Descent with Modification: A Darwinian View of Life

Question 1

What is evolution?

Answer 1

The process by which species accumulate differences from their ancestors as they adapt to different environments over time

Question 2

What were the ideas of Georges Cuvier?

Answer 2

• Paleontology, the study of fossils
• The older strata contained fossils that were less similar to current organisms
• Boundaries between strata represent sudden catastrophic events

Question 3

What did James Hutton propose?

Answer 3

The Earth’s geologic features were formed gradually (Ex. valleys being formed by rivers)

Question 4

What did Charles Lyell propose?

Answer 4

The same geologic processes operate today as in the past, at the same rate

Question 5

What did Jean-Baptiste de Lamarck propose?

Answer 5

• Use and disuse
• Inheritance of acquired characteristics

Question 6

What was use and disuse?

Answer 6

Body parts used extensively became larger and stronger while unused parts deteriorate

Question 7

What was inheritance of acquired characteristics?

Answer 7

Modifications acquired in ones lifetime can be passed to offspring

Question 8

What are adaptions?

Answer 8

Inherited characteristics that enhance an organism’s survival and reproduction in specific environments

Question 9

What is natural selection?

Answer 9

A process in which individuals with certain inherited traits tend to survive and reproduce at higher rates because of those traits

Question 10

What is artificial selection?

Answer 10

Breeding only individuals with desired traits

Question 11

Do humans use natural selection or artificial selection?

Answer 11

Artificial selection

Question 12

Descent with modification by natural selection explains what three broad observations?

Answer 12

• Unity of life
• Diversity of life
• The ways organisms are suited to life in their environments

Question 13

What is descent with modification?

Answer 13

All organisms are related by descent from a common ancestor that lived in the past

Question 14

What were Darwins observations?

Answer 14

• Members of a population vary in inherited traits
• Produce more offspring than the environment can support

Question 15

What were Darwins inferences?

Answer 15

• Those with more adaptable traits produce more offspring
• Unequal ability of individuals to survive and reproduce will lead to accumulation of favorable traits in population over generations

Question 16

What are the key features of natural selection?

Answer 16

• Individuals with certain heritable traits survive and reproduce at a higher rate
• Increases frequency of adaptations
• Give rise to new species
• Individuals do not evolve, population does
• Can only increase or decrease heritable traits
• Vary with environment

Question 17

Evolution by natural selection can occur ___ in species with ___ generation times

Answer 17

Rapidly ; short

Question 18

Does natural selection create new traits?

Answer 18

No, it selects traits already present in population

Question 19

What are homologous structures?

Answer 19

Similar physical features but different functions

Question 20

What is convergent evolution?

Answer 20

Similar features in distantly related groups (Ex. sugar glider and flying squirrel)

Question 21

How do analogous traits arise?

Answer 21

Not through common ancestry, but through independent adaption to similar environments