Front | Back |
Speciation
|
Origination of a new species, shown in fossil record
|
Macroevolution
|
Term that means an evolutionary change above the species level, including the appearance of evolutionary developments like flight that is used to define higher taxa
|
2 Basic Patterns of Evolutionary Change
|
Anagenesis and Cladogenesis
|
Anagenesis
|
(Strictly Phyletic evolution, meaning it can only apply to one species) An accumulation of changes that gradually transform a given species with different characteristics.
|
Cladogenesis
|
(Branching evolution, meaning it can promote biodiversity by increasing the number of species) Splitting a gene pool into two or more separate pools and each gives rise to one or more species
|
Biological Species Concept
|
Follows Ersnt Mayr's definition of "a population or group of populations whose members have the potential top interbreed in nature and produce viable fertile offspring with members of other populations
|
Types of Reproductive Isolation
|
Prezygotic and Postzygotic Barriers make this up.
|
Reproductive Isolation
|
Occurs when the existence of biological factors impede individuals from two different species from producing fertile offspring
|
Prezygotic Barriers
|
Impede mating between species or hinder fertilization of ova if species do mate.
|
Types of Prezygotic Barriers: pre-mating
|
Temporal, Habitat, Behavioral
|
Types of Prezygotic Barriers: pre-fertilization
|
Mechanical and Gametic
|
Habitat isolation
|
Type of prezygotic barrier occurs before mating when two species that occupy different habitats within the same area may encounter each other rarely, if at all, even though they are not isolated by obvious physical barriers, such as mountain ranges.
|
Temporal Isolation
|
Type of prezygotic barrier that occurs before mating attempt when species that breed during different times of the day, or during different seasons, or different years cannot mix their gametes.
|
Behavioral Isolation
|
Type of prezygotic barrier that occurs before mating attempt because courtship rituals that attract mates and other behaviors unique to a species are effective reproductive barriers even between closely related species. These enable mate recognition, a way to identify potential matches of the same species.
|
Mehcanical Isolation
|
Type of prezygotic barrier occurs after mating attempt when morphological differences between species prevent successful completion
|