article_snippet.sent: 55 million years ago - First primitive primates evolve .
article_snippet.sent: 15 million years ago - Hominidae (great apes) evolve from the ancestors of the gibbon .
article_snippet.sent: 8 million years ago - First gorillas evolve.
article_snippet.sent: 5.5 million years ago - Ardipithecus, early ‘proto-human’ shares traits with chimps and gorillas . 4 million years ago - Australopithecines appeared.
article_snippet.sent: 2.8 million years ago - LD 350-1 appeared and may be the first of the Homo family .
article_snippet.sent: 2.7 million years ago 
article_snippet.sent: 2.3 million years ago - Homo habalis first thought to have appeared in Africa .
article_snippet.sent: 1.8 million years ago - Homo ergaster begins to appear in fossil record .
article_snippet.sent: 800,000 years ago - Early humans control fire and create hearths.
article_snippet.sent: 400,000 years ago - Neanderthals first begin to appear and spread across Europe and Asia .
article_snippet.sent: 200,000 years ago - Homo sapiens - modern humans - appear in Africa .
article_snippet.sent: 40,0000 years ago - Modern humans reach Europe .
article_snippet.sent: Recent discoveries have suggested that the Homo genus first began around 2.8 million years ago, but the oldest stone tools to be discovered Lake Turkana are 500,000 years older than that.
article_snippet.sent: This fossilised jawbone with teeth still in place is thought to belong to the earliest member of the Homo genus 2.8 million years ago but this is still 500,000 years short of the time when stone tools were being used .