7 Flashcards
Linnaean’s Taxonomy?
The scientific naming nomenclature (genus, species).
Rules for assigning scientific names? (2•)
•International code of botanical nomenclature (the rules for botanists)
•Each name must be unique
A scientific name is linked to? (3•)
•A specimen
•Formal published description
•An author
Classification Hierarchy? (•8)
Species -> Genus -> Family -> Order -> Class -> Phylum -> Kingdom -> Domain
Biological species concept with separate or same species? (5•)
Species separated
•Post-zygotic reproduction cannot happen. •Gene flow cannot happen. •They could interbreed but they wont in nature, thus gene flow cannot happen.
Species the same
•Individuals that are potentially interbreeding and should in nature •Gene flow should occur
If two populations of the same species stop interbreeding, are they considered separate species right away?
If they can still interbreed if they want to, then they would be the same species. So, it will take time and evolution for them to be considered separate species once they cannot interbreed at all.
Pre-zygote isolation? (5•)
•Temporal (populations are isolated because they breed at different times)
•Habitat (They are isolated because they breed in different habitats)
•Behavioural (Populations do not interbreed because their courtship displays differ)
•Gametic barrier (matings fail because eggs and sperm are incompatible)
•Mechanical (matings fail because males and females genitalia are incompatible)
Post-zygotic Isolation? (2•)
•Hybrid Viability (hybrid offspring do Nt develop normally and die as embryos)
•Hybrid sterile (hybrids offspring mature and become sterile as adults)
Why do reproductive barriers evolve?
•Isolated populations accumulate genetic differences since each population have different adaptations.
•Offspring among individuals from the same population have relatively high fitness
•Offspring among individuals from different populations may have lower fitness since they inherit a mix of traits.
•Since hybrids typically have lower fitness, selection will prefer mating between most similar individuals.
Limitations of the biological species concept? (2•)
•Organisms where determining sexual reproduction or genetic exchange is rare or absent.
•Organisms where mating tests are impractical or impossible
Morphospecies?
•Determining morphological differences when separating species.
Phylogenetic species?
The smallest possible clade determined by one or more shared derived characters (synapomorphies) but distinct enough.
synapomorphies?
A characteristic shared between an ancestral species and its descendants.
If two populations reside together in one taxa of a phylogenetic tree, then they are? (2•)
•One species because •gene flow is occurring.
Ecological Species?
A lineage or closely related set of lineages that occupy a unique niche and evolve separately from lineages occupying different niches.
Species concepts? (4•)
•Ecological species concept
•Biological species concept
•Phylogenetic species concept
•Morphological species concept
Sympatric speciation?
Geographic ranges overlap (e.g. gene flow can occur)
Dispersal and colonization? (2•)
•Isolation of a population due to a portion migrating to a new population that becomes separated. •Both populations MUST be evolving.
Vicariance? (2•)
•When a population becomes isolated due to an abiotic factor. •Both populations MUST be evolving.
Allopatric speciation?
When populations become separated by a barrier (e.g. gene flow halts).
Disruptive selection?
When two extreme phenotypes is selected for their own niches.
Mechanical isolation?
A type of prezygotic barrier where no fertilization can occur because of a physical incompatibility between reproductive organs.
Gametic Isolation?
When fertilization does not occur because the sperm and egg cannot produce a zygote.
