Chpt 25: (9) Intra and Intersexual Selection

Question 1

Sperm competition???

Answer 1

when one male removes/eliminates another male’s sperm

exp. of indirect intrasexual competition
exp. from class: male dragonflies scrape male sperm from the female damselfly’s reproductive tract

Question 2

Sneaker copulation

Answer 2

exp. of indirect intrasexual competition

Question 3

Intrasexual selection

Answer 3

results from competition between members of on sex for access/opportunity to mate with the other sex

usually male on male competition for access to females OR access to territory with resources the females need

exp. from class: elephant seals hoarding/defending prime real estate for mating on a beach

Question 4

Zahavi’s handicap hypothesis

Answer 4

the idea that individuals with well developed sexually selected characteristics have survived a test

often involve extreme, energy expensive, characteristics
that males survive in spite of, not because of

Question 5

Correlation coefficient (r)

Answer 5

tells you the direction and strength of a correlation as shown on a graph

Question 6

R^2

Answer 6

tells you how much changes one (the independent) variable explain changes in another (the dependent) variable (as communicated on a graph)

Question 7

probability (p)

Answer 7

likelihood that the relationship between independent variable and dependent variable is d/t chance

Question 8

sneaker male

Answer 8

a small male (sunfish) that can dart in and out of a spawning sperm/egg cloud to try to spray his own sperm into the mix without being noticed by the bigger/dominant males

exp of sneaking, which is an exp. of indirect sexual competition

Question 9

satellite male

Answer 9

smallish male (about the size of the female) sunfish who is able to participate in the sperm/egg cloud spawning because the bigger/dominant males don’t really notice them there

exp of sneaking, which is an exp. of indirect sexual competition

Question 10

Condition index

Answer 10

may be used on the x axis of a graph to show the average quantity for a value (like penis size) as 0, with values greater than average shown (as positive values) on the right of the 0, and values lower then the average shown (as negative values) on the left of the 0

Question 11

Mate guarding???

Answer 11

when a male physically prevents a female from mating with another male

exp. of indirect intrasexual competition
exp. from class: male cricket riding on female’s back

Question 12

why R^2 is always positive (even if r is negative)

Answer 12

because the R^2 describes a fraction, even for inverse relationships

it’s a proportion of how much of one thing is explained by another thing

Question 13

INTERsexual selection

Answer 13

(usually) when females actually have a choice in mates, and selection is based on phenotype

phenotypes often maladaptive traits that males had to survive in spite of, not because of

Question 14

what the threshold for probability (p) equals

Answer 14

it varies by study

in lab we use 0.05

Question 15

Correlation coefficient (r)

Answer 15

tells you the direction and strength of a linear relationship between 2 continuous variables as shown on a graph

can be between -1 and 1 (as in 100% negative/inverse correlation or 100% positive/direct correlation)

Question 16

Cuckoldry

Answer 16

when Males unwittingly invest parental care into unrelated offspring

exp. of indirect intrasexual competition

Question 17

Honest indicator

Answer 17

a trait that:

1. a male has survived in spite of, not because of
   and
2. actually indicates quality/superior genotype

Part of Zahavi’s handicap hypothesis

Question 18

Spawning

Answer 18

when female (fish) release eggs and males release a cloud of sperm over them

exp. from class: male sunfish building nests to protect fertilized eggs from the sperm clouds of other male sunfish