Concepções evolutivas de Charles Darwin no Origin of Species e de Alfred Russel Wallace em Darwinism: um estudo comparativo

Abstract

The British naturalists Alfred Russel Wallace and Charles Darwin reached independently the principle of natural selection and presented jointly their results to the Linnean Society of London in 1858. Thirty years after the publication of the Origin of Species by Charles Darwin, Wallace published Darwinism. The aim of this dissertation is to compare some conceptions found both in the Origin and Darwinism including struggle for life; natural selection; the survival of the fittest; sexual selection; geographical isolation; and the theory of instinct, analysing their similarities and differences. On the other hand, this work intends to provide an overview of Wallace s contribution to the evolution theory. This dissertation contains an introduction and five chapters. Chapter 1 presents the evolutionary precedents and the general context in which Darwin and Wallace presented their contributions concerning this subject. Chapter 2 analyses some evolutionary conceptions present in the Origin of Species. Chapter 3 analyses the same subject as presented in Darwinism. Chapter 4 provides a comparison between the conceptions found in the Origin and in Darwinism stressing their similarities and differences. Chapter 5 provides some final remarks on the subject. This study led to the conclusion that although several similarities between the two books may be found concerning several issues such as the relevance of the variability and its transmission to the offspring to the evolutionary process; the importance of natural selection; the relevance of the study of artificial selection to understand natural selection; the import of a widespread area (more important than the geographical isolation) in the production of new species among others, we could also detect several differences. Darwin and Wallace gave different explanations to the presence of colours and ornaments that differentiate the male and female sexes. While Darwin attributed them to the sexual selection through the choice of the male by the female, Wallace attributed them to the action of natural selection. Wallace claimed that some physical, mental and moral characteristics of man could not be explained through the action of natural selection as Darwin thought. Wallace did not accept the inheritance of acquired characteristics through use and disuse, as Darwin did. Besides that, Wallace did not accept that instincts could be inherited as Darwin believed