Land and species Flashcards
Biogeography
study of where species are found in relation to space and time
Phylogeography
genetics used to understand biogeography (fossils, ore deposits, etc.
)
Australian diversity is a result of…
history, biotic/abiotic environment and human impact
Historical movement of earth
Pangea 1 supercontinet
Laurasia/gondwana = major life forms across two continents
Separation of gondwana –> austealia breaks away
Norward movement leads to desertification
Wallaces Line
Biogeographical barrier (changes in environment between Australia and Southeast Asia)
Allopatric Speciation
diverge in isolation
- geographic isloation
- caused by drift or selection (adaptations)
- reproductive isolation
Parapatric speciation
diverge in contact
- two areas but there is contact
- primary contact = contrasting environments in close proximity -> gene breakdown
- secondary contact = separated and then reunited before completed speciation (less desired traits in hybrids - forces speciations on either end of spectrum)
Sympatric speciation
diverge among each other (mixed population)
- one population with gene breakdown
- strong selection drives ecotypes (different habitat types within the same environment)
- proximity breeding
(African fish example)
Taxonomy
classifying diversity
75% invertebrates
11% plants
7% vertebrates
Species
group of potentially and actually interbreeding populations, reproductively isolated from other groups
Reproductive isolation
cant breed together to produce successful offspring
Premating isolation
could but dont breed together
- mate choice
- flowering times
- habitat differences
Postmating isolation
mate but dont produce successful offspring
- premature death
- sterile offspring
Biological species concept
defines species taxon as group of organisms that can successfully interbreed
- based on speciation process
Issues with BSC
- hybridization
- how do you determine level of interbreeding?
- if populations dont occur together are they 100% reproductively isolated?
- asexual reproduction
Phylogenetic species concept
phyloGENETIC rule to define species
- divergence determined through tree groups
- consider genetics, morphology, ecology, and mating traits
Linnaean classification system
Kingdom Phylim Class Order Family Genus Species
Binomial nomenclature
unique names created (no species will have the same name as another)
genus species
