Terms
Analogous trait
-
A trait that is morphologically and functionally similar to another, but which
arose from a different ancestral condition. Compare with homologous traits
Area cladogram
-
A tree diagram showing the evolutionary relationships between species and the
geographical areas in which they are found.
Ecological Biogeography
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The sub-field of biogeography that deals with the current interactions of
species with their environments and each other on a relatively short time scale.
Fossil record
-
The grouping of fossilized remains according to relative and absolute age.
Historical Biogeography
-
The sub-field of biogeography concerned with the origins and evolutionary
histories of species on a long time scale.
Homologous traits
-
Traits found in different species that are morphologically and functionally
similar and that arose from the same ancestral condition. Compare with
analogous traits.
Hypothesis of neutral evolution
-
The hypothesis holding that most of the variability in molecular structure does
not affect the molecule's functionality. Most of the variability occurs outside
of the functional regions of the molecule. Changes that do not affect
functionality are called "neutral substitutions" and their accumulation is not
affected by natural selection.
Molecular clocks
-
A molecular clock is a molecule that has remained functionally unchanged for a
long period of time and that has a constant rate of accumulation of neutral
substitutions. See hypothesis of neutral evolution.
Species richness
-
The number of different species that inhabit an area.
Species richness equilibrium model
-
A model of species migration and extinction which predicts that species
richness in an area will tend toward an equilibrium number of species, where
rates of immigration and extinction balance.
Trace fossils
-
Fossilized imprints of objects. For example, fossilized footprints are trace
fossils.
