how long  have humans been on earth.?
542910
The species Homo sapiens (humans) have been around for approximately 40,000 years.\n\nHowever, aside from the species definition of a "human", creatures living ~1.8 million years ago would be certainly mistook as "human" by today's standards after a hot shower and a shave.
1053157
213,000 years (previous answer was an oops... sorry)
452046
The human population did NOT start out as two (this readily confirmed by analysis of genes found in different groups of humans across the globe).  Also, Earth is some 4.57 billion years old.  Additionally, humans have existed for several million years.\n\n\nOkay...I'll humor you...\n\n-a human generation is 20 years\n-there are only 300 generations in 6000 years\n-before healtcare each generation more or less had enough time to mature and then have offspring\n-human births are risky compared to other animals and can possibly kill the mother\n-average lifespans before healthcare is estimated 20-35\n-sexual maturity generally occurs between 12-14\n-lifespan has only started increasing since 1800 so that is 200 years or 10 generations\n-Therefore to get and maintain 6.5 billion each successive generation had to have an increase of 21,666,666.667 individuals or more per generation to get from 2 to the 6.5 billion in the necessary time AND maintain population size.\n\nTherefore it is NOT possible for humans to have started from a population of 2 and increase up to 6.5 billion considering all factors involved.
396602
4.5 billion years old maybe http://www.talkorigins.org/faqs/faq-age-of-earth.html
287962
There is no scientific proof that people lived this long, only biblical documetation.  Physically, the human body cannot live to that age at this time, or any previous time.  Maybe somewhere down the road.
288758
6 Billion years old. The Bible says that to God a day is a thousand years and a thousand years is a day, which basically means that God does not follow our time table, so the 7 days that it took God to create the Heavens and the Earth could have been millions of years.
1176345
the earth is about 4.5 billion years old
168418
4.5 Billion Years old.\nThat's also, conveniently, the age of our sun and the other planets, moons and asteroids in our Solar System.\nThey all formed at the same time, out of the same cloud of gas and dust.
329537
5 billion years or so.\n\nhttp://www.enchantedlearning.com/subjects/astronomy/sun/sundeath.shtml
813655
1000 years later! Humans have evolved beyond all base sentiments and minor jealousies. There are no religions any where. The only religion accepted willingly by all in Humanism. No terrorism . No wars. All humans dress alike and no beards or turbans or head scarfs. The world as a whole has one Government. There is no poverty or sickness. The super-biotics laboratory has solved all problems by evolving a single pill which is answer for all problems. There is no diabetes or heart disease due to stem cell research evolving solutions. Humans have established settlements on Moon and construction activity on Mars is in full swing for further Human settlements. The epoch-making technological developments on rocket fuels has resulted in these developments. The average life span of Humans is 150 years. Sex is considered  sacred and development of superior embryos has lead to men and women who are step ahead of all angels in beauty and intelligence.There are no gays. The only problem humanity is facing is the threat of aliens who have taken over planet Jupiter. Negotiations are in advanced stage for settlements. We are hopeful of Peace at last for humanity.
993258
The Earth was formed around 4.57 billion (4.57×109)[1] years ago
7283
It depends on which theory of creation you believe.  \n\nIf you subscribe to the theory of evolution, the Earth is believed to be approimately 5 billion years old.\n\nIf, however, you base the age of the earth on the bible, the earth is around 6,000 to 10,000 years old.
66159
The generally accepted age for the Earth and the rest of the solar system is about 4.55 billion years. I am not an expert on this matter, but I believe in science. If someday people find new convincing theories, I will be very open to accept them. But only 6000 years old? Come on, I don't buy it.
440289
About 4600 million years.
25726
Solar system, including the Sun and the Earth: 4.6 Ga (billion years)\nGenus Homo is generally considered to be the human race: 1.5 to 2.5 Ma (million years)\nThe term "Civilization" is not precise.\nTools were first used around 3 Ma, but note that todays apes and even dolphins and crows use tools.\nLanguage arose sometime between 2 Ma and 40 ka\nAgriculture developed around 8500 BCE\nFirst cities were around 5000 BCE\nWriting developed by 3000 BCE
2620
Somewhere around 4 or 5 billion years. Or if you choose the biblical version, around 6,000 years, depending on which religion you subscribe to.
53656
Around 4.57 billion years old.