Thursday, November 23, 2006

Surprise! It Looks Like We Are Not All the Same Genetically, After All

Recent research published in Nature, Nature Genetics and Genome Research shows that humans can be significantly different from each other, genetically--a fact that has been strenuously denied by social scientists for decades. The new genetic map, a Copy Number Variant (CNV) map, indicates that instead of being 99.9 per cent identical, humans can vary genetically by up to 10%.

One person's DNA code can be as much as 10 percent different from another's, researchers said on Wednesday in a finding that questions the idea that everyone on Earth is 99.9 percent identical genetically.

They said their new version of the human genetic map, or "book of life," fills in many missing pages and chapters to explain how genes are involved in common diseases.

....Instead of showing single variations in human DNA that make people unique, the map looks at differences in duplications and deletions of large DNA segments known as copy number variants or CNVs, which can help explain why some people are susceptible to illnesses such as AIDS and others are not.

"We're a patchwork of DNA sequences, gains and losses," Dr. Charles Lee of the Brigham and Women's Hospital and Harvard Medical School in Boston, Massachusetts told a news conference.

Scientists from more than a dozen centers around the world identified about 3,000 genes with variations in the number of copies of specific DNA segments. The changes can affect gene activity, including susceptibility to diseases.

The Human Genome Project mapped the billions of letters that make up the human genetic code. Scientists later refined the map by looking for single variations called SNPs or single nucleotide polymorphisms.

The CNV map gives researchers a different way to look for genes linked to diseases by identifying gains, losses and alterations in the genome.

"We estimate this to be at least 12 percent of the genome, similar in extent to SNPs. This has never been shown before," said Dr. Matthew Hurles of Britain's Wellcome Trust Sanger Institute.
Source.

CNV mapping is a different way of looking at the human genome which can more powerfully elicit genetic differences between humans and between humans and other animals. CNV maps may help explain the differences in aptitude and behaviour in different populations, including genetic differences that may explain different degrees of success.

This will place even more stress on western liberal values of egalitarianism, but as long as the primary focus of equality is equality of opportunity and equality before the law, the problems can be worked out. Only when society attempts to guarantee equality of outcomes does egalitarianism become completely unworkable--given the genetic differences in aptitudes and interests between groups of people--even between genders.

Excerpted from a post at Al Fin blog.

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