One of the biggest questions in biology is whether the processes of life are able to exploit quantum effects to improve their lot. 

Nobody questions whether living things are ultimately quantum at some level–we’re all made of quantum objects called atoms and glued together by quantum forces. If you look closely enough at any biological process, you’ll see quantum mechanics at work. 

The question is whether nature exploits quantum mechanics to achieve things that are not possible in the ordinary, classical world. 

There is a growing debate on this topic.  On the one hand, evidence has begun to mount that quantum mechanics may play a role in processes such as photosynthesis, bird navigation and the sense of smell.  On the other, critics say this evidence is far from conclusive and may simply show that reality always appears quantum in nature, if you look closely enough. 

Today, Neill Lambert at the Japanese research institute RIKEN in Saitama and a few pals, provide a much needed review of the evidence in this area, focusing in particular on photosynthesis and bird navigation.

These guys point out that the efforts to find evidence of quantum effects in photosynthesis are largely focused on the fact that energy somehow crosses large protein molecules with an efficiency close to 100 per cent. That’s hard to explain classically.

The evidence for quantum effects in bird navigation is a little more speculative but leaves less room for a classical explanation. It is based on the idea that that a weak magnetic field can influence the outcome of a certain type of chemical reaction in bird retinas involving radical ion pairs. 

The details make for interesting reading. 

This is an area that  has gained huge attention in recent years. The promise, of course, is that if nature has found ways to exploit quantum mechanics, then it should be possible for us to copy those techniques. Think artificial photosynthesis, robotic noses and navigation systems, perhaps even artificial life.

But the alternative is just as interesting. If nature has not found a way to exploit quantum mechanics, an equally important question is: why not? Is it merely an oversight on the part of evolution or is there some other deeper reason why evolution cannot exploit quantum mechanics?  

Important questions. And for answers, a good place to start is with a comprehensive overview of the research. 

Ref: arxiv.org/abs/1205.0883: Functional Quantum Biology In Photosynthesis And Magnetoreception