Chapter 22 - Speciation Flashcards
Macro evolution
Includes evolutionary changes that create new species and groups of species
Responsible for speciation
Speciation
The process of species formation
Most commonly used species concepts
- Morphological species concept
- Biological species concept
- Phylogenetic species concept
Morphological species concept
Biologists can identify different species based on the visible anatomical characteristics
Biological species concept
Biological species concept emphasizes on reproductive isolation
Members of different species cannot produce viable offspring
Phylogenetic species concept
Phylogenetic species concept use both morphological and genetic sequence data
Clinal variation
Cline occurs when a species occurs over a large, environmentally diverse area may exhibit a pattern of smooth variation in traits along a geographical gradient.
- Ecological isolation
Different species occupy different habitats in the same area
They are most likely not to encounter each other
Temporal isolation
Different species occupy different times or seasons
Behavioral isolation
In animal species, courtship behavior differs
If the song, call, dance, or pheromone is the wrong one, then the individual will be rejected
Mechanical isolation
Differences in the reproductive structures may prevent individuals from being able to reproduce.
Gametic isolation
There is an incompatibility between the sperm of one species and the eggs of another species
Hybrid inviability
Two different species were able to reproduce and produce a zygote but the embryo did not develop completely or the offspring died at an early age
Hybrid sterility
Hybrid sterility is when the healthy hybrid offspring cannot reproduce
Hybrid breakdown
Hybrid breakdown is when a hybrid can reproduce but the second generation of hybrids may have a reduced survivability or fertility
Allopatric speciation
Happened when a physical barrier subdivided a population and the two separated populations evolved into different species
Sympathetic speciation
Reproductive isolation evolves between subgroups that arise within one population
Gradualism
Each new species evolves continuously over long spans of time
Large phenotypic differences that produce new species are due to the accumulation of many small genetic changes
Punctuated equilibrium
Tempo more sporadic
Species in equilibrium for long period and the short rapid bursts of changes
