Describe Lamarckian evolution and the evidence for or against it.

What will be an ideal response?

You may have heard people say something like, "Because we hardly ever use our little toes, they get smaller and smaller in each succeeding generation." This idea is a carryover of biologist Jean- Baptiste Lamarck's theory of evolution through the inheritance of acquired characteristics, known as Lamarckian evolution. According to this idea, if you exercise your arm muscles, your children will be born with bigger arm muscles, and if you fail to use your little toes, your children's little toes will be smaller than yours. However, biologists have found no mechanism for Lamarckian evolution to occur and no evidence that it does. Using or failing to use some body structure does not change the genes. People's little toes will shrink in future generations only if people with genes for smaller little toes manage to reproduce more than other people do.