When did life begin? When did humans and the other primates first appear? Reasonably accurate scientific answers to these questions did not develop until the 1960's and 1970's when radiometric dating techniques were invented that could date samples that are billions of years old.
http://anthro.palomar.edu/earlyprimates/early_1.htm
Complex multicellular forms of life are surprisingly recent on our planet. They have existed only for about 600,000,000 years or slightly more. When these creatures began to appear, 87% of the earth's existence had already gone by, and 83% of the total time life has existed had already passed as well.
http://anthro.palomar.edu/earlyprimates/early_1.htm
Humans first appeared on Earth during the Paleolithic Era, in the steppes and savannah of Africa, before migrating to Eurasia, the Americas, and Australia. These humans were hunter-foragers, changing their tools and culture to adapt to their surroundings. Describe earliest humans' technology & tools.
https://quizlet.com/21296193/ap-world-history-period-1-technological-and-environmental-transformations-prehistory-to-600-bc-flash-cards/
Mammals didn't evolve until 200Ma and our own species, Homo sapiens, only 200,000 years ago. So humans have been around for a mere 0.004% of the Earth's history. Jump to: Geological timeline | Geological time periods | Big Five mass extinction events |. Mass extinction theories | Ancient Earth habitats.
http://www.bbc.co.uk/nature/history_of_the_earth
Scientists could be forced to re-write the history of the evolution of modern man after the discovery of 400,000-year-old human remains. Until now, researchers believed that homo sapiens, the direct descendants of modern man, evolved in Africa about 200,000 years ago and gradually migrated north, through the Middle East, to Europe and Asia. Recently, discoveries of early human remains in China and Spain have cast doubt on the 'Out of Africa' theory, but no-one was certain.
http://www.dailymail.co.uk/sciencetech/article-1341973/Did-humans-come-Middle-East-Africa-Scientists-forced-write-evolution-modern-man.html
The size and shape of the teeth are very similar to those of modern man. Until now, the earliest examples found were in Africa, dating back only 200,000 years. Other scientists have argued that human beings originated in Africa before moving to other regions 150,000 to 200,000 years ago.
http://www.dailymail.co.uk/sciencetech/article-1341973/Did-humans-come-Middle-East-Africa-Scientists-forced-write-evolution-modern-man.html
Humans first appeared on Earth during the Paleolithic Era. The evidence of burial grounds, as well as stone tools and other items explains this. They show a general migration path from Africa outwards. These tools show that the groups were hunter-foragers and nomadic.
https://quizlet.com/21296193/ap-world-history-period-1-technological-and-environmental-transformations-prehistory-to-600-bc-flash-cards/
The first modern humans shared the planet with at least three species of early humans. Over time, as modern humans spread around the world, the other three species became extinct. We became the sole survivors in thehuman family tree. By 164,000 years ago. Modern humans collect and cook shellfish. By 130,000 years ago.
http://humanorigins.si.edu/human-characteristics/humans-change-world
We now know that the earth is approximately 4.54 billion years old and that there have been living things on our planet for at least 3.5 billion years. Modern methods of dating the earth and the major events in the evolution of life depend on understanding radioactive decay processes.
http://anthro.palomar.edu/earlyprimates/early_1.htm
Answers.com® is making the world better one answer at a time. Hominids with the same anatomy as modern humans first appear in the fossil records about 200,000 years ago. They existed alongside earlier species that became extinct, as well as with the separate Neanderthals, with whom some interbreeding may have occurred.
http://www.answers.com/Q/When_did_modern_humans_first_appear_on_earth
when did modern humans appear on the planet
Modern humans appeared on the planet about 200,000 years ago.  Modern humans appeared on the planet in 200,000 years ago.