Canada and the World
Current Events with a Canadian Perspective
Last update
19 November 2010
People are Mutants
Since the beginnings of modern genetics scientists have been trying to figure out how often mutations occur;
now they think they have the answer
According to recent studies, each person has 100 new mutations in their DNA. Almost
70 years ago the father of modern genetics J.B.S. Haldane speculated that this might
be so.
Haldane Pioneered Population Genetics
Jack Haldane, along Ronald Fisher and Sewall Wright founded the study of population genetics; this is the science of how such things as genetic mutations, natural selection, and genetic drift brings about evolutionary change.
In 1935, Haldane studied a group of men in London with hemophilia, a disease that prevents blood from clotting to heal a wound. He came to the conclusion that each human had about 150 genetic mutations.
Sequencing Technology Confirms Haldane’s Estimate
Now an international group of 16 scientists says Haldane was right.
One of the scientists is Dr Yali Xue from the Wellcome Trust Sanger Institute in
Cambridgeshire, England. A news release from that organization (August 2009) points
out that, “Remarkably, the new research, published today in Current Biology, shows
that these early estimates were spot on -
Most of these mutations are quite harmless and cause no ill effects to people’s health or physical appearance.
Chromosomes of Chinese Men Studied
Writing for BBC News (September 2009) Sudeep Chand reports that the scientists “looked at thousands of genes in the Y chromosomes of two Chinese men. They knew the men were distantly related, having shared a common ancestor who was born in 1805.”
Picking up the story the Sanger Institute says “To establish the rate of mutation, the team examined an area of the Y chromosome. The Y chromosome is unique in that, apart from rare mutations, it is passed unchanged from father to son; so mutations accumulate slowly over the generations.”
After many generations, the researchers found there were only a dozen variations, and that only four were “true mutations that had occurred naturally through the generations.”
Medical Research Aided
by Understanding Genetic Mutations
The BBC notes that “It is hoped that the findings may lead to new ways to reduce mutations and provide insights into human evolution.”
Science Daily reports (September 2009) that “Understanding mutation rates is key to many aspects of human evolution and medical research: mutation is the ultimate source of all our genetic variation and provides a molecular clock for measuring evolutionary times scales. Mutations can also lead directly to diseases like cancer.”
Understanding the rate at which mutations occur could lead to ways in which the negative effects of such occurrences might be reduced.
The BBC quotes Joseph Nadeau, from the Case Western Reserve University in the United States as saying, “We are finally obtaining good, reliable estimates of genetic features that are urgently needed to understand who we are genetically.”
Image credit
Geoff Hutchison
Sources
“We are all Mutants.” Wellcome Trust Sanger Institute New Release, August 27, 2009.
“We’re all Mutants say Scientists.” Sudeep Chand, BBC News, September 2, 2009.
“We are all Mutants: Measurement of Mutation Rate in Humans by Direct Sequencing.” ScienceDaily, September 1, 2009.
© Canada and the World, October 2010
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“J. B. S. Haldane (above in 1914) was one of the great rascals of science—independent, nasty, brilliant, funny, and totally one of a kind.”
Stephen Jay Gould
In 1924, Jack Haldane published a novel entitled Daedalus. In it he suggested the possibility of human life being created in a test tube. This was the first book to discuss a subject that became a reality in 1978 with the birth of Louise Brown, the first human to come from in vitro fertilization.