Names and taxonomy
chart emphasizing the subfamily Homininae and the tribe Hominini. After diverging from the line to Ponginae
the early Homininae split into the tribes Hominini
. The early Hominini split further, separating the line to Homo
from the lineage of Pan
. Currently, tribe
Hominini designates the subtribes Hominina
, containing genus Homo
, genus Pan
; and Australopithecina
, with several extinct genera—the subtribes are not labelled on this chart.
A model of the evolution of the genus Homo
over the last 2 million years (vertical axis). The rapid "Out of Africa
" expansion of H. sapiens
is indicated at the top of the diagram, with admixture
indicated with Neanderthals, Denisovans, and unspecified archaic African hominins. Late survival of robust australopithecines
) alongside Homo
until 1.2 Mya is indicated in purple.
- See Homininae for an overview of taxonomy.
The Latin noun homō (genitive hominis) means "human being" or "man" in the generic sense of "human being, mankind". The binomial name Homo sapiens was coined by Carl Linnaeus (1758).[a] Names for other species of the genus were introduced beginning in the second half of the 19th century (H. neanderthalensis 1864, H. erectus 1892).
Even today, the genus Homo has not been stricly defined. Since the early human fossil record began to slowly emerge from the earth, the boundaries and definitions of the genus Homo have been poorly defined and constantly in flux. Because there was no reason to think it would ever have any additional members, Carl Linnaeus did not even bother to define Homo when he first created it for humans in the 18th century. The discovery of Neanderthal brought the first addition.
The genus Homo was given its taxonomic name to suggest that its member species can be classified as human. And, over the decades of the 20th century, fossil finds of pre-human and early human species from late Miocene and early Pliocene times produced a rich mix for debating classifications. There is continuing debate on delineating Homo from Australopithecus—or, indeed, delineating Homo from Pan, as one body of scientists argues that the two species of chimpanzee should be classed with genus Homo rather than Pan. Even so, classifying the fossils of Homo coincides with evidence of: (1) competent human bipedalism in Homo habilis inherited from the earlier Australopithecus of more than four million years ago, as demonstrated by the ; and (2) human tool culture having begun by 2.5 million years ago.
From the late-19th to mid-20th centuries, a number of new taxonomic names including new generic names were proposed for early human fossils; most have since been merged with Homo in recognition that Homo erectus was a single and singular species with a large geographic spread of early migrations. Many such names are now dubbed as "synonyms" with Homo, including Pithecanthropus,
Classifying the genus Homo into species and subspecies is subject to incomplete information and remains poorly done. This has led to using common names ("Neanderthal" and "Denisovan"), even in scientific papers, to avoid trinomial names or the ambiguity of classifying groups as incertae sedis (uncertain placement)—for example, H. neanderthalensis vs. H. sapiens neanderthalensis, or H. georgicus vs. H. erectus georgicus. Some recently extinct species in the genus Homo are only recently discovered and do not as yet have consensus binomial names (see Denisova hominin and Red Deer Cave people). Since the beginning of the Holocene, it is likely that Homo sapiens (anatomically modern humans) has been the only extant species of Homo.
John Edward Gray (1825) was an early advocate of classifying taxa by designating tribes and families.
Wood and Richmond (2000) proposed that Hominini ("hominins") be designated as a tribe that comprised all species of early humans and pre-humans ancestral to humans back to after the chimpanzee-human last common ancestor; and that Hominina be designated a subtribe of Hominini to include only the genus Homo — that is, not including the earlier upright walking hominins of the Pliocene such as Australopithecus, Orrorin tugenensis, Ardipithecus, or Sahelanthropus.
Designations alternative to Hominina existed, or were offered: Australopithecinae (Gregory & Hellman 1939) and Preanthropinae (Cela-Conde & Altaba 2002);
and later, Cela-Conde and Ayala (2003) proposed that the four genera Australopithecus, Ardipithecus, Praeanthropus, and Sahelanthropus be grouped with Homo within Hominini (sans pan).