Estrogen stimulates OPG production

TLS Online TPP Program

#Id: 9408

#Unit 11. Evolution and Behavior

Group Living Has Advantages and Disadvantages

When animals live together in groups such as flocks or herds

Disadvantage- Group promote competition for food and increased transmission of parasites and other diseases.

Advantage - Benefits relate to group defense against predators through increased vigilance and through protection in numbers.

TLS Online TPP Program

#Id: 9409

#Unit 11. Evolution and Behavior

Many eyes hypothesis‐ By living in groups, individuals may decrease the amount of time each spends scanning for predators and increase the time they have to feed. 

TLS Online TPP Program

#Id: 9410

#Unit 11. Evolution and Behavior

TLS Online TPP Program

#Id: 9411

#Unit 11. Evolution and Behavior

Sexual selection is selection that promotes traits that will increase an organism’s mating success.

TLS Online TPP Program

#Id: 9412

#Unit 11. Evolution and Behavior

Sexual dimorphism can evolve when selection favors the expression of a trait to be different in males and females. 

This situation is called sexually antagonistic selection, because an increase in the trait’s expression benefits one sex but harms the other.

TLS Online TPP Program

#Id: 9413

#Unit 11. Evolution and Behavior

An individual without gonads will leave no genes to the next generation. Gonads and genitalia are called primary sexual traits.

Secondary sexual traits, which differ between the sexes but do not play a direct role in reproduction.