Download Chapter 15

Due
• Pass to the middle.
• Intervention Signatures
• Darwin vs. Lamarck
• In 30 Seconds they will be late.
Warm up 2/4: Make a
2 columns and place
the following
according to
whether they
describe Lamarck or
Darwin.
Place In Two Columns!
Working out will make your offspring stronger.
If you are strong your offspring might be stronger.
The traits that animals desire have nothing to do
with how a species adapts and evolves.
Survival of the Fittest.
Acquired Characteristics.
Organisms adapt to the environment through
individual change.
Organism adapt to the environment because only
those with the correct genes survive to reproduce.
Chapter 15-1: Charles Darwin
Evolution and Natural Selection
Ideas Before Darwin
• Most people believed that earth
was thousands of years old and
organisms did not change.
• Fossils showed that very different
organisms lived in the past.
• Jean Baptiste Lamarck
proposed the idea of acquired
traits to explain the changes.
• Traits used most often would be
enhanced and passed to offspring
• Traits that were not used would
diminish and disappear from
offspring
Charles Darwin
• After traveling the world by ship
(H.M.S. Beagle) he published The
Origin of Species (1858)
• Two Goals
• Present evidence that evolution occurs
• Explain the variety and distribution of
organisms on earth
Darwin’s Ideas
Descent with Modification
Darwin’s idea that small changes
accumulate over generations.
Suggests that all species are
descendants from a few kinds of life.
Darwin’s Finches – 13 finch species
that evidence suggests descended from
one original species from Ecuador
Population: the number of a specific
species living in a specific place at a
specific time
Natural Selection
The mechanism for descent with
modification…
4 parts of the theory:
1) Overproduction: Organisms
have a large potential to reproduce
but are limited by environment &
resources
2) Genetic Variation: Individuals
vary within a population, and this
variation can be passed to offspring.
3) Struggle to Survive:
Individuals struggle to survive and
some variations benefit the struggle
others are a hindrance
4) Differential Reproduction:
organisms with the best adaptations
will survive the most to reproduce
Fitness = a measure of an
individual’s hereditary
contribution to the next
generation
Homework
•Read p 297-301
•Do problems p 301 # 1-6