1. The History of Evolutionary Thought

2. Aristotle (384-322 B.C.) Ladder of Life
2 types of animals – those w/ blood & those w/o
Animals classified by their way of life
Plants by structure
Observation of various marine life anatomy was remarkably accurate
Distinguished whales from dolphins

3. Carol von Linné (1707 – 1778) “Father of Taxonomy”
Linnaeus was classifying organisms based on what they looked like.
This made it difficult to classify organisms that seemed to share characteristics with both kingdoms that Linnaeus proposed, Plants and Animals.
For example, fungi including mold and mushrooms do not move (or do they?) so they seem to be plants but, unlike plants…..?????

4.                                   
           
Immutable Species???

5. Jean-Baptiste Lamarck (1744-1829)
His name is associated merely w/ a discredited theory of heredity – he died in obscurity & poverty
Darwin & Lyell give him great credit
Law of use/disuse
Law of acquired characteristics

6. LAMARCK’S THEORY

7. Charles Darwin (1809-1882) Voyaged around the world 1831-1836
Wrote On the Origin of Species which reveals his ideas on Evolution by means of Natural Selection

8. ACCORDING TO DARWIN…

9. Natural Selection Summarized:
Darwin’s theory suggests that in a species:
There is a tendency towards overproduction
Variation exists
Variations are inherited
Individuals survive in their environments with varying degrees of success
Best adapted, survive and pass favorable variation on to next generation
In time, great differences arise, until a new species evolved from an old species

11. What is biological fitness???

12. Biological fitness: The contribution an individual
makes to the gene pool
of the next generation relative
to contributions of other
individuals
Offspring should be fertile

13. Alfred Wallace ( )
Studied the way geography limited or facilitated the extension of species range
How ecology influenced the shaping of adaptations
In 1858, shared with Darwin on the Theory of Evolution by means of Natural Selection

14. Genetic variation exists in sexually reproducing populations
Different alleles are available in the population thus producing
different phenotypes.

16. The Hardy–Weinberg principle states:
Both allele and genotype frequencies in a population remain constant or are in equilibrium from generation to generation unless…
Disturbing influences happen such as non-random mating, mutations, selection, limited population size, random genetic drift and gene flow.
Genetic equilibrium is a basic principle of population genetics.

17. The Hardy-Weinberg principle is like a Punnett square for populations, instead of individuals.

19. Hardy-Weinberg Principle
p2 + 2pq + q2 = 1; p + q = 1

20. Homologous Structures
Structures that have different mature forms in different organisms but develop from the same embryonic tissues.

21. Homologous Structures