1. How the Earth formed About 4.5 billion years ago
From a cloud of gas and dust (nebula) that also formed the Sun and other planets and comets and asteroids…
“chunks” stuck together, which attracted more chunks, which stuck and attracted more chunks…

2. How the Earth formed
Kept getting hit with meteors (bombardment), volcanic eruptions
Atmosphere not like today ammonia (NH3), hydrogen sulfide gas (H2S), water vapor and methane (CH4), carbon dioxide (CO2)

3. Miller and Urey (1950’s)
Proposed that these simple atmospheric molecules at high temperatures (e.g. lightning) could form amino acids
Comets/meteorites also have traces of amino acids

4. First living things About 3.5 billion years ago
Simple, one celled, autotrophic prokaryotes
Chemosynthesis: use chemicals to make energy
Some species still around today, at bottom of ocean by volcano vents (Archaea)
Cyanobacteria
Took CO2 out of atmosphere and release O2.
Responsible for our atmosphere today
Eventually one may have been swallowed by another and survived inside to make eukaryotes (endosymbiosis)

5. Spontaneous generation
Stated that nonliving things could turn into living things (mice from wheat/cloth)
Remember that in the 17th century (and earlier) not everyone was educated
Biogenesis: living things can only come from living things…what we believe now

6. Hutton People believed Earth about 6000 years old (biblical account)
James Hutton: noticed rock layers in mountains were bent/folded, but were flat when formed
So forces inside the Earth must have done that, but it would take longer than years
Deep-time…things happened much farther back in time than we thought

7. Lyell
Said that the processes going on today, geologically, were going on back then, too
Called Uniformitarianism
Was a competing theory (Cuvier) called catastrophism where big geological events happened and species became extinct

8. Jean Baptiste Lamarck
Believed in spontaneous generation, and that simple things could become more complex in their life time
Organisms change over life-time (acquired traits)
Pass that on to children
Inheritance of acquired characteristics

9. Jean Baptiste Lamarck

10. Charles Darwin And Alfred Russel Wallace (Darwin published book first)
Noticed differences between finch (bird) species as traveled by ship around the world (HMS Beagle, Galpagos Islands)
Descent with modification
Traits passed on to children over time

11. Charles Darwin

12. Comparing Lamarck and Darwin

13. 4 Parts of the Theory
Struggle for existence: nature produces more offspring than can survive at one time. Competition for resources (food, water, space, etc.).
Variation/Adaptation: genetic differences in a population. (adaptations)
Survival of the Fittest: Creatures with best adaptations survive.
Natural selection: ones that survive reproduce more like themselves
Note: nature (environment) “picks” what’s best…different from us picking (artificial selection…breeding)

14. 4 Parts of the Theory

15. Scientific Theories Hypothesis: a working idea, educated guess,
can change drastically with new evidence, not considered fact by scientific community
Law: describes what happens, often short or mathematical (F=ma) lots of evidence to back it up, rarely changes, but could, considered fact by scientific community
Theory: explains how or why something happens, often long and detailed, lots of evidence to back it up, often changes in small details, but could, considered fact by scientific community

16. Proof for Evolution So over time, what a species looks like can change
Transitional species
Fossils of species in between modern and older set up a series where can see changes

17. Transitional species

18. Proof for Evolution Rocks form in flat layers Older ones at bottom
Fossils in rocks similar closer together
Farther apart fossils are, more different

19. Proof for Evolution Embryology: Creatures look very similar when young
From common ancestor

20. Proof for Evolution Anatomy:
Homologous structures look alike inside and out (common ancestor, e.g. human arms, dog legs, bird wings)
Analagous structures look the same outside, but inside very different (evolved separately, e.g. bird wings, insect wings)
Vestigial structures seem to serve no function, but “left over” from ancestor (e.g. appendix, tail bone)

21. Structures
Homlogous
Analogous

22. Structures Vestigial Humans: Muscles that move ears Appendix Tonsils
Body hair
Tail bone
Wisdom teeth

23. Proof for Evolution Biogeography: Organisms far apart look similar
Organisms close together have slight differences

24. Proof for Evolution Molecules/genetics:
DNA and RNA sequences are incredibly similar between similar creatures
Many genes similar between organisms