(† =extinct =fossil)
The HOMININI is a taxonomical tribe of the subfamily
Homininae ; it
comprises three subtribes:
Hominina , with its one genus
Australopithecina , comprising at least three extinct (or, fossil)
genera (see inset at bottom right); and
Panina , with its one genus
Pan , the chimpanzees (see the evolutionary tree below). Members of
the human clade , that is, the subtribe Hominina, include only the
genus Homo; it is the "human" branch as depicted in an evolutionary
tree chart (see below). Over the past several decades, a broad
community of scientists and scholars have adopted the term "HOMININS"
to emphasize the history of proto-humans speciating from the stem
chimpanzees—which process began about eight million years ago; see
chimpanzee-human last common ancestor (CHLCA) . Thus, the genus Homo
and those species of the australopithecines that arose after the split
from the last common ancestor with chimpanzees are called "hominins".
Not all hominins are directly related to the emergence of early Homo.
Researchers proposed the taxon
Hominini on the basis that the least
similar species of a trichotomy should be separated from the other
two. The common chimpanzee and the bonobo of the genus Pan are the
closest living evolutionary relatives to humans, sharing a common
ancestor with humans about four to seven million years ago. Most DNA
studies find that humans and Pan are 99% identical, but one study
found only 94% commonality, with some of the difference occurring in
* 1 Taxonomy
* 1.1 Complex speciation and hybridization
Cladogram of the superfamily
* 2 Pan–
* 3 See also
* 4 References
* 5 External links
The human clade, the subtribe Hominina, contains only Homo; it is the
"human" branch as depicted in a tree of life or in an evolutionary
tree chart (see below). It is a branch of the family
hominids—one of the families of the order primates known as the
"family of great apes ". One community of scientists and scholars
emphasizes the long, drawn-out speciation of proto-humans from stem
chimpanzees—which process started sometime after about eight million
years ago (Mya) and may have taken until four Mya to completion (see
Complex ... hybridization ). This community applies the term HOMININ
Homo species and those species of australopithecines and other
genera that arose after the split from the line to chimpanzees (see
cladogram below); that is, they distinguish fossil members on the
human side of the split, as hominins, from those on the chimpanzee
side, as not hominins.
It is likely that the australopithecines gave rise to the earliest
Homo genera. The earliest hominins also produced lines, whether of
australopithecines or other genera, that arose after speciating from
the line to chimpanzees but went extinct without developing into Homo;
thus, not all hominins are ancestral to the emergence of early Homo.
(See "Genera", classification infobox.)
All the listed fossil genera currently are being, or have been,
evaluated for: 1) probability of being ancestral to Homo, and 2)
whether they are more closely related to
Homo than to any other living
primate—two traits that could identify them as hominins. Some,
Ardipithecus , and
Australopithecus , are broadly thought to be ancestral and closely
related to Homo; others, especially earlier genera, including
Sahelanthropus (and perhaps
Orrorin ), are supported by one community
of scientists/ scholars but doubted by another. Evolutionary
tree chart emphasizing the family
Hominidae and the tribe Hominini.
After diverging from the line to
Ponginae the subfamily Homininae
split into the tribes
Gorillini . The
further, splitting the line to
Homo from the line to Pan. Currently,
Hominini designates three subtribes:
Hominina , containing genus
Panina , containing genus Pan; and the extinct Australopithecina
, the australopithecines—several genera that arose on the 'human
side' after the split from the line to the chimpanzees. (The
subtribes, including the genera Australopithecina, are not labelled on
Orrorin existed during the estimated duration
of the (ancestral) chimpanzee-human speciation events, within the
range of eight to four million years ago (Mya); see
CHLCA . So one or
both of these specimens may yet prove to be "hybrid" (see Complex
..hybridization ), and thereby ancestral to both Pan and Homo—or to
Pan instead of Homo. Very few fossil specimens have been found on the
Pan 'side' of the split from the common ancestral line. News of the
first fossil chimpanzee, found in Kenya, was published in 2005.
However, it is dated to very recent times—between 545 and 284
thousand years ago radiometric (kyr).
In the proposal of Mann and Weiss (1996), the tribe Hominini
includes Pan as well as Homo, but within separate subtribes.
(by inference) all bipedal apes are referred to the subtribe Hominina
, while Pan is assigned to the subtribe
Panina . Wood (2010) discusses
the different views of this taxonomy.
COMPLEX SPECIATION AND HYBRIDIZATION
Regarding the speciation of proto-humans from stem chimpanzees there
is evidence that a complex speciation -hybridization process—rather
than a clean split—occurred between the two lineages. Such a complex
process greatly confuses estimating the actual age of the final
Homo-Pan divergence, or split. Different chromosomes appear to have
split at different times, over possibly as much as a four-million-year
period; this indicates a long and drawn out speciation process with
broad-scale hybridization activity occurring between the two emerging
lineages as late as the period 6.3 to 5.4 Mya, according to Patterson
et al. (2006), This research group noted that one (hypothetical) late
hybridization period was based in particular on the similarity of X
chromosomes in the proto-humans and stem chimpanzees, suggesting the
final divergence even as recent as 4 Mya. Wakeley (2008) rejected
these hypotheses; he suggested alternative explanations, including
selection pressure on the
X chromosome in the ancestral populations
prior to the chimpanzee–human last common ancestor (CHLCA).
CLADOGRAM OF THE SUPERFAMILY HOMINOIDEA
This cladogram shows the clade of superfamily
Hominoidea and its
descendent clades; it features the hominids, which is the family
Hominidae. The hominids comprise the orangutans, gorillas, and the
clade of the tribe Hominini—which groups the subtribe Panina
(chimpanzees), the extinct subtribe Australopithecina
(australopithicenes), and the subtribe
Hominoidea (≈20 to 15 Mya)
Hominidae (≈14 Mya)
Australopithecina (australopithecines )
The scientist/ scholar community has not reached a consensus
regarding a taxon for the (probable) ancestral stem between the
Hominina and Australopithecina—hence the blank space (*)
after the tribe-label "Hominini". However, the community has
informally adopted a name to refer to humans and their closest
biological relatives. These comprise the several
one of which is not extinct—plus those australopithecines that rose
after the splitting of the lineage of chimpanzees from the last common
ancestor(s) (LCA). These humans and australopithecines collectively
are called HOMININS.
Morphological and geological/ radiometric analyses indicate that
ancestral hominids, that is, the most recent common ancestors (MRCA,
the equivalent of LCA) of the subfamilies
Homininae and Ponginae,
lived until at least about 14 million years ago (Mya), prior to the
ancestors of orangutans speciating from the common ancestors.
Previously, the common ancestors of hominids had speciated from the
superfamily Hominoidae between 20 and 15 million years ago. Recent
molecular analyses have refined some paleo-chronological dates for the
emergence of specific clades.
It has been suggested that Chimpanzee–human last common ancestor
be merged into this article. (Discuss ) Proposed since December 2015.
Dawn of Humanity (2015 PBS film)
History of hominoid taxonomy
List of human evolution fossils (with images)
* ^ Fuss, J; Spassov, N; Begun, DR; Böhme, M (2017). "Potential
hominin affinities of
Graecopithecus from the Late Miocene of Europe".
PLoS ONE. 12 (5).
* ^ "Chimps and Humans Very Similar at the
News.mongabay.com. Retrieved 2009-06-06.
* ^ Mary-Claire King (1973) Protein polymorphisms in chimpanzee and
human evolution, Doctoral dissertation, University of California,
* ^ Wong, Kate (1 September 2014). "Tiny Genetic Differences
between Humans and Other
Primates Pervade the Genome". Scientific
* ^ Minkel JR (2006-12-19). "Humans and Chimps: Close But Not That
Close". Scientific American.
* ^ Bradley, B. J. (2006). "Reconstructing Phylogenies and
Phenotypes: A Molecular View of
Human Evolution" . Journal of Anatomy.
212 (4): 337–353. PMC 2409108 . PMID 18380860 . doi
* ^ Wood and Richmond.; Richmond, BG (2000). "
taxonomy and paleobiology" . Journal of Anatomy. 197 (Pt 1): 19–60.
PMC 1468107 . PMID 10999270 . doi
:10.1046/j.1469-7580.2000.19710019.x . Thus human evolution is the
study of the lineage, or clade, comprising species more closely
related to modern humans than to chimpanzees. Its stem species is the
so-called ‘common hominin ancestor’, and its only extant member is
Homo sapiens. This clade contains all the species more closely-related
to modern humans than to any other living primate. Until recently,
these species were all subsumed into a family, Hominidae, but this
group is now more usually recognised as a tribe, the Hominini.
* ^ A B Coyne, Jerry A. (2009) Why
Evolution Is True, pp.197-208,
244, 248. ISBN 978-0-670-02053-9 (hc), ISBN 978-0-14-311664-6 (pbk).
Penguin Books Ltd, London. "Anthropologists apply the term hominin to
all the species on the "human" side of our family tree after it split
from the branch that became modern chimps." (p.197)
* ^ Coyne, Jerry A. (2009) Why
Evolution Is True, pp.202-204. ISBN
978-0-670-02053-9 (hc), ISBN 978-0-14-311664-6 (pbk). Penguin Books
Ltd, London. "After A. afarensis, the fossil record shows a confusing
melange of gracile australopithecine species lasting up to about two
million years ago. … he late australopithecines, already bipedal,
were beginning to show changes in teeth, skull, and brain that presage
modern humans. It is very likely that the lineage that gave rise to
modern humans included at least one of these species."
* ^ Cameron, D. W. (2003). "Early hominin speciation at the
Plio/Pleistocene transition.". HOMO - Journal of Comparative Human
Biology. 54 (1): 1–28. PMID 12968420 . doi :10.1078/0018-442x-00057
* ^ A B
* ^ Potts, Richard and Sloan, Christopher. “What Does It Mean to
Be Human?”, pp. 31-42. ISBN 978-1-4262-0606-1 . National Geographic
* ^ Brunet, Michel; Guy, F; Pilbeam, D; MacKaye, H. T.; Likius, A;
Ahounta, D; Beauvilain, A; Blondel, C; Bocherens, H; Boisserie, JR; De
Bonis, L; Coppens, Y; Dejax, J; Denys, C; Duringer, P; Eisenmann, V;
Fanone, G; Fronty, P; Geraads, D; Lehmann, T; Lihoreau, F; Louchart,
A; Mahamat, A; Merceron, G; Mouchelin, G; Otero, O; Pelaez Campomanes,
P; Ponce De Leon, M; Rage, J. C.; et al. (July 2002), "A new hominid
from the Upper Miocene of Chad, Central Africa", Nature, 418 (6894):
145–151, PMID 12110880 , doi :10.1038/nature00879 , Sahelanthropus
is the oldest and most primitive known member of the hominid clade,
close to the divergence of hominids and chimpanzees.
* ^ Wolpoff, Milford; Senut, Brigitte; Pickford, Martin; Hawks,
John (October 2002), "
Sahelanthropus or 'Sahelpithecus'?", Nature, 419
Bibcode :2002Natur.419..581W, PMID 12374970 , doi
Sahelanthropus tchadensis is an enigmatic new
Miocene species, whose characteristics are a mix of those of apes and
Homo erectus and which has been proclaimed by Brunet et al. to be the
earliest hominid. However, we believe that features of the dentition,
face and cranial base that are said to define unique links between
this Toumaï specimen and the hominid clade are either not diagnostic
or are consequences of biomechanical adaptations. To represent a valid
clade, hominids must share unique defining features, and
Sahelanthropus does not appear to have been an obligate biped.
* ^ McBrearty, Sally; Nina G. Jablonski (2005). "First fossil
chimpanzee". Nature. 437 (7055): 105–108. Bibcode
:2005Natur.437..105M. PMID 16136135 . doi :10.1038/nature04008 .
* ^ Mann, Alan; Mark Weiss (1996). "Hominoid Phylogeny and
Taxonomy: a consideration of the molecular and Fossil Evidence in an
Historical Perspective". Molecular Phylogenetics and Evolution. 5 (1):
169–181. PMID 8673284 . doi :10.1006/mpev.1996.0011 .
* ^ B. Wood (2010). "Reconstructing human evolution: Achievements,
challenges, and opportunities" . Proceedings of the National Academy
of Sciences. 107: 8902–8909.
Bibcode :2010PNAS..107.8902W. PMC
3024019 . PMID 20445105 . doi :10.1073/pnas.1001649107 .
* ^ Patterson N, Richter DJ, Gnerre S, Lander ES, Reich D; Richter;
Gnerre; Lander; Reich (June 2006). "Genetic evidence for complex
speciation of humans and chimpanzees". Nature. 441 (7097): 1103–8.
Bibcode :2006Natur.441.1103P. PMID 16710306 . doi :10.1038/nature04789
. CS1 maint: Multiple names: authors list (link )
* ^ Wakeley J (March 2008). "Complex speciation of humans and
chimpanzees". Nature. 452 (7184): E3–4; discussion E4. Bibcode
:2008Natur.452....3W. PMID 18337768 . doi :10.1038/nature06805 .
"Patterson et al. suggest that the apparently short divergence time
between humans and chimpanzees on the
X chromosome is explained by a
massive interspecific hybridization event in the ancestry of these two
species. However, Patterson et al. do not statistically test their own
null model of simple speciation before concluding that speciation was
complex, and—even if the null model could be rejected—they do not
consider other explanations of a short divergence time on the X
chromosome. These include natural selection on the
X chromosome in the
common ancestor of humans and chimpanzees, changes in the ratio of
male-to-female mutation rates over time, and less extreme versions of
divergence with gene flow. I therefore believe that their claim of
hybridization is unwarranted."
* ^ Andrew Hill; Steven Ward (1988). "Origin of the Hominidae: The
Record of African Large Hominoid
Evolution Between 14 My and 4 My".
Yearbook of Physical Anthropology. 31 (59): 49–83. doi
* ^ A B Dawkins R (2004) The Ancestor's Tale.
* ^ "Query: Hominidae/Hylobatidae". Time Tree. 2009. Retrieved
December 2010. Check date values in: access-date= (help )
Wikispecies has information related to: HOMININI
Human Timeline (Interactive)