how to Present the special-temporal distribution CHART of all hominids (7mya to present)

Hominid refers to any of the modern or extinct bipedal primates of the family hominidae including all species of the general Homo and Australopithecus. In biology and ecology, extinction is the end of an organism or of a group of organisms (taxon), normally a species. (World English Dictionary)

Generally hominid refers to any human like species including a modern man. They are biological family to which human being belong. Our immediate evolutionary family is comprised of the hominoids, the group of primates that includes the "lesser apes" (siamangs and gibbons) as well as the "great apes" (chimpanzees, bonobos, gorillas, and orangutans). The ancestors of hominids are regarded as great Apes including chimpanzee, bonobos, gorillas and orangutans, among the great ape our closest relatives are chimpanzees, and bonobos. The fossil record, along with studies of human and ape DNA, indicate that humans shared a common ancestor with chimpanzees and bonobos sometime around 6 million years ago (mya). However this does not means that the modern man was evolved from the chimpanzees but we just share the common ancestor.  

Hominids are linked to theory of evolution of man propounded by Charles Darwin (1809-1882), he claimed that a great variety of plant and animal life in the earth are developed gradually through natural processes, but species change or adopt over time in response to the environment. His theory of “Natural Selection” based on observation that members of single species vary greatly in shape size, color, strength to which he believed that these variations are inherited. However fossil records along with the study of Human and Apes DNA indicate that human being is similar to Great Apes family especially champs in genetic make up about 99 %. Before 7mya they shared the same ancestor but after this era they diverged.

Hominids especially human are considered to be best and most intelligent biological family on the earth or planet regarding the cranium capacity of the brain they possess. The homo genus are distinguished from apes because of bipedalism (walking and standing with two limbs) and using simple tools such as sticks to catch the insects.

The hominin lineage origin can be understood from the ancestral state, for our lineage The Human-Chimpanzee Last Common Ancestor (HC-LCA) is the species from which the hominin lineage and the chimpanzee & bonobo lineage diverged. This was during the Miocene about 7 million years ago (7mya), where there was great diversity of ape species with dozen of species known from the fossil record across Africa, Europe and Asia.  These species varied in their anatomy and ecology, and it is not clear which, if any, of the fossil species discovered thus far represent the Human-Chimpanzee Last Common Ancestor, although we know from fossil and comparative evidence that it was much more similar to living apes than to living humans. (Kunimatsu et al. 2007; Young and MacLatchy, 2004)

The Humman-Chempanzee Last Common Ancestror would have had an ape-sized brain and body, with relatively long arms and fingers and a grasping foot that allowed it to forage in the trees. The canine teeth were probably large and sharp, as seen in several Miocene hominoids. Moreover, the canines were probably sexually dimorphic, with males having much larger canines than females, as seen among the living great apes and Miocene fossils. Like living apes it would have walked quadrupedally (on all fours) when on the ground, and its diet would have consisted almost entirely of plant foods, primarily fruit and leaves.

The following is the distribution of the hominids from seven millions years ago to present (7mya to present); -

Sahelanthropus tchadensis from Chad and Orrorin tegenensis from Kenya are the oldest hominins currently known. In both Orrorin and Sahelanthropus the canine teeth of males are larger and more pointed than in modern humans, but are small and blunt compared to the canines of male apes. This suggests that canine sexual dimorphism and by extension, competition among males for mating access to females was diminished in these early hominins compared to the great apes.

 Sahelanthropus tchadensis, named TM 266 (Toumai) discovered in 2001 Chad by Alain Beauvilain, Fanone Gongdibe, Mahamat Adoum and Ahounta Djimdoumalbaye and dated to 7 mya, is known from a largely complete skull and some other fragmentary remains. Its brain size, 360cc, is within the range seen in chimpanzees, and the skull has a massive brow ridge, similar in thickness to male gorillas. However, the position and orientation of the foramen magnum, the hole in the base of the skull through which the spinal cord passes, suggests that Sahelanthropus stood and walked bipedally, with its spinal column held vertically as in modern humans rather than horizontally as in apes and other quadrupeds.

 Orrorin tugenensis, named Bar 1000’00 discovered in 2000 in Kenya by Martin Pickford, Kiptalam Cheboi, Dominique Gommery, Pierre Mein, and Brigitte Senut and dated to about 6 mya, is known primarily from postcranial fossils, including a partial femur. The proximal portion of the femur shows similarities to those of modern humans, suggesting the species was bipedal. No skulls of Orrorin have been recovered, and so it’s cranial morphology and brain size are uncertain.

Ardipithecus ramidus, named Ardi from Ethiopia discovered in 1994 by Yohannes Haile Selassie and dated to 4.4 mya, is known from a nearly complete skeleton as well as numerous other dental and skeletal remains. Ardipithecus ramidus and an older related species known from fragmentary remains Ardipithecus kadabba (5.8–5.2 mya), have reduced canines similar to those of Orrorin and Sahelanthropus. The skull of Ardipithecus ramidus is rather ape-like and broadly similar to that of Sahelanthropus, with a small chimpanzee-sized brain of 300–350cc. The Ardipithecus postcranial skeleton is intriguing. Although badly fragmented, the pelvis recovered reveals morphology quite different from that of living apes, with a shorter, more bowl-like shape that strongly suggests Ardipithecus walked bipedally; this is consistent with the foramen magnum position, which suggests an upright posture. However, its long forelimbs and fingers and its divergent, grasping first toe (hallux) suggest Ardipithecus spent much of its time in the trees. The overall impression is of a largely arboreal species that walked bipedally whenever it ventured to the ground.

Australopithecus, were discovered around 4mya they were hominins which were adept terrestrial bipeds but continued to use the trees for food and protection. The first specimens of Australopithecus were discovered in South Africa in 1924 and named Taung 1 (Taung Child) such as Australopithecus africanus discovered by Raymond Dart dated 2.5 mya. (Dart, 1925), and research efforts over the subsequent eight decades have produced hundreds of fossils from several species at sites all across East and Southern Africa. Australopithecus was a highly successful genus that persisted for nearly three million years. The best-known Australopithecus species are Australopithecus afarensis (3.6–2.9 mya) like Australopithecus afarensis named LH 4 discovered in 1974 at Laetoli, Tanzania by Donald Johanson dated about (2.9 – 3.9 mya) from East Africa and Australopithecus africanus (3.2–2.0mya) from South Africa. The pelvis and lower limb of these species clearly indicates that they were fully bipedal: the pelvis is short and bowl-shaped, bringing the gluteal muscles around to the side of the body, as in modern humans, for trunk stabilization during bipedalism, and the first toe is in line with the other toes (Ward, 2002; Harcourt-Smith and Aiello, 2004).

 The Australopithecus foot may even have had a human-like arch, based on analysis of the metatarsals and the fossilized Laetoli footprints (Ward et al. 2011). the forearms were long and the fingers and toes were long and somewhat curved, suggesting that Australopithecus regularly used the trees to forage and perhaps as a refuge from predators at night. This mixed terrestrial & arboreal strategy would have served these species well in the mixed woodland and savannah environments they inhabited. Brain size in Australopithecus ranged between 390 and 515cc, similar to chimpanzees and gorillas (Falk et al. 2000), suggesting cognitive abilities were broadly similar to living apes. Body size in Australopithecus was rather small and sexually dimorphic, about 30kg for females and 40kg for males (McHenry, 1992). This level of dimorphism is not reflected in the canines, which were small, blunt, and monomorphic as in earlier hominins.

Paranthropus robust, is a subgroup of Australopithecus, they are named as separate genus because of their enormous teeth and chewing muscles, took this adaptation to the extreme. Most Australopithecus species were extinct by 2 mya, but some robust forms persisted until about 1.2 mya in East and South Africa. For instance Paranthropus robusts named TM 1517 discovered 1938 in South Africa by Gert Terblanche dated about 2 mya.

Homo, these were the earliest genus of our own, they are early specimens similar in brain and body size to Australopithecus, but show differences in their molar teeth, suggesting a change in diet. Indeed, by at least 1.8 mya, early members of our genus were using primitive stone tools to butcher animal carcasses, adding energy-rich meat and bone marrow to their plant-based diet.

The oldest member of the genus Homo, is Homo habilis dated (2.3–1.4 mya) is found in East Africa and is associated with butchered animal bones and simple stone tools, like Homo rudolfensis named Uraha 501, discovered in 1991 in Malawi by Tyson Msiska, Timothy Bromage and Friedemann Schrenk.

Homo erectus is more formidable and widespread descendant found throughout Africa and Eurasia and persisted from 1.9 mya to 100 kya, and perhaps even later (Anton, 2003). Like modern humans, Homo erectus lacked the forelimb adaptations for climbing seen in Australopithecus. Its global expansion suggests Homo erectus was ecologically flexible, with the cognitive capacity to adapt and thrive in vastly different environments. Not surprisingly, it is with Homo erectus that we begin to see a major increase in brain size, up to 1,250cc for later Asian specimens (Anton, 2003). Molar size is reduced in Homo erectus relative to Australopithecus, reflecting its softer, richer diet. For instance Homo erectus named D2700 dicovered in 2001 Georgia dated about 1.8 mya. Also Homo erectus named Yuanmou Man discovered in 1965 China by Fang Qian dated about 1.7 mya to between 0.5 and 0.6 mya. Homo erectus named Sangiran 2 discovered in 1937 Indonesia by G. H. R. von Koenigswald dated about 0.7 – 1.6 mya.

Homo heidelbergensis, is a species very much like us in terms of body proportions, dental adaptations, and cognitive ability followed Homo erectus (Rightmire, 2009). Homo heidelbergensis, often referred to as an "archaic" Homo sapiens, was an active big-game hunter, produced sophisticated Levallois style tools, and by at least 400 kya had learned to control fire (Roebroeks and Villa, 2011). For instance Homo heidelbergensis or Homo erectus named Madam Buya discovered in 1997 Eritrea by Ernesto Abbate dated about 600k – 1.4 mya, another was Homo heidelbergensis named Bodo discovered in 1976 Ethiopia by A. Asfaw dated 600 kya. As well as Homo heidelbergensis named Mauer 1 (Heidelberg Man) discovered in 1907 Germany by Daniel Hartmann dated 500 kya.

Homo neanderthalensis, evolved from Homo heidelbergensis populations in Europe by at least 250 kya, they are said to be cold-adapted hominins with stout physiques, complex behaviors, and brains similar in size to ours, for instance Homo neanderthalensis named Altamura Man discovered in Italy dated 250 kya. Homo neanderthalensis named Bontnewydd(Pontynewydd) discovere in 1981 United Kingdom dated 230 kya.

Homo sapiens in which Fossil and DNA evidence suggests that it’s our own species evolved in Africa 200 kya, probably from Homo heidelbergensis. The increased behavioral sophistication of Homo sapiens, as indicated by our large brains (1,400cc) and archeological evidence of a broader tool set and clever hunting techniques, allowed our species to flourish and grow on the African continent. For instance Homo sapiens named Omo 1 discovered in 1967 Ethiopia by Richard Leakey dated 190 kya. Also Homo sapiens named Jebel Irhoud 1 discovered in 1991 Morocco dated 160 kya.

Homo neanderthals, were displaced from our species and they were in Europe and Asia. By 100kya, our species spilled into Eurasia, eventually expanding across the entire globe into Australia and the Americas. Studies of ancient DNA extracted from Neanderthal fossils suggest our species may have occasionally interbred with them. For instance Homo naenderthalensis named Krapina discovered in 1899 Croatia by Dragutin Gorjanovic Kramberger dated 100 kya – 127 kya. Homo naenderthalensis named Scladina discovered in Belgium dated 80 kya – 127 kya. Also Homo naenderthalensis named La Ferrassie 1 discovered in 1909 in France by R. Capitan and D. Peyrony dated 70 kya.

The following is the CHART representing the distribution of the hominids as explained above.

NAME	AGE	SPECIES	YEAR DESCOVERED	COUNTRY	DISCOVERED BY
TM 266(Toumai)	7 mya	Sahelanthropus tchadensis	2001	Chad	Alain Beauvilain, Fanone Gongdibe, Mahamat Adoum and Ahounta Djimdoumalbaye
BAR 1000’00	6 mya	Orrorin tugenensis	2000	Kenya	Martin Pickford, Kiptalam Cheboi, Dominique Gommery, Pierre Mein, Brigitte Senut
Ardi	4.4 mya	Ardipithecus ramidus	1994	Ethiopia	Yohannes Haile Selassie
Taung 1 (Taung Child)	2.5 mya	Australopithecus africanus	1924	South Africa	Raymond Dart
LH 4	2.9 3.9 mya	Australopithecus afarensis	1974	Laetoli, Tanzania	Donald Johnson
TM 1517	2 mya	Paranthropus robustus	1938	South Africa	Gert Terblanche
Uraha 501	2.3-2.5 mya	Homo rudolfensis	1991	Malawi	Tyson Msiska, Timothy Bromage, Friedemann Schrenk
D2700	1.8 mya	Homo erectus	2001	Georgia
Yuanmou Man	1.7 mya/0.5-0.6mya	Homo erectus	1965	China	Fang Quian
Sangiran 2	0.7-1.6 mya	Homo erectus	1937	Indonesian	G. H. R. von Koenignswald
Madam Buya	600k-1.4mya	Homo heidelbergensis or Homo erectus	1997	Eritrea	Erasto Abbate
Bodo	600k	Homo heidelbergensis or Homo erectus	1976	Ethiopia	A.  Asfaw
Mauer 1 (Heidelberg Man)	500k	Homo heidelbergensis	1907	Germany	Daniel Hartmann
Altamura Man	250k	Homo neanderthalensis		Italy
Bontnewydd (Pontynewydd)	230kya	Homo neanderthalensis	1981	UK
Omo 1	190kya	Homo sapiens	1967	Ethiopia	Richard Leakey
Jebel Irhoud1	160kya	Homo sapiens	1991	Morocco
Krapina	100kya-127kya	Homo neandthalensis	1899	Croatia	Dragutin Garjanovic-Kramberger
Scladina	80kya-127kya	Homo neanderthalensis		Belgium
La Ferrassie 1	70kya	Homo neanderthalensis	1909	France	R. Capitan and D. Peyrony

Therefore, the evolution of man from 7mya as  represented by distribution of hominids shown above had is showing how processes of man evolution were taking place as the hominids were sharing their ancestral and they were evolving from one stage of change to another in the aid of the environmental changes.

 REFERENCES

Anton, S. C. (2003). “Natural history of Homo erectus”. American Journal of Physical Anthropology S37, 126-70.

Dart, R.A. (1925). “Australopithecus africanus”: the southern ape-man of Africa. Nature 115, 195-199.

Falk, D. et al. (2000). “Early hominid brain evolution: a new look at old endocasts”. Journal of Human Evolution 38, 695-717.

Kunimatsu, Y. et al. (2007). “A new Late Miocene great ape from Kenya and its implications for the origins of African great apes and humans”. PNAS USA 104, 19661-19662.

McHenry, H. M. (1992). “Body size and proportions in early hominids”. American Journal of Physical Anthropology 87, 407-431

Ward, C. V. et al. (2011). “Complete fourth metatarsal and arches in the foot of Australopithecus afarensis”. Science 331, 750-753