The Environment in Evolution : Darwinism and Lamarckism Revisited

Abstract

Evolutionary biology has begun to re-evaluate the role of organisms in the construction of their own environment or niche. Rather than the passive victims of natural selection, organisms are increasingly seen as active agents by means of the impact they exert on their environments. The resurgence of environmentalism and the role of the subject in its construction make sense in view of the enormous impact of living beings on their immediate surroundings. The physiological needs of organisms created by their interactions with the environment drive Lamarckian evolution. Lamarck emphasized that organisms must first be faced with a different mode of environment that would trigger some sort of pressure for an altered gene, to be inherited in the next generation. Darwin‟s theory was one of natural selection and survival of the fittest. As the environment underwent changes, the species affected by these changes underwent changes in response to changes in the environment. The environment then plays very different roles in the thinking of the two legendary biologists. For Lamarck, the environment steers adaptive change by Inheritance of Acquired Characters, while in Darwin‟s thought, it performs the cruel but immensely important task of selecting the fittest organisms.