By Jonathan BallBBC News
13 February 2018
Evolutionary theory suggests that species
favouring asexual reproduction will rapidly become extinct, as their genomes
accumulate deadly mutations over time.
But a study on an Amazon fish has cast doubt
on the rapidity of this decline.
Despite thousands of years of asexual
reproduction, the genomes of the Amazon molly fish are remarkably stable and
the species has survived.
Details of the work have been published in
Nature Ecology and Evolution.
There are two fundamental ways in which new
generations of life come to being - sexual and asexual reproduction.
Sexual reproduction relies on special
reproductive male and female sex cells, the eggs and sperm, joining together
during the process of fertilisation.
Each sex cell contains half the number of
chromosomes of normal parent cells, then following fertilisation, when the egg
and sperm fuse, the normal cell chromosome number is reinstated.
Asexual reproduction is different.
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