Jean de Baptiste Lamarck formulated a hypthosesis that greatly influenced Darwin's theory of evolution, a theory that is widely accepted among today's biological community, including myself. Lamarck's theory includes the idea that forces which cause the evolution of a species include when an organism does not use an organ, the organ will shrivel and offspring will likely be affected by this. Basically speaking, that the experience a parent has can affect it's offsprings genetic makeup. It also included bone shaping from stress and disfigurement that comes with age; durability. Recent scientific experiments, that have been reproduced by different groups, and are now accepted as having significant results, shows that a certain type of flea clearly and abruptly displays this type of genetic inheritance.
The flea, when living it's life in a controlled environment with no predators existing, is born with a round, smoothe shaped head. When it reproduces it's offspring develop the same as it's parents, showing the same shaped head. But, when the flea exists with predators present, the offspring show extremely obvious mutations to the structure of their head. When cohabitated with the predators, certain fleas live without ever contacting a predator before they reproduce and lay eggs. These 'inexperienced' unborn fleas grow and develop with the same head structure as it's parents, round and smoothe. When a flea in this environment has an encounter where it experiences an attack from a predator, but survives, and then later reproduces, it's offspring then exhibit an evident change in the structure of their head. The head of the 'experienced' offspring have a very large, sharp spike, similar to a unicorn horn. The spike is thought to have a useful defense function for the flea.
Lamarck, being a respected and innovative scientist contributing to relatively new field, was a major influence on Darwin's formulation of his evolutionary theory. In Darwin's theory, the only thing that can cause a species to change is from genetic mutation. This is a very slow process, and leaves a lot to statistics. Although it is definitely a major force in the evolution of a species, probably the greatest force in the overall development of such a wide range of biodivirsity, all having come from a single life form, it does not explain or include instances such as the flea. Lamarck and Darwin agree that this is what explains the amazing diversity in life forms here on earth, as do most people who consider the idea with a logical scientific approach.
This new evidence, which not only strongly supports Lamarck's theory, shows that relatively abrupt, drastic, and most importantly - functional, mutations occur and influence the evolution of different species. I think that functional is the most important aspect of this evidence for various reasons. I think this mutation is caused from a trait inherited down and exists in all the fleas, and that when a flea is attacked, a chemical reaction occurs that causes the flea to pass down a trait that would otherwise be dormant, had it's parents not experienced an encounter with a predator. I say this being relatively inexperienced in genetics, but i recognize it's significance. It means that a parent's experiences in life can, if nothing more, influence which traits that we inherit from them be dormant and which be active.
Basically, to anyone who says nature over nurture, another blow to the dome. And another reason why I am a product of my environment.
