Charley Lineweaver, a provocative cosmologist with The Australian National University, believes the “Planet of the Apes Hypothesis” -a theory subscribed to by Carl Sagan and the astronomers involved with the Search for Extraterrestrial Intelligence (SETI), that human-like intelligence is a convergent feature of evolution -that there is an intelligence niche, into which other species will evolve if the human species goes extinct is based on a flawed notion of evolution, a notion that could have serious implications for our search for intelligent life elsewhere in the Milky Way Galaxy.
Let’s take a quick look at the plot of the 1968 movie, “Planet of the Apes,” with Charlton Heston playing the role of Taylor, an astronaut on an interstellar journey. After traveling for over two thousand years at nearly the speed of light (during which the astronaut crew ages only 18 months due to time dilation), the spacecraft crash lands on a planet that has oxygen comprising 20 percent of the atmosphere, and a 23 hour 56 minute sidereal period.
Charley Lineweaver, a cosmologist with The Australian National University, believes the “Planet of the Apes Hypothesis” -a theory subscribed to by Carl Sagan and the astronomers involved with the Search for Extraterrestrial Intelligence (SETI), that human-like intelligence is a convergent feature of evolution -that there is an intelligence niche, into which other species will evolve if the human species goes extinct is based on a flawed notion of evolution, a notion that could have serious implications for our search for intelligent life elsewhere in the Milky Way Galaxy.
A newly identified species, a loriciferan identified as a species of the genus Spinoloricus discovered by Roberto Danovaro at the Polytechnic University of Marche in Ancona, Italy last year may provide a preview of future discoveries of alien lifeforms.
“The discovery of these life forms opens new perspectives for the study of metazoan life in habitats lacking molecular oxygen,” wrote Danovaro, a marine biologist.
Electron microscopy revealed the three new species of loriciferans, resembling jellyfish sprouting from a conical shell, that lack mitochondria, the energy-making organelles or components in our cells that allow us to generate energy from oxygen among other functions. Instead, they possess large numbers of organelles resembling hydrogenosomes — anaerobic forms of mitochondria — that were previously seen in single-celled organisms inhabiting zero-oxygen environments.
Stephen Hawking: Warum wimmelt es in unserer Galaxis nicht von mechanischem oder biologischem Leben?
In his famous lecture on Life in the Universe, Stephen Hawking asks: “What are the chances that we will encounter some alien form of life, as we explore the galaxy?”
If the argument about the time scale for the appearance of life on Earth is correct, Hawking says “there ought to be many other stars, whose planets have life on them. Some of these stellar systems could have formed 5 billion years before the Earth. So why is the galaxy not crawling with self-designing mechanical or biological life forms?”
Why hasn’t the Earth been visited, and even colonized? Hawking asks. “I discount suggestions that UFO’s contain beings from outer space. I think any visits by aliens, would be much more obvious, and probably also, much more unpleasant.”
Hawking continues: “What is the explanation of why we have not been visited? One possibility is that the argument, about the appearance of life on Earth, is wrong. Maybe the probability of life spontaneously appearing is so low, that Earth is the only planet in the galaxy, or in the observable universe, in which it happened. Another possibility is that there was a reasonable probability of forming self reproducing systems, like cells, but that most of these forms of life did not evolve intelligence.”
We are used to thinking of intelligent life, as an inevitable consequence of evolution, Hawking emphasized, but it is more likely that evolution is a random process, with intelligence as only one of a large number of possible outcomes.
Intelligence, Hawking believes contrary to our human-centric existece, may not have any long-term survival value. In comparison the microbial world, will live on, even if all other life on Earth is wiped out by our actions. Hawking’s main insight is that intelligence was an unlikely development for life on Earth, from the chronology of evolution: “It took a very long time, two and a half billion years, to go from single cells to multi-cell beings, which are a necessary precursor to intelligence. This is a good fraction of the total time available, before the Sun blows up. So it would be consistent with the hypothesis, that the probability for life to develop intelligence, is low. In this case, we might expect to find many other life forms in the galaxy, but we are unlikely to find intelligent life.”