Re: Human Evolution Speeds Up

Jeffrey Turner <jturner@xxxxxxxxxxxx> wrote:

http://news.yahoo.com/s/livescience/20071210/sc_livescience/humanevolution
speedsup;_ylt=As9rYWbo1SuSzECSYRQuljgE1vAI

Human Evolution Speeds Up

Andrea Thompson
LiveScience Staff Writer
LiveScience.com Mon Dec 10, 5:02 PM ET

Our Stone Age ancestors were more genetically similar to Neanderthals
than they are to us, as our species has evolved 100 times faster in the
past 5,000 years than at any other time in human evolution, a new study
indicates.

Conventional wisdom has held that human evolution slowed as modern
humans emerged and even stopped with us, but genetic data is now showing
that the opposite is true, with aspects of our cultures, such as diet
and medicine, and the ballooning human population pushing the gas pedal
on the evolution of our species.

Anthropologist John Hawks of the University of Wisconsin-Madison and his
colleagues analyzed data from the International HapMap Project, which
works to catalog the genetic similarities and differences among humans
from cultures around the globe—this map of genetic variation can give
insight into changes in human genes over time.

New genes

DNA is constantly being reshuffled via recombination, so researchers
examine genetic changes over evolutionary time by locating long
sequences of DNA variations—because they are uninterrupted, they seem to
have been positively selected for over time.

Hawks and his team found evidence of recent selection on approximately
1,800 genes, or 7 percent of all human genes.

One example of such a gene is lactase, which helps people digest milk.
The gene normally declines and stops all activity in the teen years,
said Hawks. But northern Europeans developed a variation that allowed
them to drink milk their whole lives—a relatively new adaptation that
resulted from domestic farming.

The biggest new pathway for selection relates to disease resistance,
Hawks said. As people started living in large communities about 10,000
years ago, epidemic diseases such as malaria, smallpox and cholera,
swept through and changed patterns of human mortality. As a result,
humans with genetic adaptations for resistance to these diseases were
selected for.

As much as I respect John Hawks, this is not new. One-time t.o denizen
Marc Buhler researched a particular gene that arose in the northern
European population and spread down Viking trade routes along the river
systems to central Asia which conferred (and still does) limited
resistance to plague, smallpox and now AIDS.

The "conventional wisdom" here is conventional only outside the genetics
community. And evolution has not "accelerated" - it's just that with
larger populations there are more mutations and a more diverse range of
selective sweeps. The rate of evolution remains, so far as I know,
constant.
--
John S. Wilkins, Postdoctoral Research Fellow, Philosophy
University of Queensland - Blog: scienceblogs.com/evolvingthoughts
"He used... sarcasm. He knew all the tricks, dramatic irony, metaphor,
bathos, puns, parody, litotes and... satire. He was vicious."

.

Relevant Pages

  • Human evolution
    ... The claim counters a common theory that human evolution has slowed to a crawl or even stopped in modern humans, since in modern society the survivors no longer have to be the fittest, and is based on data from an international genetics project that can chart how evolution has shaped mankind over the past 40,000 years. ... In a study published in the Proceedings of the National Academy of Sciences, a team led by University of Wisconsin-Madison anthropologist Prof John Hawks suggests that humans are in the evolutionary fast lane and many changes in our genes are driven by the dramatic rise in population, culture, changes in diet brought on by the advent of agriculture, and resistance to epidemic diseases that became major killers after the growth of human civilisations. ... "This is always a tough question, because selection depends on the environment and our environment has been changing," he explains. ...
    (uk.philosophy.humanism)
  • Re: Are you Conscious?
    ... without relying too much on the precise sets of genes and neuronal ... Sociobiology and evolutionary psychology take ... Genetics and molecular biology have provided some significant insights ... alot more leeway for their theories of human evolution. ...
    (sci.bio.evolution)
  • Re: News: Four Ways We May, or May Not, Evolve.
    ... Human Evolution Is Dead ... Natural selection, as outlined in On the Origin of Species, occurs ... Steve Jones, a genetics professor at University College London, put ... advanced the technology gets, ...
    (talk.origins)
  • Re: Humans did not have gill slits
    ... Natural selection: ... Mutations provide new information however. ... It's not evolution until they become turkeys or some other bird? ... J. Genetics, 55:511-24.] ...
    (talk.origins)
  • Re: Humans did not have gill slits
    ... How do they "go against" biolgical evolution, ... Natural selection: ... which comes from mutations, and recombination of traits. ... There are no genetics textbooks which claim this. ...
    (talk.origins)
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