Phylogenies Flashcards
Define taxonomy.
The science of the classification of organisms.
Define systematics.
Encompasses nomenclature, classification and taxonomy.
Define phylogeny.
The history of descent of a group of organisms from a common ancestor.
Define phylogenetics.
Evolutionary relationships between organisms.
Define ‘character’ in terms of phylogenetic trees.
A feature of the organisms e.g. flower colour, height.
Define ‘trait’ in terms of phylogenetic trees.
One form of a character e.g. blue flower colour, short height.
Define ‘homologous’ in terms of phylogenetic trees.
Traits inherited from a common ancestor.
Define ‘derived’ in terms of phylogenetic trees.
Traits that differ from the common ancestor.
Define homoplasies.
Similar character in two or more taxa that are not derived from a common ancestor.
Define ‘convergent evolution’.
Independent evolution of similar traits due to similar selection pressure e.g. wings in birds and bats.
Define parallel evolution.
Independent evolution of common traits in organisms sharing distant relatives e.g. patterns of butterfly wings.
Define evolutionary reversals.
The loss of a derived trait e.g. limbs of snakes, teeth of frogs.
