Ch. 5 Adaptations and Natural Selection

Question 1

The structure of an organism ultimately affects ______ (and therefore fitness)

Answer 1

survival

Question 2

When relating to structure and function, a change in one results in

Answer 2

change in other

Question 3

Prior to the mid 19th century, the apparent match between organism and environment was seen as the work of

Answer 3

a creator

Question 4

Natural history was thought of as cataloging the creations of a divine architect. This was reflected in the _____ ______

Answer 4

Scala Naturae

Question 5

Scala Naturae

Answer 5

• the great chain of being
• a concept derived from Aristotle’s proposed tree of life
• life had a hierarchical order with lesser organisms at the bottom and man sitting atop the list

Question 6

Who brought the most widely accepted view of the natural world into question with one basic idea: couldn’t there have been enough time for generations and generations to differ in their success?

Answer 6

Charles Darwin

Question 7

Where did Darwin first get his idea for the Origin of Species?

Answer 7

voyage of the HMS Beagle (1831)

-22 years old

Question 8

In the Origin of Species, Darwin includes one figure which depicts what?

Answer 8

• shows evolution
• phylogenetic relatedness
• extinction
• speciation

Question 9

Biological evolution

Answer 9

genetic change over time (generations)

Question 10

Natural selection

Answer 10

the differential success of individuals within a population that results from interactions with their environment

Question 11

What are the 4 Tenants of Natural Selection?

Answer 11

1. more offspring are produced than survive (competition)
2. Organisms produce offspring with different traits (variability)
3. traits are genetic (inherited)
4. Offspring experience differences in survival (and reproduction): (adaptation)

Question 12

Why is natural selection not about:

• survival of the fittest
• longest-lived
• fastest
• most intelligent
• prettiest

Answer 12

none of these matter unless they improve an individual’s ability to pass their genes on to the next generation

Question 13

Evolutionary Stable Strategies

Answer 13

a strategy that once adopted by a population, cannot be invaded by an alternative strategy

Question 14

Why are most strategies not evolutionarily stable?

Answer 14

something else wins eventually

Question 15

_______ are a product of natural selection

Answer 15

adaptations

Question 16

adaptation

Answer 16

any heritable behavioral, morphological, or physiological trait of an organism that maintains or increases fitness of an organism in a given environment

Question 17

Fitness

Answer 17

long-term reproductive success; relative reproductive success of one individual compared to members of the same species in a particular environment

Question 18

______ are the units of inheritance

Answer 18

genes

Question 19

Genes

Answer 19

what pass adaptations to offspring; stretches of DNA that code for a functional product

Question 20

Alleles

Answer 20

variations in genes; alternative forms of the same gene

Question 21

Ultimately, the genotype produces the ______

Answer 21

phenotype

Question 22

Natural selection can achieve similar results from completely different __________

Answer 22

sources of material (genes)

Question 23

The _______ is the physical expression of the genotype

Answer 23

phenotype

Question 24

Qualitative traits

Answer 24

discrete, categorical traits (presence/absence)

Question 25

Quantitative traits

Answer 25

measurable traits (ex. height, weight, etc.)

Question 26

Heritability

Answer 26

a statistic used that estimates how much variation in a phenotypic trait is due to genetics and not environment

Question 27

The expression of most phenotypic traits is affected by the _______.

Answer 27

environment

Question 28

Phenotypic plasticity

Answer 28

the ability of a genotype to give rise to different phenotypic expressions under different environmental conditions

Question 29

Reaction norm

Answer 29

the set of phenotypes expressed by a single genotype across a range of environmental conditions

Question 30

Acclimation

Answer 30

organisms respond to brief changes in environmental conditions

Question 31

Genetic variation occurs at the level of the ________.

Answer 31

population

Question 32

Genetic differentiation

Answer 32

occurs when there is genetic variation among subpopulations

Question 33

Gene pool

Answer 33

the sum of the genetic variation across all individuals of a population

Question 34

Evolution

Answer 34

change in gene frequency over time

Question 35

Phenotypic evolution

Answer 35

change in the average phenotypic trait over time

Question 36

Natural selection is a product of what two conditions?

Answer 36

- heritable variatioin | - variation results in differential survival and reproduction

Question 37

Target of selection

Answer 37

the phenotypic trait that selection acts directly upon

Question 38

Selective agent

Answer 38

the environmental cause of the fitness difference among organisms with different phenotypes

Question 39

What are the three different types of natural selection?

Answer 39

- directional - disruptive - stabilizing

Question 40

Directional selection

Answer 40

when natural selection shifts the average phenotype away from the previous average

Question 41

Stabilizing selection

Answer 41

occurs when there is selection against the extreme phenotypes

Question 42

Disruptive selection

Answer 42

occurs when there is selection against an intermediate phenotype

Question 43

Mutation

Answer 43

random and unpredictable change in a gene

Question 44

What is the ultimate driver of evolution?

Answer 44

mutations

Question 45

Genetic Drift

Answer 45

change in allele frequency due to random chance

Question 46

Migration

Answer 46

movement of individuals into or out of a local population

Question 47

Gene flow

Answer 47

movement of genes between populations

Question 48

Five processes that can drive evolution

Answer 48

1. natural selection 2. mutation 3. genetic drift 4. migration 5. non-random mating

Question 49

Clines

Answer 49

measurable, gradual change in a population along an environmental gradient

Question 50

Clines can produce complicated species interactions. An example is

Answer 50

ring species; a connected series of neighboring populations which can interbreed, but the two "end" populations cannot

Question 51

Adaptations reflect _____ and ______.

Answer 51

trade-offs; constraints

Question 52

Constraints

Answer 52

limitations imposed on an organism due to their adaptations to their local environment

Question 53

Trade-offs

Answer 53

an increased ability in one task often results in a decreased ability in another