1996/09/01 by John Gatesy, Cheryl Y. Hayashi, Matthew A. Cronin +2 · 2 citations
Biochemistry, Genetics and Molecular Biology · Engineering · Environmental Science · #Biology #Borehole #Cetacea #Clade #Deposition (geology) #Drainage #Drill cuttings #Drilling #Drilling and Well Engineering #Drilling fluid #Engineering #Environmental science #Evolutionary biology #Gene #Genetics #Genomics and Phylogenetic Studies #Geology #Geomorphology #Geotechnical engineering #Groundwater flow and contamination studies #Hippopotamus #Identification and Quantification in Food #Marine animal studies overview #Materials science #Mechanics #Metallurgy #Mineral Processing and Grinding #Most recent common ancestor #Particle deposition #Petroleum engineering #Phylogenetic tree #Phylogenetics #Sediment #Shear stress #Sister group #Suspension (topology) #Turbulence #Water flow #Water hammer #Zoology
paper · pdf · doi:10.1093/oxfordjournals.molbev.a025663
openalex publication_date 2014/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/04/28
The inferred transition from terrestrial hoofed mammal to fully aquatic cetacean has been intensively studied with fossil evidence. However, large sections of this remarkable evolutionary sequence are missing. Phylogenetic analysis of extant taxa may help to fill in some of these gaps. In this report, kappa-casein (exon 4) and beta-casein (exon 7) milk protein genes from cetaceans and other placental mammals were PCR-amplified, sequenced, and aligned to previously published sequences. Phylogenetic analyses of the casein data suggest that hippopotamid artiodactyls are more closely related to cetaceans than to other artiodactyls (even-toed hoofed mammals). An analysis of the nuclear casein sequences combined with published mitochondrial cytochrome b DNA sequences also supports the Cetacea/Hippopotamidae sister group. This affinity implies that some of the aquatic traits of cetaceans were derived in the common ancestor of Cetacea and Hippopotamidae. An extant "missing link" to Cetacea may have been overlooked by science since the description of the semiaquatic Hippopotamus in 1758. Paleontological information is grossly inconsistent with this hypothesis. If the casein phylogeny is accurate, large gaps in the fossil record as well as extensive morphological reversals and convergences must be acknowledged.