Abstract

When talking about environment, about ecology, we mainly talk about changes: climate change, collapse of biodiversity-according to Pierre Henry Gouyon-, worsening of land degradation and desertification2... But there have always been changes. It is true, we are not going to dispute this fact: Concerning the climate, there have been successions of periods of glaciation and warming (medieval climatic optimum from the 10th century until the 14th). Concerning biodiversity we talk about the 6th great extinction period, which means that there were 5 before. Some people conclude that our planet is constantly evolving and that these current (dynamic) evolutions are in no way linked to anthropic activities or only to a small extent. According to them, humans, like the rest of the living world, must simply adapt to these changes, as they have always done for billions of years, with varying degrees of success: some species disappearing (the dinosaurs, the dodo3...), others mutating, others having adaptive capacities thanks to a natural selection based on a possible “genetic progress” due to the maintenance of a great genetic diversity. Other species