Phylogenetics uses evidence about organisms and genes to infer evolutionary history. This lesson introduces the kinds of evidence used, what phylogenetic trees represent, and how rooted and unrooted trees differ.
Phylogenetics is the study of evolutionary history through observable characteristics of organisms or genes. Phylogenetic inference uses empirical observations and heritable traits to estimate relationships and evolutionary history. Evidence can include DNA sequences, protein amino acid sequences, protein structure, and morphology—the form and structure of organisms.
All flashcards
Phylogenetic inference
Using empirical observations and heritable traits to estimate evolutionary relationships and history.
Homology and homoplasy
Homology reflects similarity explained by common ancestry; homoplasy is similarity arising independently or through independent loss.
Bootstrapping in phylogenetics
Repeatedly resampling data sites to estimate how consistently branches appear; it does not prove a tree is correct.
Phylodynamics
The study of how pathogen phylogenies relate to transmission processes and other population dynamics.
Phylogenetic drug discovery
Using evolutionary relationships to prioritize related organisms for screening for useful biological compounds.
Quiz questions
What does maximum-likelihood phylogenetic inference seek?Answer: Trees with high likelihood for the observed data under an evolutionary model.
Which approach groups organisms by overall observable similarity without using evolutionary history as its basis?Answer: Phenetics
What does a higher bootstrap replicability for a branch indicate?Answer: The branch appears more consistently across resampled datasets.
In an HIV forensic investigation, what can genetic relatedness between samples establish by itself?Answer: It cannot establish that one person transmitted HIV to another.
What is NeighborNet designed to display when distance data contain conflicting signals?Answer: A network that can represent relationships with conflicting signals.
Based on the Wikipedia article Phylogenetics, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.