The taxonomy of the Hominoidea is in a state of flux, as molecular evidence has drawn close lines of relationship than expected. Below are two of the many current phylogenetic classifications. Clearly, they are not clearly defined and the final classification has not been decided.
In the Science Week reference below, they state:

"hominine: The terms hominine, hominin, hominoid, hominid, are not interchangeable, but their classification criteria are variously in a state of flux. In general, the hominoids are a primate superfamily, the hominid family comprises the great apes within the hominoid superfamily, the hominini are a "tribe" within the hominids characterized by a number of features including bipedalism, and the hominini are further partitioned into the genera Homo and Australopithecus. Concerning research in human evolution, most paleoanthropologists agree that what is important is to achieve an understanding of the evolutionary transitions and transformations, and any classification scheme must be secondary to this objective. In other words, in this context, classification must ultimately reflect phylogeny (the actual evolutionary relationships), and as knowledge of phylogeny changes, so must the extant classification schemes."

[See skulls of Homininae ].

The divergence of Old World monkeys and hominoids at the Oligocene-Miocene boundary (approximately 23 million years ago) provides the best primate calibration point for hominid evolution and yields a time and 95% confidence interval of 5.4 +/- 1.1 million years ago (36 nuclear genes) for the human-chimpanzee divergence. Older splitting events are estimated as 6.4 +/- 1.5 million years ago (gorilla, 31 genes), 11.3 +/- 1.3 million years ago (orangutan, 33 genes), and 14.9 +/- 2.0 million years ago (gibbon, 27 genes) (Stauffer et al, 2001).

The changes and variability in human taxonomy reflects the finding that little confidence can be placed in phylogenies generated solely from higher primate craniodental evidence (Collard and Wood, 2000). Existing phylogenetic hypotheses about human evolution reflect unreliable tools of analysis. New approaches and methods are needed to address the problem of hominin phylogeny.

Molecular genetics has had a major impact on phylogenetics, so hominoid paleontologists and morphologists need to use this genetic data. Genetic evidence shows that chimpanzee and human hominoids are closely related,  sharing many postcranial similarities. Miocene hominoid fossil postcrania show that few of these taxa share significant similarities with living apes, suggesting that few if any are related to specific extant lineages. Given the genetically inferred relationships of hominoids and the morphology of the earliest hominids, the common ancestor of humans and chimpanzees was probably chimp-like, a knuckle-walker with small thin-enameled cheek teeth. Miocene hominoids, mostly postcranially archaic and with large, thickly enameled cheek teeth, probably throw little if any direct light on hominid origins (Pilbeam, 1996).

Neanderthal genetic sequences appear to fall outside of the modern human lineage, possibly sharing a common ancestry with our lineage around a half million years ago. Human ancestry appears to be derived from an African population that may have remained relatively isolated in Africa for tens of thousands of years before migrating out in the last 100,000 years. This replaced archaic humans, including neanderthals, throughout the old world (Disotell, 1999).

References:

• http://www.ludusvitalis.org.mx/palma2000/syst-english.html
• http://ijolite.geology.uiuc.edu/00SummerClass/geo143/lectures/hominidtaxa.html
• http://instruct1.cit.cornell.edu/Courses/bionb420.07/mfreedman/Neuro/Phylogeny/phy.htm
• http://www.gate.net/~rwms/primegendistold.html
• http://scienceweek.com/search/reports1/scardeh.htm
• Collard, M., and Wood, B., 2000. How reliable are human phylogenetic hypotheses? Anthropology Vol. 97, Issue 9, 5003-5006, April 25, 2000.
• Disotell, T.R. 1999. Human evolution: Origins of modern humans still look recent. Current Biology 1999, 9:R647-R650 http://biomednet.com/elecref/09609822009R0647.
  
• Goodman, M., Czelusniak, J., Page, S. & Meireles, C.2000. Where DNA Sequences Place Homo sapiens in a Phylogenetic Classification of Primates. HUMANITY FROM AFRICAN NAISSANCE TO COMING MILLENNIA. Wayne State University School of Medicine, Department of Anatomy and Cell Biology, 540 E. Canfield Avenue, Detroit, Michigan, 48201, USA. pp 279-289.
• Pilbeam, D. 1996. Genetic and morphological records of the Hominoidea and hominid origins: a synthesis. Mol Phylogenet Evol 1996 Feb;5(1):155-68
  
• Stauffer, R.L., Walker A., Ryder O.A., Lyons-Weiler M., Hedges S.B. 2001.
  Human and ape molecular clocks and constraints on paleontological hypotheses. J Hered 2001 Nov-Dec;92(6):469-74.
  
• Wood, B. and Richmond, B. 2000. Review. Human evolution: taxonomy and paleobiology. J. Anat. (2000) 196, pp.19-60.

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