Chapter 7

Question 1

Allopatric speciation

Answer 1

geographic isolation separating populations

Question 2

Sympatric

Answer 2

no geographic isolation needed to create a new species

Question 3

Graduated model

Answer 3

Shows how a species developed over time

Question 4

What do “trees” represent?

Answer 4

The evolutionary relationships among sets of organisms

Question 5

Phylogenetic trees

Answer 5

One way to reflect the evolution of organisms

Question 6

Who was the first to suggest change over time?

Answer 6

Lamarck

Question 7

Which two observations led Darwin to conclude that there is competition for survival?

Answer 7

Overproduction and limited resources

Question 8

A population is…

Answer 8

A group of individuals of the same species living in the same place at the same time that can interbreed.

Question 9

gene pool

Answer 9

consists of all versions of all the genes carried by all the individuals in a population

Question 10

Genetic variation in a gene pool can arise through…

Answer 10

Mutation

Question 11

Sexual reproduction ensures that …

Answer 11

Genes are randomly mixed

Question 12

microevolution

Answer 12

A generation-to-generation change in the gene pool

Question 13

Changes to the genetic makeup of a population can arise via two mechanisms. What are they?

Answer 13

Mutations and sexual recombination

Question 14

What proves that sexual reproduction leads to variation?

Answer 14

1. Independent assortment
2. Random fertilization
3. Crossing over

Question 15

Darwinian fitness

Answer 15

the contribution that an individual makes to the gene pool of the next generation in comparison to the contributions from other individuals.

Question 16

What are other mechanisms that can also contribute to evolution in gene pools?

Answer 16

– Genetic drift
– Bottleneck
– Gene flow
– Sexual selection

Question 17

Genetic drift

Answer 17

a change in a gene pool due to chance. Important in small or isolated populations

Question 18

If a population is drastically reduced in numbers, that is a…

Answer 18

bottleneck

Question 19

Gene flow

Answer 19

tends to reduce differences among gene pools.

Question 20

Sexual selection

Answer 20

a form of natural selection that depends on an individual’s ability to obtain a mate.

Question 21

nonbranching evolution

Answer 21

An ancestral population changing gradually over time

Question 22

branching evolution

Answer 22

an ancestral population splits into two or more populations.

Question 23

How many mass extinctions have been documented?

Answer 23

5

Question 24

When did the dinosaurs go extinct?

Answer 24

65 mya

Question 25

What are the highlights of the precambrian era?

Answer 25

-- 4.6 bya: Earth forms -- 3.5 bya: Oldest known prokaryote (primitive-celled) fossils -- 2.1 bya: Oldest known eukaryote (modern- celled) fossils

Question 26

What are the highlights of the Paleozoic era?

Answer 26

``` • 541 mya: Explosion in animal diversity within the oceans • 420 mya: Plant life begins on land • 370 mya: Animals migrate to land • 251 mya: Mass extinction event ```

Question 27

Highlights from the mesozoic era?

Answer 27

• 230 mya: First dinosaurs • 100 mya: Flowering plants begin to dominate the land

Question 28

Highlights from the Cenozoic era?

Answer 28

• 65 mya: Extinction of dinosaurs and diversification of mammals • 200,000 years ago: Appearance of anatomically modern humans

Question 29

What did Aristotle believe about a species?

Answer 29

They were immutable

Question 30

Who suggested that an old Earth had gradually changed | through slow, accumulating processes.

Answer 30

Lyell

Question 31

What two points were made in Darwin's "Origin of the Species"?

Answer 31

1. modern species have descended from common ancestors (evolution). 2. natural selection is the mechanism of evolution.

Question 32

What year did the Voyage of the Beagle take place?

Answer 32

1831-1836

Question 33

Evolution by Natural Selection is decidedly...

Answer 33

non-random

Question 34

Factors that affect Natural Selection:

Answer 34

1. overproduction and limited resources, resulting in competition 2. Variation leading to natural selection 3. heritability leading to evolution

Question 35

adaptation

Answer 35

the accumulation of favorable traits over time

Question 36

What areas in biology provide evidence for evolution?

Answer 36

Fossils, anatomy, molecular biology, biogeography, direct observation

Question 37

How does the fossil record provide | evidence of evolution?

Answer 37

Fossil records reveal an ordered appearance of life on Earth

Question 38

Transitional forms...

Answer 38

provide evidence of change within lineages.