}

Provided in nature

2005/03/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

The sizes of the limbs and body are usually proportional in living beings; it is said that evolution tends to maintain these proportions. Well, in view of the results of the research carried out with a species of butterfly, it can be said that it is specifically due to the natural selection.

At Princeton University have grown the Bicyclus anynana butterflies, and have chosen the most disproportionate of each generation to reproduce. After 13 generations they have achieved two types of butterflies: small and large wings, and big wings and small body. As they have put them at the same time as the butterflies of proportionate measures and have seen that they are not successful in reproduction.