-
Happens between 5-7 million years ago. Humans were thought to originate from Africa. They mostly likely evolved from some ape like creature that was able to walk on two legs.
-
About 65 million years ago, (at the end of the Cretaceous Period).
There are several different theories as to how this event happened. Such as, climatic change, diseases, meteors impacting earth, eruptions with volcanoes, etc. could all have played a role. -
270 million years ago.
Plate tectonics were mostly to blame for this separation. Pangea did not break apart all at once but rather fragmented in different stages. Plate tectonics also bring the assumption that the continents joined with one another and broke apart several times in Earth’s geologic history. -
Been nicknamed The Great Dying, since a staggering 96% of marine species died out. Many causes have been proposed for the event: asteroid impact, a drop in oxygen levels, sea level fluctuations or some combination of these.
-
Happens about 600 million years ago. Thought to happen from cell division of unicellular organisms or by aggregation of many single cells.
-
Affected marine communities the most by far, causing the extinction of most of the marine invertebrates of the time. Reefs didn't reappear for about 10 million years, the greatest hiatus in reef building in all of Earth history
-
Happened about 480 million years ago.
This theory was created by Alfred Wegener. Pangea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. Was a gradual process that occurred because of the Continental drift. -
1.5 billion years ago.
Because of eukaryotic cells seem structurally far more complex than their prokaryotic counterparts, evolutionary steps must have separated the two. The development was gradual. -
3.8 billion years ago. The first organism is thought to come from fossilized mats of cyanobacteria called stromatolites that originated from modern day Australia. However, they were already biologically complex—they have cell walls protecting their protein-producing DNA, so scientists think life must have begun much earlier.
-
Around 3.5 million years ago. A popular belief to how this occurred is "...believe the amount of atmospheric oxygen was insignificant up until about 2.4 billion years ago when the Great Oxidation Event (GOE) occurred."(Michael Schirber)
-
about 4.54 billion years ago
Gravity collapsed the material in on itself as it began to spin, forming the sun in the center of the nebula. Once this occurred, remaining material began to clump up. Lighter ones were blown away, and the ones that remain were heavy, rocky materials to create smaller terrestrial worlds like Earth. -
Occurred around 4.6 billion years ago.
A collision occured between two planetary bodies. Such an impact between the Earth and a Mars-sized object was what likely formed the Moon. -
Occured around 13.7 billion years ago.This cosmic explosion marked the beginning of the universe
