Question

What do we learn from the identification of individuals and populations?

Answer 1

Systematic is the scientific study that attempts to recognize, describe, name, and arrange the diverse (unlike in form and structure) organisms according to an organized plan based on the unique features of species and groups. Systematic is also defined as the science of diversity of organisms in an evolutionary context because it involves the sifting of unity (similarity) from diversity (unlikeness) through comparison.

Complete answer:
Systematic include the following four fields
1. Identification
2. Classification
3. Nomenclature
4. Taxonomy
Introduction: It is aimed at finding the correct name and the proper position of an organism in the already established plan of classification.
This is done by examining its morphological (external) and anatomical (internal) characters.
Identification is accomplished with the help of biological keys.
Systematic enables us to identify the organisms of special interest so that these may be propagated or eliminated.
Applied Biology: Identification of useful plants and animals is necessary for raising them on a commercial scale and for improving their race to increase their yield.
Pest control: Many insects are pests stored in grains and other household articles. A variety of weeds are a drain on soil nutrients. Identification of these harmful organisms and the knowledge of their habits can help us get rid of them.
Disease control. Certain bacteria, fungi, protozoans, worms, and insects cause or transmit diseases in human beings, domestic animals, crops, and fruit trees. Identification of these harmful organisms and the knowledge of their natural history has helped in working out control measures for them.
Fossil study: Systematic enables us to identify the fossils which give useful clues about the phylogeny of organisms and also about oil and gas.

Note: The other utility of identification is quarantine control, preservation of wildlife, newly discovered organisms, indicator organisms.
Biological keys refer to a set of alternate characters in such a manner that helps in the identification of plants and animals by selecting and eliminating the characters according to their presence or absence in the organism under study.