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EVOLUTION
There is variation among individuals
of the same species.
No two individuals are exactly alike.
meerkats
Fig. 17.3, p. 272,3
V
Many, many generations…
Thousands, sometimes millions of years…
Climate, food, predators,
vegetation, protection…
Color, size, long legs, short legs, better vision,
hearing…
Evidence for Evolution –
FOSSILS
Evidence for Evolution –
ARCHAEOPTERYX
FOSSILS
Evidence for Evolution – HOMOLOGOUS STRUCTURES
Evidence for Evolution –
EMBRYOS
Recent discoveries of the conservation of molecular mechanisms of development are
even more compelling.
Natural Selection We
Can See
The Case of the Peppered Moth
Case of the Peppered Moth
• Peppered moths are
common in England.
• Variations in color:
Silvery white w/gray
speckles, dark gray, black.
• Most common (about
90%) form pre-1850:
a mixture of white and black
called “peppered.”
Case of the Peppered Moth
B
b
B
BB
Bb
Black
Peppered
b
Bb
bb
Peppered
White
What type of inheritance is this?
• Industrial Revolution
Case of the
Peppered Moth
• Pollution killed the
lichen on urban trees.
• Also…Coal soot
coated tree trunks,
turning them black.
• Let’s look at lichen on
trees…outside
Case of the Peppered Moth
• Try to find the silvery-white colored
peppered moth in the next slide.
Case of the Peppered Moth
Moth
Population
Light
Colored
Dark
Colored
1850 1950 1972
95%
5%
25%
5%
95%
75%
Today, about 90% of the population is light colored. Why
did the population shift back to pre-Industrial Revolution
composition?
Biston betularia
Theory of Natural Selection
(a) The dark form is more
visible on the light, lichencovered tree.
(b) On trees darkened by
pollution, the lighter form is
more visible.
Variation in the peppered moth.
Understanding Physical Anthropology and Archaeology, 9th ed., p. 29
But look at them without color vision.
Theory of Natural Selection
• The moths satisfy all four conditions for natural
selection:
• they reproduce;
• their color pattern is inherited;
• there is variation in their color patterns;
• the different forms have different fitness.
Evolution
• Change in the frequency of an allele within
the gene pool.
• Caused by: Natural Selection & Genetic
Drift
Evolution
• The Adaptation was the change in the
moth’s coloring
• Brought about by Natural Selection
Adapted to become…
Biston betularia f. typica
The white-bodied pepper-moth
The Black Bodied Peppr Moth
Biston betularia f. carbonaria
The black-bodied peppered moth
Conspicuous Behaviors
• California Killifish
Conspicuous behavior (increases or decreases)?
as
Intensity of Infection (increases or decreases)?
FUNGUS and FUNGI
• Parasitic FUNGI can change their hosts
behavior
• “Bite & Die” example
The fungi Cordyceps
A victimized carpenter ant
Cricket Suicide
• Parasitic worm (larvae)
•
•
•
•
Hairworm a.k.a. Gordian worm
Larvae are parasitic…Adults are free-living
Adults can only reproduce in WATER
http://neurophilosophy.wordpress.com/2006
/11/20/brainwashed-by-a-parasite/
The incredible story of
Phineas Gage
1823-1860
It all started on September 13th, 1848.
Gage was 25 years old, working on a railroad
construction crew in Vermont…
On display at
Harvard Medical School