evanth pt 3
absolute dating
A technique used to determine the actual age of a fossil
Homo sapiens
Africa first, then everywhere Major sites: Jebel Irhoud, morocco, Ologesailie, Kenya, Klasies and Border, South Africa How old: 300 kya-today Key features: Brain size 1350 cc; culture: Upper paleolithic. Art symbolism language
vertebrate formation
All vertebrates come from a disk of embryos; brain and spinal cord start off as empty space Hox genes (patterning genes) that determine the basic body plan are more than 500 million years old; same genes in humans, fish, and insects. Vertebrate body plan is conserved; lots of homology, vertebrates and heads are the same Pharyngeal arches in water animals become gill arches, for us it because our jaw, our ear etc
where can you typically find fossils
East African Rift System- EARS- running through Ethiopia and down East African in river-cave sites, rich in hominin fossils Chad also is the source of one of the hominins C-Sahelanthropus - in Chad Ar- Ardipithecus - In North-East Africa O-Orrorin - East Africa, further south
when might eating tubers have started
Eating tubers may have started with Australopithecus - could be why they have big molars and thick enamel
Cenozoic Era
Cenozoic 45 million years, age of mammals How are fossils formed: sediment in a thick river
earliest Homo sapiens in east Asia
Daoxian Cave, China; 80k years ago Earliest homo sapiens in australia, madjedbebe rock shelter, 65 kya, many blade tools, stone axes, ocher "crayons," grinding stones Modern humans "cultural explosion" 50k years ago, limited and debated evidence of similar behavior in Neanderthals Australian Rock art ~30,000 years ago Indonesia Cave paintings 44k years ago Modern humans cultural explosion 50k years ago
el argar group
El argar Complete turnover of Y-chromosome lineages along with the arrival of steppe-related ancestry, this pattern is consistent with a founder Cultural transmission
trade off between abundance and energy tensity
Energy dense foods are harder to acquire The trophic pyramid Foods that are the easiest to acquire are the most energy dense due to dumping fossil fuel energy into the earth Humans get 20,000 food energy per hour of work, hadza get 2,000
food takes what amount of energy to produce
Every 1 kcal of your food takes 7 kcal to produce
dmanisi tools and fossils
Evidence for moderate dimorphism Dmanisi tools: similar to oldowan Behavior: evidence for butchery and meat eating
how did humans evolve such a big expensive brain
Expensive tissue hypothesis Diet changes to include more meat Guts get smaller which saves energy Natural selection favors putting that energy into big brains and increased intelligence for better foraging
neolithic revolution
Farming (plants and animals) begins around 12k years ago Domesticated animals and plants, dietary modifications
farming and wealth
Farming associated with greater wealth inequality (gini coefficient) Us Gini coefficient is 0.4 to 0.5
food sharing and birth intervals
Food sharing shortens inter birth intervals and increases family size, total fertility rate is about ~6 children in hunter-gatherers and farmers As countries industrialize and life expectancies increase, total fertilityy rates decrease The average number of kids is less than 1.9 in USA
homo Erectus tools
From about 1.7 mya and onward: acheulian stone tools with homo erectus Earliest solid evidence for fire; wonderwerk cave in south africa, 1mya Burned plant and bone in sediments deep in the cave Acheulian hand axes suggest homo erectus
limb development and evolution stage
Hox genes also determine basic limb plan, segment identity, hands
Kadanuumuu Skeleton- Austra. Afarensis
Large male Big compared to lucy skeleton: 45 kg Large teeth Curved, parabolic tooth row- small canines and big molars Thick enamel Fibrous diet
hunting and gathering- Hadza
Live in grass houses in Northern Tanzania, get all of their food from the wild landscape around them Family, extended family, camp -> tribe (language group) No hierarchy or government
cranial morphology of homo Erectus
Long, low cranium Big brow ridges Transverse torus: for neck muscle attachment Post orbital constriction
hadza men
Men walk ~12 km per day, hunt solo to sneak up on game Men climb and chop trees to collect honey which is 15% of the diet Chimpanzees and other hominoids eat honey, early hominins likely did also, but humans eat the most- 10-20% of diet in some cultures
relative dating
Method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock
Olorgesailie: Kenya humans
Modern human behavior at 300k years ago Long distance ~50 km transport of Obsidian for tools; red ochre pigment (decorations for art)
neanderthal body proportions
Neanderthal postcrania: shorter esp limbs; wider pelvis; powerfully built Neanderthal body proportions: Allen and bermann rules for body shape and climate Tropical climates: tall and thin; arctic short and stocky
neanderthal hunting and gathering
Neanderthals gathered mollusks from the sea floor, up to 4m deep - evidence from recovered shells in neanderthal cave sites Neanderthal culture: cave art and symbolism successfully hunted reindeer, rhinoceros Microfossils of plants stuck to the dental calculus indicates that many plants were eaten too Exostoses, bony growths in the ear canal, indicate lots of cold water diving
earliest Homo sapiens in pacific islands
Ocean voyaging begins 3500 years ago Pottery used to reconstruct migrations and cultures
why is provisioning unlikely
Socio-behavioral changes with homo encephalization
hadza tools
Tools are simple but effective Baobab fruit with pods, sweet and tangy - seeds have a lot of energy Fire and cooking as an important tool Potatoes- energy/gram doubles with cooking Earliest fire- ~1 may, wonderwerk cave in South Africa, associated with Homo Erectus Cooking gives us high energy diets Human digestive system requires cooked food
Superposition
a principle that states that younger rocks lie above older rocks if the layers have not been disturbed
Biostratigraphy
a relative dating technique based on the regular changes seen in evolving groups of animals as well as the presence or absence of particular species
first true primates
adapids and omomyids - eocene, small animals (smaller/squirrel-size animals)
holocene calendar
add one to the current year, gives a better sense of recent human history;
First non-debatable anthropoids-
aegyptopithecus - 33mya
earliest Homo sapiens in Europe
apidima 1 skull in greece, 210k years ago; 2 skulls embedded in rock inside a cave; both initially thought to be neanderthal Skull shape of apidima 1 looks like HS Apidima 2 looks more like N Aside from apidima, earliest evidence for homo sapiens in europe is 45k years ago
agreed upon idea leading to bipedalism
arboreal origins
hominins
bipedalism, tool use, large brain, complex culture, non-honing premolar, reduced canine
mesozoic
dinosaurs Earliest mammals begin to evolve, 230 mya, har, warm blooded, nurse their young, live birth 251-65 mya KT extinction event 65 million years ago wipes out the dinosaur
When does bipedalism appear in fossil record?
early hominins
how can you tell that a species is quadrupedal
elongated pelvis, non-opposable big toe
first anthropoids
eosimias sinensis - 45 mya - apes and monkeys
population movement and admixture since neolithic era
example europe, ancient DNA evidence, in-migration from Farmers from near east 9k-7k years ago Resurgence of hunter gatherers from western Europe 7k-5k years ago In migration of Yamnaya steppe farmers, 4.5k years ago
what will happen if the earth warms 5-8 degrees
flooded coastline, this has happened before
early hominins brain size
from smallest to largest: chimpanzee- apes; Ardipithecus; early hominins; australopithecus; Homo erectus; humans
farmers compared to hunter gatherers
greater efficiency and more energy produced
what happened to body size with farming
height and weight, decreased with farming and increased population due to disease burden Decreased nutrients Also brains get smaller- 1% change, weird that it happens at all
humans difference from neanderthals
high round cranium with tall forehead, smaller nose, chin, face does not project
Gluteus medius
hip stabilizing muscle
homo features
humanesque skull, versatile hands, long legs, humanlike feet
humans era and tools
humans (upper paleolithic) and complex tools; clothing 72kya ; bow and arrow 20 kya
honeyguide
indicator -> guides humans to beehives, origins 2+ mya Men spend a lot of time hunting, find big game
rule of 50
industrialized humans use ~50 times more energy and produce ~50 times more stuff than hunter-gatherers
Australopithecus Generally
is now a well-documented Hominin Genus Hundreds of fossils, including some partial skeletons Look more like apes than humans
embodied capital
knowledge that is both consciously acquired and passively inherited through socialization Food energy- reproduction or growth- maintenance- fat- brains- activity- > foraging social> sharing> food
hypothesis about homo species
limping , splitting, ultra-splitting
farming domestically and what it does to population and birth int.
more energy, less fiber, fewer nutrients Domestic animals: twice the fat, livestock is 10k years ago Changes: number of infants, increased fertility from farming by 20%, an additional 1-2 children per family Population post-farming skyrocketed - in era of city-states and empires Explosion of inventions
interpreting function from fossils
one common approach: biomechanics Compression, tension Gravity, buildup of bone tissue in an X ray
miocene
origins and expansion of hominoids- dryopithecus, proconsul, otavipithecus, morotopithecus, Today: 6 hominoid genera Miocene: at least 27 hominoid genera
paleocene
plesiadapiforms - early primate-like mammals The skull has a big gap in the tooth row called the diastema
postural feeding probability
possibly Arm-hanging and stabilization during chimp feeding BUT Chimps aren't bipedal on the ground
suspensory mechanical probability
possibly Suspensory apes forced to ground Gibbons walk bipedally on the ground LCA branched into bipedal and knuckles walker
bipedalism main hypothesis
postural feeding, savannah/thermo, provisioning, suspensory mechanical
paleomagnetism
refers to earth's magnetic field preserved with ferrous sedimentary rocks
why are savannah and thermo discredited
seems unlikely, earliest hominins found in forests, not savannahs; bipedalism is not more efficient
one complication of many in identifying fossils
sexual dimorphism
radiometric dating
the process of measuring the absolute age of geologic material by measuring the concentrations of radioactive isotopes and their decay products some unstable chemicals break down into a different form Parent element, daughter element Carbon 14, up to 50 million years Potassium-argon- millions of years
dmanisi compassion
toothless dmanisi individual; lived 2-3 years without teeth Was probably helped by other individuals Painful bone disease in knmer 1808 specimen, could not have hunted and gathered
culture of neanderthal
very clever use of fire; built kilns to make bitumen, a primitive glue complex social world; Burial of the dead- ritual, religion; Cannibalism at a couple of sites Individuals were eaten; bones broken for marrow and used to retouch stone tools. Widespread? Within group? Ritualistic?
arboreal theory
walk on two feet in trees, on ground more comfy to also be bipedal
evidence for hunting
~2mya with early homo; oldowan tools, butchered bones, meat in the Diet Bows and arrows, poison for arrows, knife Women sew with needles and thread Hunting is ecologically risky- large game: every ~30 days of hunting; small game more often; most days, nothing Depend on the gathering, take the risk on the hunting
humans jebel irhoud
(morocco) modern human anatomy at 315k years ago Skull and mandible retain some primitive features Brow ridge and small chin; Omo kibish skulls, 195 kya, herto skull 160 kya
harbin cranium
(China) Discovered in 1933, not properly analyzed until 2021; 146,000 years old, brain size 1420 cc, long low and larger than heidelbergensis
holocene era
11.7kya to now
danuvius
12 mya in Germany Suspensory
sivapithecus
12 mya, Pakistan Skull and dentition: looks like an orangutan No tail: but arboreal quadrupedal body
Big Bang explosion
13.7 billion years ago, development of galaxies, planets, etc
neanderthal vs human
1450 vs 1350 cc; more projecting vs less projecting; long occipital bun vs more round cranium; brow ridges large vs very small; tools mousterian vs many
earliest Homo sapiens in the americas
15k years ago Genetic evidence clearly groups native americans with asians Clovis culture- 13.2k years ago-12.9k years ago But then last year White Sands NP human footprints were found dating back to 23k years ago
Raymond Dart
1858-1940 Taung Child Sterkfontein: fossil cave site in South Africa Thought it was a bipedal ape 1925- Raymond Dart describes the first australopithecus fossils (the child skull) Establishes Aust africanus and hominin origins
Pleistocene Epoch
2.5mya, 11,700 years ago
Miocene Epoch
23-5.3 mya
inter birth intervals of humans vs hg vs apes
28% of energy used in US goes to transportation Industrialized interbirth interval is 21 months vs hunter gatherer is 36 months and apes are 60 months
life origins and Cambrian explosion up to first vertebrates
3.5-3.6 bya, bacteria, photosynthesis which produces oxygen Oxygen catastrophe Bacteria figure out how to use oxygen Cambrian explosion: 580-500 mya, major diversification of animal life, ediacaran fauna that persists for 80 million years- we don't even know what type of fauna they are Species figured out how to make skeletons from mineral When dinosaurs go extinct 65 mya, age of mammals First vertebrates: bodies and brains
human location years
315 kya; near east; 170 kya, east asia, 80 kya; Madjedbebe, 65kya; olorgesailie; 300 kya; border and klasies; 125 kya
pliocene epoch
5.3-2.6 mya
Paleozoic era
542-251 mya- all of vertebrate life is in the sea, basic body plan of a head and two sides develops
Carpolestes simpsoni
55 mya- early primate, grasping hands and feet but no stereoscopic vision, supports angiosperm and challenges nocturnal visual predation
what percentage of hominin species have gone extinct
90
homo Erectus brain size
970cc
Wolff's Law
A bone grows or remodels in response to forces or demands placed upon it
Proconsul
A genus of early Miocene proconsulids from Africa, ancestral to catarrhines.21-14 mya in kenya
industrialization overview and energy use
Another major change in the way we acquire/burn energy Tapping into fossil fuels, mechanization, chemistry Global energy use today: 140 quadrillion kcal/year 50,000 kcal person per day US: 200,000 kcal/person per day
tree use in the lineage
Austrolopithecus have some tree use, then in homo erectus it is rare
suspensory mechanical hypothesis
Bipedal in the trees Walking bipedally as well
How do we define the boundary between Australopithecus and Homo:
Homo Brains > 600cc Smaller teeth Stone tools
homo Erectus body and post crania
Homo erectus teeth are sharper and smaller than Australopithecus Suggests meat in diet Homo erectus postcrania: body and limbs 6' tall, 60 kg Long legs, narrow pelvis Large leg joints Foot arch Endurance Running Hypothesis: Homo erectus (and maybe earlier homo) was adapted to run long distances to hunt and scavenge prey)
evolutionary tree from homo Erectus
Homo erectus- heidelbergensis- neanderthal and denisovan Erectus right to modern homo sapiens
savannah hypothesis
Humans are in the savannah Exposed to less solar radiation by standing up to help thermoregulation Climate-driven More efficient on the savannah
Homo sapiens in Southern Africa
Klasies River and Blombos Caves ~125k years ago Complex hunting and gathering strategies- seasonal exploitation Evidence of symbolic behavior at 100k years ago Bead shells and geometric patterns in ochre Oldest drawing 73k years ago
where do we find fossils
Olduvai gorge, eastern Africa Dmanisi, republic of georgia
how do teeth preserve fossil records
P3 canine honing complex
eras and dates of eras within the age of mammals
Paleocene- 65.6-55.8 mya Eocene-55.8-33.9 mya Oligocene-33.9-23 mya Miocene- 23-5.3 mya
how do you know if a primate is bipedal or quadrupedal
Position of foramen magnum shows if you are bipedal or quadrupedal b/c it determines where the spine is
process of energy
Process of energy- acquire process digest, thermoreg., movement, reproduce
what happens to canines and molars throughout primate lineage
Reduction in canines and molar size throughout the lineage
homo erectus dmanisi
Republic of Georgia Lots of fossils found here outside of Africa Dmanisi Homo Erectus: 1.75mya Georgia 5 feet tall, 45 kg 650 cc Primitive stone tools Site formation: lava flow created a lake, on the shore, fossil site found
human language and speaking
When we speak, pressure waves created without larynx, voice box, are shaped by the vertical throat and horizontal mouth parts of our vocal tract Human infants have the epiglottis and larynx positioned high behind the nasal cavity. They can nurse and swallow and breath without choking, a baby also cannot make the full set of sounds that adults can make Infant anatomy is similar to apes As kids grow, the larynx descends, permits full speech abilities, increases choking risk,
neanderthals
Where: Europe, middle east Major sites: Neandertal germany, la chapelle france, shanidar iraq, kebara Israel
Kenyanthropus Platyops
Where: Kenya, Africa How old: 3.5-3.2 mya Key features: Flat face, small molars, fragmented
paranthropus robustus
Where: south africa Sites: Swartkrans, Krombrai How old: 2.0-1.4 mya Robust adaptations: extreme chewing adaptation, hard object specialists, tough fibrous foods, temporalis muscle, masseter muscle
hadza women roles
Women leave camp together to collect plant foods, walk ~6km per day Digging stick Women go in groups as a matter of safety- elephants and cats Women gather berries and tubers Sharing afters tubers are brought to camp
evolving of bodies stage
Your lungs are developed from your guts because they are an evolved fish air bladder, gut tract and air bladder in a fish use evolved air bladders