It all started when, a few years ago, a balloon returned from a high-altitude flight covered in microscopic life forms that seemed out of this world and reignited the debate about whether life on Earth started here, or really somewhere else.
Some scientists have claimed that life originated on Mars, due to a mineral found in Martian meteorites, a crucial concept for the genesis of life.
Another experiment showed that amino acids could have arrived with comet impacts, suggesting that life could be widespread and not just in the solar system.
But a book by American conservationist Ellis Silver, titled “Humans Are Not From Earth,” argues that humans may not have come from Earth.
Silver presents arguments, based on human physiology, suggesting that we did not evolve with other life forms on Earth, but came from somewhere else, brought here by extraterrestrials only a few tens of thousands of years ago. ‘years.
Ellis Silver, an environmentalist currently involved in the Pacific plastic waste cleanup effort, says his book is meant to provoke debate and is based on scientific work on the difference between humans and animals. other animals.
“Earth is roughly meeting our needs as a species, but perhaps not as intensely as those that brought us here in the first place,” Silver said in an interview with Yahoo News.
“Lizards can bask in the sun for as long as they want, and many of them do. We can get by for a week or two… But day after day in the sun? Forget that. »
“It’s the same as lying on the highway and waiting for a vehicle to hit you, we get sun glare, which is also rare, most animals don’t. »
Silver claims that certain chronic diseases affecting the human race (like back problems) could be a sign that we have evolved into a less severe world.
Silver points to other unique human characteristics, such as the fact that babies’ heads are so big that women have trouble giving birth, which in ancient times was often fatal to mother, child, or both. .
“No other truly native species on this planet has this problem,” he says. Silver also points to the 223 “extra” genes present in humans not found in any other species, and the lack of “missing link” fossils.
He also asserts that the human race has flaws that mark us as “not of this world”. “We are all chronically ill,” Silver says.
“In fact, if you can find a single person who is 100% fit and healthy and does not have a condition or disorder (perhaps hidden or undeclared), I would be extremely surprised. , I couldn’t find anyone. »
“I believe a lot of our problems stem from the simple fact that our internal body clocks have evolved to expect a 25 hour day (this has been shown by sleep researchers), but the Earth day is only 24 hours. »
“It is not a modern condition, the same factors can be traced throughout human history on Earth. »
Silver does not suggest an answer, but rather a possibility that early pre-humans such as Homo erectus interbred with other species. It also suggests several possible origins, including the closest star system to the sun, Alpha Centauri.
“Humanity is supposed to be the most developed species on the planet, yet it is surprisingly maladjusted and ill-equipped for the Earth’s environment: sun damage, strong aversion to naturally occurring (raw) foods , ridiculously high rates of chronic disease, etc. »
“Furthermore, many people feel that they don’t belong here or that something is wrong. This suggests that (to me at least) humanity may have evolved on another planet, and may have been brought here as a highly developed species. »
“One of the reasons for this phenomenon, which he discusses in his book, is that the Earth could be a prison planet, because we seem to be a naturally violent species, and we are here to learn how to behave. »
“The book ‘Humans Are Not From Earth’ was published primarily to gauge reader reaction and to provoke thought, especially among those who may not have considered the possibility before. »
The claim that bacteria arrived from space has also sparked controversy and revived the idea of ’panspermia’, according to which life on Earth could have ‘pollinated’ other nearby planets.
“There’s probably some truth in the report about the discovery of curious things in the atmosphere,” said NASA astrobiologist Chris McKay. “The jump to the conclusion that it is extraterrestrial life is a big leap and would require extraordinary evidence.”
Professor Wainwright and his colleagues at the University of Sheffield intend to carry out further tests.
“In the absence of a mechanism by which large particles like these could be transported into the stratosphere, we can only conclude that the biological entities originated in space,” Wainwright added:
“So our conclusion is that life is continuously coming to Earth from space, that life is not limited to this planet and almost certainly did not originate there. »
Silver’s more radical idea is presented as controversial, intended to inspire argument. “The initial reaction was positive, although one reviewer thought it was a parody, while others found the writing style very dictatorial,” he admits.
Supercomputer simulations carried out at the Lawrence Livermore National Laboratory in the United States have revealed that amino acids, the building blocks of life, may have arrived on Earth via comets.
This suggests that life could be found elsewhere in our solar system, or even beyond.
Nir Goldman suggests that simple molecules found on comets (such as water, ammonia and carbon dioxide) could have provided the raw material and that impact with early Earth could have “ignited” a prebiotic reaction.
A series of experiments in which projectiles were fired at a comet with mixtures of ice resulted in the formation of amino acids (the building blocks of life).
“These results confirm our previous predictions regarding the synthesis of prebiotic materials by impact, where the impact itself can yield life-supporting compounds,” Goldman said.
“These results represent an important advance in our understanding of the origin of the building blocks of life. And that raises the possibility of the appearance and spread of life in our solar system,” Goldman said.
However, Silver wants to raise the question of whether humans arrived separately, “recent scientific reports suggest that life itself may not have originated on Earth, but arrived here in meteorites or comets.
“This primitive life form then evolved over millions of years to become what we find on Earth today. »
“My thesis,” says Silver, “proposes that humanity did not evolve from this particular strain of life, but evolved elsewhere and was transported to Earth (as fully evolved Homo sapiens) between 60 000 and 200,000 years, for all the reasons mentioned above. »