Classification and phylogeny Flashcards
What is a phenogram?
A diagram showing taxonomic relationships based on observable similarities without regard to evolutionary history.
What is a dendrogram?
A tree diagram showing taxonomic relationships.
What is cladistics/cladograms?
Attempts to infer phylogentic branching. It aims to present one single, real pattern of phylogenetic branching. Phylogeny is put first and classification is a by product.
How can a cladogram be produced?
Decide what the homologous characteristics are. Code them as discrete states and derive a minimum-length bifurcating network, retaining information on character distributions. Root the network.
What is the Euclidean distance?
The ordinary straight-line distance between two points.
What is the Manhattan distance?
The distance calculated using the number of coordinate point changes only.
What does parsimoneous mean?
A hypothesis in which the fewest evolutionary changes takes place.
What is a shared, derived character called?
A synapomorphy monophyletic group.
What is a shared, ancestral character?
A symplesiomorphy paraphyletic group.
What is a independently derived character called?
Analogy polyphyletic group.
What are the key features of a cladogram?
It’s a hierarchial clustering diagram (dendrogram), groups are formed on the basis of snapomorphies, characters have polarity and the cladogram is rooted, result is a phylogeny and the evolution of characters can be traced.
