Vocabulary Words Flashcards
Protandry
An organism changes sexes from male to female.
Extra-Pair Copulation
An Individual mates with someone whom they are not socially paired
Population Bottleneck
A temporary large reduction in the number of individuals due to a random event, which results in the loss of genetic diversity.
Lek
An aggregation of very small territories upon which males preform sexual displays to attract females.
Eupyrene
Sperm that is successful in fertilizing an egg.
P2
The portion of young sired by the last male to mate with a female.
ZW System
A Chromosomal Sex determination system found in birds and some reptiles.
Sexual dimorphism
Morphological and anatomical differences in secondary sexual characteristics between males and females of the same species.
Homogametic
Two copies of the same sex chromosome.
Monoecious
An Individual that produces both eggs and sperm
Adaptive sperm Loading
A male increases sperm production when there is more competition.
Diploid
Two full sets of chromosomes in a cell.
Mutation
Any change in the DNA Sequence.
Bateman’s Principle
Males maximize fitness by selecting many females, while females maximize fitness by selecting high quality males.
Genotype
The combination of alleles an individual possesses
Gamates
Sex cells
Aromatase
The enzyme which stimulates the production of estrogen at high temperatures in temperature-dependent sex determination.
Fissparity
A type of asexual reproduction found in some starfish.
Mate Assistance Hypothesis
Males remain with a female to help guard and rear their young and therefore achieve greater fitness.
Red Queen Hypothesis
Species must keep evolving, or they will be overcome by rapidly evolving parasites.
Polygyny Threshold Hypothesis
Females achieve higher fitness by selecting a high-quality territory over selecting an unpaired male who will assist with rearing offspring.
Kamikaze Sperm Hypothesis
Sperm from competing males destroy one another.
Calculating Relative Fitness
Dividing by the absolute fitness of the highest absolute fitness.
Mullers Ratchet
population threshold of
mutations; applies to only small
populations.
Kondrashov’s Hachet
individual
threshold of mutations; applies to any
population size
Ploidy Number
he number of full
sets of chromosomes within a cell
Heterogametic
an organism possesses two
different sex chromosomes (e.g. XY)
XY System
CHROMOSOMAL SEX DETERMINATION SYSTEMS
In these systems individuals that are
heterogametic (i.e., XY) produce sperm
and individuals that are homogametic
(i.e., XX) produce eggs.
Found in: mammals, fruit flies, some
plants
XO System
In these systems there is only one
type of sex chromosome, “X” (no Y
chromosome)
*Males only have one copy of X and
females have two copies
*E.g., grasshoppers, cockroaches,
crickets
Dichogamous
when an
individual
changes from
one sex to
the other
Protogyny
Female to male
Intrasexual Selection
Male-male combat for access to females or the resources they require.
Intersexual Selection
Members of one sex choose to
mate with members of the other sex
based on certain phenotypic traits
(“Inter” = “Between”)
Monogamy
One male paired with one female
Life-long Monogamy
Monogamous for multiple
breeding episodes or seasons
Serial Monogamy
Monogamous for multiple
breeding episodes or seasons
Polygyny
One male is paired with more than one female
Harem Defense Polygyny
male defends
a harem of females from other males
ex: Northern sea seals
Resource Defense Polygyny
male
defends a resource that females need for
reproduction
ex: Red-winged Blackbirds
polyandry
one female paired with
more than one male
Sequential polyandry
emales compete
for males and lay a separate clutch of
eggs for each male
This is the most common type of polyandry
Simultaneous polyandry
female mates with
multiple males simultaneously (most common in
externally fertilizing species)
polygynandry
more than one male
mates with more than one female; all look
after the young together
Promiscuity
both males and females
mate multiply, but do not form any sort of
pair-bond
Apyrene
sperm = non-fertilizing
(unsuccessful) sperm
Cryptic Female Choice
Females select which sperm is
successful in inseminating them
*Use physical or chemical means
to do this
Ex: Nursery Web Spiders
Dioecious
A plant species where individuals are either exclusively male or female.
Siment Mutation
Mutations that do not change the amino acid sequence of a protein, potentially altering its function.
Evolution
The change in allele frequencies in a population over generations.
