Reply
Wed 12 Dec, 2007 08:41 am
This article says that Human evolution is accelerating.
But I'm wondering what they mean by "Evolution" exactly. I can see a lot of variation going on due to the population increase mentioned in the article. But is there really much selection going on?
Without a corresponding amount of selection, can we really call what's happening "evolution", or is it just a whole lot of genetic drift?
I haven't read the article yet, but it also seems like greater genetic drift could be kind of the opposite of evolution -- the world is less lethal, in general, so more variety is tolerated. (That is, a "weakness" doesn't prove fatal because it can be accommodated in one way or another.) But I guess that's a form of evolution...?
Hmm, read the article and it wasn't what I expected.
Pondering...
First, i would point out that the article refers to an acceleration in "evolution" in the last 5000 years. That is not unreasonable, nor is the premise they advance, which refers to the development of agriculture and "resistance" to diseases. However, the reference to disease "resistance" is misleading. There really is no way to know if people are more resistant to diseases in the last 5000 years than they were in the preceding 25,000 years. (Edit: the article says that the time when genetic changes took place can be pinpointed--but can the disease environment of 30,000 years ago be accurately and comprehensively described?) However, what can be stated with a reasonable amount of certainty is that the capacity of human society to deal with disease has increased--although for most of the last 5000 years, the means of dealing with disease has almost always been quarantine; but whatever the method, any means which effectively curtails the spread of disease can be considered a useful adaptation, even if taken in the midst of a lot of superstitious nonsense about the origin of disease and effective means of dealing with it.
I remain skeptical about the impact of agriculture, as well. While agriculture allows people to give up a nomadic lifestyle, i doubt very much that it resulted in a more varied diet. Hobbes famously observed that life in a state of nature is "solitary, poor, nasty, brutish, and short." Settled agricutlure perhaps makes life less solitary, but there is no good reason to assume that it is any less poor, nasty, brutish and short, until quite recently in human affairs. I would point out that life for the boys and girls up at the temple and the palace probably involved a good deal more food than your average peasant, and that therefore, their lives might have been longer, and less solitary, poor, nasty and brutish. However, the record of history with regard to the behavior of priests and kings does not suggest to me that their lives and the lives of those upon whom their powers impinged was any less nasty or brutish--once again, until quite recently in human history.
Although i am not qualified to argue the validity of their conclusions about diet and disease resistance, i would point out that evolution operates through breeding opportunity. Given that until quite recently (only within little more than a century), less than half of all children born survived childhood, with much higher death rate from malnutrition and simple exposure to filth among the less well-off classes, i think they are rather naively making a point about life for those on the top of heap, rather than those at the bottom. No amount of improved disease resistance is going to save you if malnutrition has destroyed your body's ability to resist disease, and ignorance prevents you from taking those daily sanitary measures which will help you to avoid exposure to disease.
Soz says that the world is less lethal. I understand what she means, but i would state that in another manner--our ability to mitigate or avoid the lethality of our world has improved. I have long maintained that we have removed our evolutionary future from our bodies, and deposited it in our schools, libraries and research facilities. That point of view on my part is not changed by this article. This article refers to the last 5000 years. The researchers may well be correct with reference to the last 5000 years, less the last century. We now stand at the dawn of an age in human history in which we are able to effectively deal with nearly every danger of the natural world around us, or to better survive the consequences of that danger, or better recover from the effects of that danger. More than anything else, we have destroyed much of the natural world around us, and erected our own beneficial environment around us. We don't know what the long-term consequences of that will be, since it has been such a relatively short period of time that this has been true.
So, i have no reason to doubt the claims of the researchers. I have my doubts, however, about the significance of this information for humans living in the early 21st century. The world we inhabit now is radically different from the world of the first agriculturalists. We don't yet know what the consequences of that fact will be. Perhaps we will have created a situation in which "evolution" slows down; or speeds up. We just have insufficient data to make a reasonable judgment about how evolution will play out for humans now.
Just heard a weekly science program on CBC on this very topic. There was a gentleman discussing this study, but unfortunately, i can't tell you his name, because i wasn't paying attention until i realized what topic they were discussing. However, he makes a similar point to mine. This data is good over thousands of years, but cannot tell us anything about the implications for human evolution going into the future.
Oh, and he obliquely made the point about "genetic drift"--that there's no evidence that this process continues (or that it doesn't), but that the implication of the increasing homogeneity of the human race is that most genetic changes are matters of individual detail and not matters of survival or breeding opportunity.
Would it not be safer to say that as a longer term predictive mechanism it would be more likely that further acceleration in human evolution* (perhaps I should call it human change) will come from manmade influences such as genetic engineering and cybernetics?
* "Beneficial genetic changes have appeared at a rate roughly 100 times higher in the past 5,000 years than at any previous period of human evolution, the researchers determined." (source as quoted)
All bullshit.
Darwin used the words "unimaginable periods of time"
Don't you trust him or something?
Are you not up to speed on the science?
There's nothing anyone can say on this subject that isn't bullshit but I daresay Setanta was favourite in the betting to provide the biggest pile of it at about 20 gets you 1.
Quote: I have long maintained that we have removed our evolutionary future from our bodies, and deposited it in our schools, libraries and research facilities.
So is the act of building a university then 'evidence' of evolution?
What of societies that have no universities, not even a written language?
Are they less evolved than we?
How does the building of a university change one's genetic makeup?
Seems like a rather Lamarckian POV.
You demonstrate once again just how dimwitted you are, "real life." The hominids survived and prospered not because they were faster than the predators in their environment, nor stronger, nor equipped with better teeth or claws--they survived because they exploited pattern recognition, binocular vision, color vision and cooperative hunting and gathering methods. They survived and prospered because they eventually created languages (whether or not written).
So, the point which you missed, and probably due to the sheer magnitude of your ignorance and lack of intellectual subtlety, is that we have removed the confines on our memory and perception which were imposed by capacity of our skulls, and the capacity of the skulls of our fellows. We know have available to us repositories of memory and the functionalities of perception which are greater by orders of magnitude than our individual or even clan or tribal capacities.
This enables us, for example, to develop medical techniques which assure the survival of individuals who were once doomed by disease or genetic malformities never to reach reproductive age.
But i'm never surprised when you give new evidence of your complete failure to understand the implications of a theory of evolution.
I've no problem agreeing that education benefits man in a number of ways.
But the word 'evolution' refers to a genetic/biological process.
You've not shown how education alters man's biological makeup to cause him to evolve any differently.
If you still maintain that it's so, then please answer: are humans that live in societies with no written language and no universities to be considered 'less evolved' than you and I ?
You can't have it both ways , Setanta. If education is part of evolution, then face the consequences of your view.
Mathematically it makes sense, since extra alleles are presented at a greater frequency by merely increasing genetic exchange . As Population explodes extra alleles are presented and reinforced. This only gives the appearance of speeding up as f(time), when actually its f(critical mass).
In the fossil record increased diversity always followed(or paralleled) increased population within a clade.
Used to be we were taught that genetic changes were only perpetuated (selected for) if they provided a survival advantage.
So the evolutionists taught us.
But that was too limiting (i.e. evolution wouldn't work if that was the case) so now we are told that genetic changes are 'selected for' if they provide a survival advantage OR if they are neutral (i.e. they provide neither advantage nor disadvantage).
But as we all know, genetic changes that are a distinct DISadvantage get passed down thru thousands of generations. Genetically based diseases, birth defects etc are not occurring with LESS frequency (which would be the case if they were being 'weeded out' ) .
So pretty much we see that a genetic change (good, neutral or bad) may be considered to have been 'selected for' (except when it is not) for just about any reason we care to pin to it.
That is the great benefit of evolution. One may selectively apply evolutionary principle where it is wanted and ignore it when it proves inconvenient.
It's unfalsifiable.
Long ago in my lifetime, I seem to remember that mutation happens at a steady rate, something like 1 in 10 to the 6th. Whether that mutation is effective or useless in some organism's term life on earth would show up, or not show up, in the genetic parade of evolution. What I don't remember knowing anything about was if things could affect this usual mutation rate (radiation for example)..
Since I think of mutation as being the core element of what turns out to be evolution, I wouldn't think it was accelerating or decelerating, but that the effects such as described by farmerman are consistent with the survival benefits of some portion of routine mutations.
ossobuco wrote:Whether that mutation is effective or useless in some organism's term life on earth ............
How 'bout harmful?
That's the option evolutionists don't want to talk about.
Far more mutations are harmful than beneficial.
So just run the numbers and evolution is a loser's game.
Even mutations that may be beneficial have to show up at the right time in history, in the right organism (one that has the benefit of other beneficial mutations that will serve to combine into an ultimate benefit) or they are STILL useless.
Consider trying to evolve an eye.
It would take multiple beneficial mutations to produce even one of the sub-structures of the eye, such as the lens; or the retina; or the orbit ( a whole in the skull to accomodate an eye); or the eyelid........
ALL of those beneficial mutations have to show up in the same critter AND at the right time.
What good would a retina be without a pupil?
Take a look at the eye.
http://www.myeyeworld.com/files/eye_structure.htm
In what order did these structures have to appear to be useful?
Yet evolutionists want us to believe that the eye evolved not just once, but DOZENS of times independently.
real life wrote:
Yet evolutionists want us to believe that the eye evolved not just once, but DOZENS of times independently.
Yet creationists want us to believe that it all happened in a couple of days when an omnipotent fairy waved his magic hand.
Quote:What good would a retina be without a pupil?
, I dont think that, in this case , the question of "what good would one be without the other"? the fossil record is loaded with examples of one without the other, eg crystalline eyes, and compound eyes, and we have many living primitive creatures that get along nicely with no variable focal mechanism in their eye. I believe the evolutional consequence of the existence of a feture is :use it or lose it"
The apparent paradox that genetics presents to you RL is something that is explained quite nicely wrt to evolutional theory.
real life wrote:What good would a retina be without a pupil?
What good would pelvic bones be in a whale... but there they are.
Evolution helps us understand something like that. Creationism on the other hand just leaves us shrugging our shoulders saying, "god works in mysterious ways". Not very useful.
rosborne979 wrote:real life wrote:What good would a retina be without a pupil?
What good would pelvic bones be in a whale... but there they are.
Evolution helps us understand something like that. Creationism on the other hand just leaves us shrugging our shoulders saying, "god works in mysterious ways". Not very useful.
How many generations do you suppose it took mammals to lose their legs in their move to the sea, ros?
Do you really think that successive generations of critters with smaller and less functional legs experienced a 'survival advantage'?
Kinda mysterious too. But I suppose all things are possible to them that believe.
(Trying to picture cow with no remaining legs only feet....................nah wouldn't work. Easy steak dinner for any predator, even a slow one.)
I guess you don't keep up with scientific news real...
Missing link in whale evolution found