Gene mutation 'varies sex appeal'
UK scientists believe they have discovered why the spread of "good genes" throughout the
population does not make everyone good-looking.
If women select the most attractive men, the genes should quickly become commonplace, according
to Darwin.
But the new research suggests that genetic mutations routinely affect the DNA repair kit, resulting in
greater variations as damage goes unrepaired.
The findings, by Newcastle University, are published in the journal Heredity.
Critics of evolutionary theory claim that widespread physical differences among sexually selecting
species such as humans are proof that Darwinism is flawed - the so-called "lek paradox".
However, the new research by Professor Marion Petrie and Dr Gilbert Roberts suggests that sexual
selection can in fact cause greater genetic diversity by a mechanism not previously understood.
'Disease defending'
The scientists claim that since genetic mutations can occur anywhere in the genome, some will affect
the DNA repair kit possessed by all cells.
As a result, some individuals have less efficient repair kits, resulting in greater variation in their
DNA as damage goes unrepaired.
Professor Petrie said: "We started this research 10 years ago and our model has now produced a good
fit with what we observe in terms of genetic variation, which leads us to believe that our theory is
correct.
We find that sexual selection can promote genetic diversity despite expectations to the contrary."
It has long been known that greater variation of DNA in the disease defending regions makes it more
likely that an individual can resist attacks by bacteria and viruses.
mutation 突變 a change in the GENETIC structure of an animal or plant that makes it different from others of the
same kind
commonplace 平凡的；普通的 something that is ordinary or boring
DNA repair kit
DNA 修補元件
variation 變異；變種 difference between similar things, or a change from the usual amount or form of something
heredity 遺傳 the process by which mental and physical qualities are passed from a parent to a child before the
child is born
flawed 有缺點的；錯誤的 spoiled by having mistakes, weaknesses, or by being damaged
so-called 所謂的 used to suggest that the words used to describe sb/sth are not appropriate
lek (a lek is a group of males congregated for mating)
paradox 自相矛盾的議論 a statement that seems impossible because it contains two opposing ideas that are both true
diversity 多樣性 the fact of including many different types of people or things
genome 基因組 all the GENEs in one cell of living thing
in terms of 就...而論;在...方面
contrary 相反的；對立的 used to add to a negative statement, to disagree with a negative statement by
someone else, or to answer no to a question