Sexual Selection Flashcards
Natural is the primary mechanism of what?
Sexual selection.
Why do some birds have ornaments and colors that do not improve their survival ability?
This is due to sexual selection. These traits evolve from sexual selection.
Sexual selection increase the reproductive sucess of the individuals even in the expense of their survival.
(True or false?)
True
How does sexual selection come about?
(According to darwin’s theory?)
The challenge for males to access females lead to sexual selection
What are the two mechanisms of sexual selection?
Intersexual selection and
Intrasexual selection
What is intersexual selection?
Members of one sex choose the opposite sex.
What is intrasexual selection?
(Also known as competition)
Members of the same sex evoke selection on each other.
Describe the gametes of females and males?
Male: Abundant and motile
Females: Fewer, Highly nutritious, Larger and non-motile gametes.
What are limitations to reproduction in Females and Males?
- Males are limited by access to females.
- Females are limited to access of resoures to produce their large gametes.
What is anisogamy?
The fusion or union of two gametes which different in size and form.
It is a form of sexual reproduction.
Bateman’s Principle
(2 things)
- Females should be choosier than males due to their eggs being expensive. Females reproductive success is limited compared to females.
- Because females are choosier than males it will lead to greater variation in the reprodutive success of males.
What influences stronger effects of sexual selection?
Higher reproductive variance.
With stronger variance there will be sexually dimorphic traits that are exaggerated in the sex with the highest reproductive variance.
(true or false)
True
What is the characteristics of successful females?
- Will not take away reproduction opportunities from females.
- Results in smaller variance in reproductive success.
What is characteristics of a successful males?
- If receives a disproportionate share of reproduction they will take away reproduction opportunities from other males.
- Can potentially sire many offsprings.
- Leads to higher reproductive variation among males.
Parental care
(female biased)
- Female biased postzygotic investment.