Chapter 13, Problem 1LTB

How many different species have been identified by science? How many are estimated to exist?

Summary Introduction

To write:

About the estimation of species that have been described by science.

Introduction:

On Earth, a characteristic of life is that it is full of variety. Experts refer that the variation among and within living species is known as biodiversity. These studies not only provide interesting stories and fodder for arguments about the “best species”, but they also help us to understand the evolutionary origins of different groups of organisms and their function in biological systems. Systematists are scientists specializing in the description and categorization of a specific group of organisms.

Explanation of Solution

In central databases, 1.5 million identified species were described. The new estimation of total species on Earth is around 8.7 million i.e., on land 6.5 million species are present and in oceans 2.2 million. 20% of the total is known to science at the moment. Scientists use extrapolation to determine how many species are yet to be discovered. Thegraphs below showed the number of new groups of animals within each taxonomic level (taxa) over time. In the graph, leveling off showed that few new groups are probably left to discover. The dotted lines that showed on each group will level off, based on the historical pattern.

Conclusion

Till date, around 1.5 million species are identified.