UNIT ONE DAY TWO: Prehistoric Eras

ELE (Extinction Level Event):

An extinction event (also known as a mass extinction or biotic crisis) is a widespread and rapid decrease in the biodiversity on Earth. Such an event is identified by a sharp fall in the diversity and abundance of multicellular organisms. It occurs when the rate of extinction increases with respect to the background extinction rate and the rate of speciation. Estimates of the number of major mass extinctions in the last 540 million years range from as few as five to more than twenty.

Era:

An era is the second largest geochronologic time unit and is equivalent to a chronostratigraphic erathem. There are ten defined eras: the Eoarchean, Paleoarchean, Mesoarchean, Neoarchean, Paleoproterozoic, Mesoproterozoic, Neoproterozoic, Paleozoic, Mesozoic and Cenozoic, with none from the Hadean eon.

The "Big Bang" (theory):

The Big Bang was the initiation of the continuing expansion of the universe from a state of high density and temperature (its central singularity). It was first proposed as a physical theory in 1931 by Roman Catholic priest and physicist Georges Lemaître when he suggested the universe emerged from a "primeval atom".

Cretaceous (Period)

Is a geological period that lasted from about 145 to 66 million years ago. It is the third and final period of the Mesozoic Era, as well as the longest. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now-extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. Click on the pic to the left to learn more!

Eon:

An eon is the largest geochronologic time unit and is equivalent to a chronostratigraphic eonothem. There are four formally defined eons: the Hadean, Archean, Proterozoic and Phanerozoic.

Holocene:

Is the current geological epoch, beginning approximately 11,700 years ago. The Holocene corresponds with the rapid proliferation, growth, and impacts of the human species worldwide, including all of its written history, technological revolutions, development of major civilizations, and overall significant transition towards urban living in the present.

Jurassic (period):

The Jurassic is a geologic period and stratigraphic system that spanned from the end of the Triassic Period 201.4 million years ago (Mya) to the beginning of the Cretaceous Period, approximately 145 Mya. By the beginning of the Jurassic, the supercontinent Pangaea had begun rifting into two landmasses: Laurasia to the north and Gondwana to the south. Click on the picture to the left to learn more!

Pleistocene (epoch):

Often referred to colloquially as the "Ice Age," it is the geological epoch that lasted from c. 2.58 million to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology Click on the picture to the left to learn more!

Triassic (period):

The Triassic is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic.

Epoch:

Is the second smallest geochronologic unit. It is equivalent to a chronostratigraphic series. There are 37 defined epochs and one informal one. There are also 11 subepochs which are all within the Neogene and Quaternary.

UNIT ONE DAY THREE: Early Humans

Hominids/Hominins:

The family Hominidae whose members are known as the great apes or hominids are a taxonomic family of primates that includes eight extant species in four genera: Pongo (the Bornean, Sumatran and Tapanuli orangutan); Gorilla (the eastern and western gorilla); Pan (the chimpanzee and the bonobo); and Homo, of which only modern humans (Homo sapiens) remain.

Homo Sapiens:

Or modern humans, are the most common and widespread species of primate, and the last surviving species of the genus Homo. They are great apes characterized by their hairlessness, bipedalism, and high intelligence. Humans have large brains, enabling more advanced cognitive skills that enable them to thrive and adapt in varied environments, develop highly complex tools, and form complex social structures and civilizations. Click on the picture to the left to learn more!

Hunter/Gatherers:

A hunter-gatherer or forager is a human living in a community, or according to an ancestrally derived lifestyle, in which most or all food is obtained by foraging, that is, by gathering food from local naturally occurring sources, especially edible wild plants but also insects, fungi, honey, bird eggs, or anything safe to eat, and/or by hunting game (pursuing and/or trapping and killing wild animals, including catching fish). Hunter-gatherer societies stand in contrast to the more sedentary agricultural societies, which rely mainly on cultivating crops and raising domesticated animals for food production.

Hunter/Gatherers:

A hunter-gatherer or forager is a human living in a community, or according to an ancestrally derived lifestyle, in which most or all food is obtained by foraging, that is, by gathering food from local naturally occurring sources, especially edible wild plants but also insects, fungi, honey, bird eggs, or anything safe to eat, and/or by hunting game (pursuing and/or trapping and killing wild animals, including catching fish). Hunter-gatherer societies stand in contrast to the more sedentary agricultural societies, which rely mainly on cultivating crops and raising domesticated animals for food production. Click on the picture on the left to learn more!

Neanderthals:

Homo neanderthalensis, lived in Europe and Asia from 400,000 to about 28,000 years ago. There are a number of clear anatomical differences between anatomically modern humans (AMH) and Neanderthal specimens, many relating to the superior Neanderthal adaptation to cold environments. Neanderthal surface to volume ratio was even lower than that among modern Inuit populations, indicating superior retention of body heat. Neanderthals also had significantly larger brains. The larger size of the Neanderthal orbital chamber and occipital lobe suggests that they had a better visual acuity than modern humans, useful in the dimmer light of glacial Europe. Neanderthals may have had less brain capacity available for social functions.

"Out of Africa" theory:

Is the most widely accepted model of the geographic origin and early migration of anatomically modern humans (Homo sapiens). It follows the early expansions of hominins out of Africa, accomplished by Homo erectus and then Homo neanderthalensis. H. sapiens most likely developed in the Horn of Africa between 300,000 and 200,000 years ago. There were at least several "out-of-Africa" dispersals of modern humans, possibly beginning as early as 270,000 years ago. There is evidence that modern humans had reached China around 80,000 years ago.

AGES -- The Stone Age:

Also called the Paleolithic Era, is a period in human prehistory that is distinguished by the original development of stone tools, and which represents almost the entire period of human prehistoric technology. It extends from the earliest known use of stone tools by hominins, c. 3.3 million years ago, to the end of the Pleistocene, c. 11,650. Click on the picture to the left to learn more!

AGES - The Bronze Age:

The Bronze Age is a historical period lasting from approximately 3300 to 1200 BC. It is characterized by the use of bronze, the use of writing in some areas, and other features of early urban civilization. The Bronze Age is the middle principal period of the three-age system, between the Stone and Iron Ages. The periodisation of the Bronze Age is generally ended with the Late Bronze Age collapse, a time of widespread societal collapse between c. 1200 and 1150 BC. Click on the picture to the left to learn more!

AGES - The Iron Age:

The Iron Age is the final epoch of the three historical Metal Ages, after the Chalcolithic and Bronze Age .Although meteoric iron has been used for millennia in many regions, the beginning of the Iron Age is defined locally around the world by archaeological convention when the production of smelted iron (especially steel tools and weapons) replaces their bronze equivalents in common use. Only with the capability of the production of carbon steel does ferrous metallurgy result in tools or weapons that are harder and lighter than bronze. Click on the picture to the left to learn more!