Week 3 -Modern scientific thought -Influences on Darwin's theory of - - PowerPoint PPT Presentation

week 3
SMART_READER_LITE
LIVE PREVIEW

Week 3 -Modern scientific thought -Influences on Darwin's theory of - - PowerPoint PPT Presentation

Week 3 -Modern scientific thought -Influences on Darwin's theory of natural selection -Natural selection -Examples of natural selection Textbook progress: ch. 2 and some ch. 3 1 https://www.lbcc.edu/post/notetakers Office hours: T-Th, 12-1pm


slide-1
SLIDE 1

Week 3

  • Modern scientific thought
  • Influences on Darwin's theory of natural selection
  • Natural selection
  • Examples of natural selection

Textbook progress: ch. 2 and some ch. 3

1

slide-2
SLIDE 2

2

https://www.lbcc.edu/post/notetakers

Office hours: T-Th, 12-1pm

slide-3
SLIDE 3

3

slide-4
SLIDE 4

Pre-scientific thinking

4

Common views before the 18th century Fixity of species Young Earth

slide-5
SLIDE 5

Pre-scientific thinking

Changes before the 18th century

  • discovery of the New World
  • new tools (e.g., telescope)
  • heliocentrism

5

slide-6
SLIDE 6

Precursors to evolutionary theory

John Ray: species: a group of organisms that are reproductively isolated Carolus Linnaeus: binomial nomenclature E.g., Homo sapiens = Genus species

slide-7
SLIDE 7

Precursors to evolutionary theory

Georges-Louis Buffon: posited a correlation between changes in the environment and changes in an organism

7

slide-8
SLIDE 8

Precursors to evolutionary theory

Jean-Baptiste Lamarck: emphasized organism-environment interaction First to try and explain evolution... Inheritance of acquired characteristics

  • traits altered through use or disuse
  • altered traits are inherited

8

slide-9
SLIDE 9

Precursors to evolutionary theory

Jean-Baptiste Lamarck: emphasized organism-environment interaction First to try and explain evolution with: Inheritance of acquired characteristics

  • traits altered through use or disuse
  • altered traits are inherited

Problem: says traits are altered during the lifetime of an individual

9

slide-10
SLIDE 10

Georges Cuvier: tried to explain geology with catastrophism

  • first to say species go extinct

Charles Lyell: Uniformitarianism explains geology points to an old Earth https://youtu.be/o_wmulBtWlk

10

slide-11
SLIDE 11

11

slide-12
SLIDE 12

12

Thomas Malthus: populations grow exponentially but resources grow linearly

  • leads to competition for resources
slide-13
SLIDE 13

13

  • learned about Lamarck, Buffon, etc.
  • BFFs with Lyell
  • a 5-year voyage around the world inspired his theory of natural

selection

Charles Darwin (1809-1882)

slide-14
SLIDE 14

14

Artificial selection

  • All dogs share a common ancestor
  • Explains the extreme variation between breeds

Natural selection: artificial selection analogy

slide-15
SLIDE 15

15

Individuals with favorable traits have higher reproductive success compared to individuals with less favorable traits. (1) all species produce offspring faster than the food supply (2) there's biological variation in all species (3) each generation more offspring are born than survive

Natural selection in detail - Eight processes

slide-16
SLIDE 16

16

(4) more favorable traits lead to more fit individuals (5) environment determines which traits are favorable (6) traits are inherited and passed on to yield greater reproductive success

Natural selection in detail - Eight processes

slide-17
SLIDE 17

17

(7) over time, changes accumulate leading to new species (8) geographical isolation leads to new species through selective pressure

https://youtu.be/hOfRN0KihOU?t=399

Natural selection in detail - Eight processes

slide-18
SLIDE 18

Reproductive success: # of reproductively viable offspring produced Fitness: relative measure of reproductive success Selective pressures: environmental factors determining reproductive success. https://youtu.be/Uf-mOCN7rUU http://peppermoths.weebly.com/

18

Important terms for evolution by natural selection

slide-19
SLIDE 19

19

Natural selection