Early Species of the Genus Homo Chapter 14

Early Homo 2.5 mya 2 mya Homo originates in Africa Early Homo coexsisted with Paranthropus and both likely evolved from Australopithecus 2 mya Hominins expanded out of Africa Since the earliest fossils have been found only in Africa, hominins were likely isolated there for approximately 5 million years Universal agreement that any hominins found outside of Africa are members of genus Homo Less diversity than in their australopithecine predecessors These species were larger, more committed to a terrestrial habitat, and used elaborate stone tools

Homo habilis Discovered in 1960 Olduvai Gorge, Tanzania Dated 2.1 to 1.5 mya Structure Tiny “Lucy- sized” creature about 3 ft tall Longer arms than later Homo May still have spent some time in trees Brain 600-700 cc Double that of late, robust australopithecines Olduwan tools

Homo rudolfensis Discovered in 1972 Dated to approximately 1.9 mya Lake Turkana, Kenya Dated to approximately 1.9 mya Originally dated 2.5 mya Taxonomic problems Approx. five specimens discovered Larger brain suggests Homo classification Persisting large back teeth suggests Australopithecus May also be large H. habilis May or may not be ancestral to H. erectus

Homo naledi Discovered in 2015 in Gauteng, SA 15 individuals at a single site Largest find of a single species at one site in Africa Intentional body disposal? Dating All 3 methodologies used so far have failed 3 mya to 100,000 ya Comparison Human-like features Hand, foot, leg limbs Australopithecus-like features Trunk, shoulder, pelvis, braincase (500 cm3)

Homo erectus and Homo ergaster New species name proposed for the African representatives of what was formerly called Homo erectus Unclear relationship to H. erectus Subspecies or descendant? Homo erectus Found outside Africa, in places such as Indonesia, Eastern Europe and China Very successful hominin Probably the first to leave Africa Earliest date of 1.9 mya, well established by 1.7 mya Existed on Earth for over 1 million years

Morphology of Homo erectus Body Size Adults weighed over 100 lbs with an avg. height of 5’6” Sexually dimorphic Increased robusticity Brain Cranial capacities 700 cc to 1250 cc Brain size closely linked with overall body size and relative brain size is about the same Relative brain size of H. erectus is considerably less encephalized than later members of genus Homo

H. Erectus Crania Thick cranial bone with large browridges Nuchal torus A thickening of bone in the back of the cranium where neck muscles attach; used to hold up the head Not ever-present Little forehead development Cranium wider at base, compared with earlier and later species Sagittal Keel Small ridge from front to back along skull Reflects a very robust skull, rather than a specific function

Homo erectus Out-of-Africa Earlier hominins than H. erectus all occur in Africa Evidence suggests rapid migration Equates to less than 200,000 years to travel from East Africa to Southeast Asia Earliest H. erectus fossils Same location as earlier australopithicines Smallest cranium of any African H. erectus Most gracile of the East African H. erectus finds Likely a female

H. erectus Technological Trends Expansion of the brain Oldowan and Acheulian tool kit Acheulian Used to cut, scrape, pound, and dig Multifunctional tools, including uses for butchery Raw materials transported more consistently and for longer distances Suggests foresight They knew they needed a stone tool in the future and carried that which they regarded as being useful

H. Erectus Culture Hearths Language Fire use Fireside conversation? 800,000 to 1.5 mya Not definitive until 500,000 Used for protection – cave bears, saber-toothed tigers Killing parasites through cooking Expansion into colder climates Fireside conversation? Language Cooperative hunting

Oldowan tools

Turkana Boy Nariokotome Skeleton (WT 15000) Found in Kenya in 1984 Dated to about 1.6 mya Produced the most complete H. erectus skeleton ever found Includes facial bones, a pelvis, most of the limb bones, ribs, and vertebrae Likely a boy about 12 years of age Estimated height of 5’3”

Dmanisi Hominins Discovered in the Republic of Georgia in the early 1990s A number of stone tools, similar to Olduwan tools, have been recovered Best-preserved hominins outside of Africa Body proportions 4’9” in to 5’5” Similar to H. erectus (and H. sapiens) Different from earlier hominins

Possibilities Raised by Dmansi First hominins to leave Africa were small-bodied early form of H. erectus Smaller brains than later forms Carrying typical African Oldowan stone tools These hominins had none of the adaptations hypothesized to be essential to hominin migration Tall Relatively large brains Perhaps two migrations out of Africa Small-brained, short-statured Dmanisi hominins Robust body build of H. erectus populations in Asia

Homo Erectus from Indonesia Six sites in eastern Java Dating from 1.6 mya to 1 mya (Early to Middle Pleistocene) The famous Trinil skullcap found by Eugene Dubois in Java in 1891

Homo erectus from China Zhoukoudian Dated 500,000 to 700,000 years ago Cranial remains Ritualistic treatment, Cannibalism, or Leftovers from a predatory kill (Giant Hyenas) Cultural Material Over 100,000 artifacts indicate occupation of several thousand years No evidence to suggest control of fire and the bone accumulation present lead to the question, is this a home or hearth?

Lantian and Yunxian China Dated 800,000- 580,000 years ago Similar in age to the Zhoukoudian finds Fauna and paleoenvironmental analysis Suggests limited hunting of young and old animals Lantian Dated 1.15 mya Two H. erectus adult females in association with fire-treated pebbles and flakes Mandible with several teeth similar to those at Zhoukoudian

H. Erectus Timeline

Later Homo erectus in Europe Atapuerca, Spain, appx 1.2 mya Partial jaw with few teeth Closely resembles Dmanisi fossils Simple flake tools and animal bones Gran Dolina, Spain, appx 850,000-780,000 ya Fragmentary nature of the remains makes assignment difficult Homo antecessor or subspecies H. erectus antecessor Heidelberg, Germany, appx 500,000 ya Homo Heidelbergensis Shares H. erectus and H. sapiens traits Could be grouped with one, the other, or neither

Bodo Cranium The earliest evidence of Homo heidelbergensis in Africa May be a late H. erectus Possibly defleshed with stone tools May imply cannibalism, ritual purpose, or both Dated to approx. 600,000 ya

The Pleistocene Epoch 1.8 mya to about 11,700 ya “The Ice Age” Marked by advances and retreats of continental glaciations At least 15 major and 50 minor glacial advances have been documented in Europe Glacials - continental ice sheets cover much of the northern continents Interglacials - continental ice sheets are retreating, eventually becoming much reduced in size Impact on hominins Climate change Flaura and faunal life shifted

Middle Pleistocene Culture Continued Acheulian tool technology H. erectus tools carried over into the Middle Pleistocene Little change until near the end of the period Levallois Technique Later premodern humans in Africa and Europe Better control of flake size and shape “Tortoise core” Suggests increased cognitive abilities in later premodern populations

The Levallois Technique

Pleistocene Diet Food sources Fruits, vegetables, fish, seeds, nuts, bird eggs Each in its own season Sea exploitation New to human evolution during this period Little, but some evidence supporting advanced hunting among early Homo Schöningen, Germany Wood spears found Most likely used as throwing spears to hunt large animals Horse, deer, etc.

Neandertals Homo neanderthalensis vs Homo sapiens neanderthalensis Increasingly being placed by researchers into a separate species Discovered in 1856 In Neander Valley, Germany Before discovery of H. erectus or any Australopithecine Three years before On the Origin of Species Remains have been found in Europe and the Middle-east Neandertal-like early Homo has been found in China and Africa Interglacials subside, and glacials arise in Europe Clothing Mousterian tools Hunting Mammoths

Mousterian Tool Industry Trimmed flint nodule Core is struck down into nearly nothing, and discarded a larger proportion of flake tools than the Acheulian Flakes are trimmed into various forms Scrapers Points Knives

Neandertal Morphology Brain Size 1520 Ccc Less encephalization Perhaps an adaptation to colder climates Cranium Large, long, low, and bulging at the sides Structure Robust, barrel-chested, and powerfully muscled Shorter limbs than modern H. sapiens Short stocky bodies reduce heat loss Long broad noses Warming the air

La Chapelle-aux-Saints Skull Projecting face, and low vault Occipital bun Expands the back of the cranial vault Origins are unclear Cranial balance Expanding brain Hunting Still remain in some human populations today

Shanidar Cave Finds Fieldworkers found partial skeletons of nine individuals Four of them deliberately buried Evidence of injuries that made it impossible to perform normal activities leading researches to believe he must have been helped by others Neandertal compassion for the disabled?

Symbolic Behavior of Neandertals Speech Prevailing consensus has been that Neandertals were capable of articulate speech Even if Neandertals did speak, they did not have the same language capabilities of modern Homo sapiens Burials Burials included grave goods Animal bones and stone tools Bodies of their dead are often placed in a flexed, sometimes fetal, position

Subsistence Neandertals were successful hunters Evidenced by fauna remains at Neandertal sites Used close-proximity spears for hunting Spear thrower and bow and arrow not invented until the Upper Paleolithic Patterns of trauma in Neandertal remains Match those of contemporary rodeo performers Indicates close proximity to prey

The Denisovans: Another Hominin? Denisova Cave, southern Siberia Discovered while analyzing the Neandertal genome Finger and tooth dated to 50,000-30,000 ya Mitochondrial DNA shows significant genetic distance from both Homo sapiens and Neandertals Suggests interbreeding soon after AMH emergence from Africa 50,000 years ago Split from Neandertal ancestors 400,000 years ago, Neandertals head west, Denisovans head East Melanesians Residence of Papua New Guinea share 1/20th Denovian DNA Suggests interbreeding

Phylogeny of Genus Homo - Very Modest Species Diversity

Phylogeny of Genus Homo - Considerable Species Diversity