Chapter 15: Theory of Evolution
Section 1: History of Evolutionary Thought
Section 2: Evidence of Evolution
Section 3: Evolution in Action
Georges Cuvier
•
•
French anatomist (1769-1832)
Reconstructed the appearance of unique organisms
from fossil bones
1. Organisms in past differ greatly from any living
species
2. Extinction
3. Many sudden changes in the kinds of organisms
Catastrophism: sudden geologic catastrophes caused
extinction of large groups of organisms at certain
points in the past
Tornados, Hurricanes, Meteorites: abrupt events (catastrophes)
Charles Lyell
• English geologist (1797-1875)
• Shared some of Cuvier’s thoughts
Uniformitarianism: geologic processes that
have changed the shape of the Earth’s
surface in the past continue to work in the
same ways
Darwin: ideas fit with evidence from biology
“The present is a key to the past”
Grand Canyon: took millions of years to form
Jean Baptiste Lamarck
• French Biologist (1744-1829)
Inheritance of acquired characteristics:
individuals could acquire traits during their
lifetimes as a result of experience or
behavior, then could pass on those traits
*not supported
Charles Darwin
“On the Origin of Species by Means
of Natural Selection”
1. Overproduction
2. Genetic Variation
3. Struggle to Survive
4. Differential Reproduction
“Descent with modification”
“Survival of the fittest”
Section 2: Evidence of Evolution
Fossils
• Most powerful evidence of evolution
• Superposition: the lowest stratum was formed before the
strata above it
• Fossils formed
– Rapidly buried by fine sediment
– Wetland, streams, lakes, volcano
• Fossil links between
– Fishes and Amphibians
– Dinosaurs and Birds
– Reptiles and Mammals
Video: Transitional Species
http://www.pbs.org/wgbh/evolution/library/03/4/l_034_49.html
Video: Fish with fingers
http://www.pbs.org/wgbh/evolution/library/03/4/l_034_03.html
Video: How do we know evolution happens
http://www.pbs.org/wgbh/evolution/library/11/2/e_s_3.html
Seminar
Science Video:
– Research in Gobi Desert (Dino) golb_N
– Fossil Preparation (Dino) Prepare_N
– Microraptor (Dino) micro_N
– Research on the origin of feathers 1&2
(Dino)
Homologous structures
Anatomical structures that occur in different species
and that originated by heredity from a structure in the
most recent common ancestor of that species
They each have different functions, but are constructed of the same anatomic elements
Analogous Structures
Structures that have closely relate functions, but do
not derive from the same ancestral structure
Wings: serve the same function, but derived independently
Vestigial Structures
Structures that seem to serve no function but
resemble structures with functional roles in
related organisms.
Any ideas?
Embryology
Some stages of
vertebrate embryo
development are
very alike
Phylogenetic tree diagram
Section 3: Evolution in Action
How does evolution really work
http://www.pbs.org/wgbh/evolution/library/11/2/e_s_4.html
Toxic newts
http://www.pbs.org/wgbh/evolution/library/01/3/l_013_07.html
Ancient farmers of the amazon: coevolution
http://www.pbs.org/wgbh/evolution/library/01/3/l_013_01.html
Evolution of Camouflage
http://www.pbs.org/wgbh/evolution/library/01/1/l_011_03.html
Peppered Moths
Most are white with black spots
Rare mutant moth will be black and caught by predators
Industrial Revolution, birch trees became covered with
pollutants and turned black
Black survived more than white
More Evolution in Action
• Pocket Mouse (natural selection clip)
• Stickleback
Divergent evolution
Descendents of a single ancestor diverged into species that
each fit different parts of the environment
QuickTime™ and a
decompressor
are needed to see this picture.
Rhea in S. America
QuickTime™ and a
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Emu in Australia
QuickTime™ and a
decompressor
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Ostrich in Africa
Evolved from a common ancestor but are now in widely separated regions
Divergence among
Honeycreepers in the
Hawaiian islands
Each with a beak
specialized for its food,
evolved from a
single ancestor to fit
ecological niches
Undergoes divergence
until the population fills
many parts of the
environment:
Adaptive radiation
QuickTime™ and a
decompressor
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Convergent Evolution: each came from different
ancestors, but evolved similar adaptations to similar
habitats
QuickTime™ and a
decompressor
are needed to see this picture.
Evolved in isolation on the Australian continent
Artificial Selection
Human breeder chooses individuals that will
parent the next generation
* dogs, cats, horses, etc
* plants (rice, flowers, vegetables, etc)