Unit 1: Evolution foundationWeek 2 slides

1

Summary - Mon and Wed1. Wrap up red tape

2. Short answers - the tautology

3. Recap scientific method/inference to the best explanation

4. The natural sciences before Darwin

5. Influences on Darwin's theory of evolution by natural selection

6. Darwin's theory

7. Opposition to Darwin2

Short answer questions and science writing

Instructions (will also be on the test and creason.co)Answer each question in less than three sentences.

Do'sSimplicityJump right in

Do not'sPlagiarize or quote (use own words)Go over three sentences (unless specified)

Tautologies3

Tautologies are statements which are......in themselves redundant."Unsolved mystery" or "ATM machine" or "Please RSVP"

...trivially true.Oh Neo...

...essentially meaningless and/or offer no new information. "We'll cross that bridge when we get to it."

Statements that are empty truisms."I like my friends."

Generic examples I've seen:"The scientific method is a method used in science.""Darwin's theory says that only reproductively successful individuals have offspring.""Darwin's theory added to science by contributing new concepts"

4

Short answer questions and science writing

Instructions (will also be on the test and creason.co)Answer each question in less than three sentences.

Do'sSimplicityJump right in

Do not'sPlagiarize or quote (use own words)Go over three sentences (unless specified)

Tautologies5

Science is about hypothesis testing

6

} Analysis OHAT

UNIT 1: Explanatory Virtue

7

PREDICTIVE POWER-A theory is a good explanation of something if it has predictive potential

Ask: If my explanation is true, what future observations would we expect to see?-see if predictions are confirmed

PrecursorsScientific Revolution - undermined long standing views of nature

-Is there a fixity of species?

-Is the Earth really just 6,000 years old?

Important thinkers

1. Gave us a language

2. Recognized living things are diverse and change - they evolve

3. Established an older planet

Important concepts underlying Darwin's theory8

Classification - the language

9

John Ray (1627-1705)-Grouped organisms by reproductive viability-First to use "species" and "Genus" Carolus Linnaeus

(1707-1778)-Binomial Nomenclature

E.g., Homo sapiens, Tyrannosaurus rex, etc.

-Taxonomic classification of biological organisms

Change - the relationship between environment and organism

10

Comte de Buffon (1707-1788)-Plants and animals interacted with the environment-Environmental changes correlated with changes in plants and animals

Precursors - Dynamic Biology

11

Jean-Baptiste Lamarck (1744-1829)-Species alter their characteristics to meet their environment.-First to really attempt and explain evolutionary process

Precursors - Ancient age of the Earth

12

Charles Lyell (1797-1875)-Father of modern geology

Uniformitarianism: The gradual processes happening today were the same in the past.

Georges Cuvier (1769-1832)-Extinction-Catastrophism

13

Thomas Malthus (1766-1834)-Populations grow exponentially while food supplies/production grow arithmetically-Populations outgrow food supply - survival of individuals dependent on access to food supply or resources

Alfred Wallace (1823-1913)-Independently generated the

concept of Natural Selection-Father of Biogeography

Precursors - Environment influences organisms

Charles Darwin - the beginning-heavily influenced by these thinkers

*5 year voyage on the HMS Beagle

-What he observed informed his theory explaining why things change.

14

How Darwin changed the natural sciences

Darwin's theory of natural selection explains what guides evolutionary change

Took all the best parts of theories posited by the thinkers we just surveyed and made one that we still use today.

15

Natural Selection - Initial requirements

Individuals with favorable variations --> survive and reproduce at higher rates

1. Populations grow faster than the growth of available resources.

2. Populations have differential variation among members

3. More offspring are produced than survive due to competition for resources.

4. Individuals with favorable traits (speed, disease resistance, size) are more likely to survive* than individuals without those traits.

Fitness - A relative measure of reproductive success.

*Not who can live the longest but who can survive long enough to reproduce.

16

Natural Selection5. Favorable traits determined by environmental context

6. Offspring resemble their parents

Reproductive success - favorable traits are inherited and become more common.

7. This favorable variations accumulates in a population over many generations so newer generations are distinct from ancestral generations.

New species emerge

8. Geographical isolation - populations become geographically isolated and over time they respond to selective pressures - different ecological contexts - to become distinct species.

17

Natural Selection in ActionReproductive success - favorable traits are passed on with a higher frequency compared to less advantageous traits which decrease in frequency over time.

Selective pressures - Environmental forces influencing the reproductive success of individuals in a population.

Fitness - A relative measure of reproductive success.

Adaptations - The evolutionary shifts in the variation of traits in a population in response to environmental changes..

18