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Evolution
for test- 1.29.10
42
Science
8th Grade
01/28/2010

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Term
Evolution
Definition
changes in inherited characteristics of a species over time
Term
Species
Definition
a group of organisms that share similar characteristics and can reproduce among themselves
Term
Lamark's theory
Definition
-acquired characteristics
-not supported by evidence
Term
Darwin
Definition

-through studying finches figured out natural selection

-first to realize that we need to look at traits of a population over time (population genetics)

Term
Natural Selection
Definition
organisms with traits best suited to their environment will more likely survive and reproduce
Term
variation
Definition
an inherited trait that makes an individual different from other members of its species
Term
adaptation
Definition
a variation that makes an organism better suited for its environment
Term
geographic isolation
Definition
can make two populations so different that they become different species
Term
gradualism
Definition
describes evolution as a slow, ongoing process
Term
punctuated equilibrium
Definition
model says that gene mutation can result in a new species in a relatively short time
Term
fossils
Definition
-found in sedimentary rock
-show evidence that living things evolved
Term
relative dating
Definition
looks at fossil location in a particular layer of rock, older rock layers are under new rock layers
Term
radiometric dating
Definition
compares the amount of radioactive element with the amount of nonradioactive element in a rock
Term
why might fossil records not be accurate?
Definition
-most organisms do not become fossils
Term
Embryology
Definition
-type of indirect evident supporting evolution
-study of embryos and their development, shows similarities among all vertebrate species
Term
Homologous structures
Definition
-type of indirect evident supporting evolution
-body parts can indicate that 2 or more species share common ancestors
-construction is similar but purpose is different
Term
Vestigial Structures
Definition
-type of indirect evident supporting evolution
-structures that don't seem to have a function but might have once functioned in an ancestor
Term
DNA (-type of indirect evident supporting evolution)
Definition
-can provide how closely related organisms are
Term
A. Genetic drift (changing allelic frequencies)
Definition
-any change in allelic frequencies that is due to chance
-2 types
Term
A. Founder effect
Definition
small percent of population migrate away and become a new population
Term
A. Bottleneck
Definition
a population declines to a very low number and then rebounds
Term
A. Migration (changing allelic frequencies)
Definition
creates a constant gene flow between populations
Term
A. Genetic mutations (changing allelic frequencies)
Definition
Term
A. Natural Selection (changing allelic frequencies)
Definition
Term
A. Sexual Selection (changing allelic frequencies)
Definition
Term
A. Fitness
Definition
reproductive success
Term
A. Directional Selection
Definition
-unfit genotype removed
Term
A. Stabilizing selection
Definition
-Average genotype becomes the norm
Term
A. Disruptive Selection
Definition
Extreme genotypes are favored
Term
A. Allopatric Speciation
Definition
having different homelands (caused by genetic drift)
Term
A. Sympatric speciation
Definition
same homeland but form a sub-population in the same area as the original population
Term
A. Analogous
Definition
same purpose and construction, not the same ancestor
Term
A. Divergent Evolution
Definition
one species gives rise to many species in response to the creation of a new habitat or another ecological opportunity
Term
A. Co-evolution
Definition
2 different species share a close relationship but as one species evolves it affects the evolution of other species
Term
Primate
Definition
group of mammals characterized by opposable thumbs, binocular vision and flexible shoulders
Term
Strepsirhines
Definition
lemurs and tarsiers
Term
Haplorhines
Definition
monkeys, apes and humans
Term
Australopithecus
Definition
-small brains
-monkey-like arms
-ability to walk upright on 2 feet
-plant eaters
-found in africa
Term
Lucy
Definition
oldest hominid skeleton
Term
Homo Habilis
Definition
-used tools, larger brain
-stone age-- africa
Term
Homo Erectus
Definition
-more sophisticated tools
-traveled from Africa to Europe and Asia
-size of modern humans
-language
-hunt and gather
Term
Homo sapiens
Definition
-modern humans
2 groups: 1st: Neanderthals:Europe, short, stocky and powerful
2nd:Cro-Magnon: MODERN MAN
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