Midterm Flashcards
Anthropology definition
the field of study that examines human culture and evolutionary aspects of human biology
Four Main Fields of Anthropology
cultural, linguistic, biological and archeology
Scientific method
Question, Research, Hypothesis, Experiment, Data Analysis, Conclusion, and Communication
Theories (scientific ig)
a collection of mutually consistent hypotheses that have withstood multiple trials
Charles Darwin
- First to understand the mechanism of evolution:
More offspring are born than survive to adulthood, there is competition for resources and there is variation within species - Came up with theory of natural selection
Alfred Russell Wallace
Wrote a paper suggesting species descended from other species
Described evolution as a process driven by competition & natural selection
Prompted Darwin to publish
Gregor Mendel
PRINCIPLE OF SEGREGATION
* Each trait controlled genes, which occur in pairs
* Each offspring inherits one unit from each parent
* During meiosis, the paired chromosomes separate randomly so that each sex cell receives one or
the other with equal likelihood.
* Offspring may inherit either version of
either parent’s chromosome 1 & chromosome
2 etc… with 50% chance of each
Evolution
change in allele frequencies in a population over time
Mutation
Change in DNA that may result in variation in the physical appearance of an organism (based on error in replication, or other alteration of nucleotide base sequence)
Can produce novel variation
Creates variation for natural selection to act on (beneficial or non)
Genetic Drift
Either Bottleneck or Founder
Bottleneck = Loss of genetic diversity due to drift,
usually linked to population decline (ex. natural or human-made disaster)
Founder = Change in allele frequencies in small populations that become separated from parent populations (ex. migration to a new habitat)
Gene Flow
Transfer of genes between populations
Can affect allele frequencies and introduce
new genetic variation into a population
(gene pool)
Gene flow between species – hybridization
Natural Selection
Based on concept of ‘selective breeding’ - selection of certain beneficial traits so they will be emphasized in offspring
Evolutionary fitness
A measure of how well an organism survives and reproduces in its environment
Reproduction is just as important as survival as to pass on evolutionary advantages
Species concepts
a human-made construct to categorize variation (hard to define)
an interbreeding group of plants/animals that reproduce isolated
Homology
Homological characteristics are those an organism has due to a common ancestor
Analogy
Analogous characteristics are those an organism has due to a common function
Cladistics
methods of classification that group organisms based on using shared, derived characteristics into nested groups
Phylogenetic Traits
-result of actions from many many genes
- phylogenetic tree shows the lines of evolutionary descent from species/organisms/genes from common ancestor (phylogenetic species grouped by ancestor/descendant)
-slow evolution
Slow form of evolution
Phylogenetic gradualism
Incremental evolutionary change
Fast form of evolution
Punctual equilibrium
Bursts of change before status
Race
An ideological construct and biological differences
Race isn’t a biological division between humans however
Race was created with the idea that human variation can be categorized
Biological concept of race: those classifications are
based on our biology and are therefore immutable
Social concept of race: classifications are based on
our social identities and can include more than our
biology
Bergmann’s rule (1847)
- Body mass greater in populations living in colder climates
- Lost heat = lost energy, so being big is advantageous in cold environments
Allen’s rule (1877)
- Colder climates = shorter appendages
- Warmer climates = longer appendages
Evolutionary reasons for skin color variation
Light skin in cold weather allows for Vitamin D production (prevents rickets (misshapen and weak legs))
Dark skin in warm weather protects against sun’s UV rays (which causes mutations in skin cell DNA)
Melanin protects skin cells from UV damage by covering the nucleus, more melanin needed for more sun
Patterning of genetic variation within/between populations
Genetic variation is largely environmentally based, unlike D.N.A.
Epigenetic variation can be attributed to local factors
Genetic variation is a result of evolutionary, historic, and
ongoing social, political, economic, and other cultural processes (e.g., migration, segregation, cultural mate preferences) that influence population structure
– e.g. lingering effects of residential segregation
affect racial composition of different
neighborhoods across major cities in the US
85% of total variation in the world was present WITHIN local groups
Cline
a gradual change in the frequency of genotypes
and phenotypes from one geographic region to another (such as nose shape or skin color)
Characteristics of primates and major primate groups (including humans)
All primates have two front facing eyes, trichromatic color visions, de-emphasis on olfaction (smell) from reduced snouts, large cerebral cortex, body hair, five digits in the hand & foot (pentadactyly), nails rather than claws, single pair of mammary
Primate social organization and behavior
Characteristics of primate social groups:
- Size
- Composition (age, gender etc.)
- Social interaction
- Mating system
- Ranging behavior (movement)
- Dispersal patterns (sex that moves to a new group to reproduce)
Benefits of group living
– Finding food (more eyes, faster searching)
- Shared information
- Cooperate in hunting and defense
- Predator avoidance
- Social benefits (easier learning, mate finding, childcare)
Hierarchies are established and give priority to the strongest
Primates show evidence of cultural acts (tool use generationally etc.)
Primates can communicate vocally, visually, olfary (scent) and tactile
Primate reproductive strategies (males and females)
Males focus on gaining access to receptive females
Females focus on obtaining food to sustain babies, may secretly reproduce with males not from their group if there are healthier options
Polyandry
when there is only one breeding female who mates with all the adult males
Fission
when key resources are scarce and individuals spread out
Fussion
when resources are plentiful and individuals travel and feed as a more cohesive group
Dating methods 💏
Divided into RELATIVE (dividing tools into Stone, Bronze and Iron Age and seeing which is the oldest from there) and CHROMATIC/ABLSOULTE (specific dates)
Catarrhines
– Downward facing nostrils
– 2 premolars
– Tubular ear
– All diurnal
– Arboreal or terrestrial
– Social systems & diet vary between species
Platyrrhines
– Small bodied (a few ounces to 25 lbs)
– Flat nose with sideways facing nostrils
– 3 premolars
– Ring-like ear (ancestral)
– Some have prehensile tails (evolved twice!)
– All diurnal except for Aotus (owl monkey)
– Arboreal (almost exclusively)
– Social systems & diet vary between species
– Often referred to as “New World monkeys”
- Divided into small bodied and large bodied
Strepsirhines
- Moist nose
- Unfused mandible (chin bone)
- Split upper lip
- High emphasis on smell
- Grooming claw (second toe of foot)
- Ring like external ear bone
- Taperum lucidim (reflective layer in eye)
- Tooth comb (lower canine)
Haplorhines
- Larger brains relative to body than Strepsirhines
- Tarsiers, monkeys and apes
– Greater orbital frontality
– Cranial blood flow through promontory artery
– No naked rhinarium (continuous upper lip)
– No tapetum lucidum (reflective layer in eye) - More complex behaviors & social relationships
Hominoids
- All apes, including humans!
- Gibbons, siamangs, orangutans, gorillas, chimpanzees, bonobos and humans
- No tail
- Broad shallow rib cage
- Large brain
- Old age at first reproduction and long time between births
- Small litter sizes
- Long infant dependency
Cross-dating
relative dating method that estimates age based on artifacts’ similarities with comparable materials from dated contexts elsewhere
Biostratigraphy (faunal correlation)
relative dating method based on known evolutionary changes that occurred in particular groups of animals, or the presence or absence of particular species
Potassium-argon dating
examines radioactive decay of potassium isotope
used on sediments that have been superheated (usually volcanic deposits)
used to date materials in the 1- to 5- million-
year range, especially in East Africa
Radiocarbon dating
Chronometric dating method that accurately dates organic materials/fossils up to 55,000 years old
It is the most widely used chronometric dating method
Archaeology
a body of methods designed to understand the
human past through the examination and study of
its material remains
Anthropological archaeology
the application of archaeological methods to the understanding of the origins and diversity of modern humans in all times and places, their cultures, and cultural change
Material culture
the physical manifestation of human activities, such as tools, art, and structures
Eastern African Rift Valley sites
- Hadar, Ethiopia
- Laetoli, Tanzania
- Malapa, South Africa
Hadar, Ethiopia and Laetoli, Tanzania
Lucy (in Hadar) and other Australopithecus afarensis bones plus footprints found from 3.9-2.9 million years ago
Malapa, South Africa
Site of Cradle of Humankind, with a high quantity of ancient human remains
Australopithecus africanus and Tuang child (4-year-old hominim) and other bones from 3.3-2 million years ago
Hominims
a member of the tribe Hominini (the group to which modern humans belong)
ALL ARE HABITUALLY BIPEDAL
* smaller canines
* thick tooth enamel
* vertical face
Adaptations for bipedalism
- The vertebral column becomes centered directly beneath the skull to center gravity upright
- The pelvis becomes broad and bowl shaped to support weight of upper body in upright position
- The knee joints have a carrying or vulgus angle
- The big toe is adducted for the push off while walking
Early hominim stone tool use
Oldowan tools
Earliest found from 3.3 million years ago years ago in Turkana, Kenya, likely used by Homo habilis
Planning and stone transportation involved
Likely organic tools used but didn’t fossilize
Core
The piece of stone or fragment found in nature
Knapping
striking and crafting something out of something else
Taphonomy
study of the processes that affect animal and plant remains from when it died and became a fossil
