Lecture 2: Darwin's Big Idea

Question 1

Argument From Design

Answer 1

theory that complex adaptations that have an elaborate function were created by celestial designer (William Paley 18th century philosopher)

Question 2

Jean-Baptiste de Lamarck (1744-1829)

Answer 2

• First to use the term evolution
• First to provide a causal mechanism (the inheritance of acquired characters) even if the mechanism was WRONG
• he thought that organism had plasticity

Question 3

Charles Darwin

Answer 3

Created first comprehensive theory of evolution. Co-discovered chief mechanism of evolution (natural selection) with A.R. Wallace.

Question 4

The basic ideas discussed in The Origin of Species

Answer 4

• all organisms have descended with modification from common ancestors
• the process leading to adaptation is natural selection operating on variation among individuals

Question 5

Darwin’s Voyage

Answer 5

He was influence by botanist John S. Henslow (Cambridge).

During voyage of HMS Beagle (1831 - 1836) he acted as naturalist collected species and samples, etc.

Question 6

Charles Lyell

Answer 6

Wrote Principles of Geology, advocated for uniformitarianism (forces shaping earth in the past are the same ones shaping the earth today). Thought that present day processes can explain the history of the earth (gradualism)

Question 7

What influence did Charles Lyell have on Charles Darwin?

Answer 7

Read his book in 1830

1. Darwin realized if geological forces were dynamic, biological forces also would be.
2. The biological changes would build up gradually by same mechanisms as in the past

Question 8

What influence did Thomas Malthus have on Charles Darwin?

Answer 8

His essay on population and carrying capacity suggested to Darwin that in an environment where organisms are struggling for food favourable variations would be preserved and unfavourable ones destroyed (1838).

Question 9

What was co-discovered by Darwin and Wallace?

Answer 9

Mechanism of natural selection (survival of the fittest). A. R. Wallace wrote “On the tendency of varieties to depart indefinitely from the original type” in 1858, Darwin published Origin of Species in 1859.

Question 10

Natural selection depends on

Answer 10

Variation - individ. variation in a pop
Heredity - Progeny resemble their parents more than unrelated individuals
Selection - some forms are more successful at surviving and breeding.

Question 11

Why was Lamarck wrong?

Answer 11

• somatic cells do not function as agents of heredity
• genetic info cannot pass from soma to gametes onto next gen
  info flows from DNA to protein NEVER other way around.

Question 12

At what level does evolution occur?

Answer 12

population (not individual level)