Download Theory of Evolution

Theory of Evolution
Diversity of life
“Change over time”
Origins of Evolutionary Thought
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Spontaneous generation – life can arise form
nonliving material THIS IS FALSE
 Redi and Pasteur used controlled experiments to
disprove this idea
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Biogenesis – life only arises from existing life
 It has been accepted for over 100 years - TRUE
MORE RECENT RESEARCH
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Primordial Soup – Urey and Miller simulated
early conditions on earth and tried to form
complex organic compounds (all life is made up
of organic compounds). They made amino acids
RNA was formed from earth’s early atmosphere
RNA and DNA make amino acids (first
biological molecule) which link together to make
proteins. Protocells formed
Origins of Evolutionary Thought
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Jean-Baptiste Lamarck—1809, proposed
his hypothesis on the inheritance of
acquired characteristics. He said that by
use or disuse of organs, organisms acquired
or lost traits during their lifetime. These
traits could be passed to their offspring.
Slowly the species would change.
Ex:Parents are bodybuilders, therefore their
children will be born with big muscles.
Charles Darwin
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Evolution was first described by Charles
Darwin in his essay “Origin of Species”
written in 1859.
Most of his ideas about natural selection
came from a much earlier voyage he took
aboard the HMS Beagle, especially in the
South American Galapagos Islands.
Geologic Time Scale
Spindle diagrams – show
evolution of groups of organisms
Evidences of Evolution
Fossils, anatomy, embryology,
biochemistry
How do we know this?
Paleontology Fossils
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Fossils provide a record of evolutionary
history, and show how things have
changed over time.
The fossil record is by no means complete,
but our understanding of evolution
becomes more complete as more fossils are
found each year.
Fossils (continued)
Where do we find fossils?
Sedimentary
rock builds up
over time.
Paleontologists
may recover the
fossil at a much
later time in
history.
Relative Dating: As layers are added it
puts fossils in their order of existence.
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Index fossils are easy to recognize and have known time
periods so they are useful in determining how old that
layer is.
Ex. trilobites
Can tell which organisms are the oldest, most
recent, which have survived the most amount
of time, which covered the largest ecological
range, which locations have eroded.
Anatomy
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Examining various anatomical features
provides some evolutionary clues.
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Homologous structures
Analogous structures
Vestigial structures
Homologous Structures
Homologous Structures—Structures
with a common evolutionary origin.
Homologous structures demonstrate
divergent evolution—organisms that
have a common ancestor and were
once very similar have become
different over time
Homologous Structures
Analogous Structures
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Analogous Structures—similar structures on
very unrelated species. They don’t have a
common origin (no common ancestor) but
demonstrate adaptation to similar environments.
Analogous structures demonstrate convergent
evolution—organisms that don’t have common
ancestors and were once very different have
become more similar over time.
Vestigial Structures
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Vestigial structures—structures/organs
that serve no function in the modern
species but were useful to an ancestor.
The existence of vestigial structures
demonstrates change over time.
Vestigial Structures
Pelvic bones/femur in
whale
Blind cave salamander
(still has remnants of
eyes)
Embryology
Molecular Biology (biochemistry)
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Biochemistry—The study of the chemistry
of living things.
Similarities in the DNA, RNA, and protein
structures in species shows evolutionary
relationships.
The more similar the DNA, RNA, and
protein the more closely related the
organisms are.
Adaptations
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Adaptations amongst different organisms
in different climates/environments show
how species change over time to fit their
environment.
Ex: Camouflage, mimicry
Evolution
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Species change over time  they evolve
Takes a long time (thousands to millions of
years for the change to happen)
Spontaneous mutations lead to natural
selection
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Some organisms are more fit for survival than
others
Classifying Organisms
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Need a way to organize all of the
information we have.
Millions of species of living things on our
planet today
This gives a name based on a standard
method across the globe to each organism
so there is no confusion.
6 Kingdoms of Life
What is systematics, also
called taxonomy?
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The science of naming and grouping
organisms is called systematics
(sometimes still called taxonomy or
simply classification).
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Modern classification schemes
look beyond overall similarities and
differences and group organisms
based on evolutionary relationships
The goal of systematics
•Carolus Linnaeus was a Swedish
botanist
•Developed a 7-level (taxa)
classification system based on
similarities between organisms
•kingdom, phylum, class, order,
family, genus, species
Binomial Nomenclature
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In binomial nomenclature,
each species is assigned a
two-part scientific name.
Genus (capitalized), species
(not capitailized)
Ex. Homo sapien
For example, The polar bear is called
Ursus maritimus.
The first part of the name—Ursus—is the genus to
which the organism belongs. A genus is a group of
similar species. The genus Ursus contains five
other species of bears,
The second part of a scientific name—
maritimus for polar bears—is the species and is
often a description of the organism’s habitat or of an
important trait. The Latin word maritimus refers to
the sea:
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Human Classification
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Kingdom - Animalia
Phylum - Chordata
Class - Mammalia
Order - Primates
Family - Hominidae
Genus - Homo
Species - sapiens