Monday, May 11, 2009
Jean Baptiste Lamarck was a naturalist who wrote about the theory of evolution long before Darwin. However, Lamarck is best known for his theory that an animal's interactions with its environment change its body in a way which is passed on to its offspring - the theory of "inheritance of acquired characteristics".
In other words, Lamarck believed that interaction with one's environment changes your body, and those changes are passed on to your children.
For well over a hundred years, biology teachers have taught that Lamarck was an idiot, and that inheritance of acquired characteristics is impossible.
However, a new scientific study shows that environmental influences can, in fact, change one's genetic make up.
Can that genetic change, in turn, get passed on to one's kids? The study did not look at that question.
However, there is actually an entire field of science called "epigenetics", which studies changes in phenotype (appearance) or gene expression caused by mechanisms other than changes in the underlying DNA sequence.
Epigeneticists say that genetic changes can be caused by interaction with the environment may last for multiple generations.
But can such changes be passed down to all future generations? Was Lamarck right after all, or does inheritance of acquired characteristics only apply to a very limited set of genes or only over the course of several generations (with Darwinian evolution still accounting for the bulk evolutionary changes)?
These are hot scientific questions, and further research needs to be conducted before we have the answers.