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BLUE CARD!!!!
1. Choose a species of animals that Darwin observed and EXPLAIN the adaptation.
2. I.D. and EXPLAIN someone or something that influenced Darwin in his beliefs.
NOTE: Did I mention EXPLAIN……
Evolution
Darwin’s Theory of Evolution
Australopithecus 3.5 MYA
Neanderthal Man 80-50 TYA
Charles Darwin
English Born 1809 HMS Beagle - 1831 Naturalist Very Religious
Darwin’s Observations
Animals and plants were well adapted
Diverse reproductive strategies Puzzled by location of animals
Rabbits in Argentina, not in Australia Fossils
similar, dissimilar, Extinction
The Beagle’s Journey
Pinta IslandIntermediate shell
Pinta
Isabela IslandDome-shaped shell
Hood IslandSaddle-backed shellHoodFloreana
Santa Fe
Santa Cruz
James
Marchena
Fernandina
Isabela
Tower
Giant Tortoises of the Galápagos Islands
Section 15-1
The Galapagos Islands
DesertLarge rainfall
Intermediate Shell
Domed Shell
Saddle backed Shell
Climate variation throughout
Tortoises of the Galapagos
Saddleback long neck,
curved shell, found on Hood Island, desert like
Dome Shaped shorter neck,
domed shell, lush vegetation, covers the ground, Isabela island
Many different varieties in different locations
Finches
Journey Home
Animals and plants varied a great deal from island to island
Did the organisms on different islands belong to the same species?
Was the ancestor from S. America?
Influences on Darwin
Fossil Record
James Hutton - 1785
Earth - millions of years old, not 5700
Charles Lyell - 1833 Past events are explained by the
processes that scientists can see today. Made observations of Niagara Falls
Jean-Baptiste Lamarck - 1809 Proposes 1st theory of evolution
use vs. disuse acquired traits are passed on leads to changes in species
Lamarck’s Theory of Evolution
Thomas Malthus - 1798 Economist - unchecked population
growth leads to a lack of space and food
Frog Eggs - What detemines survival?
Artificial Selection
Farmers and breeders Selective Breeding
On his return
Marries Emma Wedgwood (1st cousin)
Has 10 children, 3 die before adulthood, many have medical issues (why do you think?) 3 sons are knighted.
1836-1859
Family Illness Atolls Barnacles Charles Lyell
1858
1858 - On Charles Lyell’s advice begins writing up his views for a book to be called Natural Selection.
1858 (June)
Receives letter from Alfred Wallace
He is collecting specimens in Indonesia.
Shared with Lyell
Darwin’s View - On the Origin of the Species - 1859
The Origin of Species
Natural Selection Survival of the Fittest Struggle for Existence Descent with Modifications
Darwin’s Evidence of Evolution
Fossil Record Distribution of Living Species Homologous Body Structures Embryo Development
Fossil Record
Information of past life, including structure of organisms and the order in which they lived
Fossils Provide Insight to the Past
Natural Variation passed on to future
generations
Struggle for Existence
Survival of the Fittest - (Natural Selection)
Individuals that are best suited for their environment have high levels of fitness and therefore survive and reproduce
Adaptations - physical characteristics or
behaviors
Camouflage
Descent with Modification
Species change overtime All organisms share a common
ancestor (common descent)
Reviewing Darwin’s Theory
Variation Large amounts of offspring Competition Struggle for Existence Survival of the Fittest Descent with Modification via
Natural Selection Common Decent
How does evolution really work?
Distribution of Living Species - I
Unrelated organisms look similar because of common ecological conditions - Convergent Evolution
Beaver
NORTH AMERICA
Muskrat
Capybara SOUTH AMERICA
Coypu
Geographic Distribution of Living Species
Beaver
Muskrat
Beaver andMuskrat
Coypu
Capybara
Coypu andCapybara
Distribution of Living Species - II
Finches - all share a common mainland ancestor, differences are due to the environment
Homologous Structures - same basic design,
modifications
Analogous StructuresSimilar Function/Looks different
Wing of insect, bird, bat, and pterosaur
Vestigial Organs - traces of homologous
structures
Embryo Development
Embryonic Cells develop in the same group and similar patterns
BiochemistryEx. Blood proteins, DNA,
etc.
Patterns of Evolution
Divergent Evolution
Adaptive Radiation Process by which a single species or
group evolves into several different forms that live in different ways
Darwin’s finches Hawaiian
honeycreepers
Convergent Evolution
Unrelated species become more and more similar in appearance as they adapt to the same environment Desert plants
Coevolution
Two species evolve due to their interactions Predators and their prey
Examples? Plants and pollinators
Examples?
Speciation Influences
Gene pool Geographic isolation Physical separation of members of a
population
Genetic Equilibrium
Results in NO EVOLUTION A population in which allele
frequencies do not change from generation to generation
1. No mutations occur2. No migration occurs3. There is a large population4. Individuals mate randomly5. Natural selection does NOT
occur
Disruption of Genetic Equilibrium
1. Mutations Physical change in a gene or
chromosome “Variations” Produce new alleles for a trait
Disruption of Genetic Equilibrium
2. Migration Movement of individual organisms into
or out of a population Immigration vs. Emigration
Disruption of Genetic Equilibrium
3. Genetic Drift A shift in the allele frequencies in a
population due to random events or chance
Disruption of Genetic Equilibrium
4. Extinction Species die off Members trait did not allow them to
survive and pass genes on to the next generation
The population didn’t have proper adaptations to survive and reproduce
Species is lost forever
Darwin’s notebooks
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