Question

Give the salient features of the following:

Neo-Darwinism

Answer 1

1. Rapid Multiplication: Organisms can reproduce rapidly and produce many offspring.
2. Limited Food and Space: Food, space and other resources available to organisms are limited.
3. Struggle for Existence: Due to limited resources, organisms struggle with one another for food, space and other necessities.
4. Genetic Variation: Inheritable variations are caused due to the following reasons:
   1. Mutation: Discontinuous variation caused by a permanent change in the genetic makeup.
   2. Gene Recombination: Rearrangement of genes produces variations among organisms.
   3. Hybridization and Gene Migration: These processes introduce new genetic variations into a population.
   4. Genetic Drift: Change in the frequency of genotypes in a gene pool is called genetic drift.
5. Natural Selection: Organisms with favourable variations are selected by nature and have a better chance of survival and reproduction.
6. Isolation: The segregation of a population by barriers that prevent interbreeding between populations.
7. Origin of New Species: The accumulation of genetic variations, natural selection and isolation over generations can lead to the formation of new species.