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Hyperglossal Canal

Hyperglossal canal

The hyperglossal canal is a hole in the bottom of the skull in humans and some other animals, through which the hyperglossal nerve passes from the brain stem to most muscles of the tongue. The size of the hyperglossal canal in fossil skulls has been used to suggest the size of the hyperglossal nerve in various extinct hominins, which in turn indicates the degree of control they had over their tongues and the probability they had developed language. Australopithecines had a small hyperglossal canal, about the same size as in modern chimpanzees; but in Homo heidelbergensis and Neanderthals the canal was twice as large, similar to modern humans.

Skull

A skull, or cranium, is a bony structure of Craniates which serves as the general framework for a head. The skull supports the structures of the face and protects the brain against injury.

Humans

brain brain In humans, the adult skull is normally made up of 28 bones. Except for the mandible, all of the bones of the skull are joined together by sutures, rigid articulations permitting very little movement. Eight bones form the neurocranium (braincase), a protective vault of bone surrounding the brain and medulla oblongata. Fourteen bones form the splanchnocranium, the bones supporting the face. Encased within the temporal bones are the six ear ossicles of the middle ear. The hyoid bone, supporting the larynx, is usually not considered as part of the skull, as it does not articulate with any other bones.

Development of the skull

The skull is a complex structure; its bones are formed both by intramembranous and endochondral ossification. The bones of the splanchnocranium and the sides and roof of the neurocranium are formed by intramembranous (or dermal) ossification, while the bones supporting the brain (the occipital, sphenoid, temporal, and ethmoid) are largely formed by endochondral ossification. At birth, the human skull is made up of 45 separate bony elements. As growth occurs, many of these bony elements gradually fuse together into solid bone (for example, the frontal bones). The bones of the roof of the skull are initially separated by regions of dense connective tissue called "sutures". There are five sutures: the frontal suture, sagittal suture, lambdoid suture, coronal suture, and squamosal suture. At birth these regions are fibrous and moveable, necessary for birth and later growth. This growth can put a large amount of tension on the "obstetrical hinge," which is where the squamous and lateral parts of the occipital bone meet. A possible complication of this tension is rupture of the great cerebral vein of Galen. Larger regions of connective tissue where multiple sutures meet are called fontanelles. The six fontanelles are: the anterior fontanelle, the posterior fontanelle, the two sphenoid fontanelles, and the two mastoid fontanelles. As growth and ossification progress, the connective tissue of the fontanelles is invaded and replaced by bone. The posterior fontanelle usually closes by eight weeks, but the anterior fontanelle can remain up to eighteen months. The anterior fontanelle is located at the junction of the frontal and parietal bones; it is a "soft spot" on a baby's forehead. Careful observation will show that you can count a baby's heart rate by observing his or her pulse pulsing softly through the anterior fontanelle.

Pathology

If the brain is bruised or injured it can be extremely serious. Normally the skull protects the brain from damage through its hard unyieldingness, but in some cases of head injury, there can be raised intracranial pressure through mechanisms such as a subdural haematoma. In these cases the raised intracranial pressure can cause herniation of the brain out of the foramen magnum ('coning') because there is no space for the brain to expand;this can result in significant brain damage or death unless an urgent operation is performed to relieve the pressure. This is why patients with concussion must be watched extremely carefully. In earlier times, a skull operation called trepanation was often performed for semi-mystical reasons and not only as an attempted life-saving technique. The skull also contains the sinus cavities. The meninges are the membranes that separate the brain from the skull.

Craniometry and morphology of human skulls

Like the face of a living individual, a human skull also can tell to a certain degree his or her life history and origin. Forensic scientists and archaeologist uses metric and nonmetric traits to estimate what the bearer of the skull looked like. When a good amount of bones are found, such as at Spitalfields in the UK and Jomon shell mounds in Japan, osteologists can use such traits, such as proportions of length, height, width, to know the relationships of population of the study, with living or extinct ones.

Sexual differences

In general, male skulls tend to be larger and more robust than female skulls. Male skulls typically have more prominent supraorbital ridges, a more prominent glabella, and more prominent temporal lines. Male skulls typically have larger, broader palates, squarer orbits, larger mastoid processes, larger sinuses, and larger occipital condyles than do females. Male mandibles typically have squarer chins and thicker, rougher muscle attachments than female mandibles. All of these features vary considerably within human populations, making it difficult to identify the sex of a skull without knowledge of the population it came from. The pelvis is considered the best skeletal indicator of sex.

Ancestry

Although persons' descents are occasionally stereotyped as different from other ethnic groups on the basis of a variety of traits like eye, hair and skin color, all such characters are not discrete nor preserved in bones. Among archaeologists and forensic scientists, it is well-known that the most consistent and unique trait of ancestry in skeleton is skull shape.

Bones of the human skull

Cranial bones


- frontal bone
- parietal bone (2)
- temporal bone (2)
- occipital bone
- sphenoid bone
- ethmoid bone

Facial bones


- mandible
- maxilla (2)
- palatine bone (2)
- zygomatic bone (2)
- nasal bone (2)
- lacrimal bone (2)
- vomer bone
- inferior nasal conchae (2)

Ear ossicles


- malleus (2)
- incus (2)
- stapes (2)

Wormian bones

In addition to the usual centers of ossification of the cranium, others may occur, giving rise to irregular isolated bones termed sutural or Wormian bones. They occur most frequently in the course of the lambdoidal suture, but are occasionally seen at the fontanelles, especially the posterior. One, the pterion ossicle, sometimes exists between the sphenoidal angle of the parietal bone and the great wing of the sphenoid bone. They have a tendency to be more or less symmetrical on the two sides of the skull, and vary in size. Their number is generally limited to two or three; but more than a hundred have been found in the skull of an adult hydrocephalic subject. Note: Ole Worm, Professor of Anatomy at Copenhagen, 1624–1639, was erroneously supposed to have given the first detailed description of these bones.

Other features of the skull

Foramina of skull base

The following is a list of holes, or foramina, in the base of the skull and what goes through each of them. Arranged from anterior to posterior:
- foramen caecum - emissary veins to superior sagittal sinus
- foramina of cribriform plate - olfactory nerve bundles
- posterior ethmoidal foramen - posterior ethmoidal artery, vein and nerve
- optic canal - optic nerve (II), ophthalmic artery
- superior orbital fissure
  - oculomotor nerve (III)
  - trochlear nerve (IV)
  - lacrimal, frontal and nasociliary branches of ophthalmic nerve (V1)
  - abducens nerve (VI)
  - superior ophthalmic vein
- foramen rotundum - maxillary nerve (V2)
- foramen ovale
  - mandibular nerve (V3)
  - accessory meningeal artery
  - lesser petrosal nerve (occasionally)
- foramen spinosum
  - middle meningeal artery and vein
  - meningeal branch of mandibular nerve
- foramen lacerum
  - internal carotid artery
  - internal carotid nerve plexus
- hiatus of canal of lesser petrosal nerve
- hiatus of canal of greater petrosal nerve
- internal acoustic meatus
  - facial nerve (VII)
  - vestibulocochlear nerve (VIII)
  - labyrinthine artery
- jugular foramen
  - inferior petrosal sinus
  - glossopharyngeal nerve (IX)
  - vagus nerve (X)
  - accessory nerve (XI)
  - sigmoid sinus
  - posterior meningeal artery
  - internal jugular vein
- hypoglossal canal - hypoglossal nerve (XII)
- foramen magnum
  - medulla oblongata
  - vertebral arteries
  - meningeal branches of vertebral arteries
  - spinal roots of accessory nerves

Notable sutures

Most sutures are named for the bones they articulate, but some have special names of their own.
- Sagittal - along the midline, between parietal bones
- Coronal - between the frontal and parietal bones
- Lambdoidal - between the parietals and the occipital bone
- Squamosal - between the parietal and the temporal bone
- Metopic - between the two frontal bones, prior to the fusion of the two into a single bone

See also

temporal bone
- Bone terminology
- Terms for anatomical location
- Great muscles of the head (cat).
- Phrenology, the pseudoscientific process of determining personality from the shape of the head.

External links


- [http://www.skullsunlimited.com/ Site with pictures of various animal skulls]
- [http://www.wtamu.edu/~rmatlack/Mammalogy/lab1.htm Skull terminology site by Texas A&M]

References


- White, T.D. 1991. Human osteology. Academic Press, Inc. San Diego, CA. Category:Head and neck Category:Skeletal system Category:Skull ja:頭蓋骨 simple:Cranium

Tongue

:Alternative meaning: Tongue, Highland Tongue, Highland The tongue is the large bundle of muscles on the floor of the mouth that manipulates food for chewing and swallowing. It is one of the organs of taste. Much of the surface of the tongue is covered in taste buds. The tongue assists in forming the sounds of speech. The word tongue can be used as a synonym for language, e.g., as in the phrase mother tongue. It is also examined and observed diagnostically in traditional Chinese medicine. The tongue is made mainly of skeletal muscle and attached to the hyoid bone, mandible and the styloid processes of the temporal bone. The muscles that attach the tongue are the extrinsic muscles of the tongue. Inside the tongue, there are four pairs of intrinsic muscles that can alter the shape of the tongue for talking and swallowing. Since it contains no supporting skeletal structures for the muscles, the tongue is an example of a muscular hydrostat, like an octopus arm. The dorsum (top side) of the tongue can be divided into two parts, an oral part that lies mostly in the mouth, and a pharyngeal part (posterior third of the tongue), which faces backward to the oropharynx. The two parts are separated by a V-shape groove, the sulcus terminalis (or terminal sulcus). The dorsal side of the anterior two-thirds (oral part) of the tongue is covered with small bumpy projections called papillae. There are four types of papillae: filiform (thread-shape), fungiform (mushroom-shape), foliate (leaf-shape), and vallate (ringed-circle). All papillae except the filiform have taste buds on their surface. At the back of the oral part of the tongue there are 3 to 14 vallate papillae arranged in a V-shape in front of the sulcus terminalis. There are no lingual papillae on the underside of the tongue. It is covered with a smooth mucous membrane, with a fold (the lingual frenulum) in the center. The upper side of the posterior tongue (pharyngeal part) has no visible taste buds, but it is bumpy because of the lymphatic nodules lying underneath. These follicles are known as the lingual tonsil. Things related to the tongue are often called lingual, which comes from the Latin word, or glossal, which comes from the Greek word for tongue. The tongue is the strongest muscle in the human body proportional to size.

Intrinsic muscles of the tongue

Four pairs of muscles originate within the tongue, and run in parallel down its length.
- The superior longitudinal muscle runs along the superior surface of the tongue under the mucous membrane, and allows the tongue to curl.
- The inferior longitudinal muscle lines the sides of the tongue, and is joined to the styloglossus muscle.
- The verticalis muscle is located in the middle of the tongue, and joins the superior and inferior longitudinal muscles.
- The transversus muscle divides the tongue at the middle, and is attached to the mucous membranes that run along the sides.

White tongue

White spots and patches or coating of the tongue are a symptom of several medical conditions:
- Antibiotics side effect
- Candidiasis
- Debauch
- Dehydration
- Leukoplakia
- Keratosis pharyngis
- Jaundice - causes a yellow tongue

See also


- Human anatomy
- Taste buds on the tongue
- Tongue-twister
- Tongue piercing
- Tongue bifurcation
- Vocal tract
- Glossitis tongue inflammation Category:gustatory system Category:Mouth ja:舌

Homininae


Gorillini (gorillas)
Hominini (humans and chimpanzees) Homininae is a subfamily of Hominidae, including Homo sapiens and some extinct relatives, as well as the gorillas and the chimpanzees. It comprises all those hominids, such as Australopithecus, that arose after the split from the other great apes (of which orangutans are the only surviving group). As of 1980, the family Hominidae contained only humans, with the great apes in the family Pongidae. Discoveries led to a revision of classification, with the great apes (now Ponginae) and humans (Homininae) united in Hominidae. But further discoveries indicated that gorillas and chimpanzees are more closely related to humans than they are to orangutans, hence their current placement in Homininae. Hominoid taxonomy has had several changes in the classification of apes in recent years. The subfamily Homininae can be further subdivided into the tribes Gorillini (gorillas) and Hominini (chimpanzees and humans). A hominin is a member of the tribe Hominini, a hominine is a member of the subfamily Homininae, a hominid is a member of the family Hominidae, and a hominoid is a member of the superfamily Hominoidea. Hominini Category:Apes ja:ヒト亜科

Australopithecine

This term australopithecine refers to two very closely related hominin genera:
- Australopithecus
- Paranthropus When used alone, the term refers to both genera together. Australopithecus is sometimes referred to as the gracile (slender) australopithecines. They appeared earlier in the fossil record and gave rise to Paranthropus, which are often called the robust australopithecines.

Chimpanzee


Pan troglodytes
Pan paniscus Chimpanzee, often abbreviated to chimp, is the common name for two species in the genus Pan. The better known chimpanzee is Pan troglodytes, the Common Chimpanzee, living in West and Central Africa. Its cousin, the Bonobo or Pygmy Chimpanzee (Pan paniscus), is found in the forests of the Democratic Republic of the Congo. The boundary between the two species is formed by the Congo River.

Lifespan

Chimpanzees rarely live past the age of 50 in the wild, but have been known to reach the age of 60 in captivity.

Chimpanzee differences

Anatomical differences between Common and Pygmy Chimpanzees are slight, but in sexual and social behaviour there are marked differences. Common Chimpanzees have an omnivorous diet, a troop hunting culture based on beta males led by a relatively weak alpha, and highly complex social relationships; Bonobos, on the other hand, have a mostly herbivorous diet and an egalitarian, matriarchal, sexually promiscuous culture.

History of human interaction

Although Africans have had contact with chimpanzees for millennia, the first recorded (Western) contact of humans with chimps was made by Europeans scouting Angola at some point during the 1600s. The first use of the name "chimpanzee", however, did not occur until 1738. The name is derived from an Angolan Bantu language term "Tshiluba kivili-chimpenze", which is the local name for the animal and translates loosely as "mockman" or possibly just "ape". The colloquialism "chimp" was most likely coined some time in the late 1870s. Science would eventually take the 'pan' occurring in 'chimpanzee' and attribute it to Pan, a rural ancient Greek god of nature. Biologists would apply Pan as the genus name of the animal. Chimps as well as other apes had also been purported to have existed in ancient times, but did so mainly as myths and legends on the edge of Euro-Arabic societal consciousness, mainly through fragmented and sketchy accounts of European adventurers. Apes are mentioned variously by Aristotle, as well as the Bible. European scientists were bemused when chimpanzees first began arriving on the European continent as a result of these ancient descriptions, which often falsely purported that chimpanzees had horns and hooves. The first of these early trans-continental chimpanzees came from Angola and was presented as a gift to the Prince of Orange in 1640 and was followed by a few of its brethren over the next several years. Scientists who examined these rare specimens were baffled and described these first chimpanzees as "pygmies" of some kind or another, but did manage to note the animals' distinct similarities to humans. The next two decades would see a number of the creatures imported into Europe, mainly acquired by various zoological gardens as entertainment for visitors. Darwin's theory of evolution (published in 1860), as it did in most life science fields, would spur scientific interest in chimpanzees and led to numerous studies of the animals in the wild and captivity. The observers of chimpanzees at the time were mainly interested in the behaviour as it related to that of humans. However, this was not as strictly and benignly scientific as it sounds, with much attention being focused on whether or not the animals had traits that could be considered 'good' and the intelligence of chimpanzees was often significantly exaggerated. At one point there was even a scheme drawn up to domesticate chimpanzees in order to have them work at various menial tasks (i.e. factory work). By the end of the 1800s there was still very little factual scientific information regarding chimpanzees established. The creatures were still very much a mystery to humans. The 20th century would see a new age of scientific research into chimpanzee behaviour, generally free from the human egotism and patronizing attitude that had marred the previous era of studies. The most progressive studies that emerged were spearheaded primarily by Wolfgang Köhler and Robert Yerkes, both of whom were renowned psychologists. Both men and their colleagues established laboratory studies of chimpanzees focused specifically on learning about the intellectual, particularly the problem-solving abilities, of chimpanzees. This typically involved basic, practical tests where laboratory chimpanzees were required to demonstrate problem-solving abilities in order to solve basic tests which required a fairly high intellectual capacity (such as how to solve the problem of reaching an out of reach banana). Notably, Yerkes also made extensive observations of chimpanzees in the wild which also added tremendously to the scientific understanding of chimpanzees and their behaviour. Yerkes studied chimpanzees until World War II, while Köhler concluded five years of study and published his famous Mentality of Apes in 1925 (which is coincidentally when Yerkes began his analyses), eventually concluding that "chimpanzees manifest intelligent behavior of the general kind familiar in human beings... a type of behaviour which counts as specifically human" (1925).

Taxonomic relationships

The genus Pan is now considered to be part of the subfamily Homininae to which humans also belong. Biologists believe that the two species of chimpanzees are the closest living evolutionary relatives to humans. Their common ancestor branched off from its latest common ancestor with us as recently as four to seven million years ago, and they have about 95 to 98 percent of their DNA in common with humans. It has even been proposed that chimpanzees should be recategorized in the genus Homo as well. The argument for this is that other species have been reclassified to belong to the same genus on the basis of less genetic similarity than that between humans and chimpanzees. However, it is very important where the differences in the genome appear. The study published by Clark and Nielsen of the Cornell University in the Science in December 2003 highlights differences related to one of humankind's defining qualities — the ability to understand language and to communicate through speech, also in the genes for smell, in genes that enable humans and chimps to metabolize amino acids and in genes that may affect the ability to digest various protein. The fact that many chimpanzees have been taught to use hundreds of sign language words, and have sometimes passed on this knowledge to their offspring, indicates that "language" may not be such a major divider between humans and other hominids. See the history of hominoid taxonomy for more about the history of the classification of chimpanzees.

Fossils

Many human fossils have been found, but chimpanzee fossils had not been described until 2005. Existing chimpanzee populations in West and Central Africa do not overlap with the major human fossil sites in East Africa. However, chimpanzee fossils have now been reported in Kenya. This result indicates that both humans and members of the Pan clade were present in the East African Rift Valley during the Middle Pleistocene.

References


- "First fossil chimpanzee." by S. McBrearty and N. G. Jablonski in Nature (2005) Sep 1, Volume 437 pages 105-108. .
- Goodall, Jane. (1986) The Chimpanzees of Gombe: Patterns of Behavior.
- Pickrell, John. (September 24, 2002). [http://news.nationalgeographic.com/news/2002/09/0924_020924_dnachimp.html Humans, Chimps Not as Closely Related as Thought?]. National Geographic.

See also


- Great ape personhood
- List of famous apes
- Great Ape research ban

External link


- [http://chimp.st-and.ac.uk/cultures/intro.htm Chimpanzee Cultures Online] Category:Apes Category:Wildlife of Africa ja:チンパンジー属

Homo heidelbergensis

Homo heidelbergensis (nicknamed "Goliath") is an extinct species of the genus Homo and the direct ancestor of Homo neanderthalensis in Europe, while similar "Archaic Homo sapiens" found in Africa (ie. Homo rhodesiensis and Homo sapiens idaltu) are thought to be direct ancestors of modern Homo sapiens. Homo antecessor is likely a direct ancestor living 750,000 years ago evolving into Homo heidelbergensis appearing in the fossil record living roughly 600,000 to 250,000 years ago through various areas of Europe. Both H. antecessor and H. heidelbergensis are likely descended from the morphologically very similar Homo ergaster from Africa but because H. heidelbergensis had a larger brain-case, about 93% size of the average Homo sapiens brain-case, and more advanced tools and behaviour, it has been given a separate species classification. The species was tall, 1.8 m (6 ft.) on average, and more muscular than modern humans. Homo heidelbergensis remains were found in Mauer near Heidelberg, Germany and then later in Arago, France and Petrolona, Greece. The best evidence found for these hominins date between 400,000 and 500,000 years ago. H. heidelbergensis stone tool technology was considerably close to that of the Archueulan tools used by Homo erectus. The first fossil discovery of this species was made on October 21, 1907 and came from Mauer where an anonymous workman spotted a jaw in a sandpit. The jaw was in good condition except for the missing premolar teeth, which were eventually found near the jaw.

Evidence of hunting

Cut marks found on wild deer, elephants, rhinos and horses demonstrate that they were butchered, some of the animals weighed as much as 1,500 lbs or possibly larger. By this era in Europe, extinct wild animals such as mammoths, European lions and Irish elk roamed the continent.

Social behaviour

Recent findings in Europe also suggest that H. heidelbergensis may have been the first species of the Homo genus to bury their dead, but that is contested at this time. Some experts believe that H. heidelbergensis, like its descendant H. neanderthalensis acquired a primitive form of language.

References


- SAUER, A. (1985): Erläuterungen zur Geol. Karte 1 : 25 000 Baden-Württ., Blatt 6618 Heidelberg-Süd (früher Blatt Neckargemünd) 110 S., Stuttgart
- SCHOETENSACK, O. (1908): Der Unterkiefer des Homo heidelbergensis aus den Sanden von Mauer bei Heidelberg. Leipzig: Wilhelm Engelmann
- WEINERT, H. (1937): Dem Unterkiefer von Mauer zur 30-jährigen Wiederkehr seiner Entdeckung, Z. f. Morphol. u. Anthropol. Bd.XXXVII, Heft 1, S.102-113 Category:early hominids Category:Pleistocene mammals Category:Pleistocene extinctions ja:ホモ・ハイデルベルゲンシス

Neanderthals

The Neanderthal or Neandertal was a species of Homo (Homo neanderthalensis) that inhabited Europe and parts of western Asia from about 230,000 to 29,000 years ago, during the Middle Paleolithic period. Neanderthals were adapted to the cold, as shown by their large braincases, short but robust builds, and large noses — traits selected by nature in cold climates, as observed in modern sub-arctic populations. Their brains were roughly ten percent larger than those of modern humans. On average, Neanderthals stood about 1.65m tall (just under 5' 6") and were muscular. The characteristic style of stone tools in the Middle Paleolithic is called the Mousterian Culture, after a prominent archaeological site where the tools were first found. The Mousterian culture is typified by the wide use of the Levallois technique. Mousterian tools were often produced using soft hammer percussion, such as bones, antlers, and wood, rather than hard hammer percussion, using stone.

Name and classification

The term "Neanderthal Man" was coined in 1863 by Irish anatomist William King. Neanderthal is now spelled two ways: The spelling of the German word Thal, meaning "valley or dale", was changed to Tal in the early 20th century, but the former spelling is often retained in English and always in scientific names, while the modern spelling is used in German. The Neanderthal or "Neander valley" was named after theologian Joachim Neander, who lived there in the late eighteenth century. The original German pronunciation (regardless of spelling) is with the sound /t/, rather than the sound /θ/ which is typical of the digraph th in English. When used in English, the term may get an anglicised /θ/ or an original /t/, depending on the speaker. For many years, professionals vigorously debated about whether Neanderthals should be classified as Homo neanderthalensis or as Homo sapiens neanderthalensis, the latter placing Neanderthals as a subspecies of Homo sapiens. However, recent evidence from mitochondrial DNA studies have been interpreted as evidence that Neanderthals were not a subspecies of H. sapiens. Still, some scientists argue that fossil evidence suggests that the two species interbred, and hence were the same biological species. It is generally accepted that both Neanderthals and Homo sapiens evolved from an earlier "archaic" Homo sapiens, but the classification of Neanderthals depends on when in time modern humans are considered a separate species from the "archaic" forms. This complication is introduced because the "archaic" forms are a chronospecies.

Discovery

A Neanderthal skull was first discovered in Forbes' Quarry, Gibraltar in 1848, eight years prior to the "original" discovery in a limestone quarry of the Neander Valley (near Düsseldorf) in August, 1856, and three years before Charles Darwin's On the Origin of Species was published. The type specimen, dubbed Neanderthal 1, consisted of a skull cap, two femora, three bones from the right arm, two from the left arm, part of the left ilium, fragments of a scapula, and ribs. The workers who recovered this material originally thought it to be the remains of a bear. They gave the material to amateur naturalist Johann Karl Fuhlrott, who turned the fossils over to anatomist Hermann Schaafhausen. The discovery was jointly announced in 1857. That discovery is now considered the beginning of paleoanthropology. These and other discoveries led to the idea that these remains were from ancient Europeans who had played an important role in modern human origins. The remains of over 400 Neanderthals have been found since.

Physical traits

The following is a list of physical traits that distinguish Neanderthals from modern humans; however, not all of them can be used to distinguish specific Neanderthal populations, from various geographic areas or periods of evolution, from other extinct humans. Also, many of these traits occasionally manifest in modern humans, particularly among certain ethnic groups. Nothing is known about the skin color, the hair, or the shape of soft parts such as eyes, ears, and lips of Neanderthals. Compared to modern humans, Neanderthals were larger in size and had distinct morphological features, especially of the cranium, which gradually accumulated more derived aspects, particularly in certain relatively isolated geographic regions. Their relatively robust stature is thought to be an adaptation to the cold climate of Europe during the Pleistocene epoch. Pleistocene]
- Cranial
  - Suprainiac fossa, a groove above the inion
  - Occipital bun, a protuberance of the occipital bone that looks like a hair knot
  - Projecting mid-face
  - Globe-shaped skull (from rear)
  - Low, flat, elongated skull
  - Supraorbital torus, a prominent browridge
  - 1200-1700 cm³ skull capacity (slightly greater than modern humans)
  - No chin
  - Crest on the mastoid process behind the ear opening
  - No groove on canine teeth
  - A space behind the last molars
  - A broad, projecting nose
  - Bony projections on the sides of the nasal opening
  - Distinctive shape of the bony labyrinth in the ear
- Post-Cranial
  - Considerably more muscular
  - Large round finger tips
  - Barrel-shaped rib cage
  - Distinctive pelvic shape
  - Large kneecaps
  - Long collar bones
  - Short, bowed shoulder blades
  - Thick, bowed shaft of the thigh bones
  - Short shinbones and calf bones Based on a 2001 study, some commentators speculated that Neanderthals exhibited rufosity, and some red-headed and freckled humans today share some heritage with Neanderthals. [http://www.gktgazette.com/2001/may/news.asp#red] However, more recent research indicates that this is not likely. [http://www.arts.telegraph.co.uk/connected/main.jhtml?xml=/connected/2002/10/04/ecfhair04.xml&sSheet=/connected/2002/10/04/ixconn.html]

Language

The theory that Neanderthals lacked complex language was widespread until 1983, when a Neanderthal hyoid bone was found at the Kebara Cave in Israel. The bone that was found is virtually identical to that of modern humans. The hyoid is a small bone that holds the root of the tongue in place, a requirement to human speech and, therefore, its presence seems to imply some ability to speak. Many people believe that even without the hyoid bone evidence, it is obvious that tools as advanced as those of the Mousterian Era, attributed to Neanderthals, could not have been developed without cognitive skills encompassing some form of spoken language. A recent study conducted on the Neanderthal hyoid found that due to the physical characteristics of Neanderthals and the fact that their larynx would have been stouter than that of modern man, the average note emitted by Neanderthals would have been high pitched and sharper than that of modern man, contrary to the media stereotype of Neanderthals having ape-like grunts. The base of the Neanderthal tongue was positioned higher in the throat, crowding the mouth somewhat. As a result, Neanderthal speech would most likely have been slow-paced and nasalized.

Tools

Neanderthal (Middle Paleolithic) archeological sites show both a smaller and a less flexible toolkit than in the Upper Paleolithic sites, occupied by modern humans that replaced them. There is little evidence that Neanderthals used antlers, shell, or other bone materials to make tools: their bone industry was relatively simple. However, there is good evidence that they routinely constructed a variety of stone implements. The Neanderthal (Mousterian) tool case consisted of sophisticated stone-flakes, task-specific hand axes, and spears. Many of these tools were very sharp. Also, while they had weapons, none have as yet been found that were used as projectile weapons. They had spears in the sense of a long wooden shaft with a spear head firmly attached to it, but these were not spears specifically crafted for flight (perhaps better described as a lance). However, a number of 400,000 year old wooden projectile spears were found at Schöningen in northern Germany. These are thought to have been made by the Neanderthal's ancestors, Homo erectus or Homo heidelbergensis. Generally, projectile weapons are more commonly associated with H. sapiens. Although much has been made of the Neanderthal's burial of their dead, their burials were less elaborate than those of anatomically modern humans. The interpretation of the Shanidar IV burials as including flowers, and therefore being a form of ritual burial (Ralph Solecki 1975), has been questioned (Sommer 1999). In some cases Neanderthal burials include grave goods such as bison and aurochs bones, tools, and the pigment ochre. Neanderthals performed a sophisticated set of tasks normally associated with humans alone. For example, they constructed complex shelters, controlled fire, and skinned animals. Particularly intriguing is a hollowed-out bear femur with four holes in the diatonic scale deliberately bored into it. This flute was found in western Slovenia in 1995 near a Mousterian Era fireplace used by Neanderthals, but its significance is still a matter of dispute. See: prehistoric music.

Key dates


- 1848: Skull of ancient human found in Forbe's Quarry, Gibraltar. Its significance is not realised at the time.
- 1856: Johann Karl Fuhlrott first recognizes the fossil called “Neanderthal man.”
- 1880: The mandible of a Neanderthal child was found in a secure context, associated with cultural debris, including hearths, Mousterian tools, and bones of extinct animals.
- 1899: Hundreds of Neanderthal bones were described in stratigraphic position in association with cultural remains and extinct animal bones.
- 1908: A nearly complete Neanderthal skeleton in association with Mousterian tools and bones of extinct tools discovered.
- 1953-1957: Shanidar Cave, Northern Iraq: Ralph Solecki uncovers nine Neanderthal skeletons.
- 1975: Erik Trinkaus’s study of Neanderthal feet confirms they walked like modern humans.
- 1987: New thermoluminescence dates in the Levant place Neanderthal levels at Kebara at ca. 60,000 BP and modern humans at Qafzeh to 90,000 BP. These dates are confirmed by ESR dates for Qafzeh (90,000 BP) and Skhul (80,000 BP).
- 1991: New Electron Spin Resonance (ESR) dates for Near Eastern remains show Tabun Neanderthal to be contemporaneous with modern humans from Skhul and Qafzeh.
- 2000: Igor Ovchinnikov, Kirsten Liden, William Goodman et al. retrieve DNA from a late (29,000 BP) Neanderthal infant from Mezmaikaya Cave in the Caucausus.
- 2005: The Max Planck Institute for Evolutionary Anthropology launches a project to reconstruct the Neanderthal genome.

Popular culture

Popular Literature has tended to greatly exaggerate the ape-like gait and related characteristics of the Neanderthals. It has been determined that some of the earliest specimens found in fact suffered from severe arthritis. The Neanderthals were fully bipedal and had a slightly larger average brain capacity than a typical modern human, though it is thought the brain structure was organised differently. In popular idiom the word Neanderthal is sometimes used as an insult, to suggest that a person combines a deficiency of intelligence and an attachment to brute force, as well as perhaps implying the person is old fashioned or attached to outdated ideas, much in the same way as "dinosaur" is also used. Counterbalancing this are sympathetic literary portrayals of Neanderthals, as in the novel The Inheritors by William Golding and Jean M. Auel's Earth's Children series, or the more serious treatment by palaeontologist Björn Kurtén, in several works including Dance of the Tiger, and British psychologist Stan Gooch in his hybrid-origin theory of man. Science fiction has depicted Neanderthals in several ways:
- In The Ugly Little Boy by Isaac Asimov, a Neanderthal child is brought into the present via time travel.
- Michael Crichton's 1976 novel Eaters of the Dead places a small Neanderthal population in Europe as the source of the battles recorded in Beowulf.
- In the Riverworld series, Philip José Farmer introduces a prominent Neanderthal character named Kazz, who interacts with modern humans. Jose Farmer's novella The Alley Man concerns a Neanderthal whose family has survived into modern times.
- Robert Sawyer's Neanderthal Parallax trilogy portrays contact with an alternate world where Neanderthals, not Homo sapiens, became the dominant species. The first book in this series, Hominids, won the Hugo Award in 2003. (Sawyer's 1997 novel Frameshift used Neanderthal DNA as an element of a plot set in modern-day America.)
- In John Darnton's 1996 novel Neanderthal a group of surviving Neanderthals is discovered in the mountains of Afghanistan. In the novel Neanderthals are said to possess the ability to read minds due to their larger cranial capacity.
- In the 1989 Doctor Who serial Ghost Light a Neanderthal named Nimrod is a butler. He shows good intelligence throughout the serial.
- Neanderthals are portrayed as having been brought back from extinction to fill low paying jobs in Jasper Fforde's novel Lost in a Good Book, as well as later novels in the series.
- Hindu Epic Ramayana mentions [http://www.theosophy-nw.org/theosnw/science/sc-moff2.htm human-like Apes and Bears] resembling Neanderthals.
- A character in Sergio Bonelli's comic book, "Martin Mystère", is a Neanderthal called Java. He is a part of the last surviving Neanderthal population, living in a hidden city in Mongolia.
- A Neanderthal named Java also appeared as a supporting character in the adventures of Metamorpho the Element Man by DC Comics. The name of this character and the 'Java' from Martin Mystère are both inspired by the Java Man remains.

See also


- Caveman
- List of neanderthal sites
- Neandertal interaction with Cro-Magnons
- Physical anthropology

External links


- [http://news.bbc.co.uk/hi/english/sci/tech/newsid_323000/323657.stm 'Neanderthals "mated with modern humans"'] - BBC (April 21, 1999)
- [http://news.bbc.co.uk/2/hi/science/nature/2884801.stm 'Neanderthals had hand like ours'] - Helen Briggs, BBC (March 27, 2003)
- [http://www.geocities.com/veldwezelt_2002/index.html geocities.com] - 'The Neanderthal Sites at Veldwezelt-Hezerwater, Belgium'
- [http://www.ifi.unizh.ch/staff/zolli/CAP/comparingNeand.htm 'Comparing Neanderthals and modern humans' (cranio-facial reconstructions)] - IFI.unizh.ch
- [http://sapphire.indstate.edu/~ramanank/ 'Neanderthals: A Cyber Perspective' ] - Kharlena María Ramanan, Indiana State University
- [http://www.krapina.com/neandertals/index_en.htm Krapina.com] - 'Krapina: The World's Largest Neanderthal Finding Site'
- [http://www.greenwych.ca/fl-compl.htm Neanderthal Flute] -- oldest known musical instrument [http://www.greenwych.ca/readings.htm matches] 4 notes of do-re-mi scale. Was it made by [http://www.greenwych.ca/chewchip.htm carnivores], or is it an artifact?
- [http://www.neanderthal.de/ Neanderthal.de] - 'Neanderthal Museum'
- [http://www.rdos.net/wiki/index.php/Neanderthal_theory RDOS.net] 'Neanderthal theory'

References


- C. David Kreger 6/30/00 [http://www.modernhumanorigins.com/neanderthalensis.html Homo Neanderthalensis] retrieved 12/26/2004
- Dennis O'Neil 12/6/04 [http://anthro.palomar.edu/homo2/mod_homo_2.htm Evolution of Modern Humans Neandertals] retrieved 12/26/2004
- Fink, Bob (1997) [http://www.greenwych.ca/fl-compl.htm The Neanderthal Flute...] (Greenwich, Canada) ISBN 0912424125
- Hickmann, Kilmer, Eichmann (ed.) (2003) [http://www.greenwych.ca/studies.htm Studies in Music Archaeology III International Study Group on Music Archaeology's 2000 symposium. ISBN 3896466402
- Solecki, R. S. (1975) Shanidar IV, a Neanderthal flower burial in N. Iraq Science 190 (28) 880
- Sommer, J.D. (1999) The Shanidar IV 'Flower Burial': A Reevaluation of Neanderthal Burial Ritual, Cambridge Archaeological Journal, 9 127-129.
- Eva M. Wild, Maria Teschler-Nicola, Walter Kutschera, Peter Steier, Erik Trinkaus & Wolfgang Wanek (19 May 2005) Direct dating of Early Upper Palaeolithic human remains from Mladeč, Nature 435:332–335. [http://www.nature.com/nature/journal/v435/n7040/full/nature03585.html link for Nature subscribers] Category:early hominids Category:European archaeology Category:Pleistocene mammals Category:Pleistocene extinctions als:Neandertaler ja:ネアンデルタール人

Human

Humans or human beings define themselves in biological, social, and spiritual terms. Biologically, humans are classified as the species Homo sapiens (Latin for "wise man" or "thinking man"): a bipedal primate of the superfamily Hominoidea, together with the other apes: chimpanzees, gorillas, orangutans, and gibbons. Humans have an erect body carriage that frees their upper limbs for manipulating objects and a highly developed brain capable of abstract reasoning, speech, language, and introspection. Bipedal locomotion appears to have evolved before the development of a large brain. The origins of bipedal locomotion and of its role in the evolution of the human brain are topics of ongoing research. The human mind has several distinct attributes. It is responsible for complex behaviour, especially language. Curiosity and observation have led to a variety of explanations for consciousness and the relation between mind and body. Psychology attempts to study behaviour from a scientific point of view. Religious perspectives emphasise a soul, qi or atman as the essence of being, and are often characterised by the belief in and worship of God, gods, spirits, or other people. Philosophy, especially philosophy of mind, attempts to fathom the depths of each of these perspectives. Art, music and literature are often used in expressing these concepts and feelings. Like all primates, humans are inherently social. They create complex social structures composed of co-operating and competing groups. These range from nations and states down to families. Seeking to understand and manipulate the world around them has led to the development of technology and science. Artifacts, beliefs, myths, rituals, values, and social norms have all helped to form humanity's culture.

Terminology

In general, the word "people" is a collective or plural term for any specific group of individual persons. However, when used to refer to a group of humans possessing a common ethnic, cultural or national unitary characteristic or identity, "people" is a singular count noun, and as such takes an "s" in the plural (examples: "the English-speaking peoples of the world", "the indigenous peoples of Brazil"). ethnic Juvenile males are called boys, adult males men, juvenile females girls, and adult females women. Humans are commonly referred to as persons or people, and collectively as Man (capital M), mankind, humankind, humanity, or the human race. Until the 20th century, "human" was only used adjectivally ("pertaining to mankind"). Nominal use of "human" (plural "humans") is short for "human being", and not considered good style in traditional English grammar. As an adjective, "human" is used neutrally (as in "human race"), but "human" and especially "humane" may also emphasise positive aspects of human nature, and can be synonymous with "benevolent" (versus "inhumane"; cf. humanitarian). A distinction is maintained in philosophy and law between the notions "human being", or "man", and "person". The former refers to the species, while the latter refers to a rational agent (see, for example, John Locke's Essay concerning Human Understanding II 27 and Immanuel Kant's Introduction to the Metaphysic of Morals). The term "person" is thus used of non-human animals, and could be used of a mythical being, an artificial intelligence, or an extraterrestrial. An important question in theology and the philosophy of religion concerns whether God is a person. In Latin, "humanus" is the adjectival form of the noun "homo", translated as "man" (to include males and females). The Old English word "man" could also have this generic meaning, as demonstrated by such compounds as "wifman" ("female person") → "wiman" → "woman". For the etymology of "man" see mannaz.

Biology

Anatomy and physiology

mannaz] Humans exhibit fully bipedal locomotion. This leaves the forelimbs available for manipulating objects using opposable thumbs. Humans vary substantially around the mean height and mean weight. Some of this variation is explained by locality and historical factors. Although body size is largely determined by genes, it is also significantly influenced by diet and exercise. The mean height of a North American adult female is 162 centimetres (5 feet 4 inches) and the mean weight is 62 kilograms (137 pounds). North American adult males are typically larger: 175 centimetres (5 feet 9 inches) and 78 kilograms (172 pounds). Human skin appears to be relatively hairless in comparison to other primates; however, most humans have a larger number of hairs on their body than a chimpanzee. The main difference is that human hairs are shorter, finer, and less coloured then the average chimpanzee's, thus rendering them harder to see. The colour of human hair and skin is determined by the presence of coloured pigments called melanins. Most researchers believe that skin darkening was an adaptation that evolved as a defence against UV solar radiation; melanin is an effective sunblock. The skin colour of contemporary humans can range from very dark brown to very pale pink. It is geographically stratified and in general correlates with the environmental level of UV. Human skin and hair colour is controlled in part by the MC1R gene. For example, the red hair and pale skin of some Europeans is the result of mutations in MC1R. Human skin has a capacity to darken (sun tanning) in response to UV exposure. Variation in the ability to sun tan is also controlled in part by MC1R. sun tanning] Because humans are bipedal, the pelvic region and spinal column tend to become worn, creating locomotion difficulties in old age. The individual need for regular intake of food and drink is prominently reflected in human culture, and has led to the development of food science. Failure to obtain food leads to hunger and eventually starvation, while failure to obtain water leads to dehydration and thirst. Both starvation and dehydration cause death if not alleviated. In modern times, obesity amongst humans has increased to almost epidemic proportions, leading to health complications and increased mortality in some developed countries, and is becoming problematic elsewhere. The average sleep requirement is between seven and eight hours a day for an adult and nine to ten hours for a child. Elderly people usually sleep for six to seven hours. It is common, however, in modern societies for people to get less sleep than they need, leading to a state of sleep deprivation. The human body is subject to an ageing process and to illness. Medicine is the science that explores methods of preserving bodily health.

Life cycle

health] The human life cycle is similar to that of other placental mammals. New human life develops from conception. An egg is usually fertilised inside the female by sperm from the male through sexual intercourse, though in vitro fertilisation methods are also used. The fertilised egg is called a zygote. The zygote divides inside the female's uterus to become an embryo which over a period of thirty-eight weeks becomes the fetus. At birth, the fully grown fetus is expelled from the female's body and breathes independently as a baby for the first time. At this point, most modern cultures recognise the baby as a person entitled to the full protection of the law, though some jurisdictions extend personhood to human fetuses while they remain in the uterus. Compared with that of other species, human childbirth is relatively complicated. Painful labours lasting twenty-four hours or more are not uncommon, and may result in injury to the child or the death of the mother, although the chances of a successful labour increased significantly during the twentieth century in wealthier countries. Natural childbirth remains an arguably more dangerous ordeal in remote, underdeveloped regions of the world, though the women who live in these regions have argued that their natural childbirth methods are safer and less traumatic for mother and child. Natural childbirth Human children are born after a nine-month gestation period, with typically 3–4 kilograms (6–9 pounds) in weight and 50–60 centimetres (20–24 inches) in height in developed countries. [http://www.childinfo.org/eddb/lbw] Helpless at birth, they continue to grow for some years, typically reaching sexual maturity at twelve to fifteen years of age. Boys continue growing for some time after this, reaching their maximum height around the age of eighteen. These values vary too, depending on genes and environment. The human lifespan can be split into a number of stages: infancy, childhood, adolescence, young adulthood, maturity and old age, though the lengths of these stages, especially the later ones, are not fixed. There are striking differences in life expectancy around the world. The developed world is quickly getting older, with the median age around 40 years (highest in Monaco at 45.1 years), while in the developing world, the median age is 15–20 years (the lowest in Uganda at 14.8 years). Life expectancy at birth is 77.2 years in the U.S. as of 2001. [http://www.cdc.gov/nchs/fastats/lifexpec.htm] The expected life span at birth in Singapore is 84.29 years for a female and 78.96 years for a male, while in Botswana, due largely to AIDS, it is 30.99 years for a male and 30.53 years for a female. One in five Europeans, but one in twenty Africans, is 60 years or older, according to The World Factbook. [http://www.cia.gov/cia/publications/factbook] African.]] The number of centenarians in the world was estimated by the United Nations [http://www.un.org/ageing/note5713.doc.htm] at 210,000 in 2002. The maximum life span for humans is thought to be over 120 years. Worldwide, there are 81 men aged 60 or over for every 100 women, and among the oldest, there are 53 men for every 100 women. The philosophical questions of when human personhood begins and whether it persists after death are the subject of considerable debate. The prospect of death may cause unease or fear. People who are near death sometimes have a near-death experience, in which they have visions. Burial ceremonies are characteristic of human societies, often inspired by beliefs in an afterlife. Institutions of inheritance or ancestor worship may extend an individual's presence beyond his physical lifespan (see immortality).

Genetics

Humans are a eukaryotic species. Each diploid cell has two sets of 23 chromosomes, each set received from one parent. There are 22 pairs of autosomes and one pair of sex chromosomes. At present estimate, humans have approximately 20,000–25,000 genes and share 95% of their DNA with their closest living evolutionary relatives, the two species of chimpanzees. [http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12368483] Like other mammals, humans have an XY sex determination system, so that females have the sex chromosomes XX and males have XY. The X chromosome is larger and carries many genes not on the Y chromosome, which means that recessive diseases associated with X-linked genes affect men more often than women. For example, genes that control the clotting of blood reside on the X chromosome. Women have a blood-clotting gene on each X chromosome so that one normal blood-clotting gene can compensate for a flaw in the gene on the other X chromosome. But men are hemizygous for the blood-clotting gene, since there is no gene on the Y chromosome to control blood clotting. As a result, men will suffer from haemophilia more often than women.

Race and ethnicity

haemophilia, Black, White (Hispanic), and Asian. Top row males, bottom row females.]] Humans often categorise themselves and others in terms of race or ethnicity. In the United States, racial categories are primarily based on language and ethnicity, although biological qualities, such as skin colour, blood type, facial features, ancestry, and other genetic variances are also key factors. Self identification with an ethnic group is usually based on kinship and descent, as well as presumed advantage. When race and ethnicity lead to variant treatment it is thought to impact social identity, giving rise to the theory of identity politics. Although most humans recognise that variances occur within a species, it is often a point of dispute as to what these differences entail, and if discrimination based on race (racism) is acceptable in the early twenty-first century. Race and intelligence, scientific racism, xenophobia and ethnocentrism are just a few of the many basis' for such practices.

Habitat

The view most widely accepted by the anthropological community is that the human species originated in the African savanna between 100 and 200 thousand years BCE, colonised the rest of the Old World and Oceania by 40,000 years BCE, and finally colonised the Americas by 10,000 years BCE. Homo sapiens displaced groups such as Neanderthals and Homo floresiensis through more successful reproduction and competition for resources, and/or extermination. (See Human evolution, Vagina gentium, and Environment of Evolutionary Adaptedness.) Technology has allowed humans to colonise all of the continents and adapt to all climates. Within the last few decades, humans have been able to explore Antarctica, the ocean depths, and space, although long-term habitation of these environments are not yet possible. Humans, with a population of about six thousand million, are one of the most numerous mammals on Earth. Most humans (61%) live in the Asian region. The vast majority of the remainder live in the Americas (14%), Africa (13%) and Europe (12%), with 5% in Oceania. (See list of countries by population and list of countries by population density.) list of countries by population density (The arctic is at the centre of the map and the numbers are millennia before present).]] The original human lifestyle is hunting-gathering, which is adapted to the savanna. Other human lifestyles are nomadism (often linked to animal herding) and permanent settlements made possible by the development of agriculture. Humans have a great capacity for altering their habitats by various methods, such as agriculture, irrigation, urban planning, construction, transport, and manufacturing goods. Permanent human settlements are dependent on proximity to water and, depending on the lifestyle, other natural resources such as fertile land for growing crops and grazing livestock, or seasonally by populations of prey. With the advent of large-scale trade and transport infrastructure, immediate proximity to these resources has become unnecessary, and in many places these factors are no longer the driving force behind growth and decline of population. Human habitation within closed ecological systems in hostile environments (Antarctica, outer space) is expensive, typically limited in duration, and restricted to scientific, military, or industrial expeditions. Life in space has been very sporadic, with a maximum of thirteen humans in space at any given time, starting with Yuri Gagarin's space flight in 1961. Between 1969 and 1974, up to two humans at a time spent brief intervals on the Moon. As of 2005, no other celestial body has been visited by human beings, although there has been a continuous human presence in space since the launch of the initial crew to inhabit the International Space Station on October 31, 2000.

Population

2000 From 1800 to 2000, the human population increased from one to six billion. It is expected to crest at around ten billion during the 21st century. In 2004, around 2.5 billion out of 6.3 billion people lived in urban centres, and this is expected to rise during the 21st century. Problems for humans living in cities include various forms of pollution, crime, and poverty, especially in inner city and suburban slums. Geneticists Lynn Jorde and Henry Harpending of the University of Utah have concluded that the variation in the total stock of human DNA is minute compared to that of other species; and that around 74,000 years ago, human population was reduced to a small number of breeding pairs, possibly as small as 1000, resulting in a very small residual gene pool. Various reasons for this bottleneck have been postulated, the most popular, called the Toba catastrophe theory, being the eruption of a volcano at Lake Toba.

Human evolution

The study of human evolution encompasses many scientific disciplines, but most notably physical anthropology and genetics. The term "human", in the context of human evolution, refers to the genus Homo, but studies of human evolution usually include other hominids and hominines, such as the australopithecines. Biologically, humans are defined as hominids of the species Homo sapiens, of which the only extant subspecies is Homo sapiens sapiens (Latin for "very wise man"); Homo sapiens idaltu (roughly translated as "elderly wise man") is the extinct subspecies. Modern humans are usually considered the only surviving species in the genus Homo, although some argue that the two species of chimpanzees should be reclassified from Pan troglodytes (Common Chimpanzee) and Pan paniscus (Bonobo/Pygmy Chimpanzee) to Homo troglodytes and Homo paniscus respectively, given that they share a recent ancestor with man. [http://news.nationalgeographic.com/news/2003/05/0520_030520_chimpanzees.html] Full genome sequencing resulted in these conclusions: "After 6 [million] years of separate evolution, the differences between chimp and human are just 10 times greater than those between two unrelated people and 10 times less than those between rats and mice." [http://news.ft.com/cms/s/43445728-1a44-11da-b279-00000e2511c8.html Chimp and human DNA is 96% identical] It has been estimated that the human lineage diverged from that of chimpanzees about five million years ago, and from gorillas about eight million years ago. However, in 2001 a hominine skull approximately seven million years old, classified as Sahelanthropus tchadensis, was discovered in Chad and seems to indicate an earlier divergence. Two prominent scientific theories of the origins of contemporary humans exist. They concern the relationship between modern humans and other hominids: The single-origin or "out of Africa" hypothesis proposes that modern humans evolved in Africa and later replaced hominids in other parts of the world. The multiregional hypothesis proposes that modern humans evolved at least in part from independent hominid populations. Human evolution is characterised by a number of important physiological trends:
- expansion of the brain cavity and brain itself, which is typically 1,400 cm³ in volume, over twice that of a chimpanzee or gorilla. The pattern of human postnatal brain growth differs from that of other apes (heterochrony), allowing for an extended period of social learning in juvenile humans. Physical anthropologists argue that a reorganisation of the structure of the brain is more important than cranial expansion itself;
- canine tooth reduction;
- bipedal locomotion;
- descent of the larynx, which makes speech possible. Humans are classified as Homo sapiens sapiens. A camp of physical anthropologists see neanderthalensis as a subspecies and classify the neanderthals as Homo sapiens neanderthalensis. A second camp of physical anthropologists see the neanderthals as a distinct species diverging from the modern human lineage over 500,000 years ago. Under this classification, neaderthals are Homo neanderthalensis. Recent DNA analysis suggests that neanderthalensis were not a subspecies. How these trends are related and what their role is in the evolution of complex social organisation and culture are matters of ongoing debate. larynx]]

Intelligence

Most humans consider their species to be the most intelligent in the animal kingdom. Certainly, humans are the only technologically advanced animal. Along with the brain's internal complexity, the brain to body mass ratio is generally assumed to be a good indicator of relative intelligence. Humans have the second highest ratio, with the tree shrew having the highest [http://www.hindustantimes.com/news/181_935198,00300006.htm], and the bottlenose dolphin very similar to humans. The human ability to abstract may be unparalleled in the animal kingdom. Human beings are one of five species to pass the mirror test — which tests whether an animal recognises its reflection as an image of itself — along with chimpanzees or bonobos, orangutans, and dolphins. Human beings under the age of four usually fail the test.

Culture

dolphin]] Culture is defined here as a set of distinctive material, intellectual, emotional, and spiritual features of a social group, including art, literature, lifestyles, value systems, traditions, rituals, and beliefs. Culture consists of at least three elements: values, social norms, and artifacts. A culture's values define what it holds to be important. Norms are expectations of how people ought to behave. Artifacts — things, or material culture — derive from the culture's values and norms together with its understanding of the way the world functions.

Origins

Essentially every culture has its characteristic origin beliefs. Creationism or creation theology is the belief that humans, the Earth, the universe and the multiverse were created by a supreme being or deity. The event itself may be seen either as an act of creation (ex nihilo) or the emergence of order from preexisting chaos (demiurge). Many who hold "creation" beliefs consider such belief to be a part of religious faith, and hence compatible with, or otherwise unaffected by scientific views while others maintain the scientific data is compatible with creationism. Proponents of evolutionary creationism may claim that understood scientific mechanisms are simply aspects of supreme creation. Otherwise, science-oriented believers may consider the scriptural account of creation as simply a metaphor.

Language

metaphor, Chinese, Korean, Hebrew and Greek]] Values, norms and technology are dependent on the capacity for humans to share ideas. The faculty of speech may be a defining feature of humanity, probably predating phylogenetic separation of the modern population. (See Proto-World language, Origins of language.) Language is central to the communication between humans. Some scientists argue that non-human animals are able to use some form of language too, and that non-human primates are able to learn human sign language [http://www.mnsu.edu/emuseum/cultural/language/chimpanzee.html] [http://www.msubillings.edu/asc/PDF-WritingLab/3-Minute%20Spr05/APA%20sample%20paper.pdf] (pdf). Language is central to the sense of identity that unites cultures and ethnicities. The invention of writing systems some 5000 years ago, allowing the preservation of speech, was a major step in cultural evolution. Language, especially written language, is sometimes thought to have supernatural status or powers. (See Magic, Mantra, Vac.) The science of linguistics describes the structure of language and the relationship between languages. There are estimated to be some 6,000 different languages, including sign languages, used today.

Music

Music is a natural intuitive phenomenon operating in the three worlds of time, pitch, and energy, and under the three distinct and interrelated organisation structures of rhythm, harmony, and melody. Composing, improvising and performing music are all art forms. Listening to music is perhaps the most common form of entertainment, while learning and understanding it are popular disciplines. There are a wide variety of music genres and ethnic musics.

Emotion and sexuality

Human emotion has a significant influence on, or can even be said to control, human behaviour. Emotional experiences perceived as pleasant, like love, admiration, or joy, contrast with those perceived as unpleasant, like hate, envy, or sorrow. There is often a distinction seen between refined emotions, which are socially learned, and survival oriented emotions, which are thought to be innate. Human exploration of emotions as separate from other neurological phenomena is worth note, particularly in those cultures were emotion is considered separate from physiological state. In some cultural medical theories, to provide an example, emotion is considered so synonymous with certain forms of physical health that no difference is thought to exist. The Stoics believed excessive emotion was harmful, while some Sufi teachers (in particular, the poet and astronomer Omar Khayyám) felt certain extreme emotions could yield a conceptual perfection, what is often translated as ecstasy. ecstasy"]] In modern scientific thought, certain refined emotions are considered to be a complex neural trait of many domesticated and a few non-domesticated mammals, developed commonly in reaction to superior survival mechanisms and intelligent interaction with each other and the environment; as such, refined emotion is not in all cases as discrete and separate from natural neural function as was once assumed. Still, when humans function in civilised tandem, it has been noted that uninhibited acting on extreme emotion can lead to social disorder and crime. Human sexuality, besides ensuring reproduction, has important social functions, creating physical intimacy, bonds and hierarchies among individuals, and that may be directed to spiritual transcendence, and/or to the enjoyment of activity involving sexual gratification. Sexual desire, libido, is experienced as a bodily urge, often accompanied by strong emotions, both positive (such as love or ecstasy) and negative (such as jealousy). As with other human self-descriptions, humans propose it is high intelligence and complex societies of humans that have produced the most complex sexual behaviors of any animal. Human sexual choices are usually made in reference to cultural norms, which vary widely. Restrictions are largely determined by religious beliefs.

Body image

norms, Japan]]The physical appearance of the human body is central to culture and art. In every human culture, people adorn their bodies with tattoos, cosmetics, clothing, and jewellery. Hairstyles and hair colour also have important cultural implications. The perception of an individual as physically beautiful or ugly can have profound implications for their lives. This is particularly true of women, whose external appearance is highly valued in most, if not all, human societies. Anthropologists believe this to be an important factor in the development of personality and social relations in particular physical attractiveness. There is a relatively low sexual dimorphism between human males and females in comparison with other mammals.

Trade and economics

sexual dimorphism.]] Trade is the voluntary exchange of goods, services, or both, and a form of economics. A mechanism that allows trade is called a market. The original form of trade was barter, the direct exchange of goods and services. Modern traders instead generally negotiate through a medium of exchange, such as money. As a result, buying can be separated from selling, or earning. The invention of money (and later credit, paper money and non-physical money) greatly simplified and promoted trade. Trade exists for many reasons. Due to specialisation and division of labor, most people concentrate on a small aspect of manufacturing or service, trading their labour for products. Trade exists between regions because different regions have an absolute or comparative advantage in the production of some tradable commodity, or because different regions' size allows for the benefits of mass production. As such, trade between locations benefits both locations. Economics is a social science that studies the production, distribution, trade and consumption of goods and services. Economics, which focuses on measurable variables, is broadly divided into two main branches: microeconomics, which deals with individual agents, such as households and businesses, and macroeconomics, which considers the economy as a whole, in which case it considers aggregate supply and demand for money, capital and commodities. Aspects receiving particular attention in economics are resource allocation, production, distribution, trade, and competition. Economic logic is increasingly applied to any problem that involves choice under scarcity or determining economic value. Mainstream economics focuses on how prices reflect supply and demand, and uses equations to predict consequences of decisions.

Artifacts, technology, and science

supply and demand.]] Human cultures are both characterised and differentiated by the objects that they make and use. Archaeology attempts to tell the story of past or lost cultures in part by close examination of the artifacts they produced. Early humans left stone tools, pottery and jewellery that are particular to various regions and times. Improvements in technology are passed from one culture to another. For instance, the cultivation of crops arose in several different locations, but quickly spread to be an almost ubiquitous feature of human life. Similarly, advances in weapons, architecture and metallurgy are quickly disseminated. Such techniques can be passed on by oral tradition. The development of writing, itself a type of artifact, made it possible to pass information from generation to generation and from region to region with greater accuracy. Together, these developments made possible the commencement of civilisation and urbanisation, with their inherently complex social arrangements. Eventually this led to the institutionalisation of the development of new technology, and the associated understanding of the way the world functions. This science now forms a central part of human culture. In recent times, physics and astrophysics have come to play a central role in shaping what is now known as physical cosmology, that is, the understanding of the universe through scientific observation and experiment. This discipline, which focuses on the universe as it exists on the largest scales and at the earliest times, begins by arguing for the big bang, a sort of cosmic explosion from which the universe itself is said to have erupted ~13.7 ± 0.2 billion (109) years ago. After its violent beginnings and until its very end, scientists then propose that the entire history of the universe has been an orderly progression governed by physical laws.

Mind

physical laws Consciousness is a state of mind, said to possess qualities such as, self-awareness, sentience, sapience, and the ability to perceive the relationship between oneself and one's environment. The way in which the world is experienced is the subject of much debate and research in philosophy of mind,