“We are more evolvable than ever before” claim geneticists, according to an article in Wired Science 29 November 2012. Joshua Akey of the University of Washington and colleagues has done a large scale survey of human genes, looking for rare mutations – variations in DNA that are found in less than one in one hundred people. The research team studied protein-coding genes from 6,515 people, and found 1,146,401 variations. They then used these to calculate how many generations ago the variations occurred, and concluded that rare variations were relatively recent, with some 73 percent of all genetic variation arising in just the last 5,000 years.
Because the variations are recent, natural selection has not had time to work on them, but according to Wired Science, “As a species, we are freshly bursting with the raw material of evolution”. Akey explained: “Most of the mutations that we found arose in the last 200 generations or so. There hasn’t been much time for random change or deterministic change through natural selection. We have a repository of all this new variation for humanity to use as a substrate. In a way, we’re more evolvable now than at any time in our history”.
Many of the variations found in the study seem to be potentially harmful, and the researchers suggest they have remained in the population because “Population growth is happening so fast that selection is having a hard time keeping up with the new, deleterious alleles”. Alon Keinan, a population geneticist at Cornell University commented: “Humans today carry a much larger load of deleterious variants than our species carried just prior to its massive expansion just a couple hundred generations ago”. The Wired Science article went on to say: “Natural selection never stopped acting, of course. New mutations with especially beneficial effects, such as lactose tolerance, still spread rapidly, while those with immediately harmful consequences likely vanished within a few generations of appearing. But most variation has small, subtle effects”.
Editorial Comment: One expert in genetics sent us his comment on this item as ‘Interesting research with “stupid” conclusion’. We agree! The claim that most human variations have occurred within 5,000 years and most are potentially harmful, does not mean we are “bursting with the raw material of evolution”. Mutations are a sign that the human race is going downhill, not evolving upwards. If mutations were really the raw material for improved, more highly evolved humans then the environmentalists and medical scientists who protest loudly against mutation-causing chemical and radiation pollution should be shouting for more pollution.
In fact, these findings fit with the Biblical history of the world, i.e. recent creation of human beings with fully functional genomes in a very good world, followed by degeneration because the environment became corrupted by human sin and God’s judgement. If you want to know how many generations may have passed since the beginning see the question: Adam’s Family Tree: Between Adam and me, how many “greats” go before the word “grandfather”? Answer here.
It is interesting that lactose tolerance is now being proclaimed as a beneficial mutation. Lactose tolerance is the ability to digest lactose, the sugar in milk, in adult life because the chemical switch that turns off the production of the enzyme needed to digest it is defunct, so instead of turning off the production of in childhood when suckling is completed, (as happens in the majority of the human race) it continues to be made into adult life. People with this mutation can continue to make use of fresh dairy products. However, it is actually the result of loss of a functioning gene, not the addition of a new one, and is not evolution. (Ref. genetics, disease, DNA)
Evidence News 12 December 2012