Question

Biological classification is a dynamic and ever evolving phenomenon which keeps changing with our understanding of life forms. Justify the statement by taking any two examples.

Answer 1

Introduction

Biological classification is a dynamic and ever evolving phenomenon which keeps changing our understanding of life forms.
As the knowledge and information about new living organisms came into existence, then there occurred a change in classification of living forms.

Example 1

• For instance, initially, all the living beings were first classified into two Kingdoms - Plantae and Animalia by Linnaeus (1758), later it was criticized because it failed to classify Euglena, which possess characters of both plants and animals.
• After the two kingdoms, there were three and four kingdom classifications. Then came the five kingdom classification by Whittaker, in which all living organisms were divided into kingdoms Monera, Protista, Fungi, Plantae and Animalia. Now Euglena is placed under the kingdom Protista.

Example 2

In the five kingdom classification:

• Some unicellular algae like Chlamydomonas are kept in kingdom Protista while many algae are kept in kingdom Plantae.
• This classification system does not provide a place for viruses, viroids and lichens.

So the work is still going on to solve this problem. Classification of new organisms is done on evolutionary relationships nowadays.