Morphological Characters Can Strongly Influence Early Animal Relationships Inferred from Phylogenomic Data Sets

Journal Article · Wed May 27 00:00:00 EDT 2020 · Systematic Biology

DOI:https://doi.org/10.1093/sysbio/syaa038· OSTI ID:1816872

Neumann, Johannes S. ^[1]; Desalle, Rob ^[2]; Narechania, Apurva ^[3]; Schierwater, Bernd ^[4]; Tessler, Michael ^[2]

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1. American Museum of Natural History, New York, NY (United States). Richard Gilder Graduate School. Division of Invertebrate Zoology. Sackler Inst. for Comparative Genomics
2. American Museum of Natural History, New York, NY (United States). Division of Invertebrate Zoology. Sackler Inst. for Comparative Genomics
3. American Museum of Natural History, New York, NY (United States). Sackler Inst. for Comparative Genomics
4. American Museum of Natural History, New York, NY (United States). Division of Invertebrate Zoology. Sackler Inst. for Comparative Genomics; Tierärztliche Hochschule Hannover (Germany). Division of Ecology and Evolution. ITZ

There are considerable phylogenetic incongruencies between morphological and phylogenomic data for the deep evolution of animals. This has contributed to a heated debate over the earliest-branching lineage of the animal kingdom: the sister to all other Metazoa (SOM). Here, we use published phylogenomic data sets ($$\sim $$45,000–400,000 characters in size with $$\sim $$15–100 taxa) that focus on early metazoan phylogeny to evaluate the impact of incorporating morphological data sets ($$\sim $$15–275 characters). We additionally use small exemplar data sets to quantify how increased taxon sampling can help stabilize phylogenetic inferences. We apply a plethora of common methods, that is, likelihood models and their “equivalent” under parsimony: character weighting schemes. Our results are at odds with the typical view of phylogenomics, that is, that genomic-scale data sets will swamp out inferences from morphological data. Instead, weighting morphological data 2–10$$\times $$ in both likelihood and parsimony can in some cases “flip” which phylum is inferred to be the SOM. This typically results in the molecular hypothesis of Ctenophora as the SOM flipping to Porifera (or occasionally Placozoa). However, greater taxon sampling improves phylogenetic stability, with some of the larger molecular data sets ($>$200,000 characters and up to $$\sim $$100 taxa) showing node stability even with $$\geqq100\times $$ upweighting of morphological data. Accordingly, our analyses have three strong messages. 1) The assumption that genomic data will automatically “swamp out” morphological data is not always true for the SOM question. Morphological data have a strong influence in our analyses of combined data sets, even when outnumbered thousands of times by molecular data. Morphology therefore should not be counted out a priori. 2) We here quantify for the first time how the stability of the SOM node improves for several genomic data sets when the taxon sampling is increased. 3) The patterns of “flipping points” (i.e., the weighting of morphological data it takes to change the inferred SOM) carry information about the phylogenetic stability of matrices. The weighting space is an innovative way to assess comparability of data sets that could be developed into a new sensitivity analysis tool.

• Sponsoring Organization: USDOE Office of Science (SC), Biological and Environmental Research (BER)
• Grant/Contract Number: SC0014377
• OSTI ID: 1816872
• Journal Information: Systematic Biology, Vol. 70, Issue 2; ISSN 1063-5157
• Publisher: Society of Systematic Biologists - Oxford University Press
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
Metazoa
Morphology
Phylogenomics
Weighting