Phylogenetic Trees and Systematics

These flashcards cover key concepts related to phylogenetic trees, systematics, and molecular evidence used in estimating evolutionary relationships.

What is phylogeny?

Phylogeny is the evolutionary history and relationships of a group of organisms.

What do phylogenetic trees represent?

Phylogenetic trees represent the evolutionary relationships and history of organisms.

What is a node in a phylogenetic tree?

A node is the point where a single lineage splits into distinct new lineages, representing an extinct ancestor.

What is the most recent common ancestor (MRCA)?

The MRCA is the youngest common ancestor for a particular group of taxa, represented by a node.

What is the difference between homology and analogy?

Homology is similarity due to inheritance from a common ancestor, while analogy is similarity due to convergent evolution.

What is the significance of branch lengths in phylogenetic trees?

Branch lengths can indicate the extent of genetic differences, evolutionary time, or are arbitrary in emphasizing branching patterns.

What is systematics?

Systematics is the field of organizing and classifying organisms based on evolutionary relationships.

What is the role of a taxonomist?

A taxonomist classifies organisms and uses a hierarchical model for naming species, developed by Carl Linnaeus.

What is the purpose of molecular systematics?

Molecular systematics uses molecular evidence, such as DNA sequences, to identify phylogenetic relationships.

What is horizontal gene transfer (HGT)?

HGT is the transfer of genes between unrelated species and complicates the estimation of phylogenies.