Turkana Boy
Encyclopedia
Turkana Boy, also occasionally, Nariokotome Boy is the common name
of fossil
KNM-WT 15000, a nearly complete skeleton of a hominid who died in the early Pleistocene
. This specimen is the most complete early human skeleton ever found. It is 1.5 million years old. Turkana Boy is classified as either Homo erectus
or Homo ergaster
.
His age has been estimated from as old as 15 years to as young as 7 years six months. The most recent scientific review suggests 8 years of age. It was initially suggested that he would have grown into 1.85 m tall adult but the most recent analysis argues for the much shorter stature of 1.63 m. The reason for this shift has been research showing that his growth maturation differed from that of modern humans in that he would have had a shorter and smaller adolescent growth spurt.
The skeleton
was discovered in 1984 by Kamoya Kimeu
, a member of a team led by Richard Leakey
, at Nariokotome near Lake Turkana
in Kenya
.
The cranial capacity of Turkana Boy was about 880 cc. In adulthood, it would have been about 910 cc, in the bottom of the modern human range. In modern humans, brain size
within this range does not determine intelligence
, although there exists a correlation between brain size and intelligence. The relative sizes of different brain parts were different in Turkana boy as compared to modern human .
The pelvis
is narrower than in Homo sapiens, which might indicate more efficient running , whether to run down small game or to avoid predators. Turkana Boy's people might have hunted more than did Homo habilis
. The Boy was relatively tall, which would have increased his surface area and helped him to dump heat.
Body hair may also have been thinner to hasten cooling. In The Evolution of Bipedality and Loss of Body hair in Hominids, P. E. Wheeler suggests that body hair was lost in the shift towards savanna
living. In equatorial Africa, modern humans evolved this trait an estimated one million years ago. However, more recent research indicates that Ardipithecus ramidus
developed bipedality for moving through trees about 4.4 million years ago.
The overall KNM-WT 15000 skeleton still had features (such as a low sloping forehead, strong brow ridges, and the absence of a chin) not seen in H. sapiens. The arms were slightly longer. Turkana Boy had a projecting nose rather than the open flat nose seen in apes.
stone tools prompt the majority of scientists to conclude that Homo ergaster and Homo erectus - unlike their more primitive ancestors – became efficient hunters. The social structure would probably have become more complex with a larger brain volume; the Broca's area
of the brain allows speech and is noted by a slight slant on the cranium. However, there are different views on the origin of language
:
Turkana Boy's thoracic vertebrae
are narrower than in Homo sapiens. This would have allowed him less motor control over the thoracic muscles that are used in modern humans to modify respiration to enable the sequencing upon single out breaths of complex vocalizations.
Epithet
An epithet or byname is a descriptive term accompanying or occurring in place of a name and having entered common usage. It has various shades of meaning when applied to seemingly real or fictitious people, divinities, objects, and binomial nomenclature. It is also a descriptive title...
of fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
KNM-WT 15000, a nearly complete skeleton of a hominid who died in the early Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
. This specimen is the most complete early human skeleton ever found. It is 1.5 million years old. Turkana Boy is classified as either Homo erectus
Homo erectus
Homo erectus is an extinct species of hominid that lived from the end of the Pliocene epoch to the later Pleistocene, about . The species originated in Africa and spread as far as India, China and Java. There is still disagreement on the subject of the classification, ancestry, and progeny of H...
or Homo ergaster
Homo ergaster
Homo ergaster is an extinct chronospecies of Homo that lived in eastern and southern Africa during the early Pleistocene, about 2.5–1.7 million years ago.There is still disagreement on the subject of the classification, ancestry, and progeny of H...
.
His age has been estimated from as old as 15 years to as young as 7 years six months. The most recent scientific review suggests 8 years of age. It was initially suggested that he would have grown into 1.85 m tall adult but the most recent analysis argues for the much shorter stature of 1.63 m. The reason for this shift has been research showing that his growth maturation differed from that of modern humans in that he would have had a shorter and smaller adolescent growth spurt.
The skeleton
Skeleton
The skeleton is the body part that forms the supporting structure of an organism. There are two different skeletal types: the exoskeleton, which is the stable outer shell of an organism, and the endoskeleton, which forms the support structure inside the body.In a figurative sense, skeleton can...
was discovered in 1984 by Kamoya Kimeu
Kamoya Kimeu
Kamoya Kimeu, is one of the world's most successful fossil collectors who, together with paleontologists Meave Leakey and Richard Leakey, is responsible for some of the most significant paleoanthropological discoveries...
, a member of a team led by Richard Leakey
Richard Leakey
Richard Erskine Frere Leakey is a politician, paleoanthropologist and conservationist. He is second of the three sons of the archaeologists Louis Leakey and Mary Leakey, and is the younger brother of Colin Leakey...
, at Nariokotome near Lake Turkana
Lake Turkana
Lake Turkana , formerly known as Lake Rudolf, is a lake in the Great Rift Valley in Kenya, with its far northern end crossing into Ethiopia. It is the world's largest permanent desert lake and the world's largest alkaline lake...
in Kenya
Kenya
Kenya , officially known as the Republic of Kenya, is a country in East Africa that lies on the equator, with the Indian Ocean to its south-east...
.
Adolescence and maturity
The shape of the pelvis identifies that the specimen was a male. His estimated age at death depends upon whether the maturity stage of his teeth or skeletal is used, and whether that maturity is compared to that of modern humans or chimpanzees. A key factor here is that while modern humans have a marked adolescent growth spurt, chimpanzees do not. While initial research assumed a modern human type of growth, more recent evidence from other fossils suggests this was less present in early Homo. This affects the estimation of both his age and his likely stature as a fully grown adult.- Anthropologists Alan Walker and Richard LeakeyRichard LeakeyRichard Erskine Frere Leakey is a politician, paleoanthropologist and conservationist. He is second of the three sons of the archaeologists Louis Leakey and Mary Leakey, and is the younger brother of Colin Leakey...
in 1993 estimated the boy to have been about 11–12 years old based on known rates of bone maturityEpiphyseal plateThe epiphyseal plate is a hyaline cartilage plate in the metaphysis at each end of a long bone...
.Walker explains: "in KNM-WT 15000, his skeletal development can only be used to place an upper limit of about 14 years on his age at death. However, a less often recognized skeletal maturational event does generally occur prior to 14 years in modern males-- the union of the trochlea and capitulum (and also the lateral epicondyle) of the humerus, prior to their joint union with the humeral shaft.... That these elements were fused in KNM-WT 15000 (at least the capitulum and trochlea) suggests a skeletal age for him of somewhat more than 11 years.... In either event, 11 to 12 years would seem to be the best compromise figure to use for his chronological age at death."(Walker & Leakey, 1993, p. 235)
- Christopher Dean (M. C. Dean) of University College London, in a Nova special, stated that Turkana Boy was 8 years old at death. Alan Walker and Richard Leakey, though, explain that dental dating often gives younger than actual ages."Just as in the case of human dental age (above), estimates based on tooth formation give slightly younger ages than those based on emergence." (Walker & Leakey, 1993, p. 207)
- Ronda Graves and colleagues in the most recent review of the problems involved conclude that he would "have grown an additional five to 14 cm before reaching adulthood" and that "if, at death, he was eight to ten years of age, [he would have been] 154 cm tall, and growing faster than a modern human but slower than a chimpanzee. According to this scenario, KNM-WT 15000 would have attained an adult stature ranging between 159 cm and 168 cm." Moreover that "according to our preferred models of growth and development, [his] growth in stature [would have been] completed by 12 years of age (4 years after death), so that the majority of growth has already occurred.
Morphology
The specimen comprises 108 bones, making it the most complete early human skeleton discovered. The skeleton is about 1.60 m (5 ft 3 in) tall. In adulthood, Turkana Boy might have reached 1.85 m (6 ft 1 in) tall and massed 68 kg (150 lb).The cranial capacity of Turkana Boy was about 880 cc. In adulthood, it would have been about 910 cc, in the bottom of the modern human range. In modern humans, brain size
Brain size
Brain size is one aspect of animal anatomy and evolution. Both overall brain size and the size of substructures have been analysed, and the question of links between size and functioning - particularly intelligence - has often proved controversial...
within this range does not determine intelligence
Intelligence
Intelligence has been defined in different ways, including the abilities for abstract thought, understanding, communication, reasoning, learning, planning, emotional intelligence and problem solving....
, although there exists a correlation between brain size and intelligence. The relative sizes of different brain parts were different in Turkana boy as compared to modern human .
The pelvis
Pelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
is narrower than in Homo sapiens, which might indicate more efficient running , whether to run down small game or to avoid predators. Turkana Boy's people might have hunted more than did Homo habilis
Homo habilis
Homo habilis is a species of the genus Homo, which lived from approximately at the beginning of the Pleistocene period. The discovery and description of this species is credited to both Mary and Louis Leakey, who found fossils in Tanzania, East Africa, between 1962 and 1964. Homo habilis Homo...
. The Boy was relatively tall, which would have increased his surface area and helped him to dump heat.
Body hair may also have been thinner to hasten cooling. In The Evolution of Bipedality and Loss of Body hair in Hominids, P. E. Wheeler suggests that body hair was lost in the shift towards savanna
Savanna
A savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of C4 grasses.Some...
living. In equatorial Africa, modern humans evolved this trait an estimated one million years ago. However, more recent research indicates that Ardipithecus ramidus
Ardipithecus
Ardipithecus is a very early hominin genus. Two species are described in the literature: A. ramidus, which lived about 4.4 million years ago during the early Pliocene, and A. kadabba, dated to approximately 5.6 million years ago ....
developed bipedality for moving through trees about 4.4 million years ago.
The overall KNM-WT 15000 skeleton still had features (such as a low sloping forehead, strong brow ridges, and the absence of a chin) not seen in H. sapiens. The arms were slightly longer. Turkana Boy had a projecting nose rather than the open flat nose seen in apes.
Vocal capabilities
The fossil skeleton and other fossil evidence such as AcheuleanAcheulean
Acheulean is the name given to an archaeological industry of stone tool manufacture associated with early humans during the Lower Palaeolithic era across Africa and much of West Asia, South Asia and Europe. Acheulean tools are typically found with Homo erectus remains...
stone tools prompt the majority of scientists to conclude that Homo ergaster and Homo erectus - unlike their more primitive ancestors – became efficient hunters. The social structure would probably have become more complex with a larger brain volume; the Broca's area
Broca's area
Broca's area is a region of the hominid brain with functions linked to speech production.The production of language has been linked to the Broca’s area since Pierre Paul Broca reported impairments in two patients. They had lost the ability to speak after injury to the posterior inferior frontal...
of the brain allows speech and is noted by a slight slant on the cranium. However, there are different views on the origin of language
Language
Language may refer either to the specifically human capacity for acquiring and using complex systems of communication, or to a specific instance of such a system of complex communication...
:
- 1.9 million years ago (Homo habilisHomo habilisHomo habilis is a species of the genus Homo, which lived from approximately at the beginning of the Pleistocene period. The discovery and description of this species is credited to both Mary and Louis Leakey, who found fossils in Tanzania, East Africa, between 1962 and 1964. Homo habilis Homo...
had a large Broca's area able to be seen in the cranium of KNM ER 1813KNM ER 1813KNM ER 1813 is a skull. It was discovered in Koobi Fora, Kenya by Kamoya Kimeu in 1973, and is estimated to be 1.9 million years old.Its characteristics include an overall smaller size than other Homo habilis finds but with a fully adult and typical H. habilis morphology.KNM means Kenya National...
), possible signs of the earliest ability for speech. - 1.5 million years ago, on the arrival of several distinct more human-like hominins spread throughout AfricaAfricaAfrica is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, EuropeEuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, and AsiaAsiaAsia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
(i.e., Homo erectus). - 600,000 and 150,000 years ago when archaic Homo sapiensArchaic Homo sapiensArchaic Homo sapiens is a loosely defined term used to describe a number of varieties of Homo, as opposed to anatomically modern humans , in the period beginning 500,000 years ago....
dominated regions in the Pleistocene epoch (several members during this period are considered fully modern Homo sapiens) - 50,000 years ago (fully modern Homo sapiens had already spread through the Old WorldOld WorldThe Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....
and slowly into the New WorldNew WorldThe New World is one of the names used for the Western Hemisphere, specifically America and sometimes Oceania . The term originated in the late 15th century, when America had been recently discovered by European explorers, expanding the geographical horizon of the people of the European middle...
20,000 BCE. Some believe language coincided solely with modern humans once cultureCultureCulture is a term that has many different inter-related meanings. For example, in 1952, Alfred Kroeber and Clyde Kluckhohn compiled a list of 164 definitions of "culture" in Culture: A Critical Review of Concepts and Definitions...
was established by groups such as Cro-Magnon man in Europe. It is still a matter of debate whether NeanderthalNeanderthalThe Neanderthal is an extinct member of the Homo genus known from Pleistocene specimens found in Europe and parts of western and central Asia...
s had a modern form of language.
Turkana Boy's thoracic vertebrae
Thoracic vertebrae
In human anatomy, twelve thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. They are intermediate in size between those of the cervical and lumbar regions; they increase in size as one proceeds down the spine, the upper...
are narrower than in Homo sapiens. This would have allowed him less motor control over the thoracic muscles that are used in modern humans to modify respiration to enable the sequencing upon single out breaths of complex vocalizations.
See also
- List of fossil sites (with link directory)
- List of hominina (hominid) fossils (with images)
External links
- http://www.amnh.org/exhibitions/permanent/humanorigins/history/turkana.php
- Turkana Boy
- http://www.rps.psu.edu/sep98/missing.html
- http://www.findarticles.com/p/articles/mi_m1511/is_n3_v18/ai_19160830
- http://www.archaeologyinfo.com/homoerectus.htm