7/ Be able to explain why the following statement is true: Natural Selection wor

Question

7/ Be able to explain why the following statement is true: Natural Selection works on individuals while evolution works on populations over generations. Or to put it another way: Individuals do not evolve, populations do.

8/ How can evolution explain the formation of complex structures such as the eye or the flagella motor?

9/ What causes variation in a species? To put this another way: all humans have the same genes, yet we do not look alike. What is the reason for the phenotypicdifferences between individuals of the same species? What is genetic recombination?

Explanation / Answer

7. Natural selection works on populations to adapt and evolve. thus individual organisms who can be best suited to the selected environment only can survive and reproduce to producing more such similarly well-adapted descendants. After numerous cycles of such breeding and selection, only the better-adapted is dominative. Thus the nature has filtered out poorly suited individuals and the population has evolved by working on individuals

8. complex biological structure such as eye or the flagella motor developed step by step via biological evolution. the term irreducible complexity is coined for this where parts of irreducibly complex biological structures will be useless unless they appear all together. hence in small populations, neutral changes or even some slightly deleterious changes will survive sometimes to carry out the evolution process and adaptation.hence,  complex structures are in fact generated by the stepwise process of gradual change thrugh natural selection.

9. though we all have the same set of genes, we all look different. the reason for this could be due to genetic recombination and polymorphism. same gene can have different alleles or polymorphic patterns in differebt individuals.genetic recombination is the process of random exchange of genes between the identical segments in the sister chromatids. it ensures the variation.therefore by rule even though the total gene set could be same, still the phenotypic appreance varies from individual to individual within species.

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