This apparent lack of success continues to create debate as to the importance of the good genes model in the field. Named after R. A. Fisher, who originally proposed it, this model suggests that ...

Because these high-quality males with large secondary sexual traits tend to father a high proportion of the offspring, their 'good genes' can spread ... simulation model, the scientists were ...

Not bad genes in that family you would guess, but Anne says their individual achievements are down to a combination of luck and good parenting. Getty Images Anne (left), Janet (centre) and Susan ...