since moved to the National University of Singapore.">

By Steve Pointing 13/07/2016

Sometimes it is easy to find science that makes you smile, and this week I feature three interesting and amusing advances by scientists in New Zealand and the UK. Listen live today on 95.0 bFM radio at 12:15 or catch the podcast on-demand.

Why thumb-sucking babies get fewer allergies

Did you suck your thumb or bite your nails as a kid? Did your parents tell you off about it all the time?  Well finally science is your instrument for revenge – as Kiwi researchers at  Otago’s School of Medicine in Dunedin prove how biting your nails and sucking your thumb actually make your body tougher in the fight against allergies as you get older. A longitudinal study of over 1,000 participants born in 1970s were studied at infancy and then again as teens and adults. The research was looking for indirect evidence that exposure to microbes by sucking your thumb or biting your nails might lead to improved immune responses due to increased exposure to microbes. The survey showed that around three in 10 were suckers or biters as children and here is where it gets interesting:  As teens 45% of them showed reaction to a range of allergens including house dust, mites, fungi and grass cuttings.  In comparison only 40% of those who had one ‘oral habit’ displayed symptoms, and this was reduced to only 30% among those who bit their nails and sucked their thumb as kids. This trend extended into adulthood and occurred irrespective of gender, lifestyle or other factors.  As a microbiologist I can’t wait to see some microbiome data that may support these observations, and in the meantime I am going to hold off telling my young nephew to stop sucking his thumb!

Did monkeys teach early humans how to use tools?

It is pretty commonly accepted that modern humans arose from ape ancestors 1-2 million years ago in Africa. They pretty soon started migrating to new habitats all over the world and we now differentiate ourselves from apes based upon anatomy, physiology and genetics – but also on social complexity. We always assume we are ‘smarter’ than apes, but a new study suggests early humans entering new habitats may have learned from more primitive primates how to adapt tools to their new environment. The study is reported by Oxford scientists who had previously found fame showing macaques in Thailand have used stone tools for decades to open shellfish and nuts. The latest study repeated this observation on capuchin, small monkeys in Brazil that also use stone tools to open cashew nuts. These little primates also have a more complex inventory of tools, such as smooth hard quartzite hammers and flat sandstones as anvils. The young learn from older individuals and these ‘little monkeys’ gather to use their tools and pass on skills at the same food processing sites year. Now a mass spectrometer has been applied to stone artefacts to demonstrate they are covered in cashew nut residues, and the depth from which they were recovered suggests the site was in use for at least 700 years. This pre-dates European colonisation of Brazil and means over 100 generations of capuchins have used tools at the site. The authors speculate early human colonists both indigenous and European may have learned about the cashew nut as a food by observing this behaviour – and speculate early humans in their first migrations out of Africa may have similarly learned from ‘lesser’ primates.

Bacteria create electricity in microscopic wind farms

Finally another story from Oxford scientists about a new way to generate electricity that I just could not resist (poor electrical pun intended!). One of the most exciting challenges is to make cheap and sustainable electrical power for small devices. The team at Oxford did this by manufacturing a tiny micro-scale wind farm that could power tiny electronic devices, and all by exploiting the random movement of bacteria. If you have ever watched bacteria under a microscope you will have noticed they appear to ‘swim’ in random directions. Generating energy from this has been considered before, but always dismissed as it was assumed this motion was too disordered to get any useful energy out. Now a solution may be at hand. Tiny micro-rotors (like wind farm propellers) were introduced to a suspension of bacteria, and although introducing an individual rotor achieved nothing, when a network of 64 rotors were placed in the bacterial ‘soup’ they all began to spin in a coordinated way in opposite directions – a bit like wind farm rotors or water turbines. Amazingly this not only produces tiny amounts of harvestable electricity, but when introducing these micro-turbines to bacteria they SELF ASSEMBLE – so in future tiny machines could not only make their own power but also make themselves!