Sex & Evolution Flashcards
what is present or true of asexual reproduction
a genetically identical offspring
a pea hen (female peacock) is described as ___ when mating
choosey
definition of intrasexual
male to male competition
what is batsman’s principal
female choosiness
natural selection in birds
beak size and shape
polyandry
more than one husband
what is an example of bateman principle
ancestral women typically could now have dramatically increased their reproductive output but adding more sex partners
when given a choice, as opposed to a stable internal predisposition, a female animal engages in sexual behaviour with another female. this is an example of an individuals:
sexual preference
name some environmental cues for sex determination in animals
temperature (crocodiles and turtles) -
available nutrients, water availability, photoperiod it time of year, competitive stress, pheromones from conspecifics
what aminals do not use environmental sex determination?
mammals and birds
what is sexual reproduction?
process of developing a genetically unique individual
what is asexual reproduction
a single parent generates offspring that are genetically identical
asexual reproduction is characterized by the absence of three sexual reproductive factors:
meiosis, reduction in ploidy (pairing of chromosomes or number of chromosomes) and the fusion of gametes
types of asexual reproduction: (3)
budding (portion of the parent buds out and goes off on its own and develops into a fully functioning organism fully attached to the parent and then breaks off
— common in vertebrates and small organisms in the sea
fragmentation (parent individual breaks off a piece of itself and then later develops into its own individual
—starfish, flatworm
parthenogenesis (develop a gamete without fertilization
— virgin births
how is sex expensive?
the cost of meiosis to generate a haploid gamete or cells (reproducing individuals that cannot reproduce on their own
the cost of finding a mate (sexual displays and rituals are energy, time and resource expensive)