AP biology: 22 Descent with Modification: Darwinian view of life

Question 1

The Origin of Species

Answer 1

Focused biologists’ attention on the great diversity of organisms

Question 2

Resistance to the Idea of Evolution

Answer 2

The Origin of Species
Shook the deepest roots of Western culture
Challenged a worldview that had been prevalent for centuries
The Greek philosopher Aristotle
Viewed species as fixed and unchanging

Question 3

Carolus Linnaeus

Answer 3

Interpreted organismal adaptations as evidence that the Creator had designed each species for a specific purpose

Question 4

Carolus Linnaeus

Answer 4

Was a founder of taxonomy, classifying life’s diversity “for the greater glory of God”
Classification system is still in use ( Binomial nomenclature)

Question 5

The study of fossils

Answer 5

Helped to lay the groundwork for Darwin’s ideas
Fossils are remains or traces of organisms from the past
Usually found in sedimentary rock, which appears in layers or strata

Question 6

Paleontology, the study of fossils

Answer 6

Was largely developed by French scientist Georges Cuvier

Believed in catastrophism, speculating that each boundary between strata represents a catastrophe

Question 7

Theories of Gradualism ( James Hutton/ Charles Lyell)

Answer 7

Gradualism

Is the idea that profound change can take place through the cumulative effect of slow but continuous processes

Question 8

Lamarck’s Theory of Evolution

Answer 8

Lamarck hypothesized that species evolve
Through use and disuse and the inheritance of acquired traits
Remember giraffe example

Question 9

Darwin’s Research

Answer 9

As a boy and into adulthood, Charles Darwin
Had a consuming interest in nature
Soon after Darwin received his B.A. degree
He was accepted on board the HMS Beagle, which was about to embark on a voyage around the world

Question 10

The Voyage of the Beagle

Answer 10

During his travels on the Beagle
Darwin observed and collected many specimens of South American plants and animals
Darwin observed various adaptations of plants and animals
That inhabited many diverse environments

Question 11

Darwin’s interest in the geographic distribution of species

Answer 11

Was kindled by the Beagle’s stop at the Galápagos Islands near the equator west of South America

Question 12

Adaptive radiation

Answer 12

From studies made years after Darwin’s voyage

Biologists have concluded that this is indeed what happened to the Galápagos finches

Question 13

In 1844, Darwin wrote a long essay

Answer 13

on the origin of species and natural selection

But he was reluctant to introduce his theory publicly, anticipating the uproar it would cause

Question 14

In June 1858 Darwin received

Answer 14

a manuscript from Alfred Russell Wallace

Who had developed a theory of natural selection similar to Darwin’s

Question 15

Darwin quickly finished

Answer 15

The Origin of Species

And published it the next year

Question 16

Darwin developed 2 main ideas in the origin of species

Answer 16

Evolution explains life’s unity and diversity

Natural selection is a cause of adaptive evolution

Question 17

The phrase descent with modification

Answer 17

Summarized Darwin’s perception of the unity of life

States that all organisms are related through descent from an ancestor that lived in the remote past

Question 18

In the Darwinian view, the history of life is like a

Answer 18

tree
With multiple branchings from a common trunk to the tips of the youngest twigs that represent the diversity of living organisms

Question 19

Observation #1

Answer 19

For any species, population sizes would increase exponentially
If all individuals that are born reproduced successfully

Question 20

Observation #2

Answer 20

Nonetheless, populations tend to be stable in size

Except for seasonal fluctuations

Question 21

Observation #3

Answer 21

Resources are limited
Inference #1: Production of more individuals than the environment can support
Leads to a struggle for existence among individuals of a population, with only a fraction of their offspring surviving

Question 22

Observation #4

Answer 22

Members of a population vary extensively in their characteristics
No two individuals are exactly alike

Question 23

Observation #5

Answer 23

Much of this variation is heritable
Inference #2: Survival depends in part on inherited traits
Individuals whose inherited traits give them a high probability of surviving and reproducing are likely to leave more offspring than other individuals

Question 24

Inference #3

Answer 24

This unequal ability of individuals to survive and reproduce

Will lead to a gradual change in a population, with favorable characteristics accumulating over generations

Question 25

Artificial Selection

Answer 25

In the process of artificial selection
Humans have modified other species over many generations by selecting and breeding individuals that possess desired traits

Question 26

Artifical Selection Results

Answer 26

Forces speed of evolutionary change to occur too quickly
Genetically engineering organisms leads to higher prevalence of disease and disorders
( small gene pool)

Question 27

Natural selection can

Answer 27

can produce an increase over time

In the adaptation of organisms to their environment

Question 28

Differential Predation in Guppy Populations

Answer 28

Researchers have observed natural selection

Leading to adaptive evolution in guppy populations

Question 29

In humans, the use of drugs

Answer 29

Selects for pathogens that through chance mutations are resistant to the drugs’ effects

Question 30

Natural selection is a cause

Answer 30

of adaptive evolution

Question 31

Researchers have developed numerous drugs to combat

Answer 31

HIV

But using these medications selects for viruses resistant to the drugs

Question 32

The ability of bacteria and viruses to evolve rapidly

Answer 32

Poses a challenge to our society
Multiple resistant strains of bacteria are evolving rapidly
MRSA ( methicillin resistant Staphylococcus aureus)- AKA flesh eating bacteris
Mycobacterium tuberculosis
vancomycin resistant

Question 33

Evolutionary theory

Answer 33

Provides a cohesive explanation for many kinds of observations

Question 34

Homology

Answer 34

Is similarity resulting from common ancestry

Question 35

Anatomical Homologies

Answer 35

Homologous structures between organisms

Are anatomical resemblances that represent variations on a structural theme that was present in a common ancestor

Question 36

Comparative embryology

Answer 36

Reveals additional anatomical homologies early in development

Question 37

Vestigial organs

Answer 37

Are some of the most intriguing homologous structures
Are remnants of structures that served important functions in the organism’s ancestors
Human examples: appendix, coccyx
Whales: hip bones

Question 38

Molecular Homologies

Answer 38

Biologists also observe homologies among organisms at the molecular level
Such as genes that are shared among organisms inherited from a common ancestor

Question 39

Anatomical resemblances among species

Answer 39

Are generally reflected in their molecules, their genes, and their gene products

Question 40

Biogeography

Answer 40

Darwin’s observations of the geographic distribution of species, biogeography
Formed an important part of his theory of evolution

Question 41

Convergent Evolution

Answer 41

Some similar mammals that have adapted to similar environments
Have evolved independently from different ancestors

Question 42

The Fossil Record

Answer 42

The succession of forms observed in the fossil record

Is consistent with other inferences about the major branches of descent in the tree of life

Question 43

The Darwinian view of life

Answer 43

Predicts that evolutionary transitions should leave signs in the fossil record

Question 44

Paleontologists

Answer 44

Have discovered fossils of many such transitional forms