Question

Unit of Evolution is
a. Population
b. Species
c. Individual
d. Subspecies

Answer 1

In biological terms, evolution is the process of the change in the inherited traits of a population from generation to generation. Unit of evolution is population as it can undergo any type of evolution.

Complete answer:
- The unit of evolution in the population. The population is the smallest unit that may undergo any type of evolutionary change.
- A population is a group of individuals of the same species who live in the same geographical area and interbreed with each other. Evolution typically occurs due to mutation that occurs in the individuals in a population and is passed in the offsprings. Then under selective pressure, such mutated individuals are selected over the individual which does not have the correct and positive mutation.
- New traits or characters can also arise from the transfer of genes between populations, that occur in migration or horizontal gene transfer between species.

Hence, the correct answer is option (A).

Additional information:
Evolution occurs when heritable variations become more common or rare in a population. This occurs either non-randomly through natural selection or randomly through the process of genetic drift. Evolution occurs as organisms with advantageous, positive traits transfers on more copies of these heritable traits to the next generation.

Note: Consider the difference between population and species. A species is a group of organisms that can reproduce with one another and produce fertile offspring. All the organisms from one particular species form a population. Two different species do not interbreed and hence are not covered in a single population term.
So, when a species is separated into populations that are prohibited from interbreeding, mutations, genetic drift, and the selection of new traits, leads to the accumulation of differences over generations and the appearance of new species.