Gorillas, chimpanzees, and hominans. Molecular evidence further suggests that between 8 and 4 mya, first the gorillas, and then the chimpanzee (genus Pan) split off from the line leading to the modern humans. However, there is no fossil record of either group of African great apes. One explanation is that bones do not fossilize well in rainforest environments. Patterson et al. (2006) reported on genetic evidence that humans and chimpanzees probably diverged less than 6.3 mya. More controversially, they speculated on the basis of the evidence that after divergence of the lineages, interbreeding again took place, before the final split about 5.3 mya.
Hominines, however, seem to have been one of the mammal groups (as well as antelopes, hyenas, dogs, pigs, elephants, and horses) that adapted to the open grasslands as soon as this biome appeared, due to increasingly seasonal climates, about 8 mya, and their fossils are relatively well known. The earliest are Sahelanthropus tchadensis (7-6 mya) and Orrorin tugenensis (6 mya), followed by:
- Ardipithecus (5.5-4.4 mya), with species Ar. kadabba and Ar. ramidus;
- Australopithecus (4-2 mya), with species Au. anamensis, Au. afarensis, Au. africanus, Au. bahrelghazali, and Au. garhi;
- Paranthropus (3-1.2 mya), with species P. aethiopicus, P. boisei, and P. robustus;
- Homo (2 mya-present).
The Australopithecus genus evolved in eastern Africa around 4 million years ago before spreading throughout the continent and eventually becoming extinct 2 million years ago. During this time period various forms of australopiths existed, including Australopithecus anamensis, A. afarensis, A. sediba, and A. africanus. There is still some debate amongst academics whether certain African hominid species of this time, such as A. robustus and A. boisei, constitute members of the same genus; if so, they would be considered to be robust australopiths while the others would be considered gracile australopiths. However, if these species do indeed constitute their own genus, then they may be given their own name, the Paranthropus.
- Australopithecus (4-1.8 Ma), with species Au. anamensis, Au. afarensis, Au. africanus, Au. bahrelghazali, Au. garhi, and Au. sediba;
- Kenyanthropus (3-2.7 Ma), with species Kenyanthropus platyops;
- Paranthropus (3-1.2 Ma), with species P. aethiopicus, P. boisei, and P. robustus;
Australopithecus afarensis and Australopithecus africanus are among the most famous of the extinct hominids. The australopithecines are now thought to be immediate ancestors of the genus Homo, the group to which modern humans belong. Both australopithecines and Homo sapiens are part of the tribe Hominini.
The genus HomoChris Stringer's hypothesis of the family tree of genus Homo, published 2012 in Nature (Stringer 2012):Homo floresiensis originated in an unknown location from unknown ancestors and reached remote parts of Indonesia. Homo erectus spread from Africa to western Asia, then east Asia and Indonesia; its presence in Europe is uncertain, but it gave rise to Homo antecessor, found in Spain. Homo heidelbergensis originated from Homo erectus in an unknown location and dispersed across Africa, southern Asia, and southern Europe (other scientists interpret fossils, here named heidelbergensis, as late erectus). Homo sapiens spread from Africa to western Asia and then to Europe and southern Asia, eventually reaching Australia and the Americas. In addition to Neanderthals and Denisovans a third gene flow in Africa is indicated at the right (Hammer et al. 2011).
In modern taxonomy, Homo sapiens is the only extant (living) species of its genus, Homo. However, the ongoing study of the origins of Homo sapiens often demonstrates that there were other Homo species, all of which are now extinct. While some of these other species might have been ancestors of H. sapiens, many were likely "cousins," having speciated away from our ancestral line. There is not yet a consensus as to which of these groups should count as separate species and which as subspecies of another species. In some cases, this is due to the paucity of fossils; in other cases, it is due to the slight differences used to classify species in the Homo genus.
The word homo is Latin for "person," chosen originally by Carolus Linnaeus in his classification system. It is often translated as "man," although this can lead to confusion, given that the English word "man" can be generic like homo, but can also specifically refer to males. Latin for "man" in the gender-specific sense is vir, cognate with "virile" and "werewolf." The word "human" is from humanus, the adjectival form of homo.
Homo habilis and H. gautengensis
H. habilis lived from about 2.4 to 1.5 million years ago (mya). H. habilis, the oldest known species of the genus Homo, appeared in South and East Africa in the late Pliocene or early Pleistocene, 2.5-2 mya, when it is considered to have diverged from the Australopithecines. H. habilis had smaller molars and larger brains than the Australopithecines, and made tools from stone and perhaps animal bones. One of the first known hominids, it was nicknamed "handy man" by its discoverer, Louis Leakey. Some scientists have proposed moving this species out of Homo and into Australopithecus due to the morphology of its skeleton being more adapted to living on trees rather than to moving on two legs like Homo sapiens (Wood and Collard 1999).
It was considered to be the first species of the genus Homo until May 2010, when a new species, Homo gautengensis was discovered in South Africa, that most likely arose earlier than Homo habilis (Viegas 2010).
Homo rudolfensis and Homo georgicus
These are proposed species names for fossils from about 1.9-1.6 mya, the relation of which with H. habilis is not yet clear.
- H. rudolfensis refers to a single, incomplete skull from Kenya. Some consider this another H. habilis.
- H.georgicus, from the country of Georgia, may be an intermediate form between H. habilis and H. erectus or a subspecies of H. erectus.
Homo ergaster and Homo erectus
The first fossils of Homo erectus were discovered by Dutch physician Eugene Dubois in 1891 on the Indonesian island of Java. He originally gave the material the name Pithecanthropus erectus based on its morphology, which he considered to be intermediate between that of humans and apes.
H. erectus lived from about 1.8 mya to 70,000 years ago. Homo erectus was apparently very successful, with fossils found in Africa, Asia (Indonesia, and China), Georgia (Caucasus region of Europe), and eastern and southern Africa (Mayr 2001). A famous example of Homo erectus is Peking Man.
Often the early phase, from 1.8 to 1.25 mya, is considered either to be a separate species, H. ergaster, or it is seen as a subspecies of erectus, Homo erectus ergaster. That is, the differences between the early populations of H. erectus, found in Africa, and the later populations, found in Asia, Europe, and Africa, are substantial enough for the separation by many researchers into two different groups: the early African H. ergaster or H. erectus ergaster, and the mainly Asian populations H. erectus (Smithsonian 2007b). Many paleoanthropologists now use the term Homo ergaster only for the non-Asian forms of this group, and reserve Homo erectus only for those fossils that are found in Asia and meet certain skeletal and dental requirements, which differ slightly from H. ergaster.
Homo erectus and H. ergaster were the first of the hominina known to leave Africa.
In the Early Pleistocene, 1.5-1 mya, in Africa, Asia, and Europe, presumably, Homo habilis evolved larger brains and made more elaborate stone tools; these differences and others are sufficient for anthropologists to classify them as a new species, H. erectus. In addition H. erectus was the first human ancestor to walk truly upright. This was made possible by the development of locking knees and a different location of the foramen magnum (the hole in the skull where the spine enters). They may have used fire to cook their meat.
Homo cepranensis and Homo antecessor
These are proposed as species that may be intermediate between H. erectus and H. heidelbergensis.
- H. cepranensis refers to a single skull cap from Italy, estimated to be about 800,000 years old.
- H. antecessor is known from fossils from Spain and England that are 800,000-500,000 years old.
H. heidelbergensis (Heidelberg Man) lived from about 800,000 to about 300,000 years ago. Also proposed as Homo sapiens heidelbergensis or Homo sapiens paleohungaricus.
Homo rhodesiensis, and the Gawis cranium
- H. rhodesiensis, estimated to be 300,000-125,000 years old, most current experts believe Rhodesian Man to be within the group of Homo heidelbergensis though other designations such as Archaic Homo sapiens and Homo sapiens rhodesiensis have also been proposed.
- In February 2006, a fossil, the Gawis cranium, was found that might possibly be a species intermediate between H. erectus and H. sapiens or one of many evolutionary dead ends. The skull from Gawis, Ethiopia, is believed to be 500,000-250,000 years old. Only summary details are known, and no peer reviewed studies have been released by the finding team. Gawis man's facial features suggest it's either an intermediate species or an example of a "Bodo man" female (IU 2006).
H. neanderthalensis, alternatively designated as Homo sapiens neanderthalensis (Harvati 2003), lived in Europe and Asia from 400,000 to about 30,000 years ago. Evidence from sequencing mitochondrial DNA indicated that no significant gene flow occurred between H. neanderthalensis and H. sapiens, and, therefore, the two were separate species that shared a common ancestor about 660,000 years ago (Krigs et al. 1997; Green et al. 2008; Serre et al. 2004). However, the 2010 sequencing of the Neanderthal genome indicated that Neanderthals did indeed interbreed with anatomically modern humans circa 45,000 to 80,000 years ago (at the approximate time that modern humans migrated out from Africa, but before they dispersed into Europe, Asia and elsewhere) (Green et al. 2010).
Nearly all modern non-African humans have 1% to 4% of their DNA derived from Neanderthal DNA (Green et al. 2010), and this finding is consistent with recent studies indicating that the divergence of some human alleles dates to one Ma, although the interpretation of these studies has been questioned (Gutiérrez et al. 2002; Hebsgaard et al. 2007). Competition from Homo sapiens probably contributed to Neanderthal extinction (Banks et al. 2008; Hortola and Martinez-Navarro 2012). They could have co-existed in Europe for as long as 10,000 years, during which human populations exploded, vastly outnumbering Neanderthals, possibly outcompeting them by sheer numerical strength (Mellars and French 2011).
Denisovans are an extinct hominid group more closely related to the Neanderthals than modern humans and identified from the nuclear and mitochondrial DNA sequences of the roughly 50,000-year-old (or older) fossils found in Siberia. The fossils unearthed from the Denisova Cave in the Altai Mountains of southern Siberia are quite limited in number: a pinkie bone (distal manual phalanx) and two teeth (molars) from three different Denisovan individuals, as of 2013. However, the entire genome has been sequenced and this DNA sequence shows the Denisovans to be a distinct group that shares a common ancestor with Neanderthals. It is believed they were more prevalent in East Asia while Neanderthals dominated Europe and western Asia.
The issue of whether the Denisovans are a unique species or a subspecies of Homo sapiens (Homo sapiens ssp. 'Denisova) has not been settled, just as it has not been settled for the Neanderthals.
H. floresiensis is the name given to a proposed species that lived about 100,000-12,000 years ago (announced October 28, 2004 in the science journal Nature) (Brown et al. 2004). It is based on fossil findings, with the main find a fossil believed to be a woman about 30 years of age. Found in 2003, it has been dated to approximately 18,000 years old. The living woman was estimated to be one meter in height, with a brain volume of just 380 cm3 (which can be considered small even for a chimpanzee). The species has been nicknamed "hobbit" for its small size, possibly a result of insular (island) dwarfism (Brown et al. 2004).
H. floresiensis is intriguing both for its size and its age, being a concrete example of what some consider a recent species of the genus Homo that exhibits derived traits not shared with modern humans. In other words, H. floresiensis is postulated to share a common ancestor with modern humans, but split from the modern human lineage and followed a distinct evolutionary path.
However, there is an ongoing debate over whether H. floresiensis is indeed a separate species (Argue et al. 2006). Some scientists presently believe that H. floresiensis was a modern H. sapiens suffering from pathological dwarfism (Martin et al. 2006). This hypothesis is supported in part, because the modern humans who live on Flores, the island where the fossil was found, are pygmies. This coupled with pathological dwarfism could indeed create a hobbit-like human. The other major attack on H. floresiensis as a separate species is that it was found with tools only associated with H. sapiens.
The hypothesis of pathological dwarfism, however, fails to explain additional anatomical features that are unlike those of modern humans (diseased or not) but much like those of ancient members of our genus. Aside from cranial features, these features include the form of bones in the wrist, forearm, shoulder, knees, and feet. Additionally, this hypothesis fails to explain the find of multiple examples of individuals with these same characteristics, indicating they were common to a large population, and not limited to one individual.
H. sapiens ("sapiens" means wise or intelligent) have lived from about 250,000 years ago to the present. Between 400,000 years ago and the second interglacial period in the Middle Pleistocene, around 250,000 years ago, the trend in cranial expansion and the elaboration of stone tool technologies developed, providing evidence for a transition from H. erectus to H. sapiens.
The direct evidence suggests there was a migration of H. erectus out of Africa, then a further speciation of H. sapiens from H. erectus/H. ergaster in Africa. Then a subsequent migration within and "out of Africa" eventually replaced the earlier dispersed H. erectus. This migration and origin theory is usually referred to as the recent single-origin theory or "Out of Africa Hypothesis". However, the current evidence does not preclude multiregional evolution or some mixtrue of the migrant H. sapiens with existing Homo populations. This is a hotly debated topic in paleoanthropology.
Based on molecular evidence, the calculation of the time of divergence of all modern human populations from a common ancestor typically yields dates around 200,000 years (Smithsonian 2007a). The oldest fossil evidence for modern humans is 130,000 years old in Africa and sometime before 90,000 years old in the Near East (Smithsonian 2007a). Some consider H. sapiens idaltu from Ethiopia, an extinct subspecies which lived from about 160,000 years ago, to be the oldest known anatomically modern human.
Notably, however, about 50,000 to 40,000 years ago, human beings appeared to have taken a Great Leap Forward, when human culture apparently changed at a much greater speed. It seems connected to the arrival of modern humans beings: Homo sapiens sapiens. (See modern man and the great leap forward.)
The Cro-Magnons form the earliest known European examples of Homo sapiens sapiens. The term falls outside the usual naming conventions for early humans and is used in a general sense to describe the oldest modern people in Europe. Cro-Magnons lived from about 40,000 to 10,000 years ago in the Upper Paleolithic period of the Pleistocene epoch. For all intents and purposes these people were anatomically modern, only differing from their modern day descendants in Europe by their slightly more robust physiology and larger brain capacity than that of modern humans. When they arrived in Europe about 40,000 years ago, they brought with them sculpture, engraving, painting, body ornamentation, music, and the painstaking decoration of utilitarian objects.
Current research establishes that human beings are highly genetically homogeneous, meaning that the DNA of individual Homo sapiens is more alike than usual for most species. Distinctive genetic characteristics have arisen, however, primarily as the result of small groups of people moving into new environmental circumstances. Such small groups are initially highly inbred, allowing the relatively rapid transmission of traits favorable to the new environment. These adapted traits are a very small component of the Homo sapiens genome and include such outward "racial" characteristics as skin color and nose form in addition to internal characteristics such as the ability to breathe more efficiently in high altitudes.
Abrahamic religions believe in a single-point origin of modern humans, beginning with an original couple, Adam and Eve, into whom God breathed life (added a spirit or soul to the material body).
Archaic human admixture
Over the course of human history, archaic human admixture has occurred with modern humans (Homo sapiens), namely through interbreeding of modern humans with Neanderthals and Denisovans respectively.
A detailed comparison of the Denisovan, Neanderthal, and human genomes has revealed evidence for a complex web of interbreeding among the lineages. Through such interbreeding, 17% of the Denisova genome represents DNA from the local Neanderthal population, while evidence was also found of a contribution to the nuclear genome from an ancient hominin lineage yet to be identified (Pennisi 2013). An estimated 1% to 4% of the DNA in Eurasians is non-modern and shared with Neanderthals rather than with sub-Saharan Africans. In Oceanian and some Southeast Asian populations, Denisovan admixture has also been observed. An estimated 4 to 6% of Melanesian DNA is derived from Denisovans.
Various theories of Neanderthal admixture in modern human DNA-i.e. the result of interbreeding of Neanderthals and anatomically modern humans during the Middle Paleolithic-have been debated throughout the 20th century, and in terms of genetics throughout the 2000s (Fagundes et al. 2007; Hodgson and Disotell 2008)). A 2010 draft sequence publication on the Neanderthal genome indicates that Neanderthals share genetic lineages with Eurasian populations and not with Sub-Saharan African populations (Green et al. 2010). According to the study, this scenario is best explained by gene flow from Neanderthals to modern humans after humans emerged from Africa and possibly before the divergence of the Eurasian groups (Green et al. 2010). The data show that 1-4% of the DNA in Europeans and Asians (e.g. French, Han Chinese, and Papua New Guinean) is non-modern and shared with Neanderthals rather than with Sub-Saharan Africans (e.g. Yoruba and San) (Green et al. 2010). Though less parsimonious than gene flow, early ancestors of Eurasians may have been more closely related to Neanderthals than those of Africans to Neanderthals, a result from incomplete genetic homogenization due ancient population sub-structure in Africa when Neanderthals diverged (Green et al. 2010). No evidence of Neanderthal mitochondrial DNA have been found in modern humans (Krings et al. 1997; Serre et al. 2004; Wall and Hammer 2006). This would suggest that successful Neanderthal admixture happened paternally rather than maternally (Mason and Short 2011; Wang et al. 2013). Possible hypotheses are that Neanderthal mtDNA had detrimental mutations that led to the extinction of carriers, that the hybrid offspring of Neanderthal mothers were raised in Neanderthal groups and became extinct with them, or that female Neanderthals and male modern humans did not produce fertile offspring (Mason and Short 2011).
Analysis of genomes of modern humans show that they mated with at least two groups of ancient humans: Neanderthals (more similar to those found in the Caucasus than those from the Altai region) (Pennisi 2013) and Denisovans )Green et al. 2010). Tests comparing the Denisova hominin genome with those of six modern humans-a ǃKung from South Africa, a Nigerian, a Frenchman, a Papua New Guinean, a Bougainville Islander, and a Han Chinese-showed that between 4% and 6% of the genome of Melanesians (represented by the Papua New Guinean and Bougainville Islander) derives from a Denisovan population. This DNA was possibly introduced during the early migration to Melanesia. These findings are in concordance with the results of other comparison tests that show a relative increase in allele sharing between the Denisovan and the Aboriginal Australian genome, compared to other Eurasians and African populations; however it has been observed that Papuans, the population of Papua New Guinea, have more allele sharing than Aboriginal Australians (Rasmussen et al. 2011).
Mitochondrial Eve, Y-chromosomal Adam, and the most recent common ancestor
Geneticists have identified individuals dubbed "Mitochondrial Eve" and "Y-chromosomal Adam," with Mitochondrial Eve the common matrilineal ancestor of all humans alive today and Y-chromosomal Adam the common patrilineal ancestor who lived many millennia after Mitochondrial Eve. (That a common patrilineal ancestor should have lived significantly after a matrilineal one is in concordance with Bible history, which gives Noah as a more recent common patrilineal ancestor than Adam.) In the founding work of this area of investigation, Cann et al. (1987) compared mitochondrial DNA sampled from women whose ancestors came from different part of the world. and concluded that Africa was the most likely root of human ancestry and that human ancestors left Africa between between 180,000 and 230,000 years ago.
Note that Mitochondrial Eve is the most recent common matrilineal ancestor, and Y-chromosomal Adam the most common patrilineal ancestor, not the original man and woman, and not the most recent common ancestor (MRCA) of all humans. All living humans can trace their ancestry back to the MRCA via at least one of their parents. That is, the MRCA's offspring have led to all living humans via sons and daughters. However, Mitochondrial Eve must be traced only through female lineages, so she is estimated to have lived much longer ago than the MRCA. While Mitochondrial Eve is thought to have been living around 140,000 years ago (Dawkins 2004) or between 100,000 and 200,000 years ago (Rhode 2005), and Y-chromosomal Adam about 35,000 to 89,000 years ago (Rhode 2005), the MRCA is estimated to have been living only around 2,000 to 5,000 years ago (Rohde et al. 2004, Rhode 2005).
Starting with "the" MRCA at around 3,000 years ago, one can trace all ancestors of the MRCA backward in time. At every ancestral generation, more and more ancestors (via both paternal and maternal lines) of MRCA are found. These ancestors are by definition also common ancestors of all living people. Eventually, there will be a point in the past where all humans can be divided into two groups: Those who left no descendants today and those who are common ancestors of all living humans today. This point in time is termed the "identical ancestors point" and is estimated to be between 5,000 and 15,000 years ago. Since Mitochondrial Eve is estimated to have lived more than hundred thousand years before the identical ancestors point, every contemporary woman of hers is either not an ancestor of all living people, or a common ancestor of all living people (Dawkins 2004; Rohde 2005).
Comparative table of Homo species
- Bolded species names indicate the existence of numerous fossil records.
|species||lived when (MYA)||lived where||adult length (m)||adult weight (kg)||brain volume (cm³)||fossil record||discovery / publication of name|
|H. rudolfensis||1.9||Kenya||1 skull||1972/1986|
|H. ergaster||1.9-1.25||E. and S. Africa||1.9||700-850||many||1975|
|H. erectus||2(1.25)-0.3||Africa, Eurasia (Java, China, Caucasus)||1.8||60||900-1100||many||1891/1892|
|H. cepranensis||0.8?||Italy||1 skull cap||1994/2003|
|H. antecessor||0.8-0.35||Spain, England||1.75||90||1000||3 sites||1997|
|H. heidelbergensis||0.6-0.25||Europe, Africa, China||1.8||60||1100-1400||many||1908|
|H. neanderthalensis||0.23-0.03||Europe, W. Asia||1.6||55-70 (heavily built)||1200-1700||many||(1829)/1864|
|H. rhodesiensis||0.3-0.12||Zambia||1300||very few||1921|
|H. sapiens sapiens||0.25-present||worldwide||1.4-1.9||55-80||1000-1850||still living||-/1758|
|H. sapiens idaltu||0.16||Ethiopia||1450||3 craniums||1997/2003|
|H. floresiensis?||0.10-0.012||Indonesia||1.0||25||400||7 individuals||2003/2004|
Out of Africa and multiregional positions
There are two dominant, and one might say polarizing, general views on the issue of human origins, the Out of Africa position and the multiregional position.
The Out of Africa, or Out of Africa II, or replacement model holds that after there was a migration of Homo erectus (or H. ergaster) out of Africa and into Europe and Asia, these populations did not subsequently contribute significant amounts of genetic material (or, some say, contributed absolutely nothing) to later populations along the lineage to Homo sapiens (Kreger 2005). Later, approximately 200,000 years ago, there was a second migration of hominids out of Africa, and this was modern H. sapiens that replaced the populations that then occupied Europe and Asia (Kreger 2005). This view maintains a specific speciation event that led to H. sapiens in Africa, and this is the modern human.
The multiregional or continuity camp hold that since the origin of H. erectus, there have been populations of hominids living in the Old World and that these all contributed to successive generations in their regions (Kreger 2005). According to this view, hominids in China and Indonesia are the most direct ancestors of modern East Asians, those in Africa are the most direct ancestors of modern Africans, and the European populations either gave rise to modern Europeans or contributed significant genetic material to them, while their origins were in Africa or West Asia (Kreger 2005). There is genetic flow to allow for the maintenance of one species, but not enough to prevent racial differentiation.
There are various combinations of these ideas. Overall, the disagreement between these two camps has caused "fairly severe strife within the paleoanthropological community" (Kreger 2005). Multiregionalism is often "portrayed as a racist theory," while Out of Africa II "has often been portrayed as a religiously motivated idea" that strives to align with the biblical story of Genesis (Kreger 2005).
Use of tools
Using tools is a sign of intelligence. Some scientists speculate that tool use also played a role in the origin of modern humans. Over the past 2 or 3 million years, human brain size has increased threefold. A brain needs a lot of energy: The brain of a modern human uses about 20 Watts (about 400 calories per day), one fifth of total human energy consumption. Early hominoids, like apes, were considered to have been essentially plant eaters (fruit, leaves, roots), their diet only occasionally supplemented by meat (often from scavenging). However, plant food in general yields considerably less energy and nutritive value than meat. Therefore, being able to hunt for large animals, which was only possible by using tools such as spears, would have made it possible for humans to sustain larger and more complex brains, which in turn allowed them to develop yet more intelligent and efficient tools.
Precisely when early humans started to use tools is difficult to determine, because the more primitive these tools were (for example, sharp-edged stones), the more difficult it is to decide whether they are natural objects or human artifacts. There is some evidence that the australopithecines (4 mya) may have used broken bones as tools, but this is debated.
Stone tools are first attested around 2.6 mya, when H. habilis in Eastern Africa used so-called pebble tools: Choppers made out of round pebbles that had been split by simple strikes. This marks the beginning of the Paleolithic, or Old Stone Age; its end is argued to be the end of the last Ice Age, around 10,000 years ago. The Paleolithic is subdivided into the Lower Paleolithic (Early Stone Age, ending around 350,000-300,000 years ago), the Middle Paleolithic (Middle Stone Age, until 50,000-30,000 years ago), and the Upper Paleolithic.
The period from 700,000-300,000 years ago is also known as the Acheulean, when H. ergaster (or erectus) made large stone hand-axes out of flint and quartzite, at first quite rough (Early Acheulian), later "retouched" by additional, more subtle strikes at the sides of the flakes.
After 350,000 BP (Before Present), a more refined, the so-called Levallois, technique was developed. It consisted of a series of consecutive strikes, by which scrapers, slicers ("racloirs"), needles, and flattened needles were made. Finally, after about 50,000 BP, ever more refined and specialized flint tools were made by the Neanderthals and the immigrant Cro-Magnons (knives, blades, skimmers). In this period, they al