Chapter 15, Problem 3A

Summary Introduction

To determine:

To replace the underlined words in a sentence to make it correct.

Introduction:

Evolution can be defined as the unrolling of nature that brings about an orderly change from one form to another which results in the descendants to become different from the ancestors.

Answer to Problem 3A

The correct sentence is Natural selection is mechanism for theory developed by Charles Darwin.

Explanation of Solution

The theory of natural selection was given by Charles Darwin and Alfred Wallace in 1858 and this theory is also known as Darwin-Wallace theory.

Natural selection is differential reproduction which means some members of population have genes that enable them to grow up and reproduce at higher rate and leave more surviving offspring in the next generation than others. It will result the gene to become predominant in the gene pool as it is producing more offspring that continue for many generations. Natural selection can result in organisms that are more likely to survive and reproduce and eventually leads to speciation and hence evolution.

The theory of natural selection was based on the following prepositions:

• Over-production or enormous fertility:
• Struggle for existence
• Variation and heredity
• Survival of the fittest