Download Patterns of Evolution

EVOLUTION
cumulative change
in the heritable characteristics
of a population
Evidence of Evolution
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fossil record
homologous structures
ex. pentadactyl limb
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selective breeding
Industrial melanism
– ex. peppered moths
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ex. antibiotic resistance
ex. finches on Daphne major
vestigial structures
molecular biology
comparative embryology
Fossil Record of Horse Evolution
Horse Evolution
Fossil
Formation
Fossils
Layers
Radioactive decay of C-14 and K-40
half-life of C-14 = 5,730 yrs
good for fossils 1,000-100,000 ys
Used to date fossils
half-life of K-40 = 1.25 billion yrs
good for fossils older than 100,000 yrs
Homologous Structures
ex. the pentadactyl limb
Selective Breeding
Example: Peppered Moth
ADAPTIVE RADIATION
Hawaiian honey creepers
Darwin’s Finches
Finches on Daphne Major, Galapagos
Daphne Major is a small island
Geospiza fortis feeds on seeds
Beak size varies & inherited
El Nino (83) brings rain & cold –
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variety of seeds
La Nina (74-77) brings droughts –
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few small soft seeds
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more large seeds
Example:
Antibiotic Resistance
http://www.youtube.com/watch?v=zjR6L38yReE&safe=active
http://www.youtube.com/watch?v=6jBD8xfbf4Y&safe=active
Vestigial Structures
Comparative Embryology
Biochemical Analysis:
DNA & Amino Acid Sequences
Trends/Patterns of Selection
Original bell curve of population:
Directional Selection
Example: elephant trunk length
Stabilizing Selection
Example: human birth weight
Disruptive selection
Example: rabbit fur color on black & white stones, black, white, grey
Frequency-dependent Selection
https://cubanosune.wordpress.com/2012/06//
Sexual Selection
http://artscienceofnature.wordpress.com/category/phylum-mollusca/
DIVERGENT EVOLUTION
Polar bear
Brown bear
Species definition: two
organisms that can mate and
produce fertile offspring
CONVERGENT EVOLUTION
shark
dolphin
Counter shading fusiform shape
tuna
CONVERGENT EVOLUTION
Australian marsupials vs. American placentals
Coyote, groundhog, spiny anteater
Tasmanian devil (ext), wombat, banded anteater
Biogeography: Wallace’s Line
Bottleneck Effect
http://content.answers.com/main/content/wp/en/thumb/a/a9/150px-Polydactyly_01_Lfoot_AP.jpg
Founder Effect
SPECIATION:
allopatric
sympatric
Speciation mechanisms
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Gradualism
Puntuated Equilibrium
Hardy-Weinberg Equilibrium:
Allele frequencies remain stable over time.
Assumptions:
1.
No immigration or emigration
2.
No mutations
3.
Large population
4.
Random mating
5.
No natural selection
HW equations:
p +q = 1
p2 +
2pq +
q2 =
1
Hybrid Vigor
(aka heterozygous advantage)
WARNING COLORATION
aposematic coloring
MULLERIAN MIMICRY
WASP
BATESIAN MIMICRY
Monarch
Viceroy
Now thought to be
Mullerian mimicry
Coral snake and California king snake
“Red touch yellow, kill a
fellow. Red touch black,
venom lack”
BATESIAN MIMICRY
CAMOUFLAGE
CAMOUFLAGE
DISRUPTIVE COLORATION
EYESPOTS/STARTLE
COEVOLUTION
Rufous hummingbird & flower
Symbiotic: mutualistic
Cleaner fish
Clown fish and sea anemone
Algae & fungi = lichen
Bacteria in root nodules of legume
Symbiotic: mutualistic
Ants & acacia trees
Oxpecker bird and ox
Aphids & ants
Symbiotic: parasitic
Strangler fig
tapeworm
mistletoe
Symbiotic: commensalism
Remoras and shark
Sponge on scallop
Barnacles on whale
EVOLUTION PATTERNS Revu
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Disruptive, Stabilizing, Directional
Selection, Sexual, Frequency dependnt
Divergent vs Convergent evolution
Allopatric vs Sympatric speciation
Gradualism vs Punctuated Equilibrium
Adaptive Radiation
Artificial Selection
Mimicry and Camouflage
Coevolution and Symbiosis