, for some part. We are growing taller, healthier, smarter, and ability to live much longer. This is all due to better nutrition and eventually leading to better genes which are being passed on. How about more attractive people? This is a product of natural selection. More attractive people reproduce with more attractive people and this is an aspect of "evolving" as well. Becoming strong and attractive makes you more likely to reproduce.

Originally Posted by ataraxis

We are growing taller, healthier, smarter, and ability to live much longer. This is all due to better nutrition and eventually leading to better genes which are being passed on. [/b]

It doesn't work like that. We are just realizing the potential that was already in our genes, not improving genes and passing on traits. That is Lamarckian evolution which has been disproved, not natural selection.

By saving individuals that would otherwise die, and with their subsequent reproduction, of course this increases the percentage of otherwise detrimental genes in the population. However, this also allows some possibly beneficial genes that these individuals may be carrying to be propagated as well. If some of their offspring inherit the "good" genes but not the "bad" genes, they and the population have benefitted. Think about if Stephen Hawking had a smart kid that didn't have the tendency to get the disease that he has.

OK, so the population expands and the weaker individuals survive and breed when times are good. This can be applied to any population, not just our current situation--humans are just an extreme example of this. Ultimately, there will be a contraction of the population due to die-off of some kind. In that case, the individuals who are the most fit for the new environment will be the ones to survive. This may include some individuals who were the product of the previous "good times" that allowed for even the weak to live, and who gained beneficial mutations from their less-than-perfect ancestors.

So, even tho there are traits amongst us that would have been selected against in a natural environment, it doesn't matter. It's not like they dilute the good genes so much that if some catastrophe causes natural selection to start working again, everyone will die. And it can allow for beneficial mutations that would otherwise have been lost to accumulate.

Disagreed
becuase for every atractive erpson that reproduces with annother attractive erpson an non-attractive erpson reproduces with another non attractive eprson
therefore making human beings less attractive aswell?
No what i mtrying to say is, better genes arent being passed on, practically all genses are being pssed on
a person with a very very low intelligence is just as likely to reporoduce as someone with a high intelligence a person with a poor bone structure is also just as likeyly to reproduce as someone with a good one
As survival of the fittest no longer really holds true for humans it seems most genes sall be passed on, not just the advantageous ones,
If your a lion and your not strong you may be killed before you can reproduce, allowing stronger lions
if your not strong and your a human, your not gonna get killed, your gonna lead a normal life and reproduce

Im saying we have either stopped it
or greatly decreased the rate at which it is happening.

Imran

Natural Selection is a totally passive process. What lives (and reproduces), passes the 'test'. It is as easy as that. You could say natural selection is gone now. However, is it? How do you define natural selection? Natural selection doesn't 'create' living things that are good at surviving, it just happens.

In terms of 'good at surviving' natural selection, humans start to suck more and more. I think 25% of the people today would die if placed (born in) a prehistoric conditions. I for instance wouldn't see a bear if it ate my hand off, my eyes are pretty bad. So are my moms, ect.

However, lets say in 2100 only Smart people get to have children. Smart people that do well in society. Doesn't that mean 'survival of the fittest'? Best equipt to survive in an environment. It would be a sort of selection too, only unnatural perhaps, but whether it is natural or not really doesn't matter.

Basically, natural selection that leads to people are are physically great at surviving in the woods, that is dead. Natural selection on looks and smarts somewhat remains, but not like being stupid kills anyone.

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One could say, that to prehistoric-survival-standards, and maybe to any standards, the human race is getting 'weaker' and 'weaker'.

I though about that, and kind of understood why Nazi's were bitching about an uber-race. I however do not really understand, and thus disagree with 'lets create uber-people and shoot handicapped people', WHY one should want super-selection and WHAT is the 'use' of a super-race, or just plainly averagely 'better' humans. What is really better about some dude with genes to be a great, smart athlete? I don't know. I think some people would think it would rock, but would tigers be that jealous? Everything is relative, so I don't care or the human race is 'crap' or not, who defines crap anyway? =)

I do believe it is over for us. Atleast until a global catastrophe hit, e.g. global warming. Then all species would fight to survive and favorible traits will be passed on. I do think that were stable now.

Don't be expecting any of us to have psychic powers anytime soon.

I reckon we're in a nose dive towards extinction in terms of medicine. It's a constant battle between technology and the evolution of diseases. In this context i think it should be high on humanity's priorities list to start putting a lot of energy into researching and putting into use genetic modification to protect our children from genetic diseases (I know, a lot easier said than done physically, economically, philosophically and politically... but come on Gattaca was awesome&#33

Ideally we would at this stage have a world government (again good luck&#33 and we could then focus our attention on finding other planets to colonize to cope with the population explosion!

Bottom line, our intelligence is our greatest survival tool, so we should not be afraid to use it!

Its my belief that Natural Selection is no longer really applicable to Human Society. Because of the advances in Genetics/Medicine, its more like "un-natural selection" Its already started getting into that area where foetus's are being screened for major genetic conditions, and being got rid of if they have anything seriously wrong. This will lead to a similar sort of process as natural selection, but over a much much smaller timeframe. Ever seen the movie GATTACA? This is exactly what could happen.

And then, because of human relationships and society, we have progressed to a stage where the typical "good genes" i.e. the ones more related to survival, are no longer being favoured in the same way that they used to, because more or less anyone can survive in the world today (and yes, I do realise that the third world countries have much lower survival rates, so there is some degree of natural selection, but as they improve themselves, it will decrease greatly)

However, 10,000 years ago humans developed the ability to process lactose, and that gene spread like wildfire. Perhaps sometime in the next few hundred years, a similar process will happen, giving such a huge survival increase, that it may spread through the population in a similar way. But then again, it may not. No-one can really tell the future afterall!

natural selection was never apart of mankind. there is evidence that pre-homo sapiens took care of their elderly and sick. since they came before us its believed we carried on their culture - a community culture were we look after eachother.

the sick and elderly were never left behind - the same cant be said for even the most social animals. as for wars and battles, well, who died first? people with weak or strong physical genes? people with strong physical genes right? they were the ones carrying the clubs getting smashed to death, and everyone else was getting away with their lives

this is why to this day, and every day since we lived in caves there is only ONE human race. natural selection really occured only once, and it was between our human race and the others. we won, they lost and are now extinct.

Originally Posted by pxb

Its my belief that Natural Selection is no longer really applicable to Human Society. Because of the advances in Genetics/Medicine, its more like "un-natural selection" Its already started getting into that area where foetus's are being screened for major genetic conditions, and being got rid of if they have anything seriously wrong. This will lead to a similar sort of process as natural selection, but over a much much smaller timeframe. Ever seen the movie GATTACA? This is exactly what could happen.

And then, because of human relationships and society, we have progressed to a stage where the typical "good genes" i.e. the ones more related to survival, are no longer being favoured in the same way that they used to, because more or less anyone can survive in the world today (and yes, I do realise that the third world countries have much lower survival rates, so there is some degree of natural selection, but as they improve themselves, it will decrease greatly)

However, 10,000 years ago humans developed the ability to process lactose, and that gene spread like wildfire. Perhaps sometime in the next few hundred years, a similar process will happen, giving such a huge survival increase, that it may spread through the population in a similar way. But then again, it may not. No-one can really tell the future afterall!
[/b]

thank you, you basiclaly said what i intended to say
and you did it far more jsutice than me lol
I must admit, science is my weak point.

Imran

All creatures are constantly adapting to their environments. This even includes the sudden temperature changes recently (I honestly don't think it's global warming... YET). Even when global warming kicks in in full-force, humans will have already adapted to the intense heat that comes with it. And don't even think about bringing up the whole "but the Earth will flood!" thing - it's estimated that the ultimate rise in worldwide sea level will only be about 2.5 feet. Even us here in the Silicon Valley will be safe from those effects.

If the Russians have learned to live in intensely freezing weather, we can learn to live in extremely hot weather.

And even if we can't do that naturally, we can do it unnaturally - weather control systems don't look like they're too far off into the future. A part of natural selection is not only adapting to your environment, but also using things that will HELP you adapt you your environment. The fact that we humans can MAKE those things as well is a bit of a perk, wouldn't you say?

Anything's possible, but nothing's been getting done because everyone's been moping about, sitting on their butts, saying "We humans are screwed!" It's only NOW that anyone's really trying to do anything about it, as the global warming issue is being addressed on the news for what seems like the first time in years.

We're not so screwed after all, because our potential is nearly limitless.

Though I wouldn't say that human evolution has completely halted, I agree that we are in a way cheating natural selection and survival of the fittest, and replacing it with survival of the richest. Though in some cultures it still exists more, in wealthier western culture we are treating "problem genes" with meds, therefore not stopping them from being passed on. This isn't a bad thing, as it means less people die needlessly, but it in a way does inhibit natural selection. I don't think it causes any devolution for people because a more attractive friendly, outgoing person has an easier time finding a mate still, but evolution will probably slow down as people become more capable of adapting the world to their needs.

it's survival of the nerdiest my friends! that's right. think about it. cell phones were invented after an idea some dude saw in Star trek. now, every boobpsy on campus has one. what about genetic engineering and test tube babies. where did this come from???? nerds, people.... NERDS!