homo

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homo
“The Vitruvian Man”, drawing by Leonardo da Vinci from 1492

“ The Vitruvian Man ”, drawing by Leonardo da Vinci from 1492

Temporal occurrence
Piacenzian (late Pliocene) to the present
2.5 to 0 million years
Locations
Systematics
without rank: Old World Monkey (Catarrhini)
Superfamily : Human (Hominoidea)
Family : Apes (Hominidae)
Subfamily : Homininae
Tribe : Hominini
Genre : homo
Scientific name
homo
Linnaeus , 1758
species

Homo ( Latin homo [ hɔmoː ] "man", "man") is a genus of great apes (hominids) in the class of mammals to which the anatomically modern humans ( Homo sapiens ) and his closest extinct relatives belong. A precise differentiation of the genus Homo from related genera within the Hominini is difficult. The use of worked stone tools ( rubble equipment )is often mentionedas a criterion .

An important common feature ( synapomorphism ) of all species of the genus Homo is the number of cusps ( tubercles ) on the rear molars : In Homo there are six or seven cusps, in the Australopithecines there were fewer.

Age

The two oldest species of the genus Homo are Homo rudolfensis and Homo habilis . They lived around 2.5 to 1.5 million years ago.

From when to when a fossil species existed can usually only be determined approximately. On the one hand, the fossil record is incomplete: There are very few specimen copies for most fossil species, this is particularly true for mosaic shapes . On the other hand, the dating methods indicate a certain age, but with considerable inaccuracy ; this inaccuracy then forms the outer limits for the "from ... to" information for lifetimes. All published age information is therefore provisional, which may also have to be revised after further specimen copies have been found.

features

Precision grip (opposing thumb - here against the middle and index finger)
Taxon
(the youngest species at the bottom)		 Body weight (in kg)
male
individuals		 female
individuals
Chimpanzees 60-90 30-47
Australopithecus afarensis 45 29
Australopithecus africanus 41 30th
Homo rudolfensis 60 51
Homo habilis 37 32
Homo naledi 40-55
Homo ergaster 68 54
Homo erectus 59 57
Homo heidelbergensis 84 78
Neanderthals 76 65
homo sapiens 68 57

To this day, there is still no precise reference value with which the potential assignment of newly discovered fossils to the genus Homo could be measured: the type species of the genus is Homo sapiens , but the criteria on which the clear morphological distance of Homo sapiens and the genus Homo from a related genus is based was never set. In 1964, in the first description of Homo habilis, the definition of the genus could be changed without further ado by reducing the lower limit of the brain volume for species of the genus Homo to 600 cm³ so that the fossils assigned to the new species could still find a place in the genus Homo . At the same time, several other criteria for assigning fossils to the genus Homo were named, including: the structure of the pelvis and legs are adapted to a habitually erect posture and to the upright gait ; the arms are shorter than the legs; the thumb is well developed and fully opposable , the hand is capable of both force and precision gripping.

According to Bernard Wood and Mark Collard , other authors have often assigned species to the genus Homo on the basis of four criteria:

  1. The internal volume of the skull - i.e. the size of the brain - of at least 600 cm³,
  2. the assumed ability to speak, derived from skull casts , on the basis of which the Broca area and the Wernicke center were recognized as well developed,
  3. proof of tool use and
  4. the opposable thumb and the precision grip of the hand.

Wood and Collard explain that it is easy to understand that these criteria can only be read inadequately from many of the fossils found. In addition, without precise knowledge of body size, the relationship between brain size and behavior remains just as unclear as the relationship between developing ability to speak and certain features of the cerebral surface; whether Homo rudolfensis used tools has not yet been established, but there are indications that representatives of the Australopithecus genus also used tools; and the mentioned features of the hand are also by no means unique to the genus Homo , but have also been proven in species of other genera.

Wood and Collard therefore argued that instead of highlighting individual characteristics, when assigning a species to the genus Homo it must be demonstrated that this species is more similar to the type species Homo sapiens than the type species of Ardipithecus , Australopithecus , Kenyapithecus and Paranthropus . In particular, it must be proven that the body structure (especially the chewing apparatus), the physical development as well as the manner of locomotion are closer to the type specimen of the genus than to the older genera of the hominini . Using these standards, Wood and Collard came to the conclusion that Homo habilis and Homo rudolfensis have greater similarities with Australopithecus and Paranthropus than with Homo and therefore belong to the genus Australopithecus ; According to Wood and Collard, Homo erectus , Homo ergaster , Homo heidelbergensis and Homo neanderthalensis, on the other hand, have a sufficiently large morphological proximity to Homo sapiens .

Tim White pointed out in 2003 that the dentition and skeleton of modern humans show considerable variability; therefore, before delimiting additional species, it should always be taken into account that the ancestors of humans may also show a similarly large variability.

Historical

Hypothesis on the relationship of Australopithecus - and homo species, such as those of due to the current situation Fund Friedemann Schrenk is represented.

The genus Homo was introduced in 1758 by Carl von Linné in the 10th edition of Systema Naturae . Two recent species were assigned to this genus : on the one hand, Homo sylvestris - occurring on Java, active at night and colloquially called " Orang Outang "; on the other hand Homo sapiens - diurnal and divided into six groups. Two of these groups - characterized as "wild" or "monstrous" - are not biological entities according to the current state of knowledge ; the other four groups correlate with the four geographic regions known to Linnaeus: Africa , America , Asia and Europe .

A first attempt to differentiate the genus Homo from other mammals on the basis of anatomical features was made in 1775 by Johann Friedrich Blumenbach in his dissertation De generis humani varietate nativa ("On the natural differences in the human race").

The first fossil species of the genus Homo was named in 1864 by the Irish geologist William King : Homo neanderthalensis ; A year earlier, King had used the name "Homo Neanderthalensis King" in a lecture to the Geology Section of the British Association for the Advancement of Sciences after discussing the skull shape of the fossil Neanderthal 1 and its deviations from modern humans . This was followed in 1899 by the species Homo spelaeus ("caveman") proposed by Georges Vacher de Lapouge , to which the fossil Cro-Magnon 1 was assigned as a type specimen ; all fossils of this age group (“ Cro-Magnon humans ”) are now counted as Homo sapiens . The third fossil homo species was named in 1908 after Otto Schoetensack had decided to designate the lower jaw of Mauer , correctly recognized as “preneandertaloid”, as Homo heidelbergensis .

The inclusion of the "primitive" lower jaw of Mauer, which is extremely massive in comparison with Homo sapiens , Homo spelaeus and even Homo neanderthalensis , in the genus Homo has significantly increased its morphological range of variation. This development continued when Arthur Smith Woodward named the species Homo rhodesiensis in 1921 and the Dutch researcher Willem Oppennoorth named Homo soloensis in 1932 .

The fossils of Homo soloensis (“Man from the Solo River” on Java ) are now assigned to Homo erectus : a taxon that from 1950 onwards at the suggestion of Ernst Mayr - in agreement with the leading paleoanthropologists at the time - numerous others, initially with his own Species names have been assigned to fossils from different sites. However, this had the consequence that the range of variation of the homo- morphology was increased still further: for example by Atlanthropus mauritanicus , Pithecanthropus erectus , Sinanthropus pekinensis and Telanthropus capensis (meanwhile separated again by some paleoanthropologists and referred to as Homo ergaster ). However, a common feature of all fossils ascribed to Homo initially remained the minimum volume of 900 cubic centimeters for the inner skull volume, established by Mayr in 1950, as well as a posture and mode of locomotion characterized by the upright gait .

However, this consensus was confirmed by Louis Leakey et al. abandoned when Homo habilis was first described : The members of this very early homo species walked upright at least for a time, but only had a brain volume of around 600 to 700 cm³. Now the lower limit was 600 cm³, and the already imprecise definition of the genus Homo became even more nebulous.

Human primates systematics mammals.png

Finally, in addition to Homo habilis , another early species of the genus Homo was found, called Homo rudolfensis . Their differentiation from Homo habilis is incomplete because hardly any skeletal bones from below the head could be assigned to Homo rudolfensis without any doubt . Differentiators for example, the teeth of Homo rudolfensis , which are larger than at the later homo- types which, compared with habilis larger intracranial volume of at least 750 cc and compared with habilis face formed wider, of thicker bone.

See also

literature

Web links

Commons : Homo  - collection of pictures, videos and audio files

Individual evidence

  1. ↑ Lee Berger et al .: Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa. In: eLife 4. 4: e09560, 2015, doi: 10.7554 / eLife.09560
  2. ↑ Friedemann Schrenk in: Spectrum of Science . No. 9/2010, p. 69.
  3. ↑ Chimpanzees: Mirror Image of Humans? On: scinexx.de of June 27, 2003
  4. ↑ a b c d e f g h i Matthew M. Skinner and Bernard Wood: The evolution of modern human life history - a paleontological perspective. In: Kristen Hawkes and Richard R. Paine (Eds.): The Evolution of Modern Human Life History. School of American Research Press, Santa Fe 2006, p. 347, ISBN 978-1-930618-72-5 . - The arithmetic mean is shown in each case .
  5. ↑ Crowdsourcing digs up an early human species. On: nature.com from September 10, 2015
  6. ^ A b Louis Leakey , Phillip Tobias and John Napier : A new species of the genus Homo from Olduvai Gorge. In: Nature . 202, 1964, pp. 7-9; doi : 10.1038 / 202007a0 , full text (PDF; 352 kB)
  7. ^ Bernard Wood , Mark Collard : The Meaning of Homo. In: Ludus vitalis. Volume 9, No. 15, 2001, pp. 63–74, full text (PDF; 697 kB)
  8. ↑ A 1.4 million year old 3rd metacarpal bone , which was recovered from the Kaitio site at the northern end of Lake Turkana in Ethiopia , was interpreted as the oldest evidence of the precision grip in Homo . Source: Ann Gibbons: When Early Hominins Got a Grip. In: Science . Volume 340, No. 6131, 2013, pp. 426-427, doi: 10.1126 / science.340.6131.426-a
  9. ↑ Tim White : Early Hominids - Diversity or Distortion? In: Science. Volume 299, No. 5615, 2003, pp. 1994-1997, doi : 10.1126 / science.1078294
  10. ↑ in volume 1, page 20; it is the first animal species that Linnaeus has listed in this work
  11. ^ Johann Friedrich Blumenbach : De generis humani varietate nativa. Friedrich Andreas Rosenbusch, Göttingen 1775, digital version of the translation from 1798
  12. ↑ William King: The reputed fossil man of the Neanderthal. In: Quarterly Journal of Science. Volume 1, 1864, pp. 88-97
  13. ^ William King: On the Neanderthal Skull, or Reasons for believing it to belong to the Clydian Period and to a species different from that represented by Man. In: British Association for the Advancement of Science, Notices and Abstracts for 1863, Part II. London 1864, p. 81 f.
  14. ↑ Otto Schoetensack : The lower jaw of Homo Heidelbergensis from the sands of Mauer near Heidelberg. A contribution to human paleontology. Verlag von Wilhelm Engelmann, Leipzig 1908, p. 40. - “Präneandertaloid” means: similar to a Neanderthal , but older than this.
  15. ^ Arthur Smith Woodward : A New Cave Man from Rhodesia, South Africa. In: Nature . Volume 108, 1921, pp. 371-372, doi: 10.1038 / 108371a0
  16. ^ WFF Oppennoorth: Homo (Javanthropus) soloensis: een plistocene Mensch van Java. In: Wetenschappelijke medeligen Dienst van den Mijnbrouw in Nederlandsch-Indië. Volume 20, 1932, p. 49 ff
  17. ^ Ernst Mayr : Taxonomic categories in fossil hominids. In: Cold Spring Harbor Symposia on Quantitative Biology. Vol. 15, 1950, pp. 109-118; Summary
  18. ↑ Gary J. Sawyer, Viktor Deak: The Long Way to Man. Life pictures from 7 million years of evolution. Spektrum Akademischer Verlag, Heidelberg 2008, p. 85
  19. ↑ Jeffrey H. Schwartz and Ian Tattersall : Defining the genus Homo. In: Science. Volume 349, No. 6251, 2015, pp. 931-932, DOI: 10.1126 / science.aac6182
  20. ↑ Bernard Wood , Brian G. Richmond: Human evolution: taxonomy and paleobiology. In: Journal of Anatomy . Volume 197, No. 1, 2000, pp. 19-60, DOI: 10.1046 / j.1469-7580.2000.19710019.x , PMID 10999270 , PMC 1468107 (free full text) (review).