Chapter 15, Problem 6A

Summary Introduction

To analyze:

Darwin’s theory of evolution.

Introduction:

Charles Robert Darwin is mainly known for his contributions to the science of evolution. He was a famous biologist, geologist and an English naturalist. Darwin on the basis of natural selection gave the theory of evolution.

Explanation of Solution

Darwin’s theory of evolution highlights a few important points. The variations in the organisms can also be inherited. Among the living organisms, there is competition for limited resources. Individuals can reproduce easily when they have favorable environmental conditions. The organisms also pass their traits from one generation to another. This selection of traits is done naturally and hence is known as natural selection. This causes species to change over time.

To support Darwin’s theory of evolution, there are various pieces of evidence. The fossil records give some evidence of evolution. Many transitional fossils have been found. In the evolution of modern species, these transitional fossils show the stages. The geographical distribution of living species also proves the same. For example, from Galapagos Islands species of finches that were collected by Darwin, and they were all found to be similar but still had some different features. Collected from different islands, these finches were different from each other as well as from the finches in mainland South America. This, therefore, gave the evidence that the finches have evolved based on their environment. In some animals, the homologous body structure gives the evidence that with some modifications from common ancestors these animals have descended four-limbed vertebrates. Example, Dolphins which live in water habitat have lungs instead of gills. Although most of the underwater creatures have gills and are not warm-blooded, Dolphins have lungs and are warm-blooded. This again gives the evidence that Dolphins have descended from land animals as only land animals show such characteristics. Similarly, during the early stages of development, an embryo grows to have common cells and tissues.

Conclusion

Therefore, using all the above-mentioned pieces of evidence, Darwin’s theory of evolution can be explained and proved.