Anthropology 101 exam 3 (2)

Homo erectus was first discovered by Eugène Dubois in

Java (1891)

Nariokotome Boy

Date: 1.6 MYA
Find location: Lake Turkana, Kenya

Homo erectus Locations

Africa (Olduvai Gorge, Lake Turkana, Ileret, Bouri, Buia, Bodo, Gona, Olorgesailie);
Asia (Dmanisi, Kocabaş, Trinil, Sangiran, Sambungmacan, Gongwangling, Majuangou, Zhoukoudian);
Europe (Gran Dolina, Mauer, Boxgrove)

Neandertals location

La Chapelle aux Saints, Krapina Neandertals
Neandertals found in Amud,Kebara, and Tabun Shanidar

bipedalism advantages

Freeing up the hands to create tools and carry things.
Being taller makes one appear more threatening to predators, and one can see further.
Effective heat management and/or greater endurance abilities also help.

bipedalism disadvantages

Being more vulnerable, and so easier to see by predators.
Enormous amounts of stress on the body(back injuries, circulatory system).
Moving on two legs rather than four would made ancestors slower (limited speed).

Seven Traits of Bipedalism

1. Position of the foramen magnum
2. Shape of the spine
3. Shape of the pelvis
4. Length of leg
5. Valgus knee
6. Longitudinal foot arch
7. Opposable big toe

Lumpers

Lumpers tend to assume there is considerable variability within genera and species and therefore tend to have relatively few taxonomic categories for the several million years of human evolution

Splitters

Splitters, on the other hand, tend to assume there is relatively little variability within genera and species,and therefore tend to recognize many different genera and species over the millions of years.

Orrorin tugenensis

Date: 6 MYA
Find location: Tugen Hills, Kenya by Brigitte Senet and Martin Pickford
Femora indicative of bipedalism; curved hand phalanges (suggests some time in trees); Non-honing chewing

AUSTRALOPITHECINE ADAPTATIONS

Australopithecus is the stem group of bipedal apes.
Finds in South and East Africa.
East African material tends to be better preserved and more reliably dated.
Evolution of earliest hominins resulted in a diverse group of species.
Early bipedal Australopithecus appear to have become more specialized in two directions:dental and mental.
Cooking, collecting, cutting vs. post-canine megadontia.
No large changes in brain size at this time
Animal bone with cut marks date to 3.3 MYA and in 2015,stone tools were found dating to 3.3 MYA.
Early stone tools were used for cutting meat from bones and smashing bones to get to marrow.
Various species of Australopithecus used stone tools.
Challenges idea that Homo (and Homo habilis) were the first to use stone tools

Pre-australopithecines

Wear on tip of canine, but with modified honing
Walked on two legs occasionally but had many features adaptive for tree climbing
Small, chimp-sized brains

Australopithecines

Canines are fully non honing with apical wear
Tree-climbing traits diminish and species are nearly fully adapted for upright, terrestrial bipedalism
Slight increase in brain size

Australopithecines anamensis

Date: 4 MYA

Find location: Lake Turkana and in Ethiopia

Named and studied by Meave Leakey Carol Ward,and Alan Walker; other remains studied by Tim White

Physically somewhat similar to Australopithecus

No complete skulls or skeletons, but isolated elements can still tell us a lot! > but nearly complete cranium found in 2019. Stay tuned!

Large canines (but with apical wear), parallel tooth rows ( = ape-like)

Arm and hand elements indicate that A. anamensis may have still climbed trees occasionally in its wooded habitat

Tibia is quite human-like and indicates that this species was well adapted for upright walking.

Australopithecines garhi

Date: 2.5 MYA

Find location: Middle Awash, Ethiopia (Berhane Asfaw)

Cranial: Small cranial capacity (450 cc); sagittal crest

Dentition is midway between gracile and robust Australopithecines

More humanlike humerus-to-femur ratio; Evidence of tool use (cut marks on gazelle bones)

Australopithecus (Paranthropus)

2 - 1.5 MYA

Swatkrans, Kromdraai,Drimolen (SouthAfrica)

Small brain (530 cc)

Terms

The earliest hominins likely evolved 7 - 6 MYA and are in the genus Sahelanthropus. Subsequent fossil finds have been placed into the genera Orrorin, Ardipithecus, and Australopithecus. Each species adds another piece to a larger picture of our hominin ancestors and relatives.

ROBUST AUSTRALOPITHECINES VERSUS EARLY HOMO

Increase in Brain size

Reduction in robusticity of the face

Reduction in robusticity of teeth

OLDOWAN TOOLS

Earliest recognizable stone tool tradition (2.5 MYA)

Consists of small rocks on which another rock has been used to knock off a few pieces, thus forming a sharp edge.

Used for food processing and procurementand are associated with early hominins like Homo habilis.

Chopper (oldwan tool)

a large, heavy stone tool with a sharp edge where small pieces of rock have been removed.

Flake (oldwan tool)

a small piece of rock that has been removed from a larger rock and can be used as is or further modified into a specialized tool.

Homo habilis

Bigger brains, tool use, and adaptive flexibility.

First discovered by Louis Leakey, Philip Tobias, andJohn Napier• 2.5- 1.8 MYA

Found in Tanzania, Kenya, Ethiopia, Malawi, South Africa


Facial reduction and cranial increase coupled with short legs and long arms (Australopithecus-like)

Homo habilis Adaptations

Associated with Oldowantools.

Anatomical evidence from the hand bones suggests precision grip.
Tools becoming fundamental to survival, unlike for Australopithecus

Adaptive shift to surviving on a landscape that was becoming more and more grassland.

More varied, generalized diet of both plants and meat.

Dietary flexibility would have helped these hominins survive in difficult times, and would have helped fuel a growing brain.

Homo erectus

1.8-0.3 million years

Africa, Asia, and Europe

Anatomy• Larger brain

Low, long, thick skull with small chewing muscles, large brow ridge,and relatively flat face

Smaller back teeth

Occipital torus, Long legs, Increased body size

Acheulean tools

The technique emerged about 1.5 MYA.

Named after a site in France (Saint-Acheul)

Starts with a flat rock with flakes knocked off both surfaces (bifacial tool).• A specialized version, the handaxe, appears 1.4 MYA

Homo Erectus

Biface (Acheulean tools)

a stone tool that had flakes of stone removed from two sides.

Acheulean Handaxe

a biface tool that is shaped like a pear or teardrop.

Patterns of evolution in Homo erectus

African fossils are the most robust and are similar to Dmanisi forms.

Earlier forms have smaller brains than forms dated later.

Cranial capacity ranges from 650 cc to 1200 cc.

Skull robusticity declined.

Reliance on the use of tools changed the structure of face sand jaws as a result of food processing.

Changes in social structure and dispersal patterns, and increasing reliance on culture for survival.

The Wrangham Cooking Hypothesis

proposed by Harvard anthropologist Richard Wrangham, suggests that the ability to cook food significantly impacted human evolution, particularly the development of larger brains and smaller guts. (One critically important cultural innovation of H. erectus was controlled fire.)

hominin meat-eating and dietary plasticity

Nutritional Advantages, Energy for Brain Expansion, Flexibility in Resource Use, Adaptation to Changing Environments, Impact on Brain Evolution

Homo naledi

Fossil site uncovered in 2013
Rising Star Cave (outside Johannesburg, South Africa)

Site produced 1,500 fossils, exceeding the number from any other site in the ENTIRE continent of Africa

Australopithecus-like - like:• cranial capacities (around 465 -560 cc)• shoulders suited for arboreal climbing

Homo erectus - like:• sagittal keel• large brow ridge• smaller teeth and mandible• human-like foot well suited to bipedalism

WHAT IS SO M O D E R N ABOUT MODERN HUMANS?

Modern humans are different from archaic humans.

Modern skeletal traits: round, tall skull with vertical forehead; small browridges; small face and teeth with a more gracile postcranial skeleton characteristic of modern humans

Archaic Homo sapiens had a longer and lower skull, larger brow ridge, bigger and more projecting face, larger nasal aperture, occipital bun, large teeth, and thicker postcranial bones.

Some hominin skeletons have a mixture of archaic and modern traits

NEANDERTALS

Neandertals found in Amud,Kebara, and Tabun Shanidar site

Long, low cranium. Large cranial capacity, Occipital bun, Retromolar gap

Cold-adapted: Large nasal aperture, Large infraorbital foramen

Fully upright posture Lots of grooves and ridges for the attachment of prominent muscles Cold adaptation of Neandertals: short limbs, wide trunks (in other words, a stocky build with short limbs)

MOUSTERIAN TOOLS

Named after a site in France (Le
Moustier)
Mousterian technology: a stone tool
technology that used the Levallois
technique to produce a variety of
specialized flake tools
Small, precise tools with finely worked
edges = refinement in lithic technology
Levallois technique: a process used to
produce regularly shaped flakes that can
be further modified into different tools
Associated with archaic Homo sapiens,
especially NeandertalsUsed in the Mousterian period, these tools were developed for specific functions and represent significant advancement in prehistoric craftsmanship.

NEANDERTAL SPEECH

Some argue Neandertals could not produce range of sound necessary for language.
Kebara hyoid bone suggests that Neandertals could talk.New research on Neandertal dentition also supports the hypothesis that they could speak.Genetic evidence, newly described,identified the FOX P2 gene, a gene implicated in speech production

Modern Homo sapiens

Africa: origin of our lineage (hominin),origin of our genus (Homo), origin of our species (Homo sapiens).

Evidence of anatomically modern humans comes from East Africa 200,000 YA.

Anatomies found in modern humans:

Upper Paleolithic Technology

a complex stone tool technology characterized by tools made from special stone flakes called blade sand also including tools made from antler and bone.Blade: a stone tool with a special-elongated form. Can be modified into a point. Harpoon for fish and blade

NEANDERTALS AND MODERN HUMANS

Recent genetic analysis supports the interbreeding element of the assimilation model.

Similarity between the Neandertal and non-African genomes suggests that humans interbred with Neandertals after they left Africa.

Neandertals and modern European humans may share between 1-4% of their nuclear DNA

Neandertals and modern humans from sub-Saharan Africa share 0.6% of their nuclear DNA

"Back-migration" over the last 50,000 years.8

DENISOVANS

The Denisovan genome is neither human nor Neandertal.

Limited fossil remains found in Siberia and now Tibet!

First fossil jaw of Denisovans finally puts a face on elusive humans remains.

Researchers believe the Denisovans are more closely related to Neandertals than to humans, and that they diverged from the human lineage as long ago as 700,000years.

Denisovans interbred with humans and Neandertals.

Some modern humans from Southeast Asian islands and Australia may share as much as 6% of their genome with Denisovans, and modern Tibetans have a gene (EPAS1) that has also been found in Denisovan DNA.

The replacement model

Also known as the out of Africa 2, proposes that modern human (homo sapiens) evolved exclusively in Africa and then migrated outward, replacing all other sapiens of homo in Europe and Asia with out interbreeding them.

The multi regional continuity model

proposes that modern humans evolved from an archaic population across Africa, Europe, and Asia over the past 200,000 years ago with gene flow preventing speciation and maintaining regional diversity.

The Assimilation model

model of modern human evolution proposes that homo sapiens originated in Africa and later dispersed across Eurasia, where they interbred with regional archaic human populations like Neanderthals

adaptive radiation

a rapid evolutionary process where a single ancestral species diversifies into a wide array of new forms adapted to different ecological niches

insular dwarfism

a phenomenon where large animals evolve to become smaller when their population is confined to a small environment, such as an island.

Adaptive flexibility in hominins

refers to their capacity to adjust their behavior, strategies, and potentially their physical traits in response to environmental changes and new challenges

evolutionary trends

1. Prokaryotes (Earliest Life): The first living organisms were single-celled prokaryotes.

2. Eukaryotes: Eukaryotic cells, with their membrane-bound organelles, evolved later.

3. Multicellularity: The transition from single-celled to multicelled organisms occurred in various lineages.

4. Bipedalism in Hominins: The shift to walking upright on two legs is a key evolutionary trend in the hominin lineage.
Increased Brain Size in Hominins: A trend towards larger brains is also seen in hominin evolution.

5. The Cambrian Explosion: A period of rapid diversification of animal life forms.

6. Extinction Events: Throughout the history of life, extinction events have shaped biodiversity, like the Permian and Cretaceous extinctions.

7. Emergence of Homo Sapiens: The evolution of modern humans, Homo sapiens, is a recent evolutionary event.
Migration and Speciation:

8. Continued diversification and migration of human populations, leading to the current global distribution of the human species.

key adaptive transitions related to domestication

Domestication was developed independently in regions around the globe.

Early plant and animal domesticates include rice, wheat, potatoes, maize (corn), sheep, goats, and cattle.

By about 10,000 years, many people had become dependent on newly domesticated plants and animals.

Generally, there was no going back

Causes? Unclear, but likely a variety off actors.

consequences of agriculture

Less leisure time than a foraging lifestyle.

People tend to have poorer nutrition and more diseases.

A larger population and sedentary lifestyle increases the likelihood of interpersonal conflict.

Environment: degradation, transformation,and loss of biodiversity