Related Experiment Video
Updated: Jan 8, 2026
10:55
Ablation of a Single Cell From Eight-cell Embryos of the Amphipod Crustacean Parhyale hawaiensis
Published on: March 16, 2014
13.0K
Phylogenetic Paradigm Shifts in Early Amniote Evolution
Kelsey M Jenkins1,2,3, Dalton L Meyer2, Bhart-Anjan S Bhullar2,3
1Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, MRC 121, PO Box 37012, Washington, DC 20013-7012, USA.
Systematic Biology
|December 13, 2025
Summary
Phylogenetic analyses reveal that taxon sampling significantly impacts early amniote evolutionary trees. Understanding these effects is crucial for accurately interpreting evolutionary patterns in mammals and reptiles.
Area of Science:
- Paleontology
- Systematics
- Evolutionary Biology
Background:
- The evolutionary relationships of early amniotes (mammals and reptiles) have seen significant shifts in recent studies.
- Canonical understandings of early amniote clades are challenged by new phylogenetic data.
Purpose of the Study:
- To construct a comprehensive amniote-wide phylogenetic dataset to clarify early amniote evolution.
- To investigate the impact of taxon sampling on phylogenetic tree topologies.
Main Methods:
- Compiled a large amniote-wide phylogenetic dataset with 590 characters and 150 taxa.
- Analyzed data using Bayesian and Parsimony frameworks.
- Conducted extensive taxon exclusion experiments to assess sampling effects.
Main Results:
- Different analytical frameworks (Bayesian vs. Parsimony) produced varying tree topologies.
- Taxon sampling was identified as a major driver of topological instability in early amniote phylogenies.
- Observed topologies align with recent publications, highlighting the influence of sampling strategies.
Conclusions:
- Taxon sampling profoundly affects early amniote phylogenetic reconstructions.
- Further detailed anatomical research and expanded morphological datasets are needed for unstable phylogenetic areas.
- Accurate interpretation of amniote evolution relies on robust phylogenetic methods sensitive to sampling biases.
Related Concept Videos
01:23Phylogeny
56.6K
Phylogeny is concerned with the evolutionary diversification of organisms or groups of organisms. A group of organisms with a name is called a taxon (singular). Taxa (plural) can span different levels of the evolutionary hierarchy. For instance, the group containing all birds is a taxon (comprising the class Aves), and the group of all species of daisies (the genus Bellis) is a taxon. Phylogenies can likewise include just one genus (i.e., depict species relationships) or span an entire kingdom.
56.6K
02:35What is Evolutionary History?
42.8K
Scientists record evolutionary history by analyzing fossil, morphological, and genetic data. The fossil record documents the history of life on Earth and provides evidence for evolution. However, both fossil and living organisms offer evidence that outlines Earth’s evolutionary history.
42.8K
01:24Eukaryotic Evolution
40.0K
The endosymbiont theory is the most widely accepted theory of eukaryotic evolution; however, its progression is still somewhat debated. According to the nucleus-first hypothesis, the ancestral prokaryote first evolved a membrane to enclose DNA and form the nucleus. Conversely, the mitochondria-first hypothesis suggests that the nucleus was formed after endosymbiosis of mitochondria.
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
40.0K
03:21Phylogenetic Trees
49.1K
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.
49.1K
01:54Convergent Evolution
31.3K
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.
31.3K
02:40The Tree of Life - Bacteria, Archaea, Eukaryotes
37.5K
The “tree of life” describes the evolution of life and the evolutionary relationships between organisms. The root of the tree is the common ancestor to all life on Earth. All other species radiate from this point, much like the branches of a tree. The numerous tips of these branches on the tree of life represent every living, or extant, species. Extinct species, which are species that no longer exist, can be found towards the center of the tree. Currently, these organisms, both...
37.5K