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Human Genes Still Evolving
MediumFormat writes "The New York Times is running an article that discusses the continuing evolution of human genes. From the article: 'The genes that show this evolutionary change include some responsible for the senses of taste and smell, digestion, bone structure, skin color and brain function.' Darwin Awards aside, what made people think that evolution stopped with the modern era?"
Evolution involves the death of weaker individuals before they can breed. With soap (the yardstick of civilisation), surgery, rescue helicopters, dentistry, wheelchairs etc, weaker individuals aren't killed off so easily before they can breed.
Environmentalism is the new Victorianism. Everyone ties on a green corset and pretends we're virtuous.
I think it will be really interesting to see what happens to humanity (genetically) over the next several thousand years. The article makes it sound like bioinformatics could really take off in an effort to better ourselves by artificial selection.
A number of things have changed that will greatly impact our evolution that hasn't been experienced by our species before:
1. Ease of migration allowing for extreme mixing of previously separated social groups (this has been in decline over the last few thousand years, but now that you can travel between continents relatively quickly and cheaply, the impact will be much much greater.)
2. Knowingly allowing, accepting, and encouraging reproduction of individuals, who...shouldn't (No, I don't mean Bush). There's some bad genes out there. Some that shouldn't be passed on. While we're at a point where we can curtail some of this through prescreening parents for likely inherited traits, we continue to become more accepting of people with, well, bad genes. Aren't we effectively letting people piss into the pool?
3. Will this spawn a new race (as in car) by parents to "maximize" the brain genes described in TFA? Do I have to listen to soccer mom's brag about their kids DNA now?
4. How will this impact governments? And more importantly, dating websites?
I guess only time will tell.
I think that article isn't seeing the forest for the trees.
In fact, natural selection has clearly operated at a huge scale, when Europeans settled every corner of the globe, while indiginous populations have disappeared or mingled. Genes associated with those Europeans have spread, while many others have nearly disappeared.
This is an example of group selection, and it has selected many genes at once; some of them may have helped Europeans in their conquests, others may have just been along for the ride.
On the flipside, medical and environmental advances probably are causing us to lose functions at a massive rate: no need to deal with food-born pathogens if you don't encounter any.
Evolution isn't as neat and simple as "better mammal wins" or "better gene gets selected".
The Chinese are illustrative of another interesting development in evolution: limiting population growth in the absence of high child mortality and in the presence of modern medical technologies and genetic testing. Whatever policies nations adopt in that environment, they'll end up acting as "natural" selection as well.
Some people lead long, healthy active lives and never reproduce through choice, lack of opportunity or possibly just inadequate social skills. Isaac Newton famously died a virgin.
Precisely. And yet Newton undoubtedly had an effect on the general society around him, not least through his work in the mint. The overall population benefited from his labours, although he never himself returned his genes to the general pool.
Lets say, as is generally thought, that Newton had genes which gave him an extreme "geek" factor. This factor benefits the general populace, although the "geek" genes themselves may never be passed on directly. However, the potential for such genes to be expressed is passed on through, for example, Newton's siblings and close relatives.
Evolution works on a macro population level, not just on an individual organisim by organism basis.
May the Maths Be with you!
Darwin Awards aside, what made people think that evolution stopped with the modern era?
The fact that through medical care and technology, we have almost eliminated "survival of the fittest" (better written as "survival of the best fit to their habitat")?
People now live and have children when they would previously have died, either through diseases, or harsh environmental conditions. The elimination of the process of natural selection should see to it that evolution in humans no longer occurs, at least not in any beneficial way. Bad genes that lead to people having chronic medical conditions are not removed from the gene pool by those people dying without producing offspring. Humankind needs to step in with more advanced medical care and gene therapy to replace what was once done by nature.
Just my $0.02 of course!
Most whites have a gene that gives partial resistance to Bubonic Plague, as those Europeans who didn't have it 600 years ago don't have living descendants now.
Will the next big evolutionary change be (partial?) resistance to Bird-flu or Ebola ?
Quidquid Latine dictum sit, altum videtur (anything said in Latin sounds important)
http://www.timesonline.co.uk/article/0,,2087-2058
"According to the study, north European women evolved blonde hair and blue eyes at the end of the Ice Age to make them stand out from their rivals at a time of fierce competition for scarce males."
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But what's in the DNA doesn't correlate particularly well with what we have culturally labelled 'races'. The genetic difference between a European, an Arab, an Indian, a Chinaman, an aboriginal, and a native American isn't all that much, compared to the genetic difference between African tribe A and African tribe B. And yet we consider David Smith and Tanaka Jiro to be of different 'races', while two Africans of far greater genetic diversity from each other we lump together as 'black'.
Real Daleks don't climb stairs - they level the building.
The trend has usually been more wealth/education == fewer children (in the last century at least). Natural intelligence doesn't really factor in.
First link I found on the subject via google.
William of Ockham had no beard. The most likely explanation is that it was chewed off by squirrels every morning.
What many people fail to realize is that it takes "evolution" on the order of tens to hundreds thousands of years to "invent" a gene.
Random mutations have to encode for a new protein that activates in the right cells and "does the right thing". From then on, this is likely to become a "gene": Almost any random mutation will invalidate the protein, and disable the "feature".
Suppose such a new "invention" is not always advantageous. Say, only during an ice age. During ice ages, those carrying the intact encoding for the protein (we say they "have the gene"), will survive best, those that don't have it will drop in numbers. Once such a condition is over (say ice age stops), natural selection suddely starts to favor those that "do not have the gene". Still, as they decend from a population where most had the gene to survive, they remain "genetically close", and the gene will easily activate and proliferate during the next ice age.
A real world example is Sicle Cell Anemia. It is a genetic disease: You're born with or without it. Advantage of HAVING the disease? You don't die of Malaria (you do die of the disease, but most have had children by then).
So depending on the amount of malaria mosquitos around, the percentage of people with the Sicle Cell Anemia gene varies a lot. Natural selection at work!
Now, if you look at 10000 to 15000 years, it is unlikely that "evolution" has "invented" a lot of new genes. That however genes have activated and deactivated is however very likely.
If the "running fast" gene was "mostly essential" 10000 years ago in africa, but now not any more, then natural selection would have ensured that 90-95% of the population had that gene 10000 years ago. Nowadays, there is no longer a selection for-or-against this gene. So, the percentage of the people having the gene will slowly drop (I don't work in the field, I have no idea how fast this goes).
Did you ever notice that different children "don't like" different foods? This is a genetic safeguard to preserve the species. Evolution apparently "invented" that a long time ago.
If five percent of your tribe "Simply doesn't like to eat chicken", and the H5N1 Chicken flue comes around, about 5% of the tribe is likely to survive to pass on a much elevated "don't like chicken" gene.
Most likely the "common knowledge" about what to eat and what not to eat has leveled out the "taste" genes: They no longer significantly influence survival.
but i think the only thing those surveys prove is that the method of calculating iq favors those who are educated
Racial biology has been proven a pseudo-science for quite some time
These beliefs are the exact kind of "politically correct" thinking that holds back research in the area of human intelligence. People are so adverse to labeling each other that they ignore real research that hopes to expand our knowledge of human intelligence. How can we possibly think that different human races could evolve to look so different but did not evolve differently at all internally?
The studies that the GP post mentioned are very, VERY numerous; but I will mention one here. A study done by the University of the Witwatersrand (a liberal college in South Africa) tested hundreds of students using Raven's Matrices. Raven's Matrices are the best known and most researched culturally-reduced tests that we have for rating IQ. They use diagrammatic puzzles with a missing part. You could hardly argue that any level of college education could help you find the missing peice of a puzzle.
It is documented that Sub-Saharan Africans have an average IQ of about 70. African university students scored an average of 84 on these tests, which is about 15 points higher than average which is the same as it is in America and Europe. Highly selected engineering students with extensive training in math and science scored about 103. This is also similar to Europe and America, where engineering students in college generally have IQs of about 15 points higher than liberal arts majors. This doesnt mean that their more intense schooling made them smarter, just that they generally must be smarter to even attempt a more intellectually intense career.
People think of sub-70 scores on an IQ test to mean mental retardation. That is only because among caucasions, people with such low IQ scores generally are retarded as a result of in utero complications. They also often have visible deficiencies in motor skills and speech. Sub-70 IQ South Africans are often technically normal, because that is not a very low score for them.
Thinking of it in terms of mental age, an adult with an IQ of 70 has the mental age of an 11 year old. I could drive, work on the farm, and shoot a gun before the age of 11. Having an IQ of 70 does not make you retarded, it is just that there is a strong correlation in America that people with low IQ are also retarded.
All of this culturally biased nonsense is just that: nonsense. Early IQ test were definetly culturally biased, but that has been fixed for the most part. Asians generally score better on American IQ tests than Americans do, so how could they possibly be culturally biased? And many tests, such as Raven's Progressive Matrices, have nothing to do with education level either.
You cannot fix a problem until you accept that it exists.
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-- All that is necessary for the triumph of evil is that good men do nothing. -- Edmund Burke