This is a Theory which I'm totally convinced by, not saying this is non-fiction, its everyone to there own just though i would like to share this with you all and get your thoughts on the matter. Maybe thats why there are so many UFO claims recently.

A new book by American ecologist Dr Ellis Silver argues that humans may well not be from Earth - and may have arrived separately, brought here by aliens as recently as a few tens of thousands of years ago.

The Earth approximately meets our needs as a species, but perhaps not as strongly as whoever brought us here initially thought, Silver said in an interview with Yahoo news.

Silver claims that some chronic illnesses that plague the human race - such as bad backs - could be a sign we evolved on a world with lower gravity.

Silver also points out to the extra 223 genes in human beings, which are not found in any other species, and to the lack of a fossil missing link.

Silver also claims that the human race has defects that mark us out as being possibly not of this world.

We are all chronically ill, says Silver. Indeed, if you can find a single person who is 100% fit and healthy and not suffering from some (perhaps hidden or unstated) condition or disorder.

He believe that many of our problems stem from the simple fact that our internal body clocks have evolved to expect a 25 hour day (this has been proven by sleep researchers), but the Earth's day is only 24 hours.

Silver does not suggest one answer - but a possibility that early pre-humans such as homo erectus were crossbred with another species. He also suggests several possible origins, including Alpha Centauri.

Mankind is supposedly the most highly developed species on the planet, yet is surprisingly unsuited and ill-equipped for Earth's environment: harmed by sunlight, a strong dislike for naturally occurring (raw) foods, ridiculously high rates of chronic disease, and more. Plus there's a prevailing feeling among many people that they don't belong here or that something "just isn't right".

This suggests that mankind may have evolved on a different planet, and we may have been brought here as a highly developed species. One reason for this, is that the Earth might be a prison planet - since we seem to be a naturally violent species - and we're here until we learn to behave ourselves.

Scientific reports suggest that life itself might not be from Earth but might have arrived here on meteors or comets. This primitive form of life then evolved over billions of years into what we find on Earth today.

Silvers thesis proposes that mankind did not evolve from that particular strain of life, but evolved elsewhere and was transported to Earth (as fully evolved Homo sapiens) between 60,000 and 200,000 years ago.