Articles

Journal of Molecular Evolution

, Volume 43, Issue 2, pp 83-92

Mammalian evolution and the interphotoreceptor retinoid binding protein (IRBP) gene: Convincing evidence for several superordinal clades

  • Michael J. StanhopeAffiliated withBiology and Biochemistry, Queen's University
  • , Marta R. SmithAffiliated withOceanographic Center, Nova Southeastern University
  • , Victor G. WaddellAffiliated withBiology and Biochemistry, Queen's University
  • , Calvin A. PorterAffiliated withDepartment of Anatomy, Wayne State University
  • , Mahmood S. ShivjiAffiliated withOceanographic Center, Nova Southeastern University
  • , Morris GoodmanAffiliated withDepartment of Anatomy, Wayne State University

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Phylogenetic relationships of 25 mammalian species representing 17 of the 18 eutherian orders were examined using DNA sequences from a 1.2-kb region of the 5′ end of exon 1 of the single-copy nuclear gene known as interphotoreceptor retinoid binding protein (IRBP). A wide variety of methods of analysis of the DNA sequence, and of the translated products, all supported a five-order clade consisting of elephant shrew (Macroscelidea)/aardvark (Tubulidentata)/and the paenungulates (hyracoids, sirenians, and elephants), with bootstrap support in all cases of 100%. The Paenungulata was also strongly supported by these IRBP data. In the majority of analyses this monophyletic five-order grouping was the first branch off the tree after the Edentata. These results are highly congruent with two other recent sources of molecular data. Another superordinal grouping, with similar 100% bootstrap support in all of the same wide-ranging types of analyses, was Artiodactyla/Cetacea. Other superordinal affinities, suggested by the analyses, but with less convincing support, included a Perissodactyla/Artiodactyla/Cetacea clade, an Insectivora/Chiroptera clade, and Glires (an association of rodents and lagomorphs).

Key words

Mammalian phylogenetics Interordinal relationships IRBP Cetaceans Elephant shrew Aardvark