Herron; Scott Freeman
Adaptation - ANSWER:a trait or integrated suite of traits that increases the fitness of
its possessor
• Differences among populations or species are not always adaptive
• Not every trait of an organism use of every trait by an organism is an adaptation
• Not every adaptation is perfect
Example of testing various hypotheses of adaptions - ANSWER:-looked at tick load,
mean number of wounds, and changes in earwax on cattle with and without birds,
adaptationist programme - ANSWER:An effort to demonstrate that the traits of
organisms are indeed adaptations
-we want need to demonstrate what a trait is for, and show that individuals who
have it have higher fitness.
-tries to isolate one variable
good experimental design - ANSWER:(fly-spider experiment)
phrase the question as precisely as possible
list alternative hypotheses
-the null says nothing is going on
create varying treatments
use controls; each treatment should be administered the same way
randomize
replicate the experiment
observational studies - ANSWER:nematodes and rocks
-we must show that an organism is behaving a certain way non-randomly
-we must show that this behavior is adaptive
Comparative method - ANSWER:bat nuts
, it evaluates hypotheses by testing for patterns across species like correlations
between traits or correlations between traits and the environment.
-uses phylogenetically independent contrasts
phylogenetically independent contrasts - ANSWER:Contrasts represent divergences
from a common ancestor. if the contrasts are correlated with each other, then we
can conclude a certain correlation.
describe reasons why populations of organisms cannot evolve optimal solutions to
all selective challenges at once - ANSWER:Tradeoffs and constraints
-lack in genetic variation
-energy trade offs
-time requirements/constraints
-dispersal ability
describe constraints on adaptation and interpret results of studies related to such -
ANSWER:Begonia flowers (male and female flowers resemble)
-genetic variation and energy
Fuschia colors (color change)
-time
Beetles
-genetic variation
Feather lice
-dispersal ability
describe selection at the level of cells, organelles, and sequences. - ANSWER:Some
organelles, like mitochondria, can replicate themselves. Parasitic mitochondria are
favored over normal
At the cell level, nonparasitic mitochondria are favored.
each has their own genome
fundamental asymmetry of sex - ANSWER:-mothers tend to make a larger parental
investment in each offspring than fathers do (more energy and time). This increases
the offspring fitness, but reduces reproductive success of mom. Eggs are expensive
males invest little to no parental care. sperm is cheap. Very little energy cost.
types of challenges and limitations the different sexes face in attracting mates and
reproducing - ANSWER:Due to the fundamental asymmetry of sex, a female's