Evolution Question 83
83. The kind of evolution in which two species of different geneology come to resemble one another closely, is termed as
[1996]
(a) progressive evolution
(b) convergent evolution
(c) parallel evolution
(d) retrogressive evolution
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Answer : b
Hints & Solution
(b) Progressive evolution is development of organisms with more elaborate and specialized structures from those having less elaborate features e.g. amphibians from reptiles. Retrogressive or degenerative evolution is development of simpler forms from more complex ones. Such evolution has occurred in case of vestigial organs, parasitic forms, and in reduction of overspecialized structures such as wings in flightless birds. Parallel evolution is formation of similar traits in related groups of organisms independently due to similar requirement e.g. running of two toed deer and one toed Horse. Evolution of wings in insects and birds serve as example of convergent evolution.
