Chapter 13- Evolution

Question 1

Aristotle

Answer 1

Greek philosopher, viewed species as permanent

Question 2

Lamark

Answer 2

French naturalist, organisms can pass on acquired traits

Question 3

Lyell

Answer 3

Wrote a book on the principles of geology, natural forces gradually change Earth’s surface

Question 4

Wallace

Answer 4

British naturalist, conceived a theory almost identical to Darwin

Question 5

Describe Darwin’s idea of “descent with modification”

Answer 5

As the descendants of a remote ancestor spread into various habitats over millions of years, they adapt separately according to the environment they live in

Question 6

List two observations Darwin made which guided him into his ideas of natural selection

Answer 6

1. Members of a population often vary in their traits, and most traits are inherited from parent to offspring
2. All species are capable of producing more offspring than the environment can support

Question 7

List two inferences Darwin made from his observations

Answer 7

1. Individuals with more favorable traits have a higher probability of of surviving to reproduce, produce more offspring than others
2. This unequal production of offspring will cause favorable traits to accumulate in a population over generations

Question 8

What did Darwin deduce from the work of Malthus?

Answer 8

The production of more individuals than the limited resources can support leads to a struggle for existence, with only some offspring surviving

Question 9

Compare and contrast natural and artificial selection

Answer 9

Artificial selection- much faster

Natural selection- over a long time

Both-select for desired traits

Question 10

Identify the three key points about evolution by natural selection summarized in section 13.2

Answer 10

1. Individuals do not evolve
2. Natural selection can amplify or diminish only heritable traits
3. Evolution is not goal directed

Question 11

List at least four different types of fossils

Answer 11

Amber, casts, remains, imprints

Question 12

Biogeography

Answer 12

Geographic distribution of species

Question 13

Comparative anatomy

Answer 13

Anatomical similarities between many species

Question 14

Homology

Answer 14

Similarity in characteristics that results from common ancestry

Question 15

Homologous structures

Answer 15

Features with different functions but similar structures

Question 16

Vestigial organs

Answer 16

Structures with marginal or no importance to the organism

Question 17

Comparative embryology

Answer 17

Comparing one organisms embryo to another

Question 18

Molecular biology

Answer 18

Enables scientists to read a molecular history of evolution in the DNA sequence of organisms

Question 19

What does an evolutionary tree represent?

Answer 19

Patterns of descent from an ancestor to a descendant species

Question 20

What information is used to create an evolutionary tree?

Answer 20

Homologous structures both anatomical and molecular

Question 21

Population

Answer 21

Group of individuals of the same species living in the same place at the same time

Question 22

Gene pool

Answer 22

The total collection of genes in a population at any one time

Question 23

Micro evolution

Answer 23

When the relative frequencies of alleles in a population change over a number of generations

Question 24

Why can’t an individual evolve

Answer 24

An individuals genes don’t change during its lifetime

Question 25

What are the sources of genetic variation

Answer 25

Mutations and sexual reproduction

Question 26

Mutation

Answer 26

A change in the nucleotide sequence of the DNA

Question 27

What three components of sexual reproduction contribute to variation

Answer 27

Independent orientation, random fertilization, crossing over

Question 28

According to the Hardy-Weinberg equation…

Answer 28

Sexual reproduction alone does not lead to evolution

Question 29

For a population to be Hardy-Weinberg equilibrium, what five main condition must it satisfy?

Answer 29

Very large population
No gene flow between populations
No mutations
Random mating
No natural selection

Question 30

What is genetic drift?

Answer 30

A change in the gene pool of a population due to chance

Question 31

What is the bottleneck effect?

Answer 31

A drastic reduction in population size and change in allele frequencies

Question 32

What is the founder effect

Answer 32

The smaller group, less likely to represent the population they left. Differences in the gene pool of a small colony compared to the original population

Question 33

What is gene flow?

Answer 33

A population may gain or lose alleles when fertile individuals move in or out of a population

Question 34

Define “fitness” as it applies to natural selection

Answer 34

Contribution an individual makes to the gene pool of the next generation relative to the contributions of other individuals

Question 35

What organism is” fit” in any population?

Answer 35

Those who produce the largest number of viable fertile offspring

Question 36

Disruptive selection

Answer 36

Favors individuals at both extremes of a phenotypic range

Question 37

Stabilizing selection

Answer 37

Favors intermediate types

Question 38

Directional selection

Answer 38

Shifts overall makeup of population by acting against individuals at one of the phenotypic extremes

Question 39

Define sexual dimorphism

Answer 39

Difference of males and females

Ex: peacock has a large tail peahen does not

Question 40

Compare and contrast intrasexual vs intersexual selection

Answer 40

Intrasexual: same sex compete against each other for mates

Intersexual: usually makes try to show off to gain approval of females

Question 41

How do diploidy and heterozygote advantage allow for the preservation of alleles which would normally be selected against?

Answer 41

Recessive alleles are hidden/protected

Question 42

Why can’t natural selection produce the “perfect” organism?

Answer 42

It can only act on existing variations, one adaptation can usually work well in one area but not another, organisms are not always the best suited for their environment if they disperse