Human evolution

[canalon]

Just a few words to react to some what I have read here:

Proof that evolution has not stopped in humans is simply described by average height.

I would not take this as a proof. Average height depend on many things, and genetic is probably not the most important in this case. A better and richer diet, well balanced during childhood is probably the best explanation for this.

Becoming taller is part of becoming bigger. Over time all species when left alone will grow larger. It is called the "Red Queen" hypothesis.

You should read SJ Gould (I think the book was called "the full house" in English) about the trend toward bigger organisms. In short its just not true.
As for the Red Queen Hypothesis (found in "beyond the looking glass", the sequel to "Alice in wonderland" by the way) it is not about organism becoming bigger, it is more about co evolution between organisms, and mostly about the role of sex in evolution.

HTH

Patrick

[biostudent84]

I cite my source for these ideas from Noel T. Boaz, Ph.D. in the book Eco Homo

[canalon]

I cite my source for these ideas from Noel T. Boaz, Ph.D. in the book Eco Homo

Do not believe everything in the books. Gould give a few examples, the most striking is coming from the horses evolutionnary tree. The main idea being that we are lead to believe that ther is a trend increase complexity is because it is impossible to revert below a certain level (statistician call this a skewed distribution ), and that usually the kind of studies that lead to this conclusion were not scientifically sound.... Read the book!

As for the red Queen hypothesis, I read the original book and papers....

Patrick, Ph.D. in bacterial evolution....

[mith]

Pulling rank a little soon aren't you Patrick?

[canalon]

Pulling rank a little soon aren't you Patrick?

Well, maybe

And I don't know if Kyle/biostudent84 sources are rather wrong, or if he misunderstand it, but I had to correct his posts.
Proofs that human being still evolve exist, and I don't think that using something as difficult to interpret as average height (depends heavily on non-genetic factors) is just not helping any demonstration.
Just a reminder to be carefull even with Ph.D: they also make mistakes (even if I'm trying not to )

Patrick

[Wilmer]

I think we are evolving we just don't know it such as people in colder places like the Alps or Tibet are becomings hairer while people in warmer places are becoming less hairy. Something like that more or less.

Haha, that is silly. People from Spain are more hairy than people from Sweden.

We have stopped evolving.
Isolation is required for evolution, to make a human evolve isolate her for several generations in a different environment.

And people from Tibet doesn't get more offspring is they are hairier. They don't survive better if they are hairier. They have clothes.

But our planet is an isolated area, why don't we evolve? Well, bad genes doesn't hinder us from getting offspring. And um...people from Isreal isn't a specific genetical group, they are a cultural group. Humans always travel and mix. Just look at your own country were most people originally are from other places (Europe, Africa, Asia).

Our evolution in the next millenias will consist of heavy mixing. As we get global isolated gene-pools will mix. I bet in ten thousand years pale skin and blue eyes will be rare when those properties just are a lack of genes.

[mith]

Isolation causes speciation, evolution happens irregarless of isolation.

According to Hardy-Weinberg, pale skin and blue eyes should remain if they confer no specific disadvantage.

[Wilmer]

Sure they will remain, but they will be rare.

Let's say you take a group of a hundred people with eyecolorgenes representing those of the worlds population and let them breed with each other. After a couple of generations the population have grown larger. The proportion of the eyecolorgenes would be the same.

So my point wasn't really that blue eyes would disappear. I meant that most poeple in the world have dark eyes and when the world population get more mixed the blue eyed folks would be more spread out. Like when you mix blue sand with a larger amount of brown sand.

Dark iris shuts out more light than a bright therefor dark eyes have sharper sight in strong sunlight. On the other hand bright eyes see better in dimmed light. That's why blue eyed africans are rare.

-edit-

Isolation causes speciation, evolution happens irregarless of isolation.

What does evolution do if it doesn't make new species?

[2small]

Since we're living in a global world and today everyone travels from one place to another, human's greatest evolution is to learn to survive everywhere. As it's a recent possibility for the mass, nobody still knows what are the "best adapted" like. We'll have to wait.

[biostudent84]

Since we're living in a global world and today everyone travels from one place to another, human's greatest evolution is to learn to survive everywhere. As it's a recent possibility for the mass, nobody still knows what are the "best adapted" like. We'll have to wait.

I'm not sure the statement that "everyone travels from one place to another" is completely correct. I read a statistic once that said most people never move more than 50 miles away from the place they were born. Whether or not this is accurate, it is true. And those that move away are very selective in their choice of mates. In another post, I mentioned that I attend Virginia Commonewealth University. This is a school particularly noted for its ethnic diversity...and while I cannot say that I have met everyone on campus, I can say that almost all (but not all all) first and second generation Americans I know here have confided to me that they would never consider marrying outside their ethnicity.

No, I'm not making a blanket statement...but I am saying that this is the general rule among the different ethnicities I have been exposed to. (Indian, Pakastani, Chinese, and Korean are the primary ethnicities I have been exposed to if anyone was wondering )

Part Two! (phew! this guy loves making long posts, lol)

As for "best adapted" I would have to say that anything living today is "best adapted" to its niche. The future will only bring "better adapted" organisms for niches.

Kyle

[2small]

Ok Kyle, sorry for my imprecision. Let's just say that today is easier than never to move away. And it's probable to find different climatological conditions there. That was the point I wanted to remark, not the marriage or sexual relations between people from different cultures. Sorry, I have to go now. I'll continue later.

[geddiknight]

evolution never stops. The only difference with humans is that the "fittest" is no longer the strongest or the fastest. We dont need to hunt animals, but open up t the idea that we now "hunt" money. Many will deny it, but money attracts the "best" ie prettiest mates. Look at any seriously rich person. They have a good looking spouce dont they? For males the "fittest" still means "most able to provide", for the female, it is now nothing to do with being well fed (plump) but to do with being healthiest (slim). This is no coinsidence.

I hate this idea, because i am not rich, but it is true. That does not mean that poor people cant have beautiful spouses, it just means that the richer you are, the more likely you are to have a beautiful wife - or if you are female and attractive, you are more likely to attract rich males.

Just like any form of evolution, there is always a large spread as some seriously poor chap may be really good-looking, popular, famous, whatever and get the top eschelon of partner.

ta