Download lamarck`s theory

WHAT IS EVOLUTION?
A CHANGE IN A POPULATION
OVER TIME
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
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 AKAPRINCIPLE 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
Maybe Lamarck was right? Vestigial Structures
Inherited from a common ancestor, but not used
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?
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
THOMAS MALTHUS 1766-1834
• 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”
THOMAS MALTHUS CONT.
• How did this influence Darwin?
• Darwin saw that PLANTS & ANIMALS
PRODUCE more OFFSPRING then can
SURVIVE as well.
INFLUENCES ON DARWIN
• 1. DARWIN thought geological changes
could influence plant & animal adaptationCHARLES 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
Alfred Wallace 1820-1903
• 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.
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
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
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
REDI’S EXPERIMENT 1668
Let’s watch the animation
But, first draw this experiment
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.
LOUIS PASTEUR’S EXPERIMENT