Biology, asked by Yash0007, 1 year ago

DESCRIBE genetic drift and natural selection.

Answers

Answered by Anonymous
6
genetic drift occurs by chance or it is a variation in gene pool which is merely by chance..

genetic drift is also said as Sewall wright effect

Natural selection is a process in which organisms which are better adapted to the conditions of environment tend to increase their genetic characters in more number..

so dominant organism would survive and continues its generations while those are less adapted would be eliminated..
Answered by DsJs
6
natural selection:

Situation I (Group of red and green beetles)





• Colour variation arises during reproduction


All beetles red except one that is green → Crows feed on red beetle → No. of beetles reduces


One beetle green → Progeny beetles green → Crows could not feed on green beetles as they got camouflaged (hide) in green bushes → Number of green bettles increases


Conclusion


→ Green beetles got the survival advantage or they were naturally selected as they were not visible in green bushes.


→ This natural selection is exerted by crows resulting in adaptations in the beetles to fit better in their environment.

genetic drift:

Situation III (Group of red beetles and Bushes)





Group of red beetles → Habitat of beetles (bushes) suffer from plant disease → Average weight of beetles decreases due to poor nourishment → Number of beetles kept on reducing → Later plant disease gets eliminated → Number and average weight of beetles increases again


Conclusion

No genetic change has occurred in the population of beetle. The population gets affected for a short duration only due to environmental changes.
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