1. Evolution Lecture 1 Name________Date ________
Chapter 22~ Descent with Modification: A Darwinian View of Life

2. Evolution
Evolution: the change over time of the genetic composition of populations
Natural selection: populations of organisms can change over the generations if individuals having certain heritable traits leave more offspring than others (differential reproductive success)
Evolutionary adaptations: a prevalence of inherited characteristics that enhance organisms’ survival and reproduction
November 24, 1859

3. Origin of species CFU: 1.What is evolution?
2.What is Natural Selection?
3.What is evolutionary adaptation?

4. Activating Prior Knowledge
4. How many of the previous scientists do you remember from 9th grade? Could you list what you remember?

5. Evolutionary history Linnaeus: taxonomy Hutton: gradualism
Lamarck: evolution
Malthus: populations
Cuvier: paleontology
Lyell: uniformitarianism
Darwin: evolution
Mendel: inheritance
Wallace: evolution

6. Check for understanding
6. Did only one scientist contribute to our understanding of evolution? Why do you think this happened?
7. What do you think taxonomy is? Look up the answer if you do not know.

7. Descent with Modification, I
5 observations:
1- Exponential fertility
2- Stable population size
3- Limited resources
4- Individuals vary
5- Heritable variation

8. Check for understanding:
8. what is exponential fertility?
9. If scientists observed this a very long time ago, could you also think of an example of this, today?
10. What organisms might have exponential fertility?
11. What does it mean to have heritable variety?

9. Descent with Modification, II
3 Inferences:
1- Struggle for existence
2- Non-random survival
3- Natural selection (differential success in reproduction)

10. Check for understanding
12. An inference is a logical conclusion or decision based on an observation or observations. Explain how a scientist might come to these three inferences, based on the five observations?

11. Evolution evidence: Biogeography
Geographical distribution of species
Examples: Islands vs. Mainland Australia Continents

12. Activate prior knowledge
13. What do you know about the strange creatures of the Galapagos Islands? These are the creatures which inspired some of Darwin’s most important conclusions.
14. How might creatures be different on islands verses a mainland? Why?

13. Evolution evidence: The Fossil Record
Succession of forms over time
Transitional links
Vertebrate descent

14. Check for understanding
15. What does the word succession mean?
16. What does succession of forms mean?
17. what does the word transitional mean?
18. What are transitional links, when one speaks of evolution, do you think? Google this if necessary.

15. Check for understanding continued
19. What is a vertebrate?
20. What does the word descent mean?
21. What does the phrase vertebrate descent mean, then, do you think? Google this if necessary.

16. Evolution evidence: Comparative Anatomy
Homologous structures (homology)
Descent from a common ancestor
Vestigial organs Ex: whale/snake hindlimbs; wings on flightless birds

17. Homology 22. What do you think homologous structures are?
Hint: the wings of pterosaurs (1), bats (2) and birds (3) are analogous as wings, but homologous as forelimbs.

18. Check for understanding cont.
23.
What are vestigial organs, in your own words?

19. Vestigial structures official definition from biologists
leftovers
Reduced in size over time
vestigial
refers to an organ or part (for example, the human appendix) which is greatly reduced from the original ancestral form and is no longer functional or is of reduced or altered function.
Vestigial structures provide a clue to the evolutionary history of a species because they are remnants of structures found in the ancestral species.

20. Evolution evidence: Comparative Embryology
Pharyngeal pouches, ‘tails’ as embryos

21. Evolution evidence: Molecular Biology
Similarities in DNA, proteins, genes, and gene products
Common genetic code

22. Check for understanding
24. What were the different arguments and evidence used to argue for Darwin’s theory of natural selection and evolution? A. B. C.

23. Final words…...
“Absence of evidence is not evidence of absence.”

24. Check for understanding?
How do you think humans have evolved?
Give an example and explain how a specific animal species may have evolved? Picture cartoons are an option.