W17 L1 - Phylogenetics Lecture Flashcards

Flashcards based on the phylogenetics lecture, covering key concepts and definitions.

What is a phylogeny?

A pattern of evolutionary relationships among species that descend from a common ancestor.

What is taxonomy?

The branch of phylogeny that studies the description, identification, nomenclature, and classification of species.

What is nomenclature?

Naming species using a two-word system (genus and species).

What is the binomial system?

An internationally agreed system in which the scientific name of an organism is made up of two words, the genus and the species.

List the categories in Linnaeus's hierarchical classification system.

Domain, kingdom, phylum, class, order, family, genus, and species.

What is a phylogenetic tree?

A hypothesis about the evolutionary relationships of species.

What are sister taxa?

Groups that share an immediate common ancestor on a phylogenetic tree.

What is an in-group in a phylogenetic tree?

All the species included in the lineage under consideration.

What is an out-group in a phylogenetic tree?

Species not closely related to the in-group used for comparison.

What is cladistics?

A group of organisms that share a common ancestry.

What is a clade?

A group of species that includes an ancestral species and all its descendants.

What is a monophyletic clade?

A clade consisting of an ancestor and all its descendants.

What is a paraphyletic clade?

A clade that includes an ancestor and some, but not all, of its descendants.

What is a polyphyletic clade?

A group that includes distantly related species but not their common ancestor.

What is homology?

Characteristics inherited from a common ancestor.

What is analogy?

Similar characteristics that evolved independently in different lineages due to similar environmental pressures.

What is synapomorphy?

A derived character shared by two or more lineages and present in their last common ancestor; defines monophyletic groups.

What is symplesiomorphy?

A shared ancestral character; related to paraphyletic groups.

What is homoplasy?

A convergent character (analogy); diagnoses polyphyletic groups.