Molecular Phylogenetics
Molecular Phylogenetics - Related Videos
12:00
A Practical Guide to Phylogenetics for Nonexperts
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Cited by 11 •
2014
Here we describe a step-by-step pipeline for generating reliable phylogenies from nucleotide or amino acid sequence datasets. This guide aims to serve researchers or students new to phylogenetic...
03:21
Phylogenetic Trees
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2021
Phylogenetic trees come in many forms. It matters in which sequence the organisms are arranged from the bottom to the top of the tree, but the branches can rotate at their nodes without altering the information. The lines connecting individual nodes can be straight, angled, or even curved.The length of the branches can depict time or the relative amount of change among organisms. For instance, the branch length might indicate the number of amino acid changes in the sequence that underlies the...
03:21
Phylogenetic Trees
0 Views •
2026
Phylogenetic trees come in many forms. It matters in which sequence the organisms are arranged from the bottom to the top of the tree, but the branches can rotate at their nodes without altering the information. The lines connecting individual nodes can be straight, angled, or even curved.The length of the branches can depict time or the relative amount of change among organisms. For instance, the branch length might indicate the number of amino acid changes in the sequence that underlies the...
01:22
Phylogenetic Species Concept in Microbiology
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2026
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...
08:57
Using Phylogenetic Analysis to Investigate Eukaryotic Gene Origin
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Cited by 17 •
2018
A method of constructing a phylogenetic tree based on sequence homology of SWEETs from eukaryotes and SemiSWEETs from prokaryotes is described. Phylogenetic analysis is a useful tool for explaining the evolutionary relatedness between homologous proteins or genes from different organism groups.
FAQs
Sequence alignment places homologous DNA, RNA, or protein sequences in comparable positions so researchers can examine shared and variable characters. This organization is essential because evolutionary comparisons depend on evaluating corresponding sequence features rather than unrelated positions. The resulting pattern of similarities and differences provides the character information used to reconstruct relationships among organisms.
Models of sequence evolution provide a framework for interpreting how molecular characters may change over evolutionary history. Applying these models helps researchers infer branching patterns from aligned sequences instead of treating every observed difference as equivalent evidence. Because different relationships may remain plausible, statistical methods can then evaluate support for competing phylogenetic trees.
Molecular data can clarify relationships when observable characteristics do not distinguish evolutionary histories clearly. Comparisons of DNA, RNA, or protein sequences add characters that may support or challenge relationships suggested by morphology. This combined perspective is useful for classifying organisms and examining ancestry when physical traits alone produce uncertain or difficult-to-interpret patterns.
A typical analysis begins by comparing selected DNA, RNA, or protein sequences and aligning homologous regions. Researchers then identify shared and variable characters, apply models of sequence evolution, and infer branching patterns in a phylogenetic tree. Statistical methods are used afterward to assess support for competing relationships, producing an evolutionary hypothesis grounded in molecular evidence.
Molecular comparisons can help investigate species boundaries by revealing patterns of sequence similarity and difference among organisms. These results provide evidence for evaluating whether groups share a close evolutionary history or represent distinct lineages. The approach is especially valuable when classification based on morphology is ambiguous, helping researchers refine organismal identification and evolutionary interpretation.
Its evolutionary framework connects genetic differences with biological history across several research areas. Comparative genomics uses these relationships to examine organisms in an evolutionary context, while pathogen surveillance can trace patterns of ancestry among pathogen sequences. Studies of adaptation also benefit by linking genetic change to evolutionary history, helping explain diversification and biological differences.