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Uncover the evolution of humanity, our closest relatives, and key species in a hands-on lab session. Discover the impacts of human features on behavior, culture, and geography. Compare modern humans and apes in physical and behavioral traits. Join us tomorrow at Bio Med Lab to delve into the fascinating journey of human evolution!
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HUMAN EVOLUTION LAB • Tomorrow!!! Yay! • Before Lab: View lab assignment and reference sheet online. Print out at least one of each per group. • Groups: (alphabetical) Meet at Bio Med Lab – Main Lobby @ 3:45 WHERE??? Bio Med Building – Tall brick building located @ Corner of Meeting and Brown Streets. Enter on Meeting St. side
What Makes us Human? Who are our nearest relatives in the animal kingdom? When did our human features first appear in the course of human evolution? What impacts did these human features have on human behavior, cultural development, and movement geographically?
What is a Hominid? Bipedalism | Arboreal Arms | Teeth
Hominid Taxonomy Linnaean Taxonomy binomial nomenclature Most specific sapiens, neanderthalensis, afarensis Homo, Australopithecus Hominidae (Great Apes: chimps, humans, gorillas, orangutans) Primates: Descent from same primate??? Missing link? Mammalia Vertabrata Here’s the proper way to write taxa: Homo sapiens or H. sapiens Australopithecus afarensis or A. afarensis Most general
Chimps vs. Humans • modern humans (Homo sapiens) • Physical • bipedal large cranial capacity, ca. 1325 cc • vocal tract with large phonetic range • small canines (both sexes) • thick tooth enamel • long lumbar region (5 vertebrae) • precision and power grips - both good • relatively hairless • estrus cycle unpronounced • menopause in older females • Behavioral • “abstract” intelligence (symbolic thought) • complex symbolic language • tool use and tool making - very complex ( fire, clothing, composite tools, etc.) • food sharing • home bases and central place foraging • division of labor • long learning periods for offspring • complex cultural behaviors • modern chimps (Pan troglodytes) • Physical • quadrupedal small cranial capacity, ca. 425 cc • vocal tract with limited phonetic range • dimorphic canines - larger in males • thin tooth enamel short lumbar region (3 vertebrae) • precision grip (poorer), power grip (good) • relatively hairy • estrus cycle pronounced • no menopause in older females • Behavioral • less “abstract” intelligence • less complex communication system • very simple tool use and tool making • no delayed food consumption • minimal food sharing • lack home bases • central place foraging lacks division of labor • shorter learning periods for offspring • simple cultural behaviors HOW ARE WE ALIKE? HOW ARE WE DIFFERENT? (How do we maintain balance)
Apes vs. Hominids • modern humans (Homo sapiens) • Physical • bipedal large cranial capacity, ca. 1325 cc • vocal tract with large phonetic range • small canines (both sexes) • thick tooth enamel • long lumbar region (5 vertebrae) • precision and power grips - both good • relatively hairless • estrus cycle unpronounced • menopause in older females • Behavioral • “abstract” intelligence (symbolic thought) • complex symbolic language • tool use and tool making - very complex ( fire, clothing, composite tools, etc.) • food sharing • home bases and central place foraging • division of labor • long learning periods for offspring • complex cultural behaviors • modern chimps (Pan troglodytes) • Physical • quadrupedal small cranial capacity, ca. 425 cc • vocal tract with limited phonetic range • dimorphic canines - larger in males • thin tooth enamel short lumbar region (3 vertebrae) • precision grip (poorer), power grip (good) • relatively hairy • estrus cycle pronounced • no menopause in older females • Behavioral • less “abstract” intelligence • less complex communication system • very simple tool use and tool making • no delayed food consumption • minimal food sharing • lack home bases • central place foraging lacks division of labor • shorter learning periods for offspring • simple cultural behaviors HOW ARE WE ALIKE? HOW ARE WE DIFFERENT? (Hint: How do we maintain balance)
Human Evolution: Figuring it Out 7 Key Species Australopithecus afarensis A. africanus A. robustus Homo habilis H. erectus H. neanderthalensis H. sapiens
genus: Australopithecus Gracile vs. Robust • africanus: • 3.3 to 2.5 million years ago • brain size = 400-500 cc • Where: Africa only (southern) • a more globular cranium and slightly higher ratio of brain size to body size than afarensis (evolved from afarensis?) • anterior pillars, which are located on either side of the nose (evolutionary link to robustus?) • More human-like cranium and larger brain than afarensis • Still not 100% sure how this relates to human ancestry • Sterkfontein – Taung baby robustus: • afarensis: • 3.2 to 2.9 million years old • 1 to 1.2 meters tall • brain size = 400-500 cc • generally ape-like face • Where: Africa only (east) • Primitive Characteristics: include long arms, short legs, and curved finger and toe bones • Human Characteristics: include hind limbs and pelvis fully adapted for a type of bipedal locomotion • LUCY – Hadar - Laetoli • 2.0-1.0 million years ago • Brain size: 410-530 cc • Build: Very heavy build; relatively long arms • Where: Africa only (southern) • Skull: Sagittal crest on top of skull; long, wide, flatter face; moderate facial buttressing, broad cheekbones • Jaws: Very thick jaws; small incisors and canines; large, molar-like premolars; very large molars • Swartkrans - Dreimulen, and Kromdraai – Sterkfontein?
genus: Homo What makes Australopithicene different from Homo? Image: L. Meszoly, Harvard U.
Australopithecine or Homo?????? Drawing Genus Boundaries • Wood and Collard suggest that a fossil species should be included in genus Homo only if most of the following criteria can be demonstrated: • The species is more closely related to H. sapiens than it is to the australopithecines • 2. The species has an estimated body mass more similar to that of H. sapiens than to that of the australopithecines • 3. The species has reconstructed body proportions that match those of H. sapiens more closely than those of the australopithecines • 4. The species has a postcranial skeleton whose functional morphology is consistent with modern human-like bipedalismand limited facility for climbing • 5. The species is equipped with teeth and jaws that are more similar in terms of relative size to those of modern humans than to those of the australopithecines • 6. The species shows evidence for a modern human-like extended period of childhood growth and development.
genus: Homo Homo habilis – “The Handy Man” • 2.5-1.6 million years ago (in existence for 400,000 years) • Brain size: highly variable from 500-800cc. • Where: Throughout Africa • First evidence of stone tool production and usage. (Sterkfontein) • Sites: Sterkfontein, and Great Rift Valley: Omo, Hadar (Ethiopia), Olduvai Gorge (Tanz), Koobi Fora (Kenya) • Fossil remains are very poor. Uknown whether evolved from A. africanus or A. afarensis.
genus: Homo Homo erectus - “Upright Man” • 1.8 million – 400,000 years ago • Brain size: 780-1225 cc (about 75% of H. sapien brain size) • Where: Throughout Africa, China, Java • Average height: 1.79m = 5’10’’ • Skull: forehead less sloping and teeth smaller than H. habilis • Tools: more sophisticated stone tool technology, from Oldowan to Acheulean (bifacial) • First use of controlled fire ~ 790,000 years ago • First hunter-gatherer society, infrequent group hunting • Crude shelters, possibility for language usage • Evidence of migration • Sites: Lake Turkana (Kenya), Choukuotien – Peking Man (China), Java Man (Indonesia)
genus: Homo Homo neanderthalensis: “Neanderthals” • 250,000 – 24,000 years ago • Coexistence with H. erectus and H. sapiens. Are we related to Neanderthals? What happened to them? • Brain capacity: 1200-1750 cc – larger than Homo sapiens! • Average male height: 1.65 m tall (5' 5") ; Average female height: 1.53 to 1.57 m tall (5'–5'2"). • Skeletal differences: larger cranium, elongated skull, short but robust builds, and large noses — traits selected by nature in cold climates. Occipital bun. Hyoid bone. • Where: Europe and western Asia • Stone tool technology: Mousterian, characterized by Levallois technique (soft hammer percussion) • whether modern man evolved from this hominid -- or was the Neanderthal a separate branch that became extinct? • Burial of dead, personal adornment, clothing, simple language, ritual behavior, use of symbols • Sites: Shanidar Cave (Iraq) flower burials – 60,000 years old, Kebara Cave (Israel) – 60,000 y.o., La Ferassie (France) oldest / most complete skeletons – 72,000 y.o.
genus: Homo Homo sapiens: Us! • From ~250,000 years ago – present • Brain capacity: 1000-1850cc • Average height: 1.4-1.9m • Worldwide • Complex societies, elaborate architecture, kinship structures, shared resources, rituals, complex language
How are we related?? Hominid Family Tree(s) Warning!! It’s dangerous to draw lines where the record’s very incomplete. Some species are still represented by very few fossils. Instead paleoanthropologists must look for patterns of evolution in the fossil remains.
Where do we come from? Hominids on the Move 2 Migration Models:Did Homo sapiens evolve in Africa or in various places around the world? Out of Africa Multi-regional Model
What exactly evolved? And why are these features so important? A summary… Cranial Capacity | Brain Size
What exactly evolved? A summary… TEETH Chimp A. africanus Homo erectus Modern homo sapiens
What exactly evolved? A summary… Skeletal Features, including:
What exactly evolved? A summary… BIPEDALISM: SPINAL COLUMN
What exactly evolved? A summary… BIPEDALISM: LIMBS and SKELETAL CHANGES Laetoli footprint