Science Literature

The quest for the Higgs boson has been headline news in the world's media, perhaps owing more to its nickname (the "God particle") than to public understanding of why it is so significant. What is not in doubt is that this attention is good for physics and good for science. With so much attention given to technology exploitation, it is important to remind ourselves that fundamental science provides the foundations for advances in technology - and we still need blue-sky research. The excitement surrounding the Higgs boson stimulated a reflective essay in Nature from science writer Heidi Ledford. The question she addresses is: "What fundamental discoveries in biology might inspire the same thrill?"

"We put the question to experts in various fields. Biology is no stranger to large, international collaborations with lofty goals, they pointed out - the race to sequence the human genome around the turn of the century had scientists riveted. But most biological quests lack the mathematical precision, focus and binary satisfaction of a yes-or-no answer that characterize the pursuit of the Higgs. "Most of what is important is messy, and not given to a moment when you plant a flag and crack the champagne," says Steven Hyman, a neuroscientist at the Broad Institute in Cambridge, Massachusetts. Nevertheless, our informal survey shows that the field has no shortage of fundamental questions that could fill an anticipatory auditorium. These questions concern where and how life started - and why it ends.""

(Source here)

The topics identified are worthy of further thought: there are serious issues that need to be explored relating to the proposed three fundamental questions. The first of these is concerned with exobiology and where life originated. The search for signs of extraterrestrial life has been a feature of so many space exploration projects. The past year has witnessed sustained interest in the string of media reports about so-called "Earth-like planets" discovered by the Kepler Mission (comment on the first rocky planet is here). This, plus on-going discussion of solar system probes, plus the possibility of discovering unusual life-forms on Earth, has the goal of finding data to inform responses to the first biological Higgs question.

"The search for extraterrestrial life can be described as one way to test "a standard model of biology", says astrobiologist Chris McKay of the NASA Ames Research Center in Moffett Field, California. "It's the model of DNA and amino acids and proteins and a genetic code," he says. "It's the common features of all biology, and the framework through which everything we know about life is based." If life fundamentally different from this standard model - perhaps relying on a wildly different biochemistry - were found on another planet, it would show that there is more than one way to produce a living system, he adds."

The second big question is "how familiar life originated on Earth". It would appear that panspermia is not currently perceived as part of the story, but the quest is "how to synthesize an evolving, replicating system from scratch". We are back to the primordial soup or something very like it (but see here). The RNA World approach is the front-runner in the minds of most researchers. RNA can encode information and catalyse chemical reactions, but researchers are working with the hypothesis that RNA could replicate itself to make possible an evolutionary pathway. Ledford interviewed Gerald Joyce of the Scripps Research Institute in La Jolla, California.

"In 2009, a paper from Joyce's lab reported the development of a system of RNA molecules that undergo self-sustaining Darwinian evolution. But enzymes and a human hand were needed to create the RNA sequences to start off the reaction, Joyce says, and so far his lab has not found conditions that would allow the system to form spontaneously. "We're still a bit challenged," he says. "But the system is running more and more efficiently all the time.""

Over and over again, it has been shown that while particular pathways of chemical evolution (abiogenesis) can be demonstrated in the lab, the reactions always need the equivalent of "enzymes and a human hand" to yield any products of interest. There are hints that these repeated failures to achieve a viable RNA World are leading to a change of direction.

"Some believe that RNA may have had a precursor. Ramanarayanan Krishnamurthy at the Scripps Research Institute, is testing novel polymers of organic chemicals that could have formed in the primordial goo, in search of those that could replicate and evolve. "RNA was not the first living entity," says Bada. "It's too complex. Something preceded RNA, and that's where the interest is right now.""

Turning to the third big question, can ageing be delayed? Higgs-like expansions of this question are: "why do we age; what pathways control it; and what are the consequences if they are switched off?" For many years, the consensus has been that the biological networks that influence ageing are highly complex and that simple interventions would achieve very little. However, Ledford draws attention to work where the mutation of a single gene in a nematode worm was successful in extending the lifespan of the organism, and another single gene mutation in mice that achieved the same outcome. Such discoveries certainly stimulate hype, but the realists in the research community know that a breakthrough is not just around the corner.

"Ageing, however, "is almost the complete inverse of the situation of the Higgs particle", reflects Thomas Kirkwood, a leader in the field at Newcastle University, UK. "Everything that we're learning tells us it's highly unlikely that we'll find a single unitary cause.""

All three of these proposals for a "biological Higgs" reveal tensions between the mind-set of the researchers and the labyrinthine complexities of the real world. The problem for the researchers is that the information-rich systems they are studying cannot be reduced to simple physics and chemistry. Until the significance of information is grasped, these research programmes will continue to flounder - despite valiant attempts to keep them alive by spinning apparent successes. Information must be recognised as a substantial entity for understanding biological systems. It is not satisfactory to invent scenarios about information being produced by natural selection acting on molecular systems - we need testable hypotheses, not story-telling.

When information issues are accepted as crucial to the science of biology, we might propose an amended trio of biological Higgs: what makes one egg turn into a fly and another into a horse? Why are we conscious? Can ageing be delayed?

And biologists should not be too keen to envy physicists - who themselves have a problem of seeking a reductionist "Theory of Everything". The search for the Higgs boson may be too closely linked to thinking that the Standard Model is the last word on the subject. Whatever the outcome, physicists are just beginning to scratch the surface in their analysis of fundamental particles. Remember, gravity is still a mystery!

The biological Higgs
Heidi Ledford
Nature, 483, 528-530, (29 March 2012) | doi:10.1038/483528a

From the opening paragraphs: Biologists may have little cause to envy physicists - they generally enjoy more generous funding, more commercial interest and more popular support. But they could have been forgiven a moment of physics envy last December when, after a week of build-up and speculation, researchers at the Large Hadron Collider (LHC) near Geneva in Switzerland addressed a tense, standing-room-only auditorium. Scientists there had caught the strongest hints yet of the Higgs boson: what some have called the 'God particle' and the final missing piece of the standard model that explains the behaviour of subatomic particles. [. . .] All this led Nature to wonder: what fundamental discoveries in biology might inspire the same thrill? We put the question to experts in various fields.