Scientists find fish cheating evolution laws
Wednesday, 23 Apr 2008 00:01
The Amazon molly fish may be cheating laws of evolution, scientists say
Science In Focus
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A fish swimming in rivers in the Americas is cheating some laws of evolution to avoid extinction, scientists believe.
Researchers at the University of Edinburgh say the Amazon molly fish has survived for 70,000 years without reproducing sexually.
The fish, which are all female, interact with males to trigger the reproduction process but none of the males' DNA is passed onto the offspring.
For most creatures which reproduce in this way, known as asexually, their genes accumulate harmful changes over many generations and can eventually become extinct.
But the researchers believe the Amazon mollies, which live in rivers in south-east Texas and north-east Mexico, may be using genetic survival tricks in order to refresh their gene pool and avoid extinction.
One of these tricks could include occasional use of DNA from the males that trigger development.
The researchers calculated the time to extinction for the fish based on modelling genetic changes over many thousands of generations.
Dr Laurence Loewe of the University of Edinburgh's school of biological sciences said: "The Amazon molly must be employing tricks to avoid extinction.
"Maybe there is still occasional sex with strangers that keep the species alive. Future research may give us some answers."