Question

Define homologous and analogous organs.

Answer 1

Homologous and analogous organs:

1. Homologous organs – They are the organs where basic structural composition, design, and origin are similar but they differ in the functions they perform.
   1. Such structures develop in related entities & exhibit divergent evolution.
   2. For eg, the forelimbs of man & frog apparently have the same basic design of bones but they seem to carry out different functions.
2. Analogous organs are said to have similar functions but have different origins.
   1. For instance, the flippers of penguins and dolphins are meant to perform a similar function (help in swimming) but have different origins so they are referred to as analogous organs.
   2. Penguins and dolphins are evolutionarily not closely related to each other but might have evolved similar traits (flippers) that show convergent evolution.
   3. Convergent evolution is said to be the evolution that is independent of similar species of different periods or epochs in time.
   4. The organisms formed analogous structures that have similar forms or functions but are absent in the last common ancestors of those groups.