HIST 103 Midterm

Contingency

Future events are dependent on past ones, but are themselves unpredictable

Markov Process

Events pile up in a certain way so history it goes in a certain direction, but not because it HAD to go that way, just because of the circumstances

Hydrogen

Most abundant element in the universe, simplest element made up of 1 proton, supports life

10^-43 seconds

First date in the history of the universe, universe was so hot that elements of physics were in their melted form

Planck Time

The time it takes an atom to cross the smallest unit of physical space

4 fundamental forces

Gravity, electromagnetism, strong and weak nuclear forces

Inflation

Began at 10^-35 seconds, Universe expands faster than the speed of light and forces and matter are interchangeable

Quantum Fluctuations

created energy differences in spacetime → like bubbles in a boiling pot of water, these fluctuations disturbed the homogeneity of the early universe allowed tiny pockets of mass to form, which pulled particles together to form nuclei and atoms

Cosmic Background Radiation

the entire universe is still permeated by the energy released from the initial inflation, photons have the freedom to move which creates flashes of light and radio static, discovered in 1964

Birth of Stars

Enormous clouds of hydrogen and helium (nurseries), fusion, heavier elements formed in the core of stars

Fusion

Hydrogen atoms collide and protons come together in the nucleus of the atom to form helium

First Generation Stars

Burned out very quickly, produced heavy elements, exploded with enough energy to create remaining elements

Spectroscopy

the analysis of the electromagnetic spectrum observed by their instruments to interpret the composition, distance, and speed of things in space, allows us to produce images of things we can't see with the naked eye

Iron

Most tightly packed and stable element, found in the core of stars

Galaxy formation

Protogalactic clouds drawn together by gravity, halo stars form, cloud collapses and settles into a spinning disk

Creation of our solar system

4.567 years ago a star exploded in a supernova and formed our sun, most matter was sucked into the sun, but remaining dust begins to spin around the sun and forms orbital tracks, object star colliding and heat makes them stick together

Planetesimals

Oddly shaped things in orbital tracks, building blocks of protoplanets

Theia

2 protoplanets on the same orbital track collided slightly off center, melted into each other and created the moon

The Moon

Made up of the same stuff as Earth, created wild tides on Earth which kept the Earth from hardening and created plate tectonics, stabilizes the Earth

Hadean Eon

Hell on Earth, oceans of lava, volcanos spewed CO2 that would later form the atmopshere, red sky because of CO2, planet still super hot but starting to cool

Archean Eon

Temperatures fell, so water vapor in the atmosphere fell and collected on the surface of the earth, created oceans with CRAZY tides, atmosphere was still mostly CO2 and no ozone layer

Prokaryotic Cells

Basically a floating bag for DNA, evolved to be the 1st photosynthesizers

Eukaryotic Cells

Humans are comprised of these types of cells, contain DNA, organelles, and a nucleus, started when one prokaryote absorbed another and they lived in symbiosis, first form of life to reproduce sexually instead of independently

Radiometric Dating

certain unstable atoms shed one of their particles and chooses particular isotopes of elements with different half lives, if you measure how much of these isotopes is present in the rocks, you get a sense of how old the rocks are

Definition of Life

organized structure (cells) with a boundary that protects the organism from the environment, capacity to reproduce/self replicate, stores information (genetics), metabolism and extraction processing, and catalysis of energy from the environment, composed of H2O, C, H, O, N, S, and P and organic molecules (building blocks of life on earth)

Geothermal volcanoes

Energy source where life began as “organic sludge,” and the ocean allowed for the building blocks of life to move around easily and intermingle

Mutations

Mistakes when DNA self replicates, successful mutations survive and allows life to evolve and change

Central Dogma

DNA has the information, RNA is the messenger

The Great Oxygenation Event

Photosynthesizing prokaryotes released oxygen as a byproduct of photosynthesis, too much oxygen in the atmosphere, and caused most life to die off, also created the ozone layer

Snowball Earth

The planet started to cool and the oceans froze, eukaryote survived, eventually ended when volcanoes broke through the ice and released enough CO2 to warm the planet back up

Philogenetic Tree

Darwin’s sketches of how species and life branches out like a bush

Cladogram

Diagram that depicts evolutionary relationships and how long ago species shared a common ancestor

Darwin’s Theory of Evolution

Individuals in a species differ more from one to another in domestication more than in nature (ex. dogs vs wolves), in nature, because of the scarcity of food, animals must struggle for existence, characteristics seem to be passed off from parent to offspring, this process is called natural selection → domestic selection

Bottleneck Events

Huge loss of diversity

Biggest examples: Great oxygenation event, which changed the composition of the earth’s atmosphere and oceans, Extreme climate change about 700 million years ago during the breakup of the supercontinent Rodenia (Pangea) that produced a massive ice age known as “snowball earth”

Edicrana Fauna

Earliest known multicelled fossils, complex soft and squishy organisms created rapidly, strange looking creatures and lack of predation and movement

Bilateral Symmetry

Distinct front and back of an animal, with roughly symmetrical internal organs

The Cambrian Explosion

A period of very rapid evolution, happened very quickly due to segmentation, major adaptations such as the creation of eyes, origin of vertebrates and the brain, and creation of predation

Arthropods

Distinct feature is segmentation, body parts are repeated units, that can be tweaked to perform different functions

Trilobite

Huge success, natural selection was able to repeat and modify parts of the animal

Hox Genes

Important developmental genes shared by almost all organisms, differences in these create diversity

Phanerozoic Eon

Covers metazoic life and the last 600 million years, 1/9 of the history of Earth, continuing increase in biodiversity from the Cambrian to the present

Cope’s Rule

Evolution tends to produce increasing body size, ex. horse

Carboniferous Period

Giant carboniferous trees increased the amount of oxygen in the atmosphere, firest fires were common, HUGE bugs, first reptiles evolved to live away from water

Random walk

a random process describing a path consisting of random steps through some mathematical space

Mass Extinctions

5 of them, sometimes considered to be living through the 6th one right now, associated with periods of Phanerozoic climate change (changes in sea level and oxygen levels)

Ordovician Period/Extinction

Plants on earth! created soil and increased oxygen content

Extinction: rapid cooling and sea level falling because of increased glaciers (because of increased oxygen)

Devonian Period/Extinction

Lush and tropical life on earth, first vertebrate on land (our ancestor)

Extinction: too much oxygen, dissolved oxygen shortages in water, and sea level and climate change

Permian Extinction

Greatest mass extinction of all time (95-97% of life), caused by a supervolcanic eruption and an increase in carbon dioxide, only life to survive were small mammals and reptiles

Triassic Period/Extinction

“Earth rebrand,” Saurian and mammal lineage diversifies intensely, extinction killed off early dinosaurs competition and dinosaurs thrived, increased volcanic activity

Extinction: caused by an increase in CO2 and climate change/rising sea levels

Cretaceous Period/Extinction

Dinosaurs ruled the earth, species starting giving live birth and marsupials were created, humans owe our existence to the mammals that survived the extinction

Extinction: asteroid, living things within the zone of the asteroid were vaporized, and caused a “nuclear winter” of atmospheric dust, no sunlight, and carbon dioxide

Lucy

Our oldest hominid ancestor, lived in what is now Ethiopia, and discovered in 1974, 3 ½ feet tall, but walked with an upright posture, not exactly an advanced ape or an early human but a rare mix of both

Mammal Characteristics

Production of milk, neocortex in the brain, and inner ear bones with more complex ears

Convergent evolution

unrelated species sometimes evolve similar behavioral and sometimes physical traits despite having distant ancestors because of unexpected conditions

Chimps

Most related to, share 98.4% of our DNA with them and have similar social structures

Chromosome Mutation

There are 48 pairs of chromosomes in apes, but only 46 pairs in humans, this is because a random mutation caused chromosome 2 and 3 to fuse together, lets us know we are descended from chimps

Hominids

Term for humans and our lineage

Bipedalism

Walking on two legs, effective because it freed hands for communication and the use of tools

Homo Habilis

Earliest member of the genus “homo,” small brain but still twice the size of lucy’s, had the ability to create basic tools

Homo Erectus

Found in Africa, Asia, and potentially even Europe, brains within the range of current humans, up to 6 feet tall, first hominids to migrate out of africa and all the way to indonesia

Tools

Designed for specific uses and demonstrates complex thinking, correlation between new tools and the increased intelligence that goes into making them

Pleistocene Period

Not a period with a stable climate, climate change correlates with changes in human evolution, cooling and drying of africa during this time period helped humans migrate

Neanderthals

Evolved and emerged in Eurasia, discovered in Germany and very close cousins with Homo Sapiens, evidence that they interbred with homo sapiens when they left Africa, modern humans share 1.5-2.1% of DNA with Neanderthals

Genome Sequencing

A, G, T, C is determined by breaking up DNA into smaller pieces, reading them, and reassembling them, 1977 breakthrough with Sanger sequencing, but still not helpful for 3 billion base pairs in humans

Mitochondrial DNA

Have their own DNA because of eukaryotes absorbing each other, passed only from mother to child, doesn’t change very often, so when it does it allows for us to date time periods easily, “Mitochondrial Eve” is the ancestor of all current mitochondrial DNA

Leaving Africa

Hypothesis #1 = volcanic eruption in indonesia that made the sahara desert warmer and wetter so homo sapiens could leave africa, climate had something to do with it

Birth of Agriculture

Group of humans settles by Greece in western Turkey, and migrates into Europe, another group moves from Iran into asia, also happened along the Yangtzee and Yellow rivers in China

Bering Strait Land Bridge

How humans crossed over into the Americas, remained inaccessible until the most recent ice age was over, but glaciers prevented humans from going further than Alaska

Collective Learning

The ability to accumulate more information with each generation, Homo Erectus showed first signs of this by expanding and growing their use of the axe, more people increases the potential for an innovator and connectivity

Great Migrations

First migration occurred when humans tried to leave Africa for the first time, 2nd time made it all the way to Indonesia through land bridges

Maximum Foraging Population

6-8 million people

Garden of Eden

End of the last ice age created a fertile crescent in the middle east, so foragers were able to switch to sedentary lives

Bottom Up Power

An experienced individual is appointed to settle disputes, and the entire community is affected

Top Down Power

Consent from the community is not needed because power is obtained and maintained through violence that is used against people who don’t obey

Beer

The earliest major agricultural product, and is as old as agriculture itself, helped make water safer to drink because of an increase in disease from sedentary livestyles, communal ideal

Anatolia

Where the development of agriculture began

Pastoralism

A semi-nomadic lifestyle where people move from place to place to feed animals and compliment farming

Effects of Agriculture

Changed way of life, shifted life expectancy and increased health problems, made life less flexible and increased human labor, and produced competition for real estate and created wars, slavery, and mistreatment of women, harshly effected the earth to make room for agriculture

V. Gordon Childe’s 10 Characteristics of Cities

• Increased settlement size

• Concentration of wealth

• Large scale public works

• Writing

• Representational art

• Knowledge of science and engineering

• Foreign trade 

• Full time specialists in non-subsistence activities

• Class-stratified society

• Political organization based on residence rather than kinship

Jericho

The world’s earliest walled settlement, circular structure built out of clay and mud

Sumerians

First humans to develop a written language on durable claw tablets, it was more hieroglyphic and picturesque than a writing script

Uruk

Dominant city in Sumar, ruled by King Gilgamesh, and prominent feature was the “White Temple,” was divided into neighborhoods, but not by social class

Cuneiform

Evolution from early pictograms, earliest form of writing

Hammurabi’s Code

Distributed around the empire, served as a uniform code of law for all citizens, and had minimal protections for minorities such as women