Unit 3:  The origin and evolution of life                          1   2   3   4   5   6 

2. The evolution

2.1. Fixism

Although today fixism is discarded as scientific theory, it still stays as religious belief.

It was born from the necessity to explain the diversity of living beings according to a religious conception of life and the literal interpretation of the Bible.

Great scientists defended this conception in the past, partly because of their own religious prejudices and partly because there was not known any mechanism to explain the evolution.

a) Creationism

Creationism supposes that species do not change. They maintain invariable along the time since they were created by God. In other cultural traditions creation is attributed to other or others superior beings, but the essence of the idea is the same.

So that, living beings belong to different species because they were created in this way and it is not possible they change or they were related to each other.

Creationism has lasted along the centuries, mainly due to it is based in the literal interpretation of sacred scriptures, something absolutely unquestionable until little time ago. Even great naturalists such as Kalt Linné (Linnaeus) accepted this model without any doubt.

b) Catastrophism

This theory was proposed by the anatomist Georges Cuvier (1769-1832). According to this hypothesis several geological catastrophic events that took place in the past provoked the disappearance of some species. There was a new creation after each extinction. According to Cuvier, the biblical Flood was the last of these catastrophes. In this way it could be explain the problem that the existence of fossils were to creationism.