History of Evolutionary Thought

Question 1

What is the scala naturae?

Answer 1

Aristotle’s belief that species are arranged on a ladder of complexity

Question 1

What did Aristotle believe?

Answer 1

Species were not variable but fixed

Question 2

What did Linnaeus believe?

Answer 2

Accepted that species are fixed, developed the binomial system of classification (still used today)
Linnaeus system was not linear but nested (species are nested within a genera)

Question 3

What did Baptiste de Lamarck do?

Answer 3

The first to propose a coherent theory of evolution (even though it was wrong)

Question 4

What were the two laws that Baptiste de Lamarck present?

Answer 4

Use and disuse leads to acquired traits
Acquired traits can be inherited

Question 5

What is homology?

Answer 5

Similarity arising from common ancestry

Question 6

What was Darwin’s Theory of Natural Selection?

Answer 6

1. individuals vary within population
2. Variants more or less suited to environment
3. Differential survival and reproduction of individuals (variation is heritable)
4. Favorable characters passed on, increase in frequency

Question 7

Natural Selection

Answer 7

differential success in reproduction results in certain alleles being passed tot he next generation in greater proportions

Question 8

What did Darwin propose in The Origin of Species?

Answer 8

• Life’s history can be explained through the evolution of species by descent, with modification, from common ancestors
• The cause of evolution is natural selection actin on hereditary variation

Question 9

What were some difficulties for Darwin’s theory?

Answer 9

Slowness of process
Intricacy of adaptations
Gaps in the fossil record
Where does variation come from?

Question 10

What was Darwin’s hypothesis of variation?

Answer 10

Pangenesis hypothesis, in which hereditary substances called gemules or pangenes are shed by all parts of the organism and carried in the bloodstream (incorrect)

Question 11

How did Mendel’s findings relate to variation?

Answer 11

Particulate, not blending inheritance
Maintains variation because character variation is discrete (3:1, 1:2:1, etc.)

Question 12

What is the evolutionary of Modern Synthesis?

Answer 12

1940s, the body of work that reconciled the sciences and findings of genetics, systematics, and paleontology with Darwin’s theory of evolution by natural selection

Question 13

What was the neutral theory of molecular evolution?

Answer 13

Most of the molecular variation within and between species is explained by drift, not selection

Question 14

Why are some individuals sterile in a population?

Answer 14

Helps continue the species (think bees and queen bee)