A trait can evolve by sexual selection if it increases a male’s overall fitness, even if it decreases survival.

Exaggerated secondary sexual traits are favored by sexual selection because they increase male mating success.

TLS Online TPP Program

#Id: 9212

#Unit 11. Evolution and Behavior

Loss of their original diversity per generation

=1/2n

Gain of their original diversity per generation

=1/2n 

Gain or Loss of their original diversity per generation

=1/4n

TLS Online TPP Program

#Id: 9213

#Unit 11. Evolution and Behavior

Probability of being heterozygote in given population

H = 1 - 1/2N

TLS Online TPP Program

#Id: 9214

#Unit 11. Evolution and Behavior

Effective population size(Ne)

Effective number of breeding adults in a population.

TLS Online TPP Program

#Id: 9215

#Unit 11. Evolution and Behavior

Some factor determine Ne

1.Sex ratio.

2.Variation between individual in reproduction success.

3.Fluctuation in population size.

4.The age structure of the population.

5.Mating is random.

TLS Online TPP Program

#Id: 9216

#Unit 11. Evolution and Behavior

Ne = Male + Female  (when both are equal)

Ne = 4 × n(male) × n(female)/n(male)+n(female) 

(When both unequal Ne is smaller than then sum of both)

TLS Online TPP Program

#Id: 4685

#Unit 11. Evolution and Behavior

Social behaviour includes all kind of interaction between individuals of the same species.