Download
1 / 42
420 likes | 444 Views
Later Human Evolution. Later Homo: Homo erectus Archaic Homo sapiens: Homo antecessor Homo heidelbergensis Homo neandertalensis. Homo erectus : Traits. Homo erectus lived from approximately 2 million to around 400,000 years ago.
E N D
Later Human Evolution Later Homo: Homo erectus Archaic Homo sapiens: Homo antecessor Homo heidelbergensis Homo neandertalensis
Homo erectus: Traits • Homo erectus lived from approximately 2 million to around 400,000 years ago. • Homo erectusis a large brained species, with adult brains ranging from 900 to 1200 cc.
Traits • Were from the neck down almost exactly like moderns • Had no chin, thick and big brow ridges • Bigger teeth than moderns • Males were much bigger than females, but this changes over time • More robust body • Body Size • male:170cm,66kg • female:150cm, 56kg
Acheulian Hand Axes • Homo erectuswas an accomplished tool maker and tool user; hand-axes were widely used in addition to sharp-edged flakes. • The tools of Homo erectusare the first in the fossil record to show conscious design of any complexity. • Wooden tools and weapons are also assumed to be present in the tool kit of this species, but none has been preserved in the fossil record.
Controlled Use of Fire • H. erectusmay have been the first species to use and control fire. • This milestone in human development occurred 1 to l.5 million years ago. • Control of fire may have enabled humans to move out of Africa and into colder climates in Europe and Asia.
Use of Fire • Homo erectus invented fire • To cook food, scare away animals and travel to colder places • controlled fire
Migrate Out-of-Africa • The earliest specimens of Homo erectusare found in Africa, but, sometime after 1 million years ago, Homo erectusapparently migrated out of Arica. • Tools and remains of this species have been found widely distributed in Europe and Asia. • Homo erectusis thus the first human species to migrate out of Africa and adapt to a variety of Old World environments.
HomoErectus Habitat/Map Asia (cold) Europe (cold) Africa (hot) Australia (hot) Htttp://www.handprint.com/LS/ANC/disp.html
HomoErectus Important Find • Peking Man • Was found near Beijing • Name used for the bones of an extinct hominid • Reconstruction of Peking man Skull http://www.inhandmuseum.com/LA/erectus/ergaster.html
Homo ergaster • By 1.9 million years ago, another lineage of the genus Homo emerged in Africa. This species was Homo ergaster. • Many researchers now separate the two into distinct species Homo ergaster for early African "Homo erectus", and Homo erectus for later populations mainly in Asia. • Scientists consider H. ergaster as the probable ancestor of later Homo populations.
Variation • Individual specimens of Homo erectusvary widely but some trends are visible over time. • These artist's reconstructions of three faces from skulls show variations over a period of about a million years.
Note the difference in the shape of the cranium. On the top, H. erectus has a long cranium with a protruding area of bone at the back of the braincase. • H. ergaster has a more globe-shaped braincase that lacks this torus. H. erectus H. ergaster
Homo ergaster: WT 15,000 Narikatome Boy • Boy, 12 years • Long legs narrow hips and shoulders • Vertebrate opening sin spinal cord smaller than moderns • Brain size large (850-1100) • Front tooth size increase, back tooth decrease • Tall (5-5.5 feet), thick bones. • 1.6 mya-200 kya
Narikatome Boy • The nearly full skeleton at the right belonged to a teen-age boy, 12 or 13, who lived 1.65 years ago near what is now Lake Turkana in east Africa. • He was five feet, four inches tall, and his body is remarkably modern looking. • This is the most complete find of an ancient human ancestor yet discovered, and it has provided a wealth of information. • Yet this immature male had already surpassed a height of five feet at the time of his death, and probably would have attained a height of 6 feet and a weight of roughly 150 lbs.
Archaic Homo sapiens • For many years, scientists placed any problematic specimens displaying mixtures of "erectus-like" and "modern" traits into a confusing category: "Archaic" Homo sapiens (basically meaning any Homo sapiens that didn't look quite modern). • Recently, it has been proposed to separate these individuals into a distinct species. For this purpose, the names Homo antecessor &Homo heidelbergensis have been assigned.
Homo antecessor • The species Homo antecessor is another very controversial species designation. The species was designated by J.L. Arsuaga et al. to the remains of several individuals found at the Gran Dolina site, Spain. • The discovery was significant because the remains have been securely dated at over 780 kyr. This makes the material the earliest known European specimens. • The find breathed new life into the argument for the validity of H. heidelbergensis, as well as creating a whole new species: H. antecessor.
Homo antecessor traits • Has a marked double-arched browridge (like later Neanderthals and Chinese erectus). • An approximate brain size of 1000 cc. • Reduced mandibular thickness when compared to ergaster or early erectus. • Has small postcanines that resemble those of the habilines (habilis and rudolfensis), but they are still within the ergaster/erectus range. • Shovel-shaped maxillary incisors (ancestral condition).
Gran Dolina Site, Spain • The most complete specimen is Hominid 3, which is also the type specimen for antecessor. • This is unusual because Hominid 3 is a 10-year old, and therefore has not fully developed its skeletal characteristics. • The specimen was chosen because it highlighted all the features that the researchers were attempting to describe as typic of the species.
Homo heidelbergensis • Homo heidelbergensis is the species name now given to a range of specimens from about 800,000 years ago to the appearance of anatomically modern Homo sapiens (the species to which we belong). • The species name was originally proposed for the fossil mandible discovered at Mauer, a town near Heidelberg, Germany. It is a nearly complete early human mandible that is very robustly built, but lacks a chin.
This mandible was found by a workman in the Rösch sandpit just north of the village of Mauer near Heidelberg, Germany, in 1907. The workman showed the find to the anatomist O. Schoentensack, who provided the initial description of the specimen. The mandible is complete with only the premolars and first two molars on the left side missing. The molars were recovered separately, although the premolars were lost.
Kabwe Skull • The date for this site based on the associated animal fossils found is at least 125,000 years old, and is probably significantly older. • Some researchers have proposed that Kabwe may be a member of the African population from which all modern humans descended, although this cannot be definitively proven.
The braincase profile is low and slopes back from a large supraorbital torus reminiscent of earlier H. erectus specimens. There is also the remnant of a sagittal keel and an occipital torus at the back of the skull, also recalling H. erectus. However, the face is more modern in appearance (less prognathic, flatter) and the brain size of about 1300 cc. is larger than seen in H. erectus. Thus, this cranium preserves many traits that are reminiscent of earlier H. erectus and hints of more modern traits known later in H. sapiens.
The cranium shows evidence of disease and wounds that occurred in the lifetime of this individual. • Ten of the upper teeth have cavities, and dental abscesses of the upper jaw are clearly visible in the upper photograph (above the right incisor/canine) and the middle photograph (above the first molar). • Additionally, a partially healed wound is visible in the bottom two photographs, above and anterior of the hole for the ear. • This wound measured roughly a quarter-inch across, and was made by either a piercing instrument or the tooth of a carnivore. Exactly which is unclear
Homo sapiens neanderthalensisNeandertals (ca. 200-32 kya) • Species restricted to Europe, eastern Middle East during height of Ice Age • Evolved to be specifically cold-adapted: • Short and stocky body type • Large nose (nasal passages for warming air) • Barrel chest (also for warming air) • Long, low, thick skull but with large cranial capacity (1250-1750 cc) • Heavy brow ridge
Not the “Cave Men” they were made out to be! • First to bury dead • First to create art on rocks and bone • Elaborate Stone and Bone Tool technology • Mousterian tools • Some degree of altruism • Old Man of La Chapelle • Individual from Shanidar
Mousterian Tools: Period of stone tools associated with Neandertals
