Question

Describe how natural selection brings about the adaptations of a species to its environment.

Answer 1

1. Individuals of the same species show variations. The variations are caused by genes that can be passed on from parents to the offsprings (inherited);
2. Some of these variation become more suitable or favourable or advantageous in the prevailing environmental conditions;
3. Because organisms usually produce more off springs than the environment can support; competition for resources sets in;
4. This leads to struggle for existence;
5. Individuals with more favourable characteristics/adaptations/gene mutation have better chance of survival in the struggle;
6. Hence they reach reproductive age, reproduce and pass on favourable characteristics to the offspring;
7. Those with less favourable characteristics or adaptations fail to reach sexual maturity; they die young;
8. Examples of natural selection include – malarial parasite/plasmodium which has developed strains that are resistant to anti-malarial drugs;
9. Sickle cell trait; the homozygous die young and the heterozygous are resistant to malaria.