Notion of phylogeny Flashcards
What is ancestral trait
What we think was present in the common ancestor of the species of interest
What is character state
the alternate forms of a particular character
What is a clade
A group of organisms that include a common ancestor and all descendants (living and extinct) of that ancestor
What is convergent evolution
Organisms evolve structures that have similar (analogous) structures or functions in spite of their evolutionary ancestors being unrelated
What are derived traits
Just appeared (by mutation) in the most recent ancestor
- present only in a smaller group
What is divergent evolution
2 groups of the same species evolve different traits within those groups in order to accommodate for differing environmental and social pressures
What is homoplasy
The development of organs or other body structures within different species, which resemble each other and have the same functions, but no common ancestral origin
What is homology
The similarity of a structure or function of parts of different origins based on their descent from a common evolutionary ancestor
What does in-group mean
The group of living organisms whose relationships are being considered in a cladogram
What does monophyletic taxons mean
A single ancestor and all of its descendants (AKA lineage or clade)
What is a taxon
Group of 1 or more populations of an organism or organisms seen by taxonomists to form a unit
What are outgroups
Species or group of species closely related to but not included within a taxon
What does phylogeny mean
Representation of the evolutionary history and relationships between groups of organisms
What does phylogenetic trees mean
Diagram depicting lines of evolutionary descent of different species, organisms, or genes from a common ancestor
What does paraphyletic mean
An ancestor and some, but not all, of its descendants
