I have a theory that I wanted to discuss here and see what everyone thinks.

If evolution is the process of natural selection, i.e. non-adapted life forms dying and being removed from the gene pool, and humanity by its very essence seeks to prevent natural selection, does this mean that the human race will not evolve? Furthmore, are our advancements in technology and culture our own method of evolution? What do you think are the implications, if any, of this cessation of natural law?

Pardon me if this is pothead discussion fodder for some of you, but I can't stop thinking about it.

having lost a few family memebers to cancer, one to aids, and a few from other causes, ive often thought about how great it would be to find a cure for these diseases. but then when i think about how many people die from cancer, aids and other diseases i see it, as cold as this is going to sound, natures way of limiting the population. believe me, i would pretty much give up most anything for my dad not to have called me at 3am to say he just took my stepmother off of life support, but when thinking of these things on the much grander global scale, you cant allow emotions to rule your thoughts.

if there was no cancer or aids or what not, nature would have created other things to cull the herd

You've really got two seperate questions here.

Firstly, I do think that humanity is evolving culturally, and that it is the future of human evolution for the foreseeable future.

And yes, I do think that physical evolution has ceased, with the possible exception that smarter people have a better chance of breeding than ever before in history (nerd power!). But for the most part, I think we're devolving as the stupidest people (at least in America) seem to be the ones who have the most children. Peeing in the gene pool, so to speak.

Generally evolution is driven by competition for resources in the environment. Our technology has overcome this. The second major cause of evolution, if I remember this correctly, is called 'cataclysmic' evolution. That's where there is a major change in the gene pool caused by non-normal events. Like the black death... or possibly bird flu. Or the asteroid that killed the dinosaurs (a mere 3000 years ago according to some learned Texans).

I think we are still evolving, but it is no longer "natural selection" that is driving it. Unless bird flu hits hard. What we will see, in our generation, are custom children grown in artificial wombs. Perfect offspring taken from the parents (or donors) and enhanced before real cell differentiation takes place. No more short, stupid, bald (man I could used this one ), ugly kids. Basically everyone, starting with the rich, will have David Beckham and Jessica Alba sporting MENSA memberships as kids.

PD, I agree that the weak remaining forces of selection (caused by our pathetic culture of morons) are making humans less intelligent as a whole. But, I think we will overcome this through genetic enhancement and biomedical technology.

There will always be dangerous menial jobs for the Epsilons.

why has physical evolution stopped though? because 10,000 years ago we decided we're better than other species and we are designed to rule the earth?

would it seem that at that point we didn't need to evolve anymore?

Changes never really stop, but once humans became entirely dependent on tools our evolution became dependent on material/technical/intellectual/cultural advancements, as has been said here.

Evolution in terms of adaptability is tricky. On the one hand we are more adaptable than ever, but on the other the more we advance the more we threaten our own survival.

No, it's cultural. When we became civilized and decided that letting the weaker in our tribes just die or be killed was "inhuman", the mechanism of survival of the fittest, in a purely physical respect, lost a great deal of sway. And it has continued to progressively lose more sway over time.

in a more general way because this is a complicated matter and i'm in no mood for an extended intellectual dialogue, but i've found that mother nature always finds a way no matter how unlikely it might seem. we can genetically-engineer perfect children but there will likely be some unforseeable design flaw that will come out of that. so what i think will happen is that people will have to change or alter their traditional interpretations of what evolution is and how it takes place.

A lot of you mentioned the flu or another such plague, and I think that has a real chance at decimating our population and "culling the herd" so to speak.

I disagree.
With the massive increases in protein intake in the western world, I think we're going to slowly evolve into a larger species. Caloric intakes are sky high right now, something's got to give. The body will also adapt to this by finding a way to manage weight gain I believe.

There is very little, if any, evolution in the physical/anatomical sense of the word for homo sapiens. Since the agricultural revolution, humans have removed/assimilated all of our competition that exists in nature. This includes trees, deer, bison, cats, dogs, etc. and also any and all diseases. Anything that is a threat to our lifestyle is on the list. A requirement of evolution is that there be several species competing for the same set of resources. Humans don't want to compete with anybody or anything for resources so we either let it live on our terms (whatever it may be) or we overpower it and take full control. So instead of humans evolving to meet the needs of the environment, humans are forcing the environment to evolve and meet the needs of humans.

So to answer your second question C_B, yes, it would seem that we don't need to evolve anymore in the traditional sense of the word. Like I said, we're forcing everything else around us to change, so why would we need to evolve? Evolve to what? We're already perfect. Perfection doesn't need to evolve. This is what we think as a species.



We've endured several flu pandemics and epidemics over the centuries and we're still here. That's not to say that another one can come along and create a real-life version of The Stand.

Eventually mother nature will win. "Mom's comin' round to put it back the way it ought to be."

One of the reasons I ask this is because I'm very curious to see what would happen if we were to evolve, and it's sad to think that it may never happen, that humanity may never change.


Another question: will genetic engineering truly work, or will the natural world "reject" such creations?

Well evolution only really occurs if it there's a new, viable species with enough genetic differences to separate it from another. It doesn't mean that Homo sapiens sapiens goes away, it just means that another Homo is viable and a legitimate population.

It's not something that we're going to just see and read about in the morning paper one day out of nowhere. You have to have some sort of isolation for this to occur most of the time. With the mixing that goes on now, it's going to be tough for that to happen.

But...humankind for 15 million years has evolved, so it's fairly obvious to me that there's no way it's going to stop just because we think we're pretty crafty. We'll eventually change, somehow. My guess is through our advanced diet and medicine somehow.

i see you've read Huxley

That book does propose some possible senerios to the question posed here. I would even say that it's very likely.

Physical evolution hasn't stopped at all. Remember, physical evolution takes place over a lllloooooonnnnnnggggg period of time.

I am pretty sure there is a Major League Baseball pitcher that has 6 fingers. Since he was born into a family with little money and in a country outside of the USA, he couldn't afford the plastic surgery required to remove the finger. These type of mutations are the main ingredient in evolution. For example, if the six-fingered guy suddenly gained some kind of advantage over his five-fingered competitors, he would prosper and the five-fingered people would become extinct.

Because of our advances in technology and medicine we are actually able to alter these mutations to fit what we think humans should look like.

This may make the average person bigger/stronger, but the real "progress" will come from changing the genes in the womb so that diet doesn't matter as much. Once the choice is available, no one is going to choose to have a son under 6'. No one is going to choose to a nearsighted child. Many of our natural faults will simply fade away into history.

Why do we think we're not evolving? It's not really something that happens over night.
Look at how much easier the younger generation takes to computer technology in comparison to older generations.
Frog in a boiling pot scenerio - maybe we're just too close to notice.

I think computer skills have more to do with nurture than nature; I was using computers at the age of eight and my dad started at the age of 48, so there's going to be a gap there.

I realize physical evolution takes a long time, but that doesn't change the fact that our the nature of our society prevents it from taking place. I was just wondering what affect this will have on human society in the long run.

http://www.foxnews.com/story/0,2933,187203,00.html

Study: Humans Still Rapidly Evolving

Wednesday, March 08, 2006

By Ker Than



A comprehensive scan of the human genome finds that hundreds of our genes have undergone positive natural selection during the past 10,000 years of human evolution.

Genes are the instructions organisms use to make proteins. They are encoded in genetic material, usually DNA, and some come in different versions, called "alleles." Positive natural selection occurs when one allele is favored over another due to changes in the environment.

Researchers from the University of Chicago analyzed the genomes of 209 unrelated individuals from three distinct human populations: East Asians from Beijing and Tokyo, Utah residents of European descent and Yorubans from Nigeria.

Each population contained roughly 250 positively selected genes; however, most of the affected genes differed depending on the group.

"This study addresses the question 'Are humans still evolving?', and the answer is 'Absolutely,'" study team member Benjamin Voight told LiveScience.

Other studies have also reached the same conclusion.

Links to history

The new study links genetic changes to major events in the history of our species.

"There have been a lot of recent changes — the advent of agriculture, shifts in diet, new habitats, climatic changes — over the past 10,000 years," said Jonathan Pritchard, a human geneticist at the University of Chicago who led the study.

Many genes were found to be evolving in all three of the human populations studied. The specific functions of many of the genes are not known, but the researchers were able to separate them into broad categories. These categories include:

— Olfaction: the researchers found many genes important for taste and smell

— Reproduction: involved in things like sperm mobility and egg fertilization

— Increasing brain size

— Bone development and skeletal changes

— Carbohydrate metabolism: positive selection was observed for genes involved in breaking down mannose in Yorubans, sucrose in East Asians and lactose for Europeans. Mannose is a sweet secretion found in some trees and shrubs, sucrose is common table sugar, and lactose is a sugar found in milk, which most Africans and East Asians cannot digest as adults.

— Disease resistance and pathogen protection

— Metabolism of foreign compounds, such as exotic plant proteins or animal toxins

A tradeoff

The researchers also found positive selection in four pigment genes important for lighter skin in Europeans that were not known before. Scientists think humans evolved lighter skin in Europe as an adaptation to less sunlight.

In East Asians, they found strong evidence of positive selection in genes involved in the production of alcohol dehydrogenase (ADH), a protein necessary for breaking down alcohol.

Many East Asians can't metabolize alcohol because they carry a mutation that prevents them from making ADH. The new finding suggests that the mutation may confer some currently unknown additional benefit.

The study, which used data collected by the International HapMap Project, is detailed in the March 7 issue of the journal Public Library of Science-Biology.