1. Early Ideas About Life & Evolution

2. Creationism
Creationism is basically the creation story from the Bible.
Archbishop James Ussher of Armagh calculated the date and time of creation to be Sunday, October 23, 4004 B.C.
In these days, people believed that living forms were immutable – unchanging – and that what you saw around you was the way it was when the Earth was created.
Fossil evidence works against a strict belief in the world being only 6000yrs old.

3. Catastrophism
Baron Georges Cuvier studied fossils and noted that many of the fossils were of creatures no longer living on the planet.
He also noted that the more complex forms of these fossils were closer to the surface and that they got less complex the deeper you dug. Also – many of the fossilized creatures in one layer of the earth did not resemble creatures in the neighbouring layers.
Instead of evolution and a flow of form, he explained it with the concept of catastrophism. Local catastrophes (like floods) would wipe out the organisms of that time and they would be replaced with newly created forms.
It explained the fossils but not the increasing complexity.

4. Actualism
James Hutton was a Scottish geologist and naturalist who proposed the idea of actualism in which he stated that the same geological processes occurring in the present also occurred in the past.
This idea would go on to help form the idea of uniformitarianism and affect Darwin’s theory of Natural Selection.

5. Uniformitarianism
Sir Charles Lyell put forth the concept of uniformitarianism.
In this, he stated:
The Earth has been affected by the same processes in the past as what are occurring presently.
Geological change is slow and gradual rather than sudden and catastrophic.
Natural laws and processes are constant and eternal – the operated with the same intensity in the past as they do in the present.

6. Georges Buffon
Georges Buffon was the first scientist to suggest that species could change over time and that these changes could lead to the formation of new species.
He brought the idea of evolution into the realm of science.
He developed a concept of the "unity of type," a precursor of comparative anatomy.

7. The Principle of Population
Thomas Robert Malthus put forth his principle of population in which he points out the problem of unchecked population growth and its effects.
On the subject of unchecked populations:
“The power of population is indefinitely greater than the power in the earth to produce subsistence for man. Population, when unchecked, increases in a geometrical ratio. Subsistence increases only in an arithmetical ratio.”
And the consequences:
“The power of population is so superior to the power of the earth to produce subsistence for man, that premature death must in some shape or other visit the human race.”
Malthus argued that population was held within resource limits by two types of checks: positive ones, which raised the death rate, and preventative ones, which lowered the birth rate.
Darwin would use these ideas greatly in terms of survival of the fittest.

8. Acquired Characteristics
Lamarck was the first biologist to recognize the role of the environment in the changing of a species in his theory of acquired characteristics.
In this he states that animals strive to survive through the use or disuse of various parts of their bodies. Those that are used will be accentuated and become stronger while those that are not used will whither and disappear.
The enhanced traits will then be passed on to the next generation.
The problem is that Lamarck has the driving force of change within the control of the organism – not the environment. It is as if to say, “If you want it bad, you can develop the traits needed to survive.”

9. Next Stop…Evolution!
Charles Darwin used parts or all of these ideas to help him form his theory of evolution through natural selection.
As we go through the ideas Darwin put forth, you will be able to make connections back to these ideas.

10. That’s All I Got…