Recaps Flashcards
Plant diversity is a result of…
Evolution
How can we tell this
Fossil evidence, shared charaters, geographical variation, ecological studies
fossils show??
Evolution of plant structures, origin and extinction of species, genera and families
Sources of variation
Mutation, Genetic recombination, Gene flow
Speciation
Allopatric, Peripheral isolation, sympatric speciation
Allopatric
(geographical) speciation- pop which are geographically separate
Peripheral isolation
Local speciation
Sympatric speciation
populations overlap geographically e.g polyploidy
Species concepts (biological)
Gap in fertility between 2 species e.g donkey and horse create a mule = sterile doesnt work within plants
Species concepts (Phenetic)
Gap in variation between species, two species are morphologically different, no clear gap in variation
Lineage has a unique history of….
-genetic, morphological and ecological changes
-interactions with other species and the other physical environment
-migration, dispersal and chance
Issues within species concepts
One set of rules for defining species, Taxa (including species) are hypotheses
Good hypotheses (species) stand up to field testing
Phylogeny
Evolutionary history of a group of organisms
Taxon (taxa)
group organisms (species or genera)
Sister group
Two taxa that share common ancestor (therefore not a unique phylogeny)
