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Period: 110 BCE to 112
Ice Ages
2.5 million years ago to present: Ice ages were caused by cooling climates. Humans evolved from apes quickly evolved and took over the planet. -
100
The formation
4.5 to 4 billion years ago was when the Earth was formed and a large impact created the moon. During this period, the oceans were also formed. There is no official evidence of life during this time, but it could have been present. -
101
Single-celled life
4 to 2.5 billion years ago was when the earliest traces of life was found. It only existed in the oceans in the form of single-celled organisms. There was very limited oxygen supply causing organisms to learn to generate energy in other ways. -
102
Proterozoic Era
The proterozoic era occurred 2.5 to 1 billion years ago. This included the paleoproterozoic and mesoproterozoic eras which was the time where photosynthesis evolved which produced oxygen. The oxygen was able to build up in the atmosphere because of changes in the ocean chemistry. Some eukaryotes emerged like red algae, but the ocean was still predominantly microbes. -
103
Neoproterozoic era
1 billion to 541 million years ago: eukaryotes continued to diversify. Eventually, early animal lineages evolved in the ocean like sponges and cnidarians. -
104
Cambrian period
541 to 485 million years ago: Living animal lineages were becoming more diversified. Invertebrates dominated the ocean ecosystems. -
105
Plants on land
485 to 419 million years ago: Early fishes became more diverse as well as invertebrates. Plants began to grow on land, of relation to fungi. -
106
Formation of forests
419 to 358 million years ago: Plants began to form forests on land which created habitat for four-legged vertebrates and invertebrates like insects. -
107
Carboniferous Period
Swampy forests came into existence from seed plants. Amphibian-like vertebrates on land became more diverse. -
108
Mass extinctions
298 to 200 million years ago: Volcanos started to erupt causing 90% of all species to become extinct. This time period was where dinosaurs emerged and early relatives of mammals. -
109
Dinosaurs dominate
200 to 66 million years ago: Dinosaurs became the major predators and herbivores on land while marine reptiles were kings of the ocean. This welcomed the emergence of aerial predates including birds and pterosaurs. Flowering plants were being pollinated by insects and mammals were small and nocturnal. -
110
Grasslands and Mammals
66 to 2.5 million years ago: Mammals took over after the large extinction of dinosaurs. Grasslands emerged as the climate cooled and carbon dioxide levels decreased. -
111
Humans emerge
200,000 years ago homo sapiens originated.