1. Thought Question
What evidence did the scientist in Great Transformations find that indicated whales evolved from land animals?

2. Theory vs. Law Law = statement about a repeatable event
Theory = explanation of a natural phenomena based on extensive evidence
Both are considered factual understandings of the natural world.
One cannot become the other, they exist independently of each other and serve different purposes.

3. The Three Foundational Theories of Biology
Cell Theory
Germ Theory
Theory of Evolution

4. Cell Theory All living things are composed of cells
Cells are the basic units of structure and function in living things
New cells are produced from existing cells
Areas of science that have contributed:
Cell biology
Microbiology
Microscopy

5. Germ theory
Infectious diseases are caused by microorganisms of different types, commonly called germs
Areas of science that have contributed:
Cell biology
Microbiology
Epidemiology
Bacteriology
Virology
Pathology
Parasitology

6. Theory of Evolution
Evolution: changes in gene frequencies in a population over time or “descent with modification”
Explanation for diversity of life on Earth
Species alive today are descended with modification from ancestral species. This process of changes from common ancestors unites all organisms on Earth.

7. History of Evolutionary Theories
1800s Europe:
Dominant belief was that Earth and all its forms of life had been created a few thousand years ago and since then neither the planet nor its living species had changed

8. History of Evolutionary Theories
James Hutton, 1795
Geologist
WHAT: Published hypothesis about the layers of rock, formation of mountains, erosion, etc that occurs over millions of years
WHY: Could no longer measure the history of the planet in terms of human lifetimes

9. History of Evolutionary Theories
Jean-Baptiste Lamarck, 1809
French naturalist
WHAT: Species changed through acquired characteristics
Example: if you lift weights, your children will have big muscles
Incorrect, but did begin to explain adaptation
WHY: Idea that species change

10. History of Evolutionary Theories
Charles Lyell, 1833
Geologist
WHAT: Argued that the formation of Earth took place through small changes over a long period of time (old Earth)
WHY: Darwin expanded this to species changing over time

11. History of Evolutionary Theories
Darwin, set sail on Beagle 1831
WHAT: Realized organisms were not fixed and unchangeable (based on fossil record and biodiversity)
WHY: Provided explanation of the process of evolutionary change (theory of evolution by natural selection)

12. History of Evolutionary Theories
Thomas Malthus, 1798
WHAT: If human population continued to grow, resources would run out
WHY: Darwin applied this struggle for resources to plants and animals
an oyster produces millions of eggs in one year, a maple tree produces thousands of seeds in a single summer
they don’t all go on to live, why do some die?

13. History of Evolutionary Theories
Alfred Russell Wallace, 1858
Naturalist
WHAT: Independently thought of idea of natural selection
WHY: Ultimately lead to Darwin publishing On the Origin of Species in 1859