Evidence for this has been accumulated in studying identical twins - they result from the same fertilized egg that, shortly after, splits into two. The emergence of epigenetics, however, is showing us that there is more to heredity than the simplistic ‘genes equals to phenotype’ model. Thus, the dominance of Darwinian evolution in tandem with Mendelian genetics in twentieth century biological thought effectively put Lamarckism to rest. Viewed under genetics, the only way the giraffes’ offspring could possibly inherit the long necks is if, somehow, the stretching of the parent giraffes’ necks led to changes in their DNA sequence. We have long understood that the units of heredity - the genes - are what give rise to traits of an organism. These giraffes would then have offspring with slightly longer necks.Īnyone with some basic understanding of Mendelian genetics would easily see something wrong with this mechanism of inheritance. When giraffes stretch their necks to reach leaves high in trees, they would strengthen and gradually lengthen their necks. This mechanism is illustrated in his hypothetical story of how giraffes got their long necks. This being the most prominent postulation of his theory, it argues that traits acquired by organisms in their lifetime can be passed on to the next generation. Lamarck proposed the inheritance of acquired characteristics.

Lamarck’s theory has been overshadowed by Darwin’s, and a majority of biologists - until recently - have ridiculed it. However, fifty years prior to Darwin’s publication of On The Origin of Species, Jean-Baptiste Lamarck had formulated his own theory on the mechanism of evolution. When people hear the term “ evolution” all they think about is Charles Darwin, the famed English naturalist who, in 1859, gave us the most notable mechanism of the evolutionary process. Has Transgenerational Epigenetics Vindicated Jean-Bapstsiste Lamarck?

The epigenetics revolution