Friday, 31 January 2014

Ole' Blue eyes.

I don't know what you imagine/ think of when you visualise a caveman. Generally I picture someone who is tall, dark and extremely hairy. Alongside this dark image, I believe I assumed that cavemen would have dark brown eyes (not sure why? maybe to match the dark hair), but recently this conceptual idea has been disproved and it has been found that some cavemen had dark skin and blue eyes.

A Spanish team began working upon a pair of skeletons found in the caves of the Cantabrian Mountains in 2006. After the skeletons had been carbon dated, it was believed that the skeletons dated back 7,000 years ago and belonged to 2 thirty-something year old men. DNA from one of the skeletons was extracted from a molar, this was possible due to the well preserved nature of the skeleton due to the cool surrounding in the cave. The skeleton's entire genome was mapped and the man was identified as a modern European living before the Neolithic revolution.

Upon analysing the genome, the man  was found to have allele traits which produced darker skin than modern Europeans have now days, and more astonishingly the man was also found to have blue eyes. Suggesting that the transition in eye colour came before the transition to paler skin tones. The genome of the neolithic man was compared to modern-day Europeans and it was found that the caveman's genome is most similar to people living in Sweden and Finland.

So rethink your image of a caveman, he may not have been particularly tall, and have brown eyes, but 2 things scientists know for sure, is that some cavemen were dark-skinned with blue eyes.

Explorer Fact: Eye colour can change. In babies with European descent their eye colour can change up to the age of 1 years old. Generally it changes from a light colour to a darker shade of green, hazel or brown, although some remain blue.

Saturday, 25 January 2014

Purple as a tomato.

Genetically modified (GM) foods have been around for quite a number of years now, and they range from grapes to types of meat. And we all consume them (mostly) quite happily as the modification is done to make the food a better quality or to make fruit look a certain way or store for longer. However not much genetic modification has been done to the colour of foods. Is it because we will be put off eating food which is a different colour to what is expected? Or is it because we will be unable to recognise what it actually is?

Tomatoes are red, well you thought they were red but the John Innes Centre in Norwich have developed tomatoes which are purple. They are purple as they contain a gene from another plant (a snap-dragon) within their genome. It is this gene which activates a process which allows the tomato to start developing anthocyanin, which gives it the purple colour.

It is thought that the darker pigment will go to give these tomatoes the same health benefit as blueberries as they are an antioxidant and are believed to fight cancer. Currently theses super purple tomatoes are being grown in Ontario, and the first shipment of purple tomato juice is bound for Norway.

Would you munch one of these GM tomatoes?

Thursday, 16 January 2014

Why birds take formation.

It's a summer evening, and the sun is just setting leaving a beautiful sunset on the horizon, and you see a flock of birds migrating to someplace else, in that well known V shape. No matter if they are turning left or right they still rigidly keep to the V shape.

 For many years the reasoning behind the flock formation was unknown, but now scientists from the Royal Veterinary College have fitted data loggers to a flock of rare birds (Ibis') as they were being trained to migrate following a microlight plane.

It seems that when in formation a bird positions itself in such a way, in relation to the other birds in the formation so that it gives them the best aerodynamic advantage. They do this in order to make the most of the air moving upwards from the bird in front of them (this is called upwash, and is created when a bird flies forward and the air is pushed downwards beneath its wings). Moreover all the birds in the formation do not beat their wings in time with each other but instead flap them to get the upwash from the bird in front. So they are all slightly off time with each other. This helps the birds to be as efficient as possible which is a necessity when they have to migrate long distances.

Thursday, 2 January 2014

That was so last year!

What with this post being the first Science Tree post of the new year (2014!!), it only seems appropriate to take a look back at the top 5 events which have happened in science last year.

The top 5 countdown

5. The discoverers of the Higgs-Boson particle were awarded the Nobel Prize for 'postulating the existence of a particle which gives mass to all others'. Amazingly legendary Physicist Stephen Hawkings said it would have been more astonishing and beneficial to Physics if the particle hadn't been found!

4. Chewing popcorn whilst watching the adverts at the start of the film in a cinema, has been found to confer an "advertising-immunity" to us. When we read something in our mind (not out loud), it is read by a little voice, known in the physiological world as 'inner speech'; and it is this voice when we watch adverts which practices imprinting the brand name in our mind; so we remember the logo or the sign for a particular brand. By eating popcorn this does not happen and so....we are less receptive to advertising.

3. Ever had trouble with your memory? Well these mice certainly did. They were 'lucky' enough to have a false memory implanted into their mind, via the manipulation of single neurons. The neuroscientists engineered brain cells in the hippocampus (the part responsible for memory) to express a gene called channelrhodopsin, and a Pavlov type of experiment was carried out on them. They were allowed to explore a cage and when given an electric shock a blue light was shone on them which activated the gene. The following day the mice were put in a different chamber and a blue light was shone on them and they got scared, even though they were not shocked and in a completely different chamber. The mice had recalled their 'memories' from the previous day of the first chamber.

2. We have heard of a test-tube baby, but 2013 was the year of the test-tube burger(!) generated from cow muscle stem cells and grown in a lab. The burger was sampled for the first time on live TV. Thoughts on the burger were mixed but it took Maastricht University 3 months to grow the cells, whilst it took food critics minutes to consume.

1. Little Connor Levy was the first US child to have his entire genome scanned for genetic abnormalities via the use of Next-generation sequencing. This method of scanning reads each individual letter checking for anything which could lead to disease or abnormal chromosomes which could have increased the chance of his mother miscarrying. Obviously it was a success as little Connor is alive and kicking in the US of A!

So that was a whirlwind whistle-stop roundup of some of the best science news last year had to offer. Hopefully this year holds just as many, if not as captivating and ground-breaking events and breakthroughs as last year had to offer.

Happy 2014 Explorers!