Could extraterrestrials be the explanation for human life on Earth?
83045
"Evolutionary chains" go a long way towards explaining the development of life, including human life, from simpler organisms, but we haven't gotten very far yet in explaining how the mutation and reproduction systems that natural selection requires  got started in the first place.  Some researchers, and by that I mean mainstream ones who fully accept evolution as the fundamental organizing theory of biology, have tried to work around this problem by postulating that the original lifeforms didn't evolve on Earth at all.  However, while this changes the debate somewhat, by allowing far greater timelines for life to evolve, it still begs the question:  OK, if life evolved somewhere else first, how did it get started *there*?  I think we are much better served by looking at whether life could have evolved here, under the conditions of the primitive earth as we know them.
912860
I highly doubt that there is intelligent life in our solar system there might be organisms on other planets like Mars. But there IS life some where out there. The Earth is infinately small compared to the the universe because the universe is forever expanding. There is no telling how many trillions and trillions of planets have intelligent life roaming around wondering if there is life on other planets just like we are.
1177396
I think aliens exist, but I don't think they live among us. Think of Earth and all of the cosmic and environmental factors that are required to sustain and promote life.  I think it would be unusual for similar conditions to exist in other galaxies that will produce intelligent beings that look exactly like humans.
306121
I would like to say that there is intelligent life in the universe besides on Earth.  Humans have gone from believing that the Earth was at the centre of all existence and the Sun and all "heavenly bodies" revolved around it, because from our Point of View it seemed that way.  Then we discovered that no, the Earth actually goes around the Sun, and there were other planets...and other suns...and other planets around other suns!! And so on.  \n\nSo why wouldn't this 'decentralising' process extend to the existence of life?  I like to think it gives us an appreciation that life itself is a natural, universal process that, where the conditions are right, would happen throughout the universe.  "Intelligent" life is a bit curlier to argue.  If intelligent life was a natural process, why have we not had communication with aliens?  We could assume they are as curious as humans are to seek life elsewhere, and humans have been sending signals into space for decades.  I cannot answer this; even if it does exist numerous places in the universe, the vastness of space may be just too great.  \n\nThe idea of intelligent life elsewhere appeals to me as it knocks us humans off our high horse, and our presumptuous and arrogant viewpoint that we are privileged with our intelligence (and yes, humans are intelligent, although one wonders sometimes).
241844
There are many reasons we want to know about other worlds.  One large reason is the possibility of extraterrestrial life.  Is there life outside of Earth?  Is it intelligent?  What benefits can we derive from contact with alien life forms?  What dangers could it pose to our way of living?  Increasing our knowledge about other worlds is probably the best method currently available for answering these important questions.\n\nFurthermore, there are pragmatic issues at stake.  The Earth cannot sustain life forever.  Eventually, human beings must populate other planets if the species is to survive.  (Examples of possible global cataclysms rendering the Earth unihabitable abound--at least a dozen blockbuster movies in the last decade have been based on some type of apocalyptic circumstance.  And though the premises remain remote, on an infinite timeline all possible events approach certainty, i.e. the habitability of the earth will eventually end).  If we are to survive, we must prepare to inhabit other worlds, and in order to do so we must learn about them.\n\nAside from the survival of humanity, another practical reason for seeking information about other planets exists:  the increasing competition for natural resources.  The nature of the system tends toward a more and more efficient consumption of resources.  Since the quantity of terrestrial resources is finite it stands to reason that very soon we will need to seek external resources to sustain systemic growth.  (This is why one of the major functions of the current probe missions is to determine the chemical composition of extraterrestrial bodies--we're looking for stuff we can use).\n\nIn the end, though, the best answer to this question is probably much more simple:  people are curious.
158702
Well, certainly an interesting theory. I cannot deny that we are aliens..but it is highly unlikely. Perhaps at the most ..in my opinion, we have alien DNA in us. \nI have never met an alien yet, and truly I really don't want to. But it is hard to deny the existence of intelligent beings. They seem to have been with us since recorded history of mankind began. Maybe they even helped us evolve (that's where DNA comes into play with my theory). I mean their UFOs have been spotted and recorded in drawings on cave walls, paintings, carvings on canvas, and then recorded on film and digital recordings.  \nI never believed..never really gave it much thought. That was until I had seen so much, many objects and crafts I could not deny it any longer. \nAre we alien? Perhaps we are like an ant farm or a little petri dish with a culture or organism in it and they are the scientists trying to be careful not to contaminate the experiment (thus the attempts to erase the memories of supposed abdutees withhout permanent brain damage). \nI don't think there are many on this planet that actually do know the truth..but I do think there are some here who do. We are VERY young. We have not been here very long, and we cannot understand the universe with our primitive minds..The way we think with Human brain prevents us. Certainly there are more people aware of UFOs then ever before and also more sightings than we have ever known. The frequency of sightings is increasing..\nLast year was a record for myself with four objects sighted in three months, while I was at a my fairly secluded lake. These crafts are not ours. They have instant speed..speed that you cannot believe, even as you witness it. Speed that we cannot achieve on Earth. \nPerhaps the time will come soon, when we all will learn of their true existence and ours. Maybe then, we might begin learn to understand what the universe has in store for us. If we can survive..as Humans to become a true intlligent species.\n\n Alien = intelligence,  Does Human = intelligent? (NO)
884066
I wouldnt say there isnt any life outsdide our solar system. there can be a very high possibility that there is inteligent life out there.
364516
I have never seen UFOs or aliens, but I think it was a sufi man who observed the following...he said: If you build a 7-story building, it does not make sense to occupy the ground floor and leave the rest unoccupied. He was referring to all the zillions of stars and planets in space that God created...meaning it does not make sense thag God would create all that and have life on earth alone. Having said that, I can not say with certainty that there IS life on other planets, but I can not say with certainty that there is No life on other planets either...but I have to admit; that sufi man's remark makes sense...don't you think? :)
362430
I think we would be very naive to believe we are the only life form in the universe.As vast and diverse as it is,I believe there has to be a reason for the formation of these planets to sustain life.That said,who knows when the life was present on these planets?And who knows what life forms are out there as we speak?Perhaps Mars and Pluto had life trillions of years ago but there are no remnants now for us to find.It's a fascinating topic.If you think about the possibilities,it's incredible.
452956
Panspermia- that means aliens were the first life on earth, they seeded the first life, which shud be a lower life form.\nI dont agree.\n\nAnd then we evolved from the alien first life!! So, it does not disprove the evolution theory still.\nNExt, if the alien first life was just a lower life-form, it proves that they could not have had space ships (which evolved human beings havent fully mastered). Hence panspermia not feasible!!
979405
The question is twofold and most responders missed that. To my knowledge there is no scientific evidence of aliens visiting earth space.\n\nBut there is plenty of independent scientific evidence of UFOs. The UFO phenonena has been studied at great length and there is evidence that something comes and goes and that that something operates intellegently.  But we do not know what they are.  \n\nMy personal opinion is that there is likely life somewhere in the vastness of the cosmos.  But I can not believe that life visits earth regularly each and every day all over the globe. So the UFOs may or may not be alien.  But highly unlikely.
747995
Although there is no concrete proof that aliens exist, it is statistically a virtual certainty that they do exist. Just think, our galaxy contains somewhere in the region of 100,000,000,000 (100 billion) stars, any one of which could have a planet or system of planets orbiting them. And ours is a medium sized galaxy, which is only one of countless billions of other galaxies in the Universe. So even considering the extremely slim possibility that *just* the right conditions for life might exist on a planet, there is still a huge number of planets cabable of sustaining life. Do they actually contain life? We might never know that one.\n\nHave aliens actually visited our planet? I'd say probably not. Although there is a mass of evidence to the contrary most of this is explained away by perfectly terrestrial means. Add to this the fact that without some extremely advanced technology (and an equally advanced understanding of the laws of physics), visiting our planet would be next to impossible. Light - which nothing can actually travel faster than, at least according to our knowledge of the Universe - takes over FOUR YEARS to travel to us. To travel from the other side of the galaxy would take thousands of years, and from the very edge of the known Universe it light takes FIFTEEN BILLION YEARS to reach us. Unless any alien life has the ability to travel at the equivalent of superluminal speeds, or has found an alternate way of travel, or just has a lot of patience, we are unlikely to ever be visited by extra-terrestrials.
217359
Yes, I fully believe there is life on other planets.  What it took to create life on Earth was not favored to happen.  The odds that Earth would hold any life at all are too small to comprehend.  But we do not know how large the universe is.  We do know that there are trillions of planets, trillions of galaxies, trillions of stars.  The odds that there is not a speck of life on any of those planets is also extremely small.\n\nI must admit that I have seen a UFO, which occurred last year.  I was driving my friends home from a party and I happen to look in the sky to see a bright white diamond-shaped object.  There were four individual diamond lights that made up the overall shape.  I was astounded, and I knew it was not anything that the United States had admitted to having.  I could name every military jet, helicopter, blimp, and passanger aircraft that I see, but I could not for the life of me figure out what it was.  I immediately turned around and drove to follow it.  Within five-ten seconds, the craft had flown so fast that the lights had disappeared (I watched it the entire time).  I'm not saying it was extra-terrestrial, but it was a UFO.  I live in Cleveland, by the way.
17615
A better question might be has there been, is there now or will there be intelligent life somewhere in the universe (other than humans)?\n\nThe earth is about five billion years old with perhaps another five billions years to go and human life has existed here perhaps a million years.  That is a tiny fraction of time and other life forms may arise here that are intelligent sometime in the future.\n\nFor outer space the prospects seem even better since there are perhaps millions of gallaxies with billions of stars each that have existed at some time in the past ten billion years with perhaps as much time left to go.  In fact there exists the possibility that life much as we know it, including DNA (a chemical compound though highly complex) may have existed millions or billions of years ago before us and are now extinct.  It takes so many light years to communicate with any other star within our own galaxie (except the very nearest) but it is impossible to reach anyone from the past.  And if we send signals into the future, we may be gone before we receive a friendly reply.
404059
There is alien  life. Perhaps not in our solar system but definately out there.\nNow this life could be simple microbes or anything like that.\nIntelligent life may be out there too, it all depends on how things developed after the big bang. There   MUST Be intelligent life out there.. There's none here!!!
485002
Could be both-God created aliens and the environment conducive to life, which and who in turn switched on life on earth.
193508
There could possibly be. Isn't it a little ridiculous to think that in all the galaxies that we are the only humanoid lifeforms? whether or not you believe in God!