Chapter 1.6, Problem 13SAQ

Summary Introduction

To name:

The three ways that human have affected life on Earth.

Introduction:

Life originated millions of years ago, but humans or Homo sapiens have existed for only $1\%$ of life’s history yet they have affected the life on the earth and pay special attention to themselves only. All the species are affected by the humans around the world.

Explanation of Solution

The activities of humans affected the life on earth in the following ways:

(i) The human activities produced increased amount of carbon dioxide than a volcano. Humans convert more atmospheric nitrogen into ammonia than the plants by industrial processes. This harnessed the powerful antibiotics that have harmed many species and benefitted the harmful bacterial strains.

(ii) Humans played major role in biology as the expansion of human population resulted in the expansion of many other populations also such as grapes, corns, apple trees, and cows leading to more crowding and unclean environment.

(iii) Conversely, humans have also reduced or extinct the populations of certain species by hunting and habitat destruction such as the dodo bird, passenger pigeons, Bali tiger, and white rhinoceros.

Conclusion

The three ways that human have affected life on Earth includes the extinction of many species due to hunting and habitat destruction, expanded the population of many species resulting in overcrowding and increased the amount of gases and harmful bacterial strains.