Question

Choose the correct statement about evolution.
(a)Populations evolve while individuals do not evolve
(b)Populations do not evolve while individuals evolve
(c)Populations evolve only when individuals evolve
(d)Populations evolve only when isolated individuals evolve
(e)Populations evolve only through mutations

Answer 1

Hint: Biological organisms continuously go through a change in the form of mutations, some useful, and some detrimental. But any change is considered as an evolution only when a population of significant individuals has the same change.

Complete answer:
 - Evolution is the change in the heritable characteristics in the form of genes in biological populations that pass on to successive generations. Evolution involves the change in gene frequencies in a population over a given period of time.
- The mechanisms of evolution are mutation, non-random mating, gene flow, genetic drift, and natural selection.
- In natural selection, a population has some individuals that possess certain inherited characteristics that produce more surviving offspring than the individuals lacking these characteristics. The conditions produce competition between the organisms for their survival and reproduction and the organisms that have the advantageous characteristics pass on their traits to the next generation.
- The subsequent populations will gradually conceive more individuals with advantageous characteristics. In this way, the population evolves and becomes better adapted to its local circumstances.

Additional Information: - Population genetics is the study of how selective forces change the allele frequencies in a population over time.
- In natural populations, natural selection, genetic drift, and gene flow do not act in isolation.
- Mechanisms of evolutions mentioned above are violations of Hardy-Weinberg equilibrium assumptions.

So, the correct answer is ‘Populations evolve while individuals do not evolve’.

Note: - The mechanism of natural selection has three facts: 1. The variation that exists in the phenotypic traits of populations. 2. Different traits confer different rates of survival and reproduction i.e. differential fitness. 3. The traits can be passed from generation to generation, or heritability of fitness.
- The concept of evolution by natural selection was laid out by Charles Darwin and Alfred Russel Wallace.