Life History and Reproduction Flashcards
Life History
Lifetime pattern of growth, development and reproduction
Includes adaptations
Life History Characteristics
Traits that affect and are reflected in the life table of an organism
What do organisms face due to energy constraints?
Energy Trade Offs
When energy is used for one purpose, diminished available for others
What imposes energy constraints?
Physiology
Energetics
Physical and biotic environment
Benefits of Reproducing to Individual Fitness
Passing on Genetic Material
Behavioural, physiological and energetic activities
Costs of Reproducing to Individual Fitness
Reduced survival, fecundity/growth
r-selected organisms
Live in a rapid growth environment
Mature quickly, short lifespan
K-selected organisms
Live near carrying capacity
Mature slowly, longer lifespan
Semelarity
Invest maximum energy in a single reproductive effort
Iteroparity
Allocate less energy each time to repeated reproductive efforts (k-selected)
Asexual Reproduction
Produces genetically identical clones of the parent
Types of Asexual Reproduction
Binary Fission
Budding
Parthenogenesis
Binary Fission
Cells divide in two (bacteria and protozoa)
Budding
A bud pinches off as a new individual
Parthenogenesis
The development of ovum into an individual without fertilization
Sexual Reproduction
Recombination of genes
Types of Sexual Reproduction
Unisexual
Hermaphroditic
Unisexual
Separate male and female individuals (Dioecious)
Types of Hermaphroditic Plants
Bisexual
Monoecious
Bisexual Plants
Sex organs on the same flower
Monoecious Flowers
Separate male and female flowers on the same individual
Types of Hermaphroditic Animals
Simultaneous Hermaphroditic
Sequential Hermaphroditic
Simultaneous Hermaphroditic
The male organ of one individual mates with the female organ of another
Sequential Hermaphroditic
Sex changes as individuals age or due to external cues (clown fish)
Costs of Sexual Reproduction
Limited by the rate at which resources can be converted into offspring
Costs of Asexually Reproducing
All resources devoted to reproduction are converted directly into progeny
Costs of Sexually Reproducing
Resources devoted to offspring are converted into tow gametic types
Isogamy
Gametes equal size
Anisogamy
Male gametes smaller, more numerous
Cost of Anisogamy
Resources used to produce excess male gametes are lost
More resources required to produce female gametes
Cost of Meiosis
Cell division, reduces chromosome number by half
Reduced genetic relatedness between sexually reproducing organisms and their offspring
Half of total reproductive expenditures
Benefits of Sexual Reproduction
Increase the rate at which favourable mutations and new genetic linkage patterns can be incorporated into evolving populations
Mating Systems
Mongamy
Polygyny
Polyandry
Promiscuity
Monogamy
Prolonged pair bonding between one male and one female
Polygyny
Prolonged pair bonding between one male and two or more females
Females take care of young
Polyandry
Prolonged pair bonding between one female and two or more males
Males take care of young
Promiscuity
An absence of prolonged pair bonding, normally implies successful males mate with more than one female per season (not random mating)
Females take care of young
