Darwin

Question 1

FitzRoy

Answer 1

Captain of the H.M.S. Beagle

Question 2

Henslow

Answer 2

A natural theologian and one of the most influential people in Darwin’s life

Question 3

Darwin became the Naturalist for the H.M.S. Beagle (1831-1836)

Answer 3

• 5 year circumnavigation of the earth
• Darwin would get dropped on land as hydrographic survey was carried out

Question 4

Components of the hydrographic survey

Answer 4

• Geological mapping
• Fossil survey and collection
• Plant & animal description and collection
• Shapes Darwin’s understanding of human variation

Question 5

Darwin’s ideas developed during trip, but he reworked them following his return…

Answer 5

Darwin returns to a celebrated reputation
- meets and befriends Lyell and many other naturalists
- Presents papers to Zoological and Geological Societies of London

Begins to seriously doubt “Fixity of Species”
- transmutation of species

Question 6

How did the Whig political party influence Darwin?

Answer 6

Overpopulation as the source of poverty
Opposition to social welfare

Question 7

In 1838, what book did Darwin read that influenced his thought process about “evolution”?

Answer 7

Malthus’s An Essay on the Principle of Population
- Population grows at a faster rate than the food supply
- Famine is a necessary outcome of the difference in growth rate

Question 8

Darwin’s first diagram of an evolutionary tree from his Notebook B on Transmutation of Species (1837)

Answer 8

Proposes branching evolution

Question 9

Vestiges of the Natural History of Creation (John Churchill in 1844)

Answer 9

Laid out a hypothesis of common descent
- God is the programmer of natural laws

People HATED it
- Theologists condemned it
- Scientists critiqued and enumerated errors

Question 10

Darwin did not publish his ideas for decades… so what pushed him to publish?

Answer 10

He was about to get scooped by Alfred Russel Wallace– a naturalist and explorer working in Indonesia

Question 11

Who independently comes up with the idea of natural selection?

Answer 11

Alfred Russel Wallace
- On the Tendencies of Varieties to depart Indefinitely from the Original Type (1858)

Question 12

On the Origin of Species by Means of Natural Selection, or the Preservation of Favored Races in the Struggle for Life

Answer 12

1st edition of Origin of Species was published in 1859 by Charles Darwin

Question 13

Darwin’s 2 Big Ideas?

Answer 13

1.) All living things descend from one or a few original life forms
2.) Natural Selection is the mechanism

Question 14

Darwin’s observations

Answer 14

1.) Populations have the potential to increase exponentially
2.) But they generally maintain a stable size
3.) Resources are limited
(struggle for existence)

4.) Variation in all species
5.) Variation is heritable
(Variation makes some individuals more successful in the struggle; those that survive and reproduce will leave offspring that have those same variants

Evolution by natural selection

Question 15

Observations summarized

Answer 15

1.) There is variation in all species
2.) Variation is heritable
3.) Struggle for existence
- potential for exponential increase
- populations generally have stable sizes
- resources are limited

Question 16

Some individuals are more likely to reproduce than others because of heritable traits…

Answer 16

So the next generation has a greater frequency of individuals that possess those specific traits

Question 17

Fitness

Answer 17

Describes how much more likely (to reproduce)
- a number that measures the reproductive output of an organism with a given trait

Question 18

“Survival of the Fittest”

Answer 18

Coined by Herbert Spencer in 1864
- incorporated by Darwin only in the 5th edition of Origin
- this phrase has created some misconceptions

Question 19

Misconceptions of “Survival of the Fittest”

Answer 19

1.) Survival isn’t really the important part
2.) Physical fitness isn’t the same as Darwinian fitness (where focus is more on reproductive success)
3.) It is necessary to decouple social values from the idea of fitness

Question 20

Common descent

Answer 20

All living things descend from one or a few original forms of life
- New/different forms of life appear by natural selection playing out over geological timescales

Question 21

What can change the relative frequency of a trait in a population?

Answer 21

Natural selection
- results in population divergence

Question 22

Darwin’s theory has implications for interpreting biological similarity

Answer 22

• Similarity indicates recent divergence (two life forms shared a more recent common ancestor)
• Dissimilarity indicates more distant ancestors with many differences accumulating in that length of time

Question 23

Did Darwin ever use the word “evolution” in first edition of Origin?

Answer 23

NO!
- instead he used phrase “descent with modification” or “transmutation”
-“Evolutionist” was a bad word because of historical association with criticized ideas
- the roots of the word evolve and how it is used colloquially today
- Reasons why that word wasn’t a good fit for Darwin’s idea:
* There is no progress in evolution
* Change does not happen wholesale

Question 24

Darwin’s theory of natural selection provides the framework for interpreting:

Answer 24

1.) Correspondence between species and their environment (adaptation)
2.) Similarity/dissimilarity among species (length of time since divergence)

Question 25

Important things about evolution!

Answer 25

1.) There is NO PROGRESS in evolution
2.) Individuals do NOT evolve, only populations