This Modern Life and the New Humanity
While I live in a country where 40-50 percent of the population thinks that Evolution is a strange and threatening idea in the same vein as Vaccines or Gay Marriage, there’s still iqnuiry within the scientific comunity as to how evolution is effecting our daily lives. This was apparently the hot-button topic at this month’s meeting of the American Association of Physical Anthropologists in Chicago.
“For most of the last century, the received wisdom in the social sciences has been that human evolution stopped a long time ago,” Harpending said. “Clearly, received wisdom is wrong, and human evolution has continued.”
Several anthopologists posit a scenario where evolution has not just continued, but is speeeding up due to sheer number of breeding people an an increase in the amount of external pressures placed upon humans.
The massive AIDS epidemic that’s raging in southern Africa , for example, is “almost certainly” causing gene variants that protect against HIV, the virus that causes AIDS, to accumulate in the African population, Harpending said.
When he was asked how many genes currently are evolving, Harpending replied: “A lot. Several hundred at least, maybe over a thousand.”
Another anthropologist, John Hawks of the University of Wisconsin-Madison , said, “Our evolution has recently accelerated by around 100-fold.”
A key reason, Hawks said, is the enormous growth of the world’s population, which multiplies the size of thegene pool available to launch new varieties.
“Today, beneficial mutation must be happening far more than ever before, since there are more than 6 billion of us,” Cochran said.
The changes are so rapid that “we could, in the very near future, compare the genes of old people and young people” to detect newly evolving genes, Cochran said. Skeletons from a few thousand or even a few hundred years ago also might provide evidence of genetic change.
So while it’s doubtful you’ll evolve a mutant healing factor in time to costume as Wolverine for this week’s movie premeire, I am actually pretty fascinated by the idea that there may soon (if there aren’t already) discernable genetic differences between generations. So while every generation always treats the next as a horrible alien species – monsters with different ideas and music and goals – what if one day that’s actually true to the point where they couldn’t even successfully interbreed?
[Via Yahoo! News]
Interbreed? Why would we want to? ew.
Mitch: Ha!
This reminds me of something I read a couple weeks back:
http://www.latimes.com/news/la-sci-jewish-iq18-2009apr18,0,3315759.story?track=ntothtml
It’s about a theory which suggests that various cultural pressures forced Ashkenazi Jews to develop higher average intelligence, but also left them with a relatively high frequency of some rare genetic diseases that affect the brain.
Of course it’s difficult to prove, but on the surface the reasoning seems sound.
Oh – that’s a touch muddled. Lions and tigers could mate and produce offspring.
We’re a bit more plastic a species.
by “a touch” you mean “very”?
As cool as this sounds from an author’s point of view, it is actually woefully ignorant. This isnt how evolution works at all. as a matter of fact, higher populations are one the signs of a dip in evolutionary speed. Its called “weak stabilizing selection” or “neutral selection” depending on whether you are talking to a biologist or an anthropologist. The fact that people live long enough with HIV to reproduce means that it isnt a stabilizing factor because it didnt stop you from reproducing.
I dont think that a 100-fold increase in evolutionary speed is even possible without reducing our reproductive age to 3 months old.
Also selection for single (100, 1000, 2000 etc. ) genes at a time doesnt happen. Life is an all or nothing game. either all your genes produce viable offspring, or none.
As far as skeletal differences over a hundred years go, that is just plain impossible at a species level. Evolution takes thousands of generations to produce even miniscule morphological changes across a population under strong selection. and that only changes things like the type of cell surface receptor that handles how you process sugar overloads. This leaves little room for skeletal differences in the time that any anthropologist can be paying attention. Speciation events are “impossible” over single generations, barring examples like mules which are sterile.
Weak stabilizing selection means that the slow, retarded rabits dont die because they can still put grass in their mouths just because the foxes arent around. Take that metaphor to people, and add in a little bit of Heinlein’s comeptent man if you want to see where the future of evolution is.
If it comes as a surprise to anyone that most people think that evolution is strange and weird, consider that the other 48% think that evolution is something other than what it is. Apparently even among people who really ought to, at least in a professional sense.
also, there is no such thing as a “beneficial mutation”, just mutations. what helps you fight cholera yesterday, causes cystic fibrosis today.
genes are like the future: it’s not worse, it’s not better, it’s just different (and interesting)
I can’t imagine us encountering a generational breeding block anytime soon without an intervention like adding artificial chromosomes of the direction like the things Gregory Stock talked about in, “Redesigning Humans”.
As Aubrey said, the fact that many sickly people live long enough to breed suggests to me that a lot of things aren’t being pressed strongly as far as selection goes. AIDS to use the example given. Considering the virus actually doesn’t always pass from an infected mother to her child, the children will often live to an age where they can reproduce, regardless if they’ve any immunity to the illness or not. They may then be infected later through any number of ways… hygiene, drugs, intercourse… blah blah blah.
Ah well, I stepped out of the gene pool a few years ago. Unless anyone knows of a science group that’s looking for genetic donations for sequencing and use, I’m outside of this game. LOL
midare: if you are looking to give up your genetic rights, I can think of handful of places that would be glad to take them. Of course the consequences of that may include the entire movie GATTACA
Echoing Aubrey’s statements. I’ve got a stale Genetics degree gather dust in a drawer somewhere and even I’m seeing holes you could drive a Mack truck through.
These folks are watching too much Heroes. Mohinder is not a real geneticist, he just plays one on T.V.
@all really – This is one of the things that fascinate me. The differences in the concept of Evolution between various strains of Anthropologists and the like and how it’s approached in (I don’t want to say Hard Sciences, I really don’t) Genetics and Biology.
I keep seeing a lot of these articles about short-term evolutionary pressures, and half of my reading list says they are not just possible, but probable, and the other half declares them bunk.
(And then more Mohinder jokes, which I never get tired of because that damn character’s nonsensical lectures is one of the reasons I could never watch that show.)
But there seems to me to be some sort of break in the dialog between the disciplines that work with the evolutionary sciences. Sadly, I don’t have enough grounding in any of them to pinpoint where that disconnect is, but I’ve seen this happen enough to recognize there is one.