Reproduction Flashcards
What are life history traits?
traits that organisms have that helped them in the past to maximize their lifetime reproductive success
What is fitness?
how well a generation can pass its genetic material to the next generation
What is the life history theory?
the theory that every different species has a pattern of growth, development, reproduction, and death shaped by natural selection
this pattern helps develop their life history traits
Why does maximizing reproductive success involve trade offs?
because of fixed energy budgets and selective pressures (from environments)
you need to sacrifice something to get something else
What are trade offs? give an example
any gains by one trait will result in a loss by the other
ex. seed size vs seed number
Bigger seed size (healthy, energized offspring), less seeds (less offspring)
What happens if an organism is above or below the trade off trend line?
Anything above the trend line would be too strong and too fit, anything below would die (too weak,less fit)
What is indeterminate growth? give examples
growth of the organism continues throughout the lifespan (never stops growing)
Ectotherms- reptiles, fish, plants
What is determinate growth? give examples
Growth of organism ceases when “adult” state is reached
The energy goes into maintaining rather than growing
Ex. Endotherms- birds, mammals
What is asexual reproduction?
producing clones (exact copies): genetic material is almost identical. Continues until food runs out
seen in prokaryotes
What is sexual reproduction?
produces recombinants (combined genomes to make something unique)
only in eukaryotes
uses up more energy
What are the reproduction trade offs?
Growth rate
Parental investment
Number of offspring (fecundity)
Frequency of reproduction (parity)
Size/age at sexual maturity
Size of offspring
Longevity/life expectancy (mortality rate)
What is the trade off between growth rate and reproduction?
higher reproduction, lower growth rate
ex. as fish makes more offspring, size of fish decreases (more energy goes toward reproducing rather than growing )
What is passive care?
pre “birth” energy investment (seed development, gestation, etc.)
What is active care?
post birth energy investment (energy put into raising offspring, dispersing seeds)
What is the trade off between parental care and survival of offspring?
When there are more eggs (offspring), only less than half of them survive, or even none
This is because there is less energy to go around (parents cannot feed them all)
