x Abu Dhabi, UAE Thursday 20 July 2017

Biology waxes as physics wanes

Scientists are abuzz over a new development in biology that could alter our views about how organisms adapt and change.

Arabidopsis thaliana is under investigation at a university in the Netherlands for possibly flouting Darwinism by passing acquired traits to its offspring.
Arabidopsis thaliana is under investigation at a university in the Netherlands for possibly flouting Darwinism by passing acquired traits to its offspring.

As college students settle in to another year of study, those taking science courses may want to check out the September 6th issue of Science – and ask themselves if they’ve made the right choice.

The journal’s content of is a bellwether of the health of the subject. And to judge by two back-to-back articles in its pages earlier this month, those wanting to be where the action is may want to consider switching to biology, where a revolution could be about to break.

In recent years physics has been seen as the place to be, with its city-sized atom smashers, billion-dollar space probes and literally cosmic ambition. Its theories encompass everything from the workings of the atom to the origin of the universe and underpin every gadget and gizmo.

Yet all is not well on the frontier. Despite their best efforts, physicists are running out of big new ideas.

In a sense they are victims of their own success. Theorists have spent decades assembling a mathematical account of the subatomic particles and forces between them, known as the Standard Model. Meanwhile, experimentalists have been putting it to the test in machines such as the 27km-long Large Hadron Collider near Geneva.

And the good news is that the theory has passed every test – culminating last year in the discovery of the Higgs boson, which may well lead to Nobel Prizes next month.

The bad news is that physicists were hoping for more. They wanted the LHC to give them some hints about what lies beyond the Standard Model, which for all its successes is known to be incomplete.

For example, it says nothing about the force of gravity, nor about the driving force of the entire cosmos, known as Dark Energy, or the most common form of mass in the universe, Dark Matter.

The LHC has found nothing to help the theorists with these riddles. Indeed, it has made things worse by ruling out some ideas they had for creating the “Theory of Everything”.

As the Science piece glumly reports, it is a similar story at the other end of the size scale. Astrophysicists are celebrating confirmation of their basic theories about the cosmos by their equivalent of the LHC, the orbiting Planck telescope.

By examining the radiation left over from the Big Bang, Planck supports the long-standing idea that the universe began about 13.8 billion years ago with a brief period of so-called inflation, resulting in a mix of matter and energy that has been expanding ever since.

But like the LHC, Planck has given theorists no clues about what drove that inflation, or why the universe is now filled with enigmatic Dark Energy and Dark Matter.

Many physicists now fear they are entering a long fallow period, unable to squeeze anything new out of their nice, neat but underpowered theories.

Yet over in biology departments, things are looking much brighter. The second piece in Science describes how biologists are facing the realisation that Darwin may not be the final word in evolution.

It reports on packed sessions at this year’s Congress of the European Society for Evolutionary Biology in Lisbon, Portugal, where researchers learnt of results apparently backing a notorious rival theory to Darwinian evolution.

First put forward over 200 years ago by the French naturalist Jean Lamarck, it claims that living organisms can inherit traits acquired by their forebears during their lifetime.

According to Lamarck, giraffes acquired their long neck from antelope forebears, who spent their lives stretching up to eat leaves on trees.

In contrast, Darwinism sees all such traits as the result of random mutation of genes that just happen to prove useful to survival, and thus have a higher chance of being passed on to offspring. The idea of genes being permanently affected by life events is regarded as ludicrous.

Yet while it is clear that genes affect cells and thus the resulting organisms, there have long been hints of the reverse happening as well. One example is diet: we can choose to alter what we eat, and thus what ends up in our cells – which in turn can affect genetically related traits.

About 20 per cent of people carry a genetic trait that boosts their risk of heart attacks by up to 60 per cent. In 2011, researchers showed that the lethal effect of this gene could be switched off by changing diet to one rich in raw fruit and vegetables.

But Lamarckism goes a step further than this “epigenetic” effect. It posits that organisms can influence not only the action of their own genes, but of those of their offspring too.

Now evidence for this is beginning to emerge, as scientists cramming into those meetings in Lisbon heard last month.

A team led by Dr Frank Johannes at the University of Groningen in the Netherlands has been looking for Lamarck-like effects in a plant called Arabidopsis thaliana.

A relative of cabbage, A thalianais has a genome that is both relatively small and thoroughly known, making it an ideal genetic test bed.

The team set about creating multiple generations of the plant to see if they could spawn genetically identical strains with permanently altered traits.

And they appear to have succeeded. In results unveiled at the meeting, the team announced the emergence of strains with different heights and flowering times that have persisted through eight generations – despite them all having the same genes.

This suggests that epigenetic effects can persist down the generations. Given that such effects can be triggered by the environment or even the organism itself, this would mean Lamarck’s ideas cannot be dismissed after all.

Not surprisingly, many researchers are demanding further evidence before accepting this contradiction of Darwin’s idea. Is there perhaps something odd about A thaliana that makes it a rare exception?

For biologists, confirmation of these findings could prove as momentous as the events that struck physics almost a century ago, when studies of a solar eclipse showed that Newton’s law of gravity was just an approximation to the larger truth revealed by Einstein.

In fact, given the likely role of epigenetics in so many human traits, the effect of what was unveiled in Lisbon last month may prove even more momentous.

O Robert Matthews is visiting reader in science at Aston University, Birmingham, England