The essential unit that evolves in nature is the _______, which can be defined as all the members of a _______ living in a specific geographic region at a given time.
Adv.
Different types of organisms occupy different habitats. Habitat is nothing but the place, where the organisms live. All the types of organisms cannot live in a particular habitat. Specific groups of organisms can survive in a particular habitat because of the presence of favourable climate and availability of food. For example, penguins cannot survive in deciduous forest or in any desert region. They need a habitat, which has cold climate.
Such groups of organisms, belonging to the same species and existing in a particular location at a particular time period is termed as population. The word, ‘population’ is used to denote the groups of organisms, which occupy a particular area. It is important to note that members of the population reproduce among themselves. They do not interbreed with other population. Also, each and every population is subjected to pressure of natural selection.
Natural selection is the force, which drives evolution. The word, ‘evolution’ used here represents the changes, which occur in organisms of a particular species due to natural selection. Organisms belonging to a species are collectively called as population. Hence, ultimately, it can be said that population evolve in nature.
Hence, population is the essential unit, which evolves in nature and it denotes the organisms of a species surviving in a particular region at a specific time period.
Match the terms with their meanings:
| a. gene pool | a variant form of a gene |
| c. allele frequency | the genetic makeup of an organism |
| d. genotype | exchange of genes between populations |
| e. gene flow | the relative representation of a given form of a gene in a population |