Chapter 24 - Biology - "Origin of Species"

Biology chapter 24

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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