Transcript Introduction to Evolution Chapter 10 Honorsx

1785- James Hutton
 1798-Thomas Malthus
 1809- Jean Baptiste Lamarck
 1831 to 1835- Voyage of the H.M.S.
Beagle
 1833- Charles Lyell
 1858- Alfred Wallace
 1859- Charles Darwin
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Geologist
 Proposed that the Earth was millions (not
thousands) of years old
 Based on the processes of rock
upheaval (uplift) and weathering
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Economist
 Proposed that humans would run out of
resources like food and space if the
human population numbers continue to
grow
 If food and space are scarce, there will
be competition for them
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French naturalist
 Proposed one of the first theories about
how species change over a period of
time (evolution)
 In Lamarck’s theory, individuals evolved
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Three Principles
› Tendency Towards Perfection
 Innate tendency towards complexity and
perfection
› Use and Disuse
 Organism develops new adaptation by using the
structure more
 Organism loses an adaption by not using the
structure
› Inheritance of Acquired Traits
 Traits acquired by an organism can be passed on
to the next generation
Geologist
 Published “Principles of Geology”
 Also proposed that the Earth is very old
 Proposed the forces at work in geology
today are the same forces that have
shaped the structures throughout time
on Earth
 This had to take a long time
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Naturalist
 Independently proposes theory of
evolution
 Writes Darwin about theory prompting
him to publish his theory formed many
years before
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Born the same day as
Abraham Lincoln
Studied theology in college
Became the naturalist
aboard the H.M.S. Beagle
Proposed theory of evolution
based off of observation
from that trip
Published theory in On
the Origin of Species in 1859
Sailed from England
 Traveled to
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› South America
› Africa
› Australia
› New Zealand
› Galapagos
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Darwin studied
› Difference within and between species
› Living specimens
› Fossils
› Geology
Group of islands off the coast of South
America
 Each island has a unique climate
 Darwin observed
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› Marine iguanas
› Tortoises
› Finches
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Variation
› Individuals naturally vary from each other
› Variations that are genetically based can be
passed on from one generation to the next
(although Darwin did not know how)
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Struggle for Existence
› Most populations grow past their resources
› Organisms within a population must
compete for their share
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Food
Space
Mates
Other necessities
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Survival of the Fittest (Natural Selection)
› Organisms have adaptations (inherited
variations) that make them a good match to
their environment (fitness)
› Individuals with better fitness survive longer
and reproduce more therefore passing on
their genes
› Future generation have more individuals with
the well-fitted adaptation
› It is about reproduction not survival!!!
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Survival
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Camouflage
Bright coloration
Big Size
Heightened senses
Behavior
Reproduction
› Big size
› Costly structures
› Behavior
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Artificial Selection
› Most fit adaptations are based on human
choices
› Individuals are bred to pass on desired traits
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Descent with Modification
› Individuals have
common descent
› Evolution over a long
period of time diversifies
species
› All species descend from
common ancestor
› Cladograms- diagram
showing evolutionary relationships
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Fossil Record
› Darwin knew fossils represented dead
organisms
› Also knew that newer organisms were closer
to the top
› Record showed evidence of change over
time
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Geographical Distribution of Living
Species
› Beaks of Galapagos Finches
› Neck Length and Shell Shape for Tortoises
› Various Variations for Marine Iguanas
› Pattern of Organisms in Similar Environment
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Homologous and Vestigial Body
Structures
› Homologous
 Structures that develop from the same
embryonic tissues
 Mature forms often have similarities but may
look different and have different functions
› Vestigial
 Structures that no longer have a function for
an organism but are still present
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Embryology
› Many embryos
look similar to
each other during
development and
develop in similar
ways
Study of Evolution at the DNA or protein
levels
 Problem - related species have similar
DNA sequences
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Related species share a common
ancestral DNA. The closer the
relationship, the more similar the DNA
sequences should be.