Transcript EVIDENCE OF EVOLUTION

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Domain Bacteria is composed of organisms that
are much more common than Archaea and live
almost anywhere. There are more bacteria in a
person's mouth than there are people in the world.
Many are decomposers, some are
photosynthesizers, and a few cause disease. Most
bacteria cause disease by producing exotoxins that
harm human cells, while others cause illness as a
result of glycoproteins found on the outside of
their capsules. The bacteria in this group are
helically shaped and usually are found alone. They
can reach .5 mm long but are extremely thin.
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Domain Archaea is mostly composed of cells that
live in extreme environments. While they are able
to live elsewhere, they are usually not found there
because outside of extreme environments they are
competitively excluded by other organisms. It is
believed that Archaea are very similar to
prokaryotes that inhabited the earth billions of
years ago. It is also believed that eukaryotes
evolved from Archaea. Therefore, it is believed
that the domains Archaea and Bacteria branched
from each other very early in history, and
membrane infolding produced eukaryotic cells in
the archaean branch approximately 1.7 billion
years ago.
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The Domain Eukarya arose from the first
prokaryotic organisms more than 1.7 billion
years ago. It includes all of the organisms with
eukaryotic cells--that is, those with
membranous organelles (including
mitochondria and chloroplasts). The organisms
in this domain will be the focus of our
classifications; indeed, they represent the vast
majority of organisms we see each day.
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BACTERIA:
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Prokaryote
Single celled
 i.e.: bacteria(yogurt), streptococci (strep throat)
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ARCHAEA:
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Prokaryote
Single celled
Extremeophiles:
 Thermophiles, methanogens, halophiles
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PROTISTA:
Eukaryote
 Multicellular & Single Celled
 Mainly Heterotrophs, but a few are autotrophs
 Not bacteria, Not animals, Not plants
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 Slime molds, algae, diatoms
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FUNGI:
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Eukaryote
Multicellular
Heterotroph
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PLANTAE:
 Eukaryotes
 Multicellular
 Autotroph
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Animalia
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Eukaryote
Multicellular
Heterotroph
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Evolution:
The process of biological change by which descendents come to
differ from their ancestry.
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ORIGINS OF LIFE:
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Endosymbiotic Theory: is the accepted mechanism for how
eukaryotic cells evolved from prokaryotic cells.
Chemical Evolution: primordial soup or synthesis of organic
molecules.
 The early Earth had a chemically reducing atmosphere.
 This atmosphere, exposed to energy in various forms, produced
simple organic compounds ("monomers").
 These compounds accumulated in a "soup", which may have been
concentrated at various locations (shorelines, oceanic vents etc.).
 By further transformation, more complex organic polymers – and
ultimately life – developed in the soup.
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All shows signs of common ancestry
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Comparative Anatomy:
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Homologous structures, Analogous Structures, &
Vestigial Structures
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Comparative Embryology:
A. There is usually a difference in form between
embryo and adult.
B. Serial structures (e.g., segments, limbs) are usually
identical in the embryo, but specialized and diverged
in the adult.
C. Different species in the same Class (e.g.,
mammals) often have very similar embryos, even if
the adult forms are quite different.
D. Embryonic structure is unrelated to "conditions of
existence", unless the embryo is active (e.g., feeding)
E. Embryos are sometimes more highly "organized"
than adults (e.g., some parasitic forms).
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COMPARATIVE EMBRYOLOGY: Common Ancestry
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FOSSILS: Traces of organisms that existed in
the past.
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How the structure & form has evolved over time.
We compare older fossils to more recent or modern
examples.
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MOLECULAR EVIDIENCE:
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DNA usually over rules everything else to
prove/disprove evidence of evolution.
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GENE FLOW:
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Movement of Alleles from one population to
another.
 Movement between populations
 Increases genetic variation
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GENETIC DRIFT:
 Allele frequencies can change due to
 chance alone, could lead to extinction.
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SEXUAL SELECTION: Certain traits increase
mating selection.
Bigger tail = more females=more offspring
 Prettier song=more females=more offspring
 Very specific strips=more females=more offspring
 **(wrong stripes=no females=no offspring)
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NATURAL SELECTION: Certain traits maybe
an advantage for survival. Alleles for these
traits increase in frequency.
Darwin’s beak- adapt and evolve to survive
food differences. The small beaks had to
adapt/evolve or they would become extinct.
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BIOGEOGRAPHY:
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Physical barriers that divide a population into 2 or
more groups (speciation).
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MUTATION:
Random change of the DNA of a gene.
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RECOMBINATION:
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New allele combination
Increases variation which helps a species
adapt/evolve.
Small populations limit genetic variation. Limit the
gene pool= less ability to adapt/evolve. Even
leading to possible extinctionl.