1. Research Paper 3-4 pages, typed, double-spaced, size 12 font
References page using APA style (does not count towards 3-4 page total)
Due start of class next Tuesday, 3/25. No late papers will be accepted for points (15 points).

2. Homework Due Today Gene Chromosome Cell DNA Allele Nucleus Nucleotide
Chromatin

3. Homework Due Today Arranged from smallest scale to largest: Nucleotide
DNA
Allele
Gene
Chromosome
Chromatin
Nucleus
Cell

4. Scaling across biology (biological hierarchy)

5. Evolution

7. What is the evidence for evolution?

8. What is the evidence for evolution?
Fossils exist for many extinct species, going back 3.5 billion years.

9. What is the evidence for evolution?

10. What is the evidence for evolution?
Biogeography: The study of where species live; their geographic distribution.
Species that live near each other tend to be closely related to each other.

12. What is the evidence for evolution?
Anatomy: Related species often share similar anatomical features because they descended from a common ancestor.

13. What is the evidence for evolution?
Anatomy: Related species often share similar anatomical features because they descended from a common ancestor.

14. What is the evidence for evolution?
Anatomy: Related species often share similar anatomical features because they descended from a common ancestor.

15. Microevolution vs. Macroevolution
Macroevolution: The evolution of entire species over long periods of time.
Microevolution: Evolution within a population over very short time periods of time.

16. Microevolution
Microevolution is a change in the allele frequencies of a population from one generation to the next.

17. Microevolution
Microevolution is a change in allele frequencies in a population from one generation to the next.
The sum of allele frequencies in a population is always 1.
Allele frequencies are expressed as decimals.

18. Microevolution Example
E= Separated eyebrows (Dominant)
e= Unibrow

19. Microevolution Example
E= Separated eyebrows
e= Unibrow
Generation 1: 5 Laney students
Genotypes: EE, EE, Ee, Ee, Ee
What is the frequency of each allele?
Generation 2: 5 Laney students
Genotypes: EE, EE, Ee, ee, ee
Has evolution occurred?

21. Mechanisms of Evolution
1. Natural Selection: “Survival of the Fittest”

23. Jean-Baptiste de Lamarck (1744-1829)
The inheritance of acquired characteristics

24. Charles Darwin ( )
Alfred Russel Wallace ( )

25. Voyage of the Beagle

26. The Malay Archipelago

29. Natural Selection: The differential survival and reproduction of individuals in a population possessing heritable traits which are adapted to the local environment.

30. Principles of Natural Selection
1. There is lots of variation in the world.

32. Where does variation come from?
New alleles arise due to mutation, which is simply a change in the nucleotide sequence of DNA.
Two types:
Nucleotide substitution: One nucleotide replaces another
Nucleotide insertion or deletion: A new nucleotide is added to a sequence or a nucleotide is deleted.

33. What causes mutation? Errors in DNA replication
High-energy radiation, such as X-rays and UV light

34. Principles of Natural Selection
There is lots of variation in the world.
Lots of the variation in traits is heritable.

35. Principles of Natural Selection
There is lots of variation in the world.
Lots of the variation in traits is heritable.
Organisms generally produce more offspring than can survive to reproductive age.

37. Important Considerations
-Darwin and Wallace had no knowledge of genes, genetics, DNA, how mutation works, etc.
-Natural selection can only play the cards that are dealt, i.e., it can only act on whatever variation exists. It cannot design “perfect” organisms.

38. Reading Questions How are conditions at high altitude different?
What is another word for a “variant of a high-altitude gene?”
What is the main difference between the high- and low-altitude Ethiopian populations?

39. Thought Question
Why do we need to get a new flu shot every year, and how does this relate to natural selection?