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†A. afarensis ("Lucy") |
The genus Australopithecus (Latin australis "of the south", Greek pithekos "ape") is a group of extinct hominids, the gracile australopithecines, closely related to humans. A genus (plural genera from Γένος Latin genus "descent family type gender" is a low-level Taxonomic Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly In Biology and Ecology, extinction is the cessation of existence of a Species or group of taxa. A hominid is any member of the biological family Hominidae (the "great apes" including the extinct and extant Humans Chimpanzees Homo is the Genus that includes modern humans and their close relatives
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Evolution
Gracile australopithecines shared several traits with modern apes and humans, and were widespread throughout Eastern and Northern Africa by a time between 3. East Africa is the Easternmost Region of the African Continent. North Africa or Northern Africa is the Northernmost Region of the African Continent, separated by the Sahara from Sub-Saharan 0 and 3. 9 million years ago. The earliest evidence of fundamentally bipedal hominids can be observed at the site of Laetoli in Tanzania. Laetoli is a site in Tanzania, dated to the Plio-Pleistocene and famous for its Hominid footprints preserved in Volcanic ash (Site G Tanzania ˌtænzəˈniːə officially the United Republic of Tanzania (Jamhuri ya Muungano wa Tanzania is a country in East Africa bordered by Kenya These hominid footprints are remarkably similar to modern humans and have been dated as 3. 7 million years old. Until recently, the footprints have generally been classified as australopithecine because that had been the only form of pre-human known to have existed in that region at that time; however, some scholars have considered reassigning them to a yet unidentified very early species of the genus Homo. In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. Homo is the Genus that includes modern humans and their close relatives
Australopithecus anamensis, Australopithecus afarensis and Australopithecus africanus are among the most famous of the extinct hominids. Australopithecus anamensis is a Fossil Species of Australopithecus. Australopithecus afarensis is an extinct Hominid which lived between 3 Australopithecus africanus was an early hominid, an Australopithecine, who lived between 2-3 million years ago in the Pliocene. A. africanus used to be regarded as ancestral to the genus Homo (in particular Homo erectus). Homo is the Genus that includes modern humans and their close relatives Homo erectus ( Latin: "upright man" is an extinct species of the genus Homo, believed to have been the first hominin However, fossils assigned to the genus Homo have been found that are older than A. FOSSIL is a standard protocol for allowing serial communication for Telecommunications programs under the DOS Operating system. africanus. Thus, the genus Homo either split off from the genus Australopithecus at an earlier date (the latest common ancestor being A. afarensis or an even earlier form, possibly Kenyanthropus platyops), or both developed from a yet possibly unknown common ancestor independently. Kenyanthropus platyops is a 35 to 32 million year old ( Pliocene) Extinct Hominin Species that was discovered in Lake Turkana
According to the Chimpanzee Genome Project, both human (Ardipithecus, Australopithecus and Homo) and chimpanzee (Pan troglodytes and Pan paniscus) lineages diverged from a common ancestor about 5 to 6 million years ago, if we assume a constant rate of evolution. The Chimpanzee Genome Project is an effort to determine the DNA sequence of the Genome of the closest living human relatives Ardipithecus is a very early hominin Genus ( Subfamily Homininae) which lived about 4 Chimpanzee (often shortened to chimp) is the common name for the two extant Species of Apes in the Genus Pan. The Common Chimpanzee ( Pan troglodytes) also known as the Robust Chimpanzee, is a great ape. The Bonobo (bə'noʊboʊ Pan paniscus) until recently usually called the Pygmy Chimpanzee (and less often the Dwarf or Gracile Chimpanzee It is theoretically more likely for evolution to happen slower, as opposed to quicker, from the date suggested by a gene clock (the result of which is given as an "youngest common ancestor", i. In Genetics, the most recent common ancestor ( MRCA) of any set of Organisms is the most recent individual from which all organisms in the group are directly e. , the latest possible date of diversion. ) However, hominids discovered more recently are somewhat older than the molecular clock would theorize. The molecular clock (based on the molecular clock hypothesis ( MCH) is a technique in Molecular evolution to relate the divergence time of two Species Sahelanthropus tchadensis, commonly called "Toumai" is about 7 million years old and Orrorin tugenensis lived at least 6 million years ago. Sahelanthropus tchadensis is a Fossil Ape that lived approximately 7-6 Million years ago. Orrorin tugenensis is considered to be the oldest known Hominin ancestor related to modern Humans and is the only species classified in genus Since little is known of them, they remain controversial among scientists since the molecular clock in humans has determined that humans and chimpanzees had an evolutionary split at least a million years later. The molecular clock (based on the molecular clock hypothesis ( MCH) is a technique in Molecular evolution to relate the divergence time of two Species One theory suggests that humans and chimpanzees diverged once, then interbred around one million years after diverging. [1]
As molecular evidence has accumulated, the constant-rate assumption has proven false—or at least overly general. However, while the molecular clock cannot be blindly assumed to be true, it does hold in many cases, and these can be tested for. For example, molecular clock users are developing workaround solutions using a number of statistical approaches including maximum likelihood techniques and later Bayesian modeling.
Morphology
The brains of most species of Australopithecus were roughly 35% of the size of that of a modern human brain. The brain is the center of the Nervous system in animals All Vertebrates and the majority of Invertebrates have a brain Human beings, humans or man (Origin 1590–1600 L homō man OL hemō the earthly one (see Humus Most species of Australopithecus were diminutive and gracile, usually standing no more than 1. 2 and 1. 4 m (approx. 4 to 4. 5 feet) tall. In several variations of australopithecine there is a considerable degree of sexual dimorphism, meaning that males are larger than females. Sexual dimorphism is the systematic difference in form between individuals of different Sex in the same Species. Modern hominids do not appear to display sexual dimorphism to the same degree — particularly, modern humans display a low degree of sexual dimorphism, with males being only 15% larger than females, on average. In australopithecines, however, males can be up to 50% larger than females. New research suggests that sexual dimorphism may be far less pronounced than this, but there is still much debate on the subject.
Species variations
Although opinions differ as to whether the species aethiopicus, boisei and robustus should be included within the genus Australopithecus, the current consensus in the scientific community is that they should be placed in a distinct genus, Paranthropus, which is believed to have developed from the ancestral Australopithecus line. The robust australopithecines, members of the Extinct Hominin genus Paranthropus (Greek para "beside" Greek anthropos "human" Up until the last half-decade, the majority of the scientific community included all the species shown in the box at the top of this article in a single genus. However, Paranthropus was morphologically distinct from Australopithecus, and its specialized morphology also implies that its behavior was quite different from that of its ancestor. The term morphology in Biology refers to the outward appearance ( Shape, Structure, Colour, Pattern) of an Organism
Evolutionary role
The fossil record seems to indicate that Australopithecus is the common ancestor of the distinct group of hominids, now called Paranthropus (the "robust australopithecines"), and most likely the genus Homo which includes modern humans. The robust australopithecines, members of the Extinct Hominin genus Paranthropus (Greek para "beside" Greek anthropos "human" Although the intelligence of these early hominids was likely no more sophisticated than modern apes, the bipedal stature is the key evidence which distinguishes the group from previous primates who are quadrupeds. Quadrupedalism (from Latin meaning "four legs" is a form of land animal locomotion using four legs. The morphology of Australopithecus upsets what scientists previously believed, namely, that large brains preceded bipedalism. If A. afarensis was the definite hominid which left the footprints at Laetoli, it strengthens the notion that A. Laetoli is a site in Tanzania, dated to the Plio-Pleistocene and famous for its Hominid footprints preserved in Volcanic ash (Site G afarensis had a small brain but was a biped. Fossil evidence such as this has made it clear that bipedalism far predated large brains. However, it remains a matter of controversy how bipedalism first evolved millions of years ago (several concepts are still being studied). The advantages of bipedalism allowed hands to be free for grasping objects (e. g. carrying food and young), and allowed the eyes to look over tall grasses for possible food sources or predators. However, many anthropologists argue that these advantages were not large enough to cause bipedalism.
A recent study of primate evolution and morphology noted that all apes, both modern and fossil, show skeletal adaptations to upright posture of the trunk, and that fossils such as Orrorin tugenensis indicate bipedalism around 6 million years ago, around the time of the split between humans and chimpanzees indicated by genetic studies. Orrorin tugenensis is considered to be the oldest known Hominin ancestor related to modern Humans and is the only species classified in genus This suggested that upright, straight-legged walking originally evolved as an adaptation to tree-dwelling. Studies of modern orangutans in Sumatra showed that these apes use four legs when walking on large stable branches, swing underneath slightly smaller branches, but are bipedal and keep their legs very straight when walking on multiple small flexible branches under 4 cm. The orangutans are two Species of great apes known for their intelligence long arms and reddish-brown hair Sumatra (also spelled Sumatera) is the sixth largest island in the world (approximately 470000 km² and is the largest island entirely in Indonesia (two diameter, while also using their arms for balance and additional support. This enables them to get nearer to the edge of the tree canopy to get fruit or cross to another tree. Climate changes around 11 to 12 million years ago affected forests in East and Central Africa so that there were periods when openings prevented travel through the tree canopy, and at these times ancestral hominids could have adapted the upright walking behaviour for ground travel. It is suggested that the ancestors of gorillas and chimpanzees became more specialised in climbing vertical tree trunks or lianas, using a bent hip and bent knee posture which matches the knuckle-walking posture they use for ground travel. Gorillas, the largest of the living Primates are ground-dwelling Herbivores that inhabit the Forests of Africa. Chimpanzee (often shortened to chimp) is the common name for the two extant Species of Apes in the Genus Pan. Humans are closely related to these apes, and share features including wrist bones apparently strengthened for knuckle walking. [2][3]
Radical changes in morphology took place before gracile australopithecines evolved; the pelvis structure and feet are very similar to modern humans. The teeth have small canines, but australopithecines generally evolved a larger post-canine dentition with thicker enamel. Australopithecines faced one particular challenge while living on the savanna. A savanna or savannah is a Tropical or Subtropical Grassland or Woodland Ecosystem.
Most species of Australopithecus were not any more adept at tool use than modern non-human primates, yet modern African apes, chimpanzees, and most recently gorillas, have been known to use simple tools (i. Gorillas, the largest of the living Primates are ground-dwelling Herbivores that inhabit the Forests of Africa. e. cracking open nuts with stones and using long sticks to dig for termites in mounds), and chimpanzees have been observed using spears (not thrown) for hunting. The termites are a group of Social Insects usually classified at the taxonomic rank of order Isoptera (but see also taxonomy However, some have argued that A. garhi used stone tools due to a loose association of this species and butchered animal remains. Australopithecus garhi is a Gracile australopithecine species whose fossils were discovered in 1996 by a research team led by Ethiopian
Diet
In a 1979 preliminary microwear study of Australopithecus fossil teeth, anthropologist Alan Walker theorized that robust australopithecines were largely frugivorous. [4] However, newer methods of studying fossils have suggested the possibility that Australopithecus was omnivorous. Omnivores (from Latin omne all everything vorare to devour are species that eat both Plants and Animals as their primary In 1992, trace element studies of the strontium/calcium ratios in robust australopithecine fossils suggested the possibility of animal consumption, as did a 1994 using stable carbon isotopic analysis. [5]
Notable Specimens
References
- Barraclough, G. Laetoli is a site in Tanzania, dated to the Plio-Pleistocene and famous for its Hominid footprints preserved in Volcanic ash (Site G AL 129-1 is the fossilized knee joint of the species Australopithecus afarensis. Lucy (also given a second ( Amharic) name dinqineš, or “Dinkenesh” meaning “You are beautiful” or "you are wonderful" is the common name of AL Mrs Ples (considered to be 215 million years old is the popular nickname for the most complete skull of an Australopithecus africanus ever found in South Africa STS 14 is a fossilized pelvis vertebral column and fragmentary rib and femur of the species Australopithecus africanus. STS 71 is a fossilized skull of the species Australopithecus africanus. Taung Child is the fossilized skull of a young Australopithecus africanus individual Selam (DIK-1/1 is the fossilized skull and other skeletal remains of a 3-year-old Australopithecus afarensis female whose bones were first found in Dikika (1989). in Stone, N. (ed. ): Atlas of World History, 3rd edition, Times Books Limited. ISBN 0-7230-0304-1.
- Leakey, Richard (1994). Richard Erskine Frere Leakey (born 19 December 1944 in Nairobi, Kenya) is a Kenyan politician The Origins of Human Kind. ISBN 0-465-03135-8.
- White, Tim D. , et al. "Asa Issie, Aramis and the Origin of Australopithecus. " Nature 440 (April 13, 2006), 883-89.
- ^ Bower, Bruce (May 20, 2006). "Hybrid-Driven Evolution: Genomes show complexity of human-chimp split" ( – Scholar search). Science News 169 (20): 308.
- ^ BBC - Science & Nature - The evolution of man. Mother of man - 3. 2 million years ago. Retrieved on 2007-11-01. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 996 - Emperor Otto III issues a deed to Gottschalk Bishop of Freising which is the oldest known document using the name Ostarrîchi
- ^ Thorpe S. K. S. ; Holder R. L. , and Crompton R. H. (24 May 2007). Events 1218 - The Fifth Crusade leaves Acre for Egypt. 1276 - Magnus Ladulås is crowned Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. PREMOG - Supplementary Info. Origin of Human Bipedalism As an Adaptation for Locomotion on Flexible Branches. Primate Evolution & Morphology Group (PREMOG), the Department of Human Anatomy and Cell Biology, the School of Biomedical Sciences at the University of Liverpool. The University of Liverpool is a University in the city of Liverpool, England. Retrieved on 2007-11-01. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 996 - Emperor Otto III issues a deed to Gottschalk Bishop of Freising which is the oldest known document using the name Ostarrîchi “Based on computer simulations of the mechanics of motion in fossil human ancestors such as the famous 'Lucy' skeleton, our research group has long argued that early human ancestors would have walked upright, rather than semi-crouched, as the old 'up from the apes' view has suggested . . . Now, research on the orangutan, suggests that upright walking may have been a basic element of the lifestyle of the earliest ancestors of modern apes, including humans, which would have been tree-dwelling specialists on ripe fruit, living among the fine branches of tropical forest trees. ”
- ^ Billings, Tom. Humanity's Evolutionary Prehistoric Diet and Ape Diets--continued, Part D).
- ^ Billings, Tom. Comparative Anatomy and Physiology Brought Up to Date--continued, Part 3B).
See also
- Aramis, Ethiopia
- List of fossil sites (with link directory)
- List of hominina (hominid) fossils (with images)
External links
Aramis is a village and Archaeological site in northeastern Ethiopia, where remains of Australopithecus and Ardipithecus This is a worldwide list of important and/or well-known localities where Fossils have been found The following charts give a brief overview of several notable Primate Fossil finds relating to Human evolution.
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