How life evolved on Earth

As said in Charles Darwin's Origin of species, Hhumans, like every other living being had its evolutionary origins from very small beginnings. Humans weren't always the way we are. Millions upon billions of years ago life didn't exist outside the Ocean.
 * 1) Molecules started to combine and form cells, and cells started to combine to create tiny living beings.
 * 2) One of the early beings were Eukaryota (although these were technically still cells) 2,100,000,000 years ago.
 * 3) Individually, those cells started evolving into separate creatures and made multicellular organisms
 * 4) The animal kingdom separated from the plant kingdom (590,000,000 years ago).
 * 5) Then came the separation between chordates and invertebrates (530,000,000 years ago).
 * 6) After that were animals with a back bone, pure vertebrates (505,000,000 years ago).
 * 7) Then came tetrapods, animals that walked on land, (395,000,000 years ago).
 * 8) Then later came mammals (220,000,000 years ago).
 * 9) Then came placental mammals (i.e. non-marsupials, 125,000,000 years ago).
 * 10) Primates came (75,000,000 years ago).
 * 11) Apes now came (28,000,000 years ago).
 * 12) Here, the great apes arrive (15,000,000 years ago).
 * 13) Humans arrive (500,000 years ago) and finally, modern humans (200,000 years ago).