Years Ago: Event

4.55 billion: Origin of the earth as a small portion of the sun
3.8–3.0 bn: Its cooling and origin of unicellular creatures
3.0–2.0 bn: Birth of blue-green algae, bacteria and oxygen
500 million: Jawless fish, wingless insects, ozone layer
400–300 m: Insects, fish, frogs, reptiles, land plants
200–150 m: Birds, mammals, dinosaurs, flowers
100–10 m: Whales, monkeys, chimpanzees
02–01 m: Homo erectus, stone tools, use of fire
400–200 K: Modern human, invention of axe and hearth
100 K: Invention of language, burials and sacrifices
100–50 K: Priests, elaborate burials, ornaments, herbs
30 K: The last Ice Age, leather, footwear, huts with hearths
25 K: Idols of goddesses, cave art, jewellery, ropes, knives
10 K: End of the Ice Age, explosion of human population
10–8 K: Agriculture, domestication, bow-arrow, canoe, pottery, villages
8–5 K: Towns, civilizations, sun temples, magic, alcohol
6–4 K: Writing, legal code, bricks, clothes, copper, wheel, phallus worship, library, goddesses
5–3.5 K: Hinduism, Rig Veda, iron, population explosion
3.5–2.5 K: Judaism, Jewish Bible, monotheism, cities, infectious diseases e.g. plague, cholera, TB, typhoid
2.5–2 K: The Buddha, democracy, Hippocrates, Socrates, Plato, Epicurus, philosophy, money, Ramayana, Mahabharata
2–1.5 K: Jesus Christ, Christian Bible, paper, clock, compass
1.5–1.0 K: Prophet Muhammad, Islam, Koran, crop rotation, gunpowder
500: Printing press by Gutenberg
350: Galileo invents microscope and rotation of the earth.
150: Louis Pasteur discovers that microbes are causing infectious diseases.
80: Alexander Fleming discovers first antibiotic Penicillin.