, 20 March 1982, photo by Jim Scarff The right whales were first classified in the genus
Balaena in 1758 by
Carl Linnaeus, who at the time considered all of the right whales (including the bowhead) as a single species. Through the 19th and 20th centuries, in fact, the family Balaenidae has been the subject of great taxonometric debate. Authorities have repeatedly recategorized the three populations of right whale plus the bowhead whale, as one, two, three or four species, either in a single genus or in two separate genera. In the early whaling days, they were all thought to be a single species,
Balaena mysticetus. Eventually, it was recognized that bowheads and right whales were in fact different, and
John Edward Gray proposed the genus
Eubalaena for the right whale in 1864. Later, morphological factors such as differences in the skull shape of northern and southern right whales indicated at least two species of right whale – one in the Northern Hemisphere, the other in the
Southern Ocean. As recently as 1998, Rice, in his comprehensive and otherwise authoritative classification listed just two species:
Balaena glacialis (the right whales) and
Balaena mysticetus (the bowheads). ,
Patagonia In 2000, two studies of
DNA samples from each of the whale populations concluded the northern and southern populations of right whale should be considered separate species. What some scientists found more surprising was the discovery that the North Pacific and North Atlantic populations are also distinct, and that the North Pacific species is more closely related to the southern right whale than to the North Atlantic right whale. The authors of one of these studies concluded that these species have not interbred for between 3 million and 12 million years. and in 2002, the Scientific Committee of the
International Whaling Commission (IWC) accepted Rosenbaum's findings, and recommended that the
Eubalaena nomenclature be retained for this genus. A 2007 study by Churchill provided further evidence to conclude that the three different living right whale species constitute a distinct
phylogenetic lineage from the
bowhead, and properly belong to a separate genus. The following cladogram of the family Balaenidae serves to illustrate the current scientific consensus as to the relationships between the three right whales and the bowhead whale. A
cladogram is a tool for visualizing and comparing the evolutionary relationships between
taxa; the point where each node branches is analogous to an evolutionary branching – the diagram can be read left-to-right, much like a timeline. on a right whale
Whale lice,
parasitic cyamid crustaceans that live off skin debris, offer further information through their own genetics. Because these lice reproduce much more quickly than whales, their genetic diversity is greater. Marine biologists at the
University of Utah examined these louse genes and determined their hosts split into three species 5–6 million years ago, and these species were all equally abundant before
whaling began in the 11th century. The communities first split because of the joining of
North and
South America. The rising temperatures of the equator then created a second split, into northern and southern groups, preventing them from interbreeding. "This puts an end to the long debate about whether there are three
Eubalaena species of right whale. They really are separate beyond a doubt", Jon Seger, the project's leader, told BBC News.
Others The
pygmy right whale (
Caperea marginata), a much smaller whale of the Southern Hemisphere, was until recently considered a member of the Family Balaenidae. However, they are not right whales at all, and their taxonomy is presently in doubt. Most recent authors place this species into the
monotypic Family
Neobalaenidae, but a 2012 study suggests that it is instead the last living member of the Family
Cetotheriidae, a family previously considered extinct. Yet another species of right whale was proposed by
Emanuel Swedenborg in the 18th century—the so-called
Swedenborg whale. The description of this species was based on a collection of fossil bones unearthed at Norra Vånga, Sweden, in 1705 and believed to be those of
giants. The bones were examined by Swedenborg, who realized they belong to a species of whale. The existence of this species has been debated, and further evidence for this species was discovered during the construction of a motorway in
Strömstad, Sweden in 2009. To date, however, scientific consensus still considers
Hunterius swedenborgii to be a North Atlantic right whale. According to a DNA analysis conducted, it was later confirmed that the fossil bones are actually from a bowhead whale. ==Characteristics==