Summary
Genome-scale data resolve deep animal relationships, such as ctenophores versus sponges as sister group.
In depth
Molecular data reorganised animals into Lophotrochozoa, Ecdysozoa and Deuterostomia. Some questions persist: whether sponges or comb jellies branched first.
Large datasets reduce error but model misspecification may remain. Fossils calibrate trees. Disputes continue.
Key idea: genome data are rewriting animal family trees.
Early trees from morphology were revised by rRNA and then genomes: the animal tree of life has Ctenophora or Porifera at the base, then Placozoa, Cnidaria and Bilateria. Bilateria split into Protostomia (Ecdysozoa: arthropods, nematodes; Spiralia or Lophotrochozoa: molluscs, annelids, flatworms) and Deuterostomia (echinoderms, hemichordates, chordates). Xenacoelomorpha may be basal bilaterians or deuterostomes.
Phylogenomics uses hundreds to thousands of genes, and rare genomic changes (gene order, indels, microRNAs) as characters. Problems include long-branch attraction, compositional bias and conflicts between genes (incomplete lineage sorting). Resolving the order of early animals clarifies the evolution of nervous systems and muscles, which may have arisen once or twice.
Frequently asked questions
What is Animal Phylogenomics?
Genome-scale data resolve deep animal relationships, such as ctenophores versus sponges as sister group.
Which area of biology covers Animal Phylogenomics, and how advanced is it?
Animal Phylogenomics is one of the 53 topics in Zoology & Animal Diversity. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Protostomes and Deuterostomes, Vertebrates and Invertebrates, Animal Kingdom.
Why does Animal Phylogenomics matter?
A correct tree is the basis for understanding the evolution of traits.
Can you give an example of Animal Phylogenomics?
Tardigrades are ecdysozoans related to arthropods.
What should I learn before Animal Phylogenomics?
Work through the Beginner topics in Zoology & Animal Diversity first, such as Animal Kingdom, Vertebrates and Invertebrates, Sponges, then return to Animal Phylogenomics. Advanced topics assume the Intermediate vocabulary.
What topics are related to Animal Phylogenomics?
The closest topics to Animal Phylogenomics are Protostomes and Deuterostomes, Vertebrates and Invertebrates, Animal Kingdom, Body Cavities. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Animal Phylogenomics?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Animal Phylogenomics. To practise the whole of Zoology & Animal Diversity, use the Zoology & Animal Diversity quiz.
How is Animal Phylogenomics different from Protostomes and Deuterostomes?
Animal Phylogenomics: Genome-scale data resolve deep animal relationships, such as ctenophores versus sponges as sister group. Protostomes and Deuterostomes: Two animal lineages differing in embryonic development; deuterostomes include echinoderms and chordates. Read both side by side and note what each one explains.
How should I study Animal Phylogenomics step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Protostomes and Deuterostomes and explain the difference aloud. Finally, take the Zoology & Animal Diversity quiz and come back to this page for any question you miss.