Darwin vs Lamarck or Darwin and Lamarck?

I was reading about Jean-Baptiste Lamarck and it dawned on me that perhaps he was partly right about evolution. So, most people believe that Darwin was the first to propose the theory of evolution, but really, evolution just states that the diversity of life is due to inheritance with alteration over a long period of time and this idea had been around a while before Darwin, (some think Lamarck‘s was the first fully described theory of evolution). Darwin just proposed that evolution occurred through natural and sexual selection, and this theory has since been shown to be astronomically likely. Lamarck proposed that evolution occurred because animals changed their phenotype (body) through use (or lack of use) and then handed this change to their off-spring. The example often given is that giraffes stretch their necks as they reach for the highest leaves and over their life-time, through use, their necks get longer; this trait is passed down to their children, who then stretch their necks even more. So on and so forth until over several generations the giraffes’ necks gets as hilariously long as they are today. This is taught in high school in New Zealand as a “how ignorant we used to be” kind of theory. However, this to me sounds very much like epigenetics. Epigenetics is the alteration in phenotype through the turning on and off of genes and these alterations can be inherited. An example would be that children born during or just after the Dutch Famine had an elevated ability to store fats and as a result had very high rates of obesity. This is essentially parents changing their phenotype (body) to conserve and store energy, and then passing this change in phenotype onto their children. This could never result in speciation – so Lamarck‘s theory of evolution is still way off – but it must be noted that the Lamarckian idea of inherited changes based on use is not entirely wrong.

01. July 2014 by jackrrivers
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