HOW heavy you were at birth could have been influenced by the country you were born in. A survey of baby weights in 130 countries has found that women in the richest and poorest countries are more likely to give birth to larger babies than women elsewhere. This pattern could be due in part to natural selection, researchers say.
In rich countries, people tend to die from non-infectious diseases such as diabetes or atherosclerosis. Because larger babies are less at risk of developing these conditions later in life, they should be favoured by natural selection, suggests the team led by Frédérick Thomas at the CNRS Centre for the Study of Polymorphism in Microorganisms in Montpellier, France. Bigger babies should also do well in poorer countries, they reason, as they are more likely to survive parasitic diseases that kill the most people later in life.
However, in eastern European nations for ...
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