final exam- sexual selection and seciation and pop gen
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what does non-random mating consist of?
intering breeding and sexual selection
Inbreeding increases?
Increases homozygosity
Inbreeding Depression
Due to increase homozygosity causes A decline in average fitness
How does increasing homozygosity decrease fitness?
Many recessive alleles -> loss of function Inbreeding -> increases deleterious, lethal alleles Disease fighting alleles —Often under natural selection for heterozygous advantage
sexual selection
a type of natural selection that favors individuals who have a combination of heritable traits that are most useful in obtaining a mate
Sexual Dimorphism
when the males are physically distinct from females
what are useful traits for males to attract females?
physical beauty, physical skills, parenting skills and Physical strength, weaponry
Bateman-Trivers Theory
Eggs are expensive and sperm is cheap
how are eggs “expensive”?
Females produce relatively few offspring in a lifetime and A female’s fitness is primarily limited by ability to gain resources to make more eggs, healthy young (not ability to find a mate)
How are sperm simple to produce?
Males can father virtually unlimited numbers of offspring Fitness limited by number of females they can mate with; not the ability to require resources to make sperm
Asymmetry of Sex
Females invest a lot in each offspring, males don’t
Female Choice
Females need to be choosy about their mates
males should be..
Males should be willing to mate with any female possible
Male-to-male competition uses?
useful trait (physical strength)
Colorful feathers, colorful beaks ~ due to
carotenoids
what does Carotenoids do?
protect tissues, stimulate immune system
Where do animals get carotenoids?
plants
Traits that evolve due to sexual selection should be found primarily in
males
speicies
An identifiable group; distinct in appearance, behavior and habitat, that regularly interbreeds, and is evolutionarily independent from others
How do species come about?
Genetic isolation to Genetic diversion
What is speciation?
The creation of two or more distinct species from a single ancestral group
how are new species decided upon?
speicies concepts
Biological Species Concept
Distinct species defined by reproductive isolation
different species- biological concept
When two populations do not interbreed