We will also start the menopause later
Women are getting shorter and fatter, according to research into the future of the human race.
They are also likely to evolve healthier hearts and lower cholesterol, and will start the menopause later than they do now, researchers say.
Some biologists have argued that medical advances and social welfare in the wealthiest parts of the world have caused evolution to ground to a halt. Without the fierce struggle for survival, they say, natural selection is no longer driving our species’ development.
But evolutionary biologist Dr Stephen Stearns of Yale University says he has found evidence that inheritable traits such as weight and height still influence how many children a woman has and how healthy they will be. Having more children increases the chance that beneficial characteristics which aid survival will be passed to future generations.
Dr Stearns looked at the Framingham Heart Study – which has tracked the medical histories of 14,000 people in Framingham, Massachusetts since 1948. Shorter, heavier women tended to have more children than lighter, taller ones.
Women with lower blood pressure and lower cholesterol also had bigger families – as did those who became mothers at a younger age or began the menopause later. These traits were passed on to their daughters, who in turn tended to have more children.
If the trend continues for ten generations, the researchers calculate that the typical woman in 2409 will be 2cm shorter and 1kg heavier than today’s average. She will have her first child five months earlier – and go through the menopause ten months later.