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22 Cards in this Set

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Biological Species Concept
(H)
A definition of species that focuses on reproduction capabilities, where organisms from different populations are considered to be in the same species if they naturally interbreed and produce natural offspring.(H)
The oposite of Cladogenesis, in that, this concept suggests that the when species "A" evolves into species "B", the change is instantaneous, because the creature either belongs to one species or the other.
Anagenesis
(H)
The transformation of a single species over time.
(H)
AKA - Strait-line Evolution
Paleospecies
(H)
Species identified from fossil remains, based on their physical similarities and differences, relative to other species.
(H)
Used more as labels than as units representing the species concept.
Cladogenesis
(H)
The formulation of one or more new species (speciation) from another over time.
(H)
AKA - Branching Evolution

-To understand this concept, we usually draw an evolutionary "tree," showing the point at which a new "branch," or species, comes into being.
Reproductive Isolation
(H)
The genetic isolation of populations that may render them incapable of producing fertile offspring.
(H)
The Mule
Speciation
The origin of a new species.
Adaptive Radiation
(H)
The formation of many new species following the availability of new environments or the developement of a new adaptation.
(H)
-When new environments open up, or when new adaptations to a specific environment develop, many new species can form.
Gradualism
A model of evolutionary change whereby evolutionary changes occur at a slow, steady rate over time.
Punctuated Equilibrium
(H)
A model of macroevolutionary change in which long periods of little evolutionary change are followed relatively short periods of rapid evolutionary change.
(H)
Eldredge and Gould's hypthesis
Orthogenesis
(H)
A discredited idea that evolution would continue in a given direction because of some vaguely described "force".
(H)
As an alternative to the theory of "Natural Selection," this idea suggested that evolution would continue in the same direction until either a perfect structure was attained or a species became extinct.
Mass Extinction
Many species becoming extinct at about the same time.
Era(H)
Subdivision of a geologic eon.(H)
Eon->Era->Periods
Eon(H)
The major subdivision of geologic time.(H)
Eon->Era->Periods
Precambrian Eon
(H)
The First eon from the earth's beginning (4.6 billion years ago) until 545 million years ago. During this eon, single-celled and simple multicelled organisms first evolved.
(H)
Covers almost 90% of Earth's history
Period(H)
Subdivision of a geologic era.(H)
Eon->Era->Periods
Therapsid
An early group of mammal-like reptiles during the Paleozoic era; they were the ancestors of later mammals.
Paleozoic Era
(H)
Geologic era of the Phanerozoic eon, dating roughly between 545 and 245 million years ago, when the first vertibrates appeared.
(H)
-When Therapsids came around.
-Paleozoic-> Mesozoic-> Cenozoic
Phanerozoic Eon
(H)
The second eon that covers the past 545 million years to now.(H)
Including the eras: Paleozoic, Mesozoic, and Cenozoic.
Mesozoic Era(H)
Geologic era of the Phanerozoic eon, dating roughly between 245 and 65 million years ago, when the first mammals and birds appeared.(H)
"Age of Reptiles"
-Paleozoic-> Mesozoic-> Cenozoic
Cenozoic Era(H)
Geologic era of the Phanerozoic eon, dating roughly to last 65 million years. The first primates appeared during this era.(H)
"Age of Mammals"
-Paleozoic-> Mesozoic-> Cenozoic
Carl Sagon (1977)
Late Astronomer who used an analogy he called the "Cosmic Calender" to help put dates into perspective. "Imagine the entire history of of the universe, from it's beginning to the present, as taking a single year."
Eldredge and Gould (1972)

-Niles Eldredge and Stephen Jay Gould
(H)
Two scientists that developed the "Punctuated Equilibrium." They argue that stabilizing selection and other factors act to keep a species the same over time, and that the tempo of macro evolution is not gradual; but stable at times and rapid at other times.
(H)
Contrasts the gradualistic model