How Long Has There Been Life On Earth?

The earth is about 4.5 billion years old, but life did not exist on this planet until about 2 billion years ago, when certain kinds of bacteria and algae began to appear.

Land plants did not appear until about 430 million years ago; reptiles, 300 million years ago; and modern mammals, 75 million years ago. The first apes appeared about 35 million years ago, and the first apelike men, about 10 million years ago. Man, himself, has been on earth for only about 300,000 years.

If the 4.5 billion year history of the earth were to be measured in proportion to one year, man would not appear until Dec. 31, at 8:30 in the evening!

Comments

  1. John says

    Why can we date man back in detail 7000 years and than nothing 100s of thousands before we see any more? Shouldn’t there be something in the middle. Or maybe the theory of evolution is floored. May be what they presume to be early man are actually extinct apes, and there dating methods don’t work beyond 10,000 years. May be we were created. Any thoughts.

  2. Jav says

    Reading some of the comments here is really interesting however each of us if entitled to our own believes however repugnant some of them may seem. first of all christianity is fictitious…..secondly the earth is definitely 4.5 billions of years old ..of has been proven through radiometric dating. You folks need to wake up the earth it’s not 6000 7000 or how many thousands of years you may want to believe..

  3. Pete Smith says

    Hi There
    Queen Victoria did a World census in 1850 and discovered 1.2 billion people lived on the Earth.
    We now have over 7 billion. So in 160 years we have added about 6 billion. Lets reverse the growth formula and go back:- we run out of people in about 8000 years.
    Fact:- man cannot have been on this Earth for billions of years. He must have had a ‘flick of the switch’ start. If not then woman also must have had to run parallel with mans development because procreation cannot take place without them both.
    The ape man stuff is all guess work. The time that we live in now is the most advanced, if we cannot find evolutionary evidence now with all the brains and equipment. Then maybe we begin to look in the other direction. Not the Big Bang but the ‘first cause’
    Regards
    Pete Smith

  4. Steven says

    We have irrefutable evidence of evolution that anyone can see. You can use animals for example, we have seen that animals can grow into something very different from what they usually would and that is because the environment around them forced them to EVOLVE. We can see it with humans. The Spanish in south America look very different from the European Spanish. We clearly adapt and evolve to our environment. Anyone who can’t see that are lying to themselves or have no comprehensive understanding of biology.

  5. Kelly says

    Interesting, but I very much regret reading the comments. As a teenager it occurred to me that when people say that Jesus “saved” us and “died for our sins” I didn’t know precisely what that meant. I didn’t understand why he had to die or what that had to do with our sins. So I asked Christian after Christian and THEY DIDN’T KNOW. I finally got the answer from an ATHEIST! Do you know why? Because nonreligious people have a desire to understand which drives them to ask questions, whereas religious people seek comfort and simplicity and don’t even think to question. This is how religion hinders the pursuit of truth and knowledge. If you want to hide under a rock clutching your Bible for dear life then feel free to do so, but please don’t try to discourage those of us who want to learn, and don’t call us stupid for trusting evidence-supported scientific theories over a nonsensical book written thousands of years ago.

  6. Rizdek says

    Regarding evolution. Simple evolution…descent with modification, is a fact. It has been demonstrated in laboratories with animals/plants with very short life cycles. In fact people have been relying on it for thousands of years…animal husbandry and crop development depend on our ability to manipulate the genes of animals and plants to produce individual the have more meat, produce more milk, lay more eggs and yield more grain/fruit. That is evolution…descent with modification…in this case modification orchestrated by humans. Then there are various “theories of evolution,” i.e. theories about how evolution plays out over long…l o n g periods of time. One theory is that the diversity of life on earth is probably due to this observed (in the lab/test tube/farm/greenhouse) evolution working over a long period of time. It is theorized that the life forms we see around us evolved from other life forms. It is also theorized that evolution, in combination with natural selection influenced and continues to influence life forms as they reproduce. And these theories are NOT simply based on the fossil record. Most theories relying on evolution would be strong theories even if there were no fossil record at all. Other factors such as genetics, biogeography, morphology and developmental biology lend themselves to support and explain evolution on a larger timescale.

    The reason I, someone NOT trained in any of the sciences used to support evolution, think evolution is the likely method by which the diverse life we see around us came to be is that it “just looks like it did.” I might be wrong, but it’s what I think. One thing…I am quite certain the earth is ancient…it certainly didn’t come to look the way it does in a few thousands of years…unless this god decided to trick us all by making it look ancient when he made it. That would be like the sign over the cabinet makers shop, “Antiques made to order.” The other factor influencing my attitude toward evolution is that I tend to rely on the method used by scientists to derive facts and come up with hypotheses and theories. If someone doesn’t understand the process or tends to mistrust “scientists” as a group and “science” as a process, then, of course you are going to be less likely to consider evolution credible. Especially if you are convinced you have a better explanation…Genesis, e.g.

    As to how “different sexes” could develop naturally, this is the way I understand it is thought to have happened. It started with life forms that were hermaphroditic. IOW many many species now have individuals that function as either sex and can bisexually reproduce with others of the species even though they are neither uniquely male nor female. Check out hermaphrodite animals on Wiki or Google it. IMHO, that kind of organism was the precursor to species that had individuals uniquely male or female…like most higher animals, so “two-sex” species could have evolved naturally from hermaphroditic species. So FORGET the idea that separate sexes had to evolve simultaneously in a given species. It would have happened along the lines of some individuals of an hermaphroditic species began behaving as uniquely male or female. They could STILL reproduce with their hermy counterparts, but for some reason those individuals had a slightly better chance of survival and produced more offspring. Eventually all that was left were individuals that were EITHER male OR female hermaphroditic individuals were no longer produced.

  7. Wal says

    Not directly related, but definitely of interest here . . . Anyone researched The Bosnian Pyramids? Thoughts?

  8. Emily says

    All the pro-evolution and science based comments make SO MUCH MORE SENSE than you God-loving people who are arguing some magical non-prooved being created the earth.

  9. AndrewF says

    Pete Smith,

    No, you can’t figure out the population of the Earth at a time in history just by extrapolating from modern population rates, for the simple reason that the birth rates and death rates have varied enormously in various places, in various times in history. The fossil and archaeological evidence suggests we (modern-ish humans) have been around for about 100 000 years. Give or take.

    Also, ‘if we can’t figure it out now, we’ll NEVER figure it out’ is not a very scientific approach! We still have a lot to learn, but to address your last point, we have a GREAT deal of evidence for evolution by natural selection.

    –Andrew

  10. Dude says

    -Plant earth has been here for billions of years.
    -Mankind was not the first thing on earth. -Dinosaurs roamed plant earth for millions of years and most species have been EXTINCT for millions of years.
    Well now that that’s been said here’s something that I don’t understand…
    Okay I’m catholic quite religious, believe in god, evolution and I love science. But here are two questions/theories for whom believe that we and everything along
    with, and before us evolved. Also If you don’t believen god…
    Q:1 If we evolved from apes, then why can’t or why don’t they evolve into humans today or when have they last evolved into one? Even if we were to put apes in different senarios of habitats, environments. Would they adapt or evolve. If they evolve… What are the chances that they would evolve into a human and what sex/gender? Q:2 If everything evolved from something, then how did the first thing that evolved… Evolve from nothing…
    Take time to think about these questions please do, and I’m not trying to say that you have to believen god or something. Just wanted to see if people could give an answer, or theory. About this topic.

    P:S this was typed by a twelve year old… Just sayin’.

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