Search results
Results From The WOW.Com Content Network
Biologists proposed that ctenophores constitute the second-earliest branching animal lineage, with sponges being the sister-group to all other multicellular animals (Porifera sister hypothesis). [8] Other biologists contend that ctenophores emerged earlier than sponges ( Ctenophora sister hypothesis ), which themselves appeared before the split ...
Other studies have presented evidence supporting Porifera as the sister to Parahoxozoa and Ctenophora as the sister group to the rest of animals (e.g. [5] [6] [7]), finding that nervous systems either evolved independently in ctenophores and parahoxozoans, [8] or were secondarily lost in poriferans. [9]
Eumetazoa (from Ancient Greek εὖ (eû) 'well' μετά (metá) 'after' and ζῷον (zôion) 'animal'), also known as diploblasts, Epitheliozoa or Histozoa, are a proposed basal animal clade as a sister group of Porifera (sponges).
The Benthozoa or Myriazoa [1] are a proposed basal animal clade consisting of the Porifera and ParaHoxozoa as a sister group of Ctenophora. [ 2 ] An alternative phylogeny is given by the Porifera-sister hypothesis in which Porifera are the first diverging animal group.
In March 2021, scientists from Dublin found additional evidence that sponges are the sister group to all other animals, [120] while in May 2023, Schultz et al. found patterns of irreversible change in genome synteny that provide strong evidence that ctenophores are the sister group to all other animals instead. [121]
Coelenterata is a term encompassing the animal phyla Cnidaria (corals, true jellies, sea anemones, sea pens, and their relatives) and Ctenophora (comb jellies). The name comes from Ancient Greek κοῖλος (koîlos) 'hollow' and ἔντερον (énteron) 'intestine', referring to the hollow body cavity common to these two phyla.
Molecular phylogenetics has supported both the sponge-sister and ctenophore-sister hypotheses. In 2017, Roberto Feuda and colleagues, using amino acid differences, presented both, with the following cladogram for the sponge-sister view that they supported (their ctenophore-sister tree simply interchanging the places of ctenophores and sponges ...
This proposed homology was however thrown into some doubt in 2013 by the still controversial suggestion that ctenophores, and not sponges, are the sister group to all other animals. [5] [6] More recent genomic work has suggested that choanoflagellates possess some of the important genetic machinery necessary for the multicellularity found in ...