Geological Time Scale:

The organization of earth history into eras, periods and epochs; commonly used by geologists and paleoanthropologists. (Focusing on Cenozoic era, and the series and epochs in that one.)

Paleocene:

65-54 mya
1st primate-like mammals
Plesiadapiformes, purgatorius

Eocene:

POMA (primates of modern aspect)
Prosimian-like Adapids and Omomyids

Oligocene:

34-23 mya
Begin to see the ancestors of modern hominoids (apes, humans and our ancestors)
Aegyptopithecus (Found in Egypt)

Miocene

23-5 mya
Origin of hominids (modern or extinct bipedal primates of the family Hominidae) (Origin of the homo genes)
Golden Age of the Apes
Proconsul

Pliocene

5-1.7 mya
Adaptive radiation of hominids
Origin of the genus Homo

Pleistocene:

1.7-10,000
“Ice Age”
Evolution of the genus Homo

Holocene

10,000-present

Continental Drift: The movements of the continents on sliding plates of the earth’s surface. As a result, the positions of large land masses have severely shifted during time.

Late Paleozoic: continents came together and formed one large landmass called Pangea
Early Mesozoic:

Gondwanaland (southern)
Laurasia (northern)

Late Mesozoic: continents began to assume their current positions, animals became isolated

Mammalian Evolution

Mesozoic: dominated by reptiles
The Cenozoic: “The Age of the mammals”
Why such rapid succes?

Larger brains
Internal development (long-term)
Variation of dentition (heterodont dentition)
Maintenance of a constant internal body temperature

PALEOCENE:

65-54 mya
Sub-tropical climate near the equator
Worldwide warm temperatures
1st primate-like mammals
Plesiadapiforms (families): they resemble a lot of our modern strepsirhines

Plesiadapidae
Carpolestidae
Purgatorius

EOCENE:

54-34 mya
Ida: considered to be the missing link between the haplorhines and strepsirrhines. Thought to be an arboreal quadruped. Has an opposable toe, the same as chimps. Supposedly 47 mya

POMA:

Primates of Modern Aspect
Euprimates:

Adapidae (adapids): Notharctus (2:1:4:3) and Teilhardina

The “Big Cut”

Massive Extinction in marine and land animals
Tropical climate ---> Dry climates
10 million years forest changed to plains

OLIGOCENE:

Aegyptopithecus: Arboreal quadruped: bridges the gap between eocene fossils and the miocene fossils.
Comparison of Bilophodont Molars: bilophodont molars as found in cercopithecoids and Y-5 molars as seen in hominoids

MIOCENE

Golden age of hominoids (apes)
Divided into 3 periods:

Early: 25-20 mya
Mid: 19-11 mya
Late: 10-5 mya

Major changes in climate
Proconsul: belongs to the early Miocene (2:1:2:3)--arboreal quadruped.

Considered to be the ancestor of apes and humans
Different from Aegyptopithecus: Proconsul is new world monkeys and Aegyptopithecus is Old world monkeys

Kenyapithecus: belongs to mid Miocene

likely ancestral to modern apes

Sivapithecus: Late Miocene
Gigantopithecus: Largest known apes that ever lived (10 ft tall) (transition from Miocene to the Pleistocene.

LANEY’S NOTES FROM 3/1/16

HOMININ EVOLUTION I

www.becomoinghuman.org

Is there a missing link?

Missing Link: a fossil that exhibits traits common to both an ancestral group and its derived descendants

Example: fossil linking modern humans to a primate ancestor

THERE IS NO MISSING LINK! It would be a constantly moving target. It is dependent upon currently existing forms.
We DO have Last common ancestors

Terminology:

Distinctive hominid characteristics include:

Bipedal locomotion
Large Brain size
Tool making behavior (later in time)

Mosaic Evolution: A pattern of evolution in which the rates of evolution in one functional system vary from those around it.

Paleoanthropology: The study of early humans

It is a diverse multidisciplinary pursuit seeking to reconstruct every bit of information possible concerning the dating, anatomy, behavior, and ecology of our hominid ancestors.

----------------------------------

The Messinian Crisis:

Occurs during the Miocene around 5.9 mya
Cooling and drying trend
The Mediterranean Sea went to nearly complete desiccation and became a salt basin
What African apes made it through the Miocene?

Kenyapithecus likely ancestor to African apes

Why did the monkeys survive?

They are small, their diet is much more efficient. (rely on less food)

Gorillas made it through:

Large body size
Eat leaves, foliage,
Metabolism is lower, can subsist on lower quality food

Chimpanzees

Diverse Diet (50% of diet is fruit, Benefit of Suspension)

Humans

Thicker Enamel (thicker than Kenyapithecus)
Adapted to eating terrestrial hard foods
Bipedalism

Why become a biped?

Cool breezes
High off the ground

Bipedalism:

Many anatomical adaptations:

Feet (non divergent toe, aligned with the rest of our toes)
Lower Limbs (valgus knee): your knee is fully extendable
Pelvis
Spine
Skull
Upper limbs

Facultative Bipedalism vs. Obligate Bipedalism

Facultative: Using Bipedalism with other types of locomotion
Obligate Bipedalism: Using Bipedalism only because it prefers it.

4-8 mya Gap

LUkeino molar (KNM-LU335)--6 mya, lower M1 or M2
Kanapoi (KNM-KP271) --Partial distal humerus
Lothagam--5.5 mya, Right portion of mandible
Tabarin (KNM-TH13150)--5 mya -Mandible (2 complete molars)

Pre-Australopiths:

MID-90’S, more fossils **MUST REMEMBER THESE**

Australopithecus ramidus → Ardipithecus ramidus

17 fossils
4.4mya
Middle Awash region in Ethiopia (East Africa)

110 Specimens: 36 individuals

Ardi:

Had thin enamel
Was a Facultative
LCA of apes and hominids?
Pre-australopith

Other Possible LCA (pre-australopiths)

Orrorin tugenensis

Discovered in 2002
6 mya
13 fossils (minimum of 5 individuals)
Postcrania looks more hominin than ape

Sahelanthropus tchadensis

Discovered in 2002
6-7 mya
Djurab desert (modern day Chad)

Australopiths

Anatomically similar to modern humans, but their heads were significantly different from ours
Adult brain size was about ⅓ that of people today
Widest part of their skull was below the brain
Big teeth, thick enamel, large jaws, and powerful jaw muscles
Early hominid faces were concave or dish-shaped
6 species of Australopiths
Australopithecines are put into two groups:

1. Gracile (“slender”)
2. Robust (muscular)

Main differences are found in the dental anatomy.
Robust forms: bigger grinding teeth, more robust jaws, more bulky chewing muscles and muscle attachments.

Australopithecus anamensis (Early Gracile)

May have been the earliest australopithecine species
4.2-3.9 mya in East Africa
Due to the scarcity of fossils and because they are highly fragmentary, little is known about them
Australopithecus Afarensis: 2 major sites:

Hadar, Ethiopia

AL 288-1 (Lucy)

Discovered in 1973
3.18 mya

Laetoli, Tanzania

LH4 (single mandible; 3.4-3.76 mya)

Lucy, AL 288-1

Discovered in 1971
40% complete skeleton
3.2 million Years old
Transitional species
2 hypotheses concerning locomotion:

Obligate, Terrestrial Biped: proposed by Lovejoy and Latimer

Short Pelvis
Valgus Knee
Flare of hips (smaller outlet)

Biped, retained arboreality: proposed by Stern, Susman and Jungers

Bent-Hip, Bent-knee biped that retained significant arboreality

Who is right?

Ward (2002)
Compared humeral-femoral index to 18 pygmies and bonobos (chimp)

Humurs/femur X100
Bonobos h-f index: 97.8
Pygmies h-f index 73.7
Lucy h-f index: 85

Australopithecus afarensis (Early Gracile)

slender curved fingers (grasping)
Canine teeth were large and pointed
Small brain size (375-500 cc)
Valgus knee
Short, curved ilium
Posterior sagittal crest
Flat cranial base
Parallel tooth rows

Australopithecus africanus

3-2.5 mya
South African Australopithecine

Dates using biostratigraphy
Pig used as a marker fossil
1st Australopithecine
The Taung child
Discovered in 1924 in S. Africa
2.5 mya
Raymond Dart found it.

Raymond Dart claimed:

1925: Nature; Dart claimed fossil represented missing link between human and ape
Australopithecus africanus
Immediate criticism
Eoanthropus dawsonii (1912)--was a fraud
Australopithecus africanus had reduced proganthism
Crowding in front teeth
Reduction in canine size
Parallel teeth rows

Australopithecus aethiopicus (Robust)

The late australopithecines (robust) had larger jaws accompanied by pronounced sagittal crests
Called the black skull (KNM-WT 17000)
Discovered in 1985
2.5 mya
Only found in East AFrica
Thought to be a transitional form from one of the gracile species that came before

Primitive vs. Derived traits in Robust forms:

Large incisors (derived)
Sagittal crest (derived)
Broad face (Derived)
Prognathism (Ancestral)
Small brain (400cc) (Ancestral)

Australopithecus robustus (Robust)

Molarization of premolars = reduction in anterior teeth (this is unique to robustus)

Australopithecus boisei

Super-robust East AFrican species
2-1 mya
OH 5
Male number: KNM-ER 406
Female: KNM-ER 732 (still very small brains)
- The ice age
- Glaciations enveloped huge areas of europe, asia, and North America
- Divided into three species
Pleistocene fossils
- Middle pleistocene: H. heidelbergensis (or archaic H. Sapiens)
- Late Pleistocene: H. Neanderthalensis
African H. Heidelbergensis (middle Pleistocene)
- Kabwe, zambia
- 200 kya
- Complete crania
European h. Heidelbergensis
- Atapuerca 5
- Spain
- 300 kya
- 1125 cc
- Low, sloping forehead
- Early evidence of neandertal ancestry
- Big nose
Asian h. Heidelbergensis
- Primitive and derived traits
- The dali skull
- 230-180 k
- China
- Most complete skull of middle or late pleistocene fossils in china
- 1120 cc
- Pronounced brow ridge is primitive
- Wide nasal opening is derived
Neandertals
- 1st d. In 1829
- “Neander” “Thal” (neander valley
- Neanderthal vs. neandertal
LA Chappelle Aux Saints
- D. in 1908
- La Chappelle, France
- Approximately 40 at age of death
- 1620 cc
- Marcellin Boule 1st described fossil
La Ferasie
- Teeth worn out, could be using teeth to crack things, use them as tools
Neandertal morphology
- Average brain size = 1400 cc
- Occipital bun
- Pre-lambdoid flattening shoveled incisors
- Low, sloping forehead
Neandertal morphology
- Very robust
- Thick cortical bone
- Males: 5.5 feet, Females: 5 feet
- Broad chested (barrel Shaped)
- stocky
- More area to volume=much heat loss
- Less area to volume
Mousterian technology
- Associated with archaic H. sapiens (H. heidelbergensis) and Neandertals
- Levallois technique
- Involved specially preparing a core in order to remove fakes of a predetermined size and shape
- Appears first during the later archaic stages but it's the neandertals that improve the levallois technique
Subsistence
- Hunting has become a critically important part of the diet
- High levels of carbons and nitrogen in neandertal bone confirms that up to 85% of their diet was meat
- Cooperative hunting
Origins of modern homo sapiens

2 hypotheses
- Replacement hypothesis: “out of africa”. Recent speciation event constrained in time and space. No interbreeding occurred
- Multiregional hypothesis: modern humans at least in part descended from their archaic regional predecessors in the OW. interbreeding occurred
Lagar velho skeleton (portugal
- 4 year old
- Chin
- No H-O foramen
- thick , arctic-like bones
- Problems? Only 1 skeleton
MTDNA evidence
- Krings et al. (1997): 1st isolated mtDNA from neandertal
- MISMATCHES=25
- Krings et al. (1999)
- MISMATCHES between subspecies of chimps
- Green et al. (2010)
- 1-4% admixture in europeans and asians
Upper paleolithic revolution
- Amh first emerged=100000 years ago, but no change in lifestyle for 60,000 years
- Upper paleolithic revolution (40,000)
- New materials (bone ivory, and antler)
- Aesthetic appreciation?
- Most advanced state is the magdalenian tools:
- Spear throwers (atlatl)
- Barbed harpoons (spears for fish)
- Bow and arrow
- Symbolic representations (art) become more prominent:
- Cave paintings sculptures
- Engravings
- Venus figurines
Upper Paleolithic
- No question of “purposeful” burials
AMH vs. Archaic and Neandertal skulls
- Small faces with the first appearance of chins
- Smaller teeth and jaws
- Rounded skulls with vertical foreheads
Human variation and adaptation
- Adaptation: one way that humans meet the challenges of the environment (aka natural selection)
- According to environmental stresses, humans can go through physiological and growth adjustments (essentially adapting)
- How do we study genes that govern adaptive traits?
- Human genome: 2003
- SNPs or Single nucleotide polymorphisms
- Homeostasis: a condition of balance (stability); maintained by physiological mechanisms that compensate for changes
- Sweating
- Pigmented skin
- Acclimatization: physiological responses to changes in the environment that occur during an individual's lifetime.
- Short term, long term, or permanent
- Example: tanning
- Developmental acclimatization: irreversible physiological changes that occur during growth and development due to an environmental challenge
Historical views
- First physical difference of humans to be explained was skin color
- 1350 b.c.: ancient egyptians classified humans according to skin color
- Linnaeus’ taxonomic classification
- Blumenbach’s taxonomic classification
- Biological determinism: the concept that phenomena, including various aspects of behavior are governed by biological factors
- Who was proposing these ideas?
- Eugenics: the philosophy of “race improvement” through the forced sterilization of members of some groups and increased reproduction among others
- Biological determinism and eugenics lasted until the 1930’s when darwin’s theory was combined with genetics
- Anthropologists began to view human variation according to darwin’s theory of natural selection
- Race: refers to geographically patterned phenotypic variation within a species
- Is a race a biological (genetically based) entity?
Richard lewontin
- Variation within a population
- Variation between populations
- “The amount of genetic variation accounted for by differences between groups is vastly exceeded by the variation that exists within groups”
Skin color
- Hemoglobin
- Carotene
- Melanin pigment
- A granular substance produced by specialized cells (melanocytes) found in the epidermis
- A tan is a temporary increase in melanin production (acclimatization)
Evolution of skin color
- Jablonski & Chaplin, 2000
- Skin + ultraviolet light + vitamins
- 2 mya early members of genus homo started moving from cool forests to open plains to find food
- Individuals born with less hair had a survival advantage
- Moving to a sunnier environment meant great exposure to UV light
- Melanin shields folate from the effects of UV light
- Folate: B vitamin produced in the dermis and epidermis, can be replenished through diet: important for proper cell division, key for proper growth in utero, and during infancy. In children and adults is important to produce healthy red blood cells and to prevent anemia
- Vitamin D: is made naturally in the body when UV sunlight hits the skin.
- Vitamin D is key for building strong bones, for a strong immune system, for cell proliferation and for an adequate functioning of the brain, heart and pancreas
- Those with less melanin could still produce vitamin D in environments with less sunlight. This is also safe in areas of high altitude because UV light is not strong enough to damage folate. problem=when they live in tropical areas with high exposure to sunlight. Skin cancer (b/c folate helps to prevent it)
- Skin color is a simple adaptation to 2 conflicting selective forces:
- Protection from overexposure to UV rays
- Adequate UV exposure
Adaptation to altitude
- Mechanisms that have evolved to maintain homeostasis evolved at lower altitudes
- High altitude environment = stress on the body
- Hypoxia: body is deprived of adequate oxygen supply
- People of tibet
- Live at 12,000 + feet
- 7,000-25,000 years of occupation at these altitudes
- Proof that natural selection (given enough time) will increase frequency of advantageous traits
- Just for comparison: knoxville (886 ft)
Antimicrobial resistance
- Since the 20th century, antimicrobial products reduced the threat posed by infectious diseases
- These “wonder drugs” (combined with improvements in sanitation, housing, and nutrition) has decreased deaths from diseases that were previously widespread, untreatable, and frequently fatal
Conclusions
- Genetics bring about human variation: gene flow, mutation
- environment /culture brings about human variation: sickle-cell anemia and antimicrobial resistance
- geography/physiological stresses bring about human variation: skin pigmentation, developmental acclimitization in high altitudes
5 April 2016

The Human Life Course

Introduction
- Genetics will always prevail over cultural influences
- Some genetically determined things can be influenced by culture
- Stature
- weight
Key terms
- Growth: increase in mass or number of cells
- Can be a type of development
- Development: differentiation of cells into types of tissues and their maturation
Examples of development
- Molar development, cells formed for vision purposes, epiphyses fuse in long bones
- All of these examples occur because of cell differentiation
Growth
- Begins at conception and ends in early 20’s
- 3 crucial growth periods: 1. First 6 months in utero., 2. From birth to 4 years of age., 3. Puberty
- Adolescent growth spurt
- Differs between girls and boys
Growth and development
- Brain development occurs in stages:
- 0-10 months (neurons develop)
- Birth to 6 years (voluntary movement, reasoning perception, frontal lobes development)
- 7 to 22 years (brain at 95% full brain size, prefrontal cortex or impulses and decision making development)
- Most mammalian species: at least 50% of its adult brain size prior to birth
- Why? (Rosenberg and Trevathan, 2001)
- Factors that influence growth and development:
- Nutrition (most important)
- Genetics (polygenic traits)
- Hormones
- Environmental factors
Nutrition
- Nutrition is the most important factor in healthy growth and development
- In utero nutrition (most important for 2 reasons)
- Our evolutionary history contributed to our nutritional requirements
- Because of culture, our evolutionary advantages are now becoming disadvantages
- Our ability to store fat
- Type 2 diabetes
- In the past, it only occurred in older individuals living in the developed world
- By 2025, predicted that 70% of cases will be in developing nations (WHO)
- Also affecting the younger people
Hormones
- 2 important hormones for growth and development:
- 1). Growth hormone: promotes growth and affects all other body cells
- 2). Insulin: affects metabolism and glucose levels. Helps
Environment
- Altitude and climate can impact growth and development
- Exposure to sunlight: vitamin D is necessary for proper skeletal growth (rickets)
- Infectious disease: if during childhood it can often delay growth
Feral Children
- Genie: found in 1970, 13 years old, 59 pounds and 54 inches tall
- Many case studies conducted on the growth and development of feral children
Pregnancy birth and infancy
- Pregnancy is different according to cultural influences
- Who can get pregnant, when, and with whom?
- Once pregnant, what should the women eat, what should she do or not do?
- Infancy is the period when nursing takes place (4 years of nursing is the norm)
- What is the evolutionary advantage to breastfeeding? (protects their immune system, less likely to ovulate)
Childhood
Childhood: the time between weaning and puberty when the brain is completing its growth and the acquisition of technical and social

	Criado por Nilah Newberry mais de 8 anos atrás

HO exam gunna bee HARD

Human Origins Study Notes