Transcript Lamarck and Darwin

Darwin vs. Lamarck Notes
June 2, 2016
Jean-Baptiste Lamarck
• French, Lived during
early 1800’s
A. Theory of Inheritance
of Acquired
Characteristics
B. Main Points
1. Principle of Use & Disuse
a. Most used body structures develop and unused
structures waste away
2. Inheritance of Acquired Characteristics
a. Once the structure is modified, the new trait can
be inherited
1.
Example: If you dye your hair purple, your children
will have purple hair
C. Why don’t we believe him?
1. Experiments
a. Show that changes that occur in an
animal’s life are not passed on to its
offspring
2. Genetics
a. Gregor Mendel discovered that traits
are passed down through genes
1. Genes aren’t affected by the
outside world in that way
Charles Darwin
“The Father of Evolution”
A. 1831: sailed on the HMS
Beagle to the Galapagos
Islands
B. Studied many species of
finches on islands
C. Published book in
1845:“On the Origin of
Species by Natural
Selection”
D. Theory of Evolution
1. Main Ideas
a. Natural Selection
b. Survival of the Fittest
III. Natural Selection
A. Definition: Process by which favorable
heritable traits become more common in
successive generations of a population of
reproducing organisms, and unfavorable
heritable traits become less common
Natural Selection
B. Main points
1. More organisms are produced than can
survive and this will lead to competition over
resources
a. Examples of resources
1. Water
2. Food
3. Habitat
4. Mates
2. Individuals within a population vary and
some of these traits are heritable
B. Main Points (cont.)
3. Some variations are favorable and increase
chances for survival/reproduction
a. Example: Male vs. Female Cardinals
1. Male color attracts female= reproductive
advantage
B. Main Points (cont.)
4. Better adapted individuals survive and
reproduce
a. These are the individuals that will pass on their
genes to the next generation
b. This can change the GENE POOL: Includes all the
genes of every reproductive member of a
population
C. What is a species?
1. A group of organisms that are genetically
similar enough to produce healthy, fertile
offspring.
D. Darwin’s Finches
1. Illustrate SPECIATION: when a species
breaks into two or more different species
a. The organisms in the two different species can
no longer interbreed
2. What could cause this to happen?
a.Geographic barriers
b.Occupy a new niche/habitat
c. Reproductive Isolation
Natural Selection
IV. What the theory of evolution is NOT!!!
A. It does NOT occur in individuals, only
populations!
B. It does NOT happen quickly; the Earth has a
long history!
C. It does NOT explain how life came to be on
Earth, just how it evolved after it was here
D. It does NOT have any driving force except the
competition for limited resources
Explain the picture below as if you were
Lamarck…
What would Darwin say to explain why
giraffe’s have such long necks?