Saturday, May 30, 2009

Ida, the “missing” link

“Ida”, a 47-million-year-old primate skeleton has been unveiled amid much fanfare and a flurry of well-orchestrated media announcements. It coincided with the release of a book and a television documentary, both of which had been prepared under a cloak of secrecy.

For a fact, the fossil is a paleontologist’s dream come true. It belongs to a species named Darwinius Masillae (after Darwin and the place of its discovery Messel, Germany) and it has been exquisitely preserved. Parts of its last meal were found inside its stomach. We thus know that she (for the specimen is probably a female) was an herbivore who feasted on fruits, seeds and leaves. She was overcome by carbon dioxide gas whilst drinking from the Messel lake: the still waters of the lake were often covered by a low lying blanket of the gas as a result of the volcanic forces that formed the lake and which were still active. X-rays revealed a broken wrist which may have contributed her demise. Hampered by her broken wrist, Ida slipped into unconsciousness, was washed into the lake, and sunk to the bottom, where she was preserved for posterity. When she died she was approximately nine months old and she measured almost three feet high.

Ida lived at a critical period in Earth’s history called the Eocene. Earth was just beginning to take the form that we recognize today – the Himalayas were being formed and modern flora and fauna evolved. Following the extinction of dinosaurs, the ancestors of modern mammals, including primates, lived amid vast jungle. Till today, scientists’ most-valued fossils of primates from that era comprised mostly of teeth. It is therefore easy to imagine the scientific excitement about Ida. But is she the common ancestor of humans and apes? Is she really the “missing” link?

Behind the media hubbub lays a bitter scientific trench war with regards to human evolution. Follow the tree of human evolution backwards and when you reach around 6 million years into the past you are going to meet the common ancestor of humans and chimpanzees. Go further back several more million years and you arrive at a big enigma: when did the earliest “anthropoid” primates (who ended up as apes, monkeys and humans) split from their even earlier ancestors who were lemur-like? The question is paramount to scientists because lemurs and anthropoids differ in many significant ways. For example, lemurs have claws and anthropoids have fingernails.

There are three fractions battling it out with their respective theories. Firstly, the discoverers of Ida who think our ultimate ancestor is their finding, Ida the Darwinius, which belongs to a lemur-look-alike species called “adapids”. Then there are those who support that the ancestral split happened thanks to the “omomyids”, an extinct group that looked like tarsiers; and, lastly, there are those who contend that our great-great-great grandfathers were sweet-looking, wide-eyed primal tarsiers (whose descendants are still around today). The science team behind Ida has received considerable criticism for trying to “steal the show” by claiming that their specimen resolved the matter for ever.

The way scientists build a case for a species being the ancestor of another is by looking at certain anatomical characteristics that are common to the two species to the exclusion of others. Darwinius is linked to anthropoids on the basis of the absence of two common lemur characteristics: a tooth comb (a set of forward-facing incisors) and a grooming claw (a special claw on the foot). Since anthropoids lack such traits too, the scientists surmise that Ida is closely connected to them. And yet, the analysis published in their paper leaves many questions unanswered. Press releases subtly claim that 95% of the evidence points out that the scientists are right. But this claim is ludicrously unscientific. The same percentage of evidence - and more – used to confirm the Ptolemaic theory that the Sun revolved around Earth; and yet the theory was completely wrong. Some critics contend that Darwinius is not an adapid at all, but a convergent subspecies of tarsier. Anyway, whatever species she may turn out to be given a more scholastic analysis, could Ida be the “missing link”?

Although the scientists who studied Darwinius deny making such statements, the promotion machine of History Channel who produced the documentary, and Brown, Little, the publisher who released the relevant book, are making the most out of this angle, calling their respective products “The Link” and the relevant website “Revealing the Link”. Which has exasperated evolutionary biologists the world over. Why? Because it chimes with the agenda of creationists who doubt the colossal corpus of evidence supporting evolution and request to see “missing fossilized links”. Because to think of evolution as an unbreakable chain made of links is woefully untrue. Species evolve from previous species following great numbers of seamless generations of gradually accumulated characteristics. There are no distinct “breaks” and therefore no “links”.

Presumably, the marketing gurus who sold the story to the media transpired that this was an excellent way to transgress the arcane scientific debates of human evolution, extract Ida from the obscurity of science journals and science meetings, and communicate her story to the public. At first glance, this may appear imaginative, commendable even. Moreover, one might argue that using a bad cliché to talk good science is sometimes de rigueur. As Jørn H. Hurum, the scientist at the University of Oslo who acquired the fossil and assembled the team of scientists who studied it, claimed: “Any pop band is doing the same thing. Any athlete is doing the same thing. We have to start thinking the same way in science.”

And yet, the sloppiness by which the scientists examined this very significant fossil if only to support their theory, their hurry to meet a publication deadline in order to coincide with History Channel’s premiering of the relevant show, as well as the ridiculous framing of Ida as the “missing link”, put all good intentions into doubt. Perhaps, cynical as it may seem, the scientists who analyzed Ida in such haste, were competing for scarce funding. Funding is undoubtedly a serious issue in today’s economic crisis. One should wonder however, if the backlash which the Ida science team currently receives will do them any good in the long run. The bad precedent of Hwang Woo-suk, the Korean geneticist “superstar” who in 2006 claimed to have cloned a human being - only to be exposed that he was lying - should have taught them a lesson. Hwang was ridiculed, discredited, and following the debacle his research got no further funding.

The only ones who are sure to gain something out of all this are the publishers and television networks who are milking the cash out of the so-called “link”. They are doing so by treating a primate fossil as a spectacle. However, what makes science different from sport, or pop music, or Paris Hilton, is that science matters much more to society in the long term. That, unlike rock stars, scientists may achieve recognition by means of truly valuable scientific discoveries and not by claiming whatever comes. The scientists who unveiled Darwinius should have known that sacrificing good science for the sake of media sensationalism does little service to science and society alike.

Published in the Athens News on May 30th 2009

Friday, May 15, 2009


A conversation with Nikos Prantzos

When trying to convey the feeling of eternity Nikos Prantzos likes to quote an ancient Nordic myth. “In a distant country stands an enormous rock in the shape of a cube, each of its sides measuring one hundred kilometers. Once every ten thousand years a small bird flies over the rock and for a few moments rubs its beak on it. When the rock has disappeared, completely worn away by the rubbing of the beak, one day in eternity will have completed.” Prantzos has calculated how long this will take; 1030 years (1 with 30 zeros following). But as the future of our universe goes, this mind-bending timescale is but a mere moment. Protons, the subatomic particles at the nuclei of every chemical element will disappear in 1033 years. Black holes, having gulped whatever remaining matter, will evaporate too in 1066 years. For an astrophysicist such as Prantzos the cosmological future is eternity raised to the power of eternity many times over.

Born in Volos in 1956 Prantzos is one of the most prominent European astrophysicists. Currently a Director of Research the Astrophysical Institute in Paris and a professor at University Paris VI, he sits on the editorial boards of several significant scientific journals, and consults the European Space Agency. His main scientific interests focus on the evolution of the universe, and he has published pioneering work in the investigation of the natural processes that take place inside stars and galaxies. He is also passionate about communicating his science to the wider public. His popular science book “Voyages in the future” has been awarded the Jean Rostand prize in France, and has been translated in a number of languages, including English and Greek. In it he tackles a major philosophical dilemma that has troubled western thinkers ever since the nineteenth century, when scientists realized that the corollary of thermodynamics was the ultimate “heat death” of the universe. “Twelve years ago”, adds Prantzos, “astronomers discovered that the expansion of the Universe became more rapid in the past few billion years. If this accelerated expansion of the Universe continues in the far future all stars will run out of energy and die. Matter will ultimately decay to elementary particles and radiation, which will be diluted in a vast and cold space.”

So since the universe is destined to end with a pathetic whimper, what could be the meaning of life? If the ultimate future is dark nothingness, why bother with anything? “The vastness of the timescales involved,” says Prantzos, “is such that it leaves plenty of time to us - or to any future civilization - to consider and construct not one but literally millions of interesting futures. Along the way, meaning and purpose will be redefined time and again”.

Of course, in an ever expanding Universe, with temperatures dropping everywhere to nearly absolute zero and matter decaying into elementary particles and diluted radiation, indefinite survival appears impossible. And this is true not only for biological creatures such as us made of flesh and blood, but also of robots made of bolts and nuts. Nevertheless, Prantzos is agnostically optimistic. He contends that one should not forget that our present understanding of the Universe, based on the physics of the 20th century, is incomplete. “New theories will certainly emerge in the decades and centuries to come, perhaps offering us different and more optimistic perspectives for the far future of intelligence in the Cosmos”.

And if we earthlings don’t manage to figure things out someone else might. Which brings in the centuries-old, and ever-fascinating, question of life and intelligence elsewhere in the Universe.

Science has firmly established that the laws of physics – and therefore chemistry - are the same everywhere in the Universe. However, even if biology is essentially chemistry, biological evolution depends on many unpredictable conditions: it was the disappearance of dinosaurs following an asteroid hitting Earth 65 million years ago that paved the way to mammals and thereof allowed the ascent of humans. Prantzos points out that evolution from bacteria towards high intelligence, and further on to a technological civilization, looks like an extremely improbable event. He is not the first to doubt the existence of ETs. In 1948, the famous Italian physicist Enrico Fermi highlighted the fact that no convincing trace of an extraterrestrial visit to Earth has ever been found, despite the fact that there are billions of stars much older than the Sun in our Galaxy. Pranztos notes that “Fermi interpreted that absence of evidence as evidence that civilizations undergo a nuclear holocaust just before mastering space travel.” He contends that if there were indeed hundreds of civilizations in our Galaxy, it is improbable that all of them blew up or failed to reach us for some reason. “We should therefore get familiar with the idea that we are probably alone in the Galaxy”, he adds. And yet he remains a supporter of SETI (The Search for Extraterrestrial Intelligence) who look for extraterrestrial signals from space. “Despite its small chances of success, the rewards would be enormous if a single such signal is ever detected”, he says.

Aliens may not be in Prantzos mind when he looks at the stars, but space travel is. As a young boy marveling at the night sky over the Pagasitikos Gulf and Mount Pelion, he dreamt of becoming an astronaut. Growing up in the 60s, with the Moon as humanity’s next frontier was inspiring to a whole generation of kids like he, and Prantzos regrets that young people today do not have that same opportunity. Today, although man conquered Moon after travelling 380,000 kilometres from Earth, no astronaut has gone further than 500 kilometres from our planet since 1972. “Progress has been terribly slow both because astronaut security is a more important and funding is considerably less,” he says. “The Cold War and the competition between United States and Soviet Union hastened progress in space matters enormously”.

What appeared an easy feat in the 60s looks much harder today. The harshness of space environment makes problematic all plans for long term exploration of space by humans. The construction of adequate protecting shelters in space will require considerable efforts and resources. Furthermore, access to space is very costly because of the gravitational attraction of our planet. Until today rockets, using chemical propulsion and design principles invented by the Chinese centuries ago, remain humanity’s only means to escape Earth. Prantzos hopes that a new generation of propulsion technologies, such as nuclear, ionic, antimatter, or solar sail pushed by Sun's radiation, will provide alternative and faster ways to visit our nearest worlds, such the Moon and Mars.

Prantzos is particularly fond of manned missions into space and a believer that investing in them is a sound decision for the future of humanity. “The situation of our planet obviously requires all of our attention today”, he says. “We should try to heal the wounds of Mother Earth before embarking to ambitious programs of space travel and colonization of space. However, this does not preclude a reasonable step-by-step, long term program of space exploration. Moon, Mars and the asteroids are the obvious targets of such a program, at least for the 21st century. All major space agencies have interesting projects for those targets. I don’t think that funding issues are prohibitive. When compared to the cost of the Iraq war, or to the one of the recent financial crisis, the annual cost of a long-term project of human space exploration is substantially smaller”.

Published in the Athens News on May 15th

Friday, May 1, 2009

A traveler’s companion to Mars

In 1894 a wealthy Bostonian by the name Percival Lowell built an astronomical observatory in Arizona dedicated to learning more about enigmatic Mars. It was the time of canal-building on Earth, with the French having completed Suez a few years earlier and the Americans getting busy on cutting across the Isthmus of Panama. Lowell, saw canals on Mars too. Inspired by Darwin, he imagined life on Mars spawning and evolving over time into intelligent creatures who built planet-wide aqueducts to bring water from the poles to the equatorial deserts. He saw lush areas of cultivation, and he imagined cities and people not very much unlike us. Lowell’s ideas, published in his widely-read book Mars the Abode of Life, culminated humanity’s timeless fascination with the red planet with a profound conclusion: that we are not alone in the universe. Indeed, the intelligent beings who presumably constructed those irrigation marvels were but a relatively small leap across the dark sea of space. H.G Wells, penned The War of the Worlds by borrowing heavily on Lowell’s ideas, if only to illustrate what bad neighbors can do to each other. At the dawn of the 20th century Earth was abuzz with Mars excitement.

Lowell had put together a wonderful theory by drawing on the latest science. Alas, the theory was completely wrong. There are no Martians. Several fly-bys by spacecrafts, beginning with Mariner 4 in 1964, and not a few landings by robotic rovers, have ascertained that. There are no canals either. But there are plenty of fascinating and intriguing features to explore. There are dried riverbeds and meandering streams, wide landforms that resemble lakes, gullies that slope down mountainsides as if sculptured by torrential rains, volcanoes and underwater ice. There are telltale signs aplenty that once upon a time Mars was a completely different world. In fact, many scientists believe that Mars used to be covered with oceans and had an atmosphere and a benign climate similar to Earth’s. Then about 3.5 billion years ago a catastrophic event turned the planet into a cold and barren desert. That is why the quest for Martian life - albeit of a more humble, bacterial nature - has not ceased. It is possible that unicellular organisms still exist, buried deep under the surface. Their discovery would be of tremendous significance, for they would provide conclusive evidence that life is not a local, earthly phenomenon, but ubiquitous, something that might permeate the cosmos.
The list of enigmas that scientists draw each time they push the Mars exploration agenda is long. Our planetary neighbor is similar to Earth in many more interesting ways. Although half its size it has roughly the same land area. Martian days (called “sols”) are only a 37 minutes longer than our 24 hours. A tilted axis of rotation creates seasons; summers, falls, winters and springs follow each other in a year that is twice as long, as Mars takes 699 “sols” to journey once around the Sun. The Sun rises in the East and sets in the West. Both planetary siblings have polar icecaps. Why then has the Red Planet met such a disastrous fate? What catastrophe happened all those billion years ago? What can we learn about its climate that can help us understand the climate here on Earth?

Mars may be a must-go destination for other reasons too. On March 31st six volunteers locked themselves inside a hermetically living space in a laboratory in Moscow. For the ensuing 105 days, they will be eating dehydrated food and breathe recycled air. Their communication with the outside world will have a twenty-minute delay. Simulated emergencies (e.g. equipment failure), as well as real ones will keep them on their toes, as will a number of scientific experiments that they will have to perform. Their every move and vital sign will be monitored around the clock. It sounds like the ultimate version of “Big Brother” but is in fact a simulation experiment for a human mission to Mars. If a real mission ever sets off, the astronauts will have to deal with the physiological and psychological aspects of being confined in a tin can hurled into space, bombarded by cosmic radiation, and sailing towards another world at a pace very unlike the zapping speeds sci-fi films have us accustomed to. The trip to Mars may take up to eight long months.

Once those future space pioneers get there however, there will have little to celebrate for. Mars is not a friendly place. Temperatures may vary from -870C at night to a “balmy” -250C in the afternoon. The atmosphere is mostly carbon dioxide and the air pressure less than 1% that of Earth’s. A space suit must be worn when walking about. But walking will be easy because the gravity is only one third that of our world. The sky would look bright pinkish because of the fine reddish dust blown aloft by Martial winds. Dustdevils roam the surface like wandering phantoms and kick up so much dust that visibility often gets close to zero. At sunset, with the winds subsiding, there may be some scattered clouds in the sky, and as our astronauts prepare for their night rest they may momentarily look up to the bright, tinkling stars, and easily recognize the same constellations, with one difference. Somewhere over the horizon a tiny bright blue ball of light will be gleaming: Earth.

There are many who doubt the usefulness, let alone wisdom, of such a risky and costly undertaking as a manned mission to Mars. To sustain a permanent base in Mars would be even more perilous. But as the Moscow experiment shows danger, and discomfort, seem to have a strange appeal to human nature, one not to be underestimated. There will always be people ready to take the challenge, no matter how impossible it may seem. The benefits are almost impossible to estimate. We will never know what there is to gain from landing humans on Mars unless we do it. For now we have at least two good reasons to attempt it. One has to do with pushing the technological envelope of space flight further. For the past sixty years very little progress has been made in space propulsion. A human mission to Mars will require a new generation of rockets and fuels; an eight-month trip is just too long and has to be cut back drastically. New technologies will have to be developed to ensure the safety of the mission. The second reason to send people instead of robots is space colonization, an agenda pushed forward by the Mars Society, a non-profit organization which has already designed the “planetary flag” of Mars, while undertaking some serious scientific work too. Establishing permanent human settlements on Mars will be a step-wise project which may take several centuries, unless an as-yet unimagined innovation comes along and revolutionizes space travel. And if living in a pressurized building and walking around in a spacesuit is not your idea of a good life, there is always terraforming. Scientists believe that given enough knowledge and time, we could pollinate the Martian atmosphere and soil with oxygen-producing organisms which will make Mars a more hospitable planet. For romantics and visionaries, it would be the “unwinding” of the ancient catastrophe and the making of a space Utopia, with canals and all. Perhaps then Lowell, as he peered into his telescope under the Arizona sky, he saw a revelation of the future. Perhaps, in that visionary future, the Martians will be our descendants.

Published in the Athens News on 24th April 2009