Question

a. What is the theory of evolution (with example)

b. How evolutionary process be measured in species that are still in existence

c. What are forces that can cause evolution (Explain how each works and how they differ) (with examples) (name at least 3)

Answer 1

Ans a) Theory of Evolution was first introduced by Charles Darwin. It states that all the species of organisms arise and develop through the process of natural selection of small and inherited variations. This increases the ability of the individual to compete, survive and reproduce efficiently as process of evolution. There are four major theories of evolution which are

i)Theory of Inheritance of Acquired characters

ii) Theory of Natural Selection

iii) Mutation Theory

iv)Synthetic theory of evolution.

One of the popular examples is the evolution of the whales. It was found that through evolution, the early whales made an transition from land to the water and this occurred in series of steps. One genetic mutation led to placing of the nostril in the whale farther back on the head and this adapted them more to marine lifestyle.

Ans b) The rate of evolution in the existing species can be measured as change in an evolutionary lineage over time. It is measured in darwins which is the unit of measuring the evolutionary rates.

Ans c) Any 3 forces of evolution are :-

1. Genetic Drift – It is the change in the frequency of existing allele in a particular population caused by random sampling of the organism. The alleles change over generations due to random fluctuation in number of gene variants.
2. Mutation – It is the permanent change or alteration in the nucleotide sequence of a particular genome in an organism that leads to changed genotypic or phenotypic characteristics.
3. Natural Selection – It is a process where the organisms that are able to adapt naturally to the surrounding or environment or shows superior traits are able to reproduce and survive. They are more likely to pass on their traits to next generation.