Related Experiment Video
Updated: May 24, 2026
12:00
A Practical Guide to Phylogenetics for Nonexperts
Published on: February 5, 2014
The probability of correctly resolving a split as an experimental design criterion in phylogenetics
1Department of Mathematics and Statistics, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4H7. susko@mathstat.dal.ca
Systematic Biology
|February 17, 2012
Summary
To improve phylogenetic tree accuracy, prioritize sampling taxa near the evolutionary split of interest. Adding more taxa is generally better than increasing sequence length, but strategic taxon deletion can also enhance reconstruction probabilities.
Area of Science:
- Phylogenetics
- Computational Biology
- Evolutionary Biology
Background:
- Accurate phylogenetic reconstruction is crucial for understanding evolutionary relationships.
- Maximum likelihood estimation is a common method for inferring phylogenetic trees.
- Evaluating experimental design for phylogenetic studies is essential for optimizing data collection.
Purpose of the Study:
- To evaluate experimental design strategies for phylogenetic reconstruction using large sequence-length approximations.
- To determine optimal strategies for increasing the probability of correctly resolving a specific evolutionary split.
- To compare the effectiveness of taxon sampling versus increasing sequence length.
Main Methods:
- Utilized large sequence-length approximations for phylogenetic reconstruction probabilities.
- Assessed maximum likelihood estimation under various experimental designs.
- Analyzed specific examples to evaluate design choices.
Main Results:
- Sampling taxa closest to the split of interest generally improves reconstruction probability.
- Increasing taxon sampling is often more beneficial than increasing sequence length.
- The benefit of sampling taxa on long edges depends on their evolutionary rates relative to sister lineages.
- Strategic deletion of distant taxa can improve, while excessive or poorly chosen deletions can decrease, reconstruction probabilities.
Conclusions:
- Experimental design significantly impacts phylogenetic reconstruction accuracy.
- Prioritizing taxon sampling near the focal evolutionary split is a key strategy.
- Careful consideration of taxon deletion and sequence length is necessary for optimal phylogenetic inference.
Related Concept Videos
02:46Chi-square Analysis
The chi-square test is a statistical hypothesis test. It is used to check whether there is a significant difference between an expected value and an observed value. In the context of genetics, it enables us to either accept or reject a hypothesis, based on how much the observed values deviate from the expected values.
The chi-square test was developed by Pearson in 1990.
The first step of performing a Chi-square analysis is to establish a null hypothesis, which assumes that there is no real...
The chi-square test was developed by Pearson in 1990.
The first step of performing a Chi-square analysis is to establish a null hypothesis, which assumes that there is no real...
01:28Microbial Phylogeny
Understanding the evolutionary relationships among microorganisms is fundamental to microbial ecology and taxonomy. Phylogenetic trees are essential tools for inferring these relationships, relying primarily on comparative analyses of molecular sequences such as DNA, RNA, or proteins. In microbial studies, these trees typically depict the evolutionary paths of diverse bacterial and archaeal species by mapping genetic differences accumulated over time.Phylogenetic trees are composed of tips,...
01:19Survival Tree
Survival trees are a non-parametric method used in survival analysis to model the relationship between a set of covariates and the time until an event of interest occurs, often referred to as the "time-to-event" or "survival time." This method is particularly useful when dealing with censored data, where the event has not occurred for some individuals by the end of the study period, or when the exact time of the event is unknown.
Building a Survival Tree
Constructing a survival tree begins...
Building a Survival Tree
Constructing a survival tree begins...
02:54Evolutionary Relationships through Genome Comparisons
Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse...
02:05Gene Evolution - Fast or Slow?
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
01:22Phylogenetic Species Concept in Microbiology
The phylogenetic species concept (PSC) is a framework used to delineate species based on evolutionary relationships, emphasizing shared ancestry and diagnosable genetic traits. Unlike morphological or biological species concepts, the PSC is particularly advantageous for microbial taxonomy, where traditional reproductive or phenotypic criteria often fall short due to the prevalence of asexual reproduction, minimal morphological differentiation, and widespread horizontal gene transfer among...