1. A CHANGE IN A POPULATION OVER TIME
WHAT IS EVOLUTION?
A CHANGE IN A POPULATION OVER TIME

2. I. JEAN BAPTISTE LAMARCK 1744-1829
A FRENCH NATURALIST, IN CHARGE OF THE INVERTEBRATE FOSSILS AT THE NATURAL HISTORY MUSEUM IN PARIS IN THE EARLY 1800’S

3. LAMARCK’S THEORY
1. ORGANISMS WILL ALWAYS TRY TO IMPROVE & BECOME ADVANCED
2. THE EFFORT TO IMPROVE CAUSES THE MOST USED STRUCTURES TO EVOLVE WHILE OTHER PARTS ARE WASTED AKA-PRINCIPLE OF USE AND DISUSE (vestigial structures)
3. ONCE A BODY STRUCTURE IS MODIFIED BY USE OR DISUSE THE MODIFICATION IS INHERITED AKA INHERITANCE OF AQUIRED CHARACTERISITICS

4. Maybe Lamarck was right
Maybe Lamarck was right? Vestigial Structures Inherited from a common ancestor, but not used

6. George Cuvier 1769-1832 French Naturalist
Studied fossils
Catastrophes caused animals to become extinct
Disagreed with Lamarck.
He believed that structure and function of animal organs was determined by the influence of their environment.
Parts could not change without affecting the entire organism. Do you agree?

7. Darwin Returns from his Beagle trip
BECAME VERY POPULAR because of all the SPECIMENS & SAMPLES he sent back from his trip
Becomes Friends with Charles Lyell, a GEOLOGIST
Lyell stated “The Earth must be very old, since geological formations are slow & gradual.”
Charles Lyell

8. THOMAS MALTHUS
CLERGYMAN WHO WROTE ABOUT ECONOMICS.
“THE HUMAN POPULATION WAS GROWING SO FAST THAT RESOURCES WOULD SOON RUN OUT, PEOPLE WOULD DIE DUE TO DISEASE, WAR & OTHER DISASTERS”

9. THOMAS MALTHUS CONT. How did this influence Darwin?
Darwin saw that PLANTS & ANIMALS PRODUCE more OFFSPRING then can SURVIVE as well.

10. Darwin suspected this also occurred in nature- “Natural Selection”
INFLUENCES ON DARWIN
1. DARWIN thought geological changes could influence plant & animal adaptation- CHARLES LYELL
2. HE OBSERVED farm animals and pets selectively bred for desirable traits FARMERS. ARTIFICIAL SELECTION
Darwin suspected this also occurred in nature- “Natural Selection”
Cuvier-Environment affects adaptation

11. Alfred Wallace
Wrote to Darwin to get advice on his theory of evolution. His theory was based on Natural Selection.
Darwin freaks! This is his work of 20 years!
Fellow scientist at the Royal Society decided to let the two present their theories.
Darwin’s was accepted based on his years of accumulated evidence.

12. IV. MAJOR COMPONENTS OF DARWIN’S NATURAL SELECTION THEORY
1844 DARWIN WROTE HIS THEORY ON EVOLUTION-NATURAL SELECTION
THERE ARE 5 POINTS TO HIS THEORY
1. VARIATION IN POPULATION-VARIATIONS ARE PASSED ON FROM PARENT TO OFFSPRING
2. SOME VARIATIONS ARE FAVORABLE-IF FAVORABLE IT IMPROVES THE ORGANISMS ABILITY TO LIVE & REPRODUCE

13. IV. MAJOR COMPONENTS OF DARWIN’S NATURAL SELECTION THEORY
3. MORE YOUNG ARE PRODUCED THAN CAN SURVIVE-ONLY A FEW LIVE LONG ENOUGH TO REPRODUCE
4. THOSE THAT SURVIVE & REPRODUCE HAVE FAVORABLE Traits. A LARGER & LARGER PORTION OF THE NEXT GENERATIONS WILL INHERIT THESE FAVORABLE VARIATIONS
5. GRADUALISM-OVER A LARGE AMOUNT OF TIME, SMALL CHANGES ACCUMULATE & POPULATIONS CHANGE

14. SPONTANEOUS GENERATION
IDEAS ABOUT HOW LIFE IS CREATED Prior to Darwin
SPONTANEOUS GENERATION
LIFE COMES FROM NON-LIVING THINGS, e.g. THE AIR
WHY DOES MEAT GET MAGGOTS?
Maggots come from MEAT

15. REDI’S EXPERIMENT 1668 Let’s watch the animation But, first draw this experiment

16. LOUIS PASTEUR 1860’S people still believed in SPONTANEOUS GENERATION!
Pasteur wanted to end the debate on where life comes from
He had an ingenious experiment
He ends up proving his theory-
Biogenesis, life comes from life.

17. LOUIS PASTEUR’S EXPERIMENT