Why do birds sing in Spring?

Wikipedia Up here in the northern hemisphere spring has just started, bringing with it daffodils, sunlight and singing birds. But why do birds sing? They don’t have calendars like we humans do, so how do they know it’s time to start breeding? After all, it can’t be the weather, because where I live it’s been snowing today, but that hasn’t stopped the birds singing.

Scientists from Britain and Japan teamed up to solve this age-old problem. The result – birds sing not because of temperature changes or weather, but because of the lengthening days. As the days get longer, hormones are released which trigger the activation of a specific gene.

This gene gives the birds the urge to attract a mate and produce offspring – and just as humans gel their hair or wear make-up to attract a companion, birds are attracted to each other by singing. I suppose humans could sing to attract a mate, but somehow I don’t think it would be too likely to work. Just as giving a blackbird makeup probably wouldn’t inspire another blackbird to want to mate with it. But you never know…

Wikipedia Anyway, as always the big question is how on Earth did the scientists work out which gene was responsible? How did they know it was because of day lengths? Basically, they put a ‘genome chip’ in a sample of birds (Japanese Quails) to work out if any genes were activated or deactivated as the birds received varying amounts of sunlight each day.

They found that certain genes on the surface of the birds’ brains were switched on when the days were longer, and the cells with these genes then produced hormones that had already BBC Newsbeen known to give the birds the urge to mate. The result: birdsong, followed not too long afterward by baby birds.

It’s amazing to think how simple yet complicated nature can be sometimes. Interestingly, it is thought that humans may have genes affected by day lengths similar to those in the birds – these could be what causes some people to feel depressed in the winter.

Check out this great post on all things spring over on Exploratorium

Discovered: Ancient islanders just 3 feet tall

Palau, the island where the bones were discovered | Image: National Geographic If you were on vacation and discovered a skeleton, what would you do? Run away? Scream? Call for help? Lee Berger, a scientist in the field of anthropology, did none of those while on holiday on an island near the Philippines (map) – after reporting them to the authorities, he went back a few months later to take a second look at his gruesome find.

Being an anthropologist, he realized that these were no normal bones. (Click here for an excellent video) In fact, there were bones from quite a number of individuals, but they all shared a strange trait: even the fully grown adults measured just 3-4 feet high. Imagine chopping your head and feet off – that’s how tall you’d be (assuming you’re an average-height adult). They lived several millennia ago.

A size comparison of modern humans with the 'hobbit human' discovered in 2004 - it was a similar size to the newly discovered skeleton. Please note that this graphic takes the height of modern humans as the average height of a North American male | Image: Wikipedia Why? The reasons why an entire population were so short are still not totally clear, but various ideas are floating around. The island was quite short on food – many studies over the past few decades have shown that less food equals less height.

Also, because the island was isolated and there were no predators, there was little genetic variation among the small population, so any peculiar traits were reinforced, rather than being watered down as usually happens in evolution.

The mystery of the story doesn’t end there, however. You may remember when scientists announced the discovery of ‘hobbit humans’ in Indonesia a while ago. The ‘hobbits’ were classified as a totally new species. The problem is that these new discoveries share many features with the hobbits, but scientists say these are definitely Homo sapiens. That obviously causes a bit of a problem, to which no-one knows the answer – yet.

It’s not nice when scientists argue – but I suppose it’s probably nicer than discovering some bones in the middle of your vacation.

The animals that could save your life: Sea Cucumbers

Sea Cucumber | Image: National Geographic Sea cucumbers aren’t the sort of things you’d think could save someone’s life – most people will never even see one in their lives. But a new material, based on the design of a sea cucumber’s skin, may just be about to start a medical revolution.

When sea cucumbers get scared, they suddenly make their skin go hard, which offers more protection against predators than their normal soft skin. The new material designed by scientists obviously doesn’t go hard when it’s scared, but instead it has nanoparticles that make it go soft when it is wet and hard when it is dry.

Sea cucumber size comparison | Image: National Geographic Wait a minute… don’t loads of other materials go from hard to soft when you get them wet? Yes, but they usually lose strength when they’re wet, or they’ll break up when they go hard again.

It’s all very well designing a material that can change from soft to hard an infinite number of times, but why? The primary application the scientists had in mind would be brain electrodes for research into Alzheimer’s and similar diseases. The electrodes would be easy for surgeons to put in, because they would be hard and rigid, and then they would go soft when they made contact with the brain, which would help the electrodes to merge in with the brain, and thus work much better.

A scanning electron microscope's view of the new material | Image: BBC News Other possible applications include bullet-proof vests that are comfortable to wear, but can suddenly go hard when needed; casts for broken bones could be made to go hard or soft as required – there are loads of possibilities.

One final question: how did they make this material? Basically, it’s all down to nanoparticles that create super-strong hydrogen bonds whenever they get wet. When they dry out, the bonds disappear. Surprisingly, all the architecture for the material is based on the skin of the sea cucumber.

Animals really can do some amazing things. Just think about that good old sea cucumber when you get cured from Alzheimer’s.

Scientists advance technology capable of seeing your dreams

Imagine being able to watch someone else’s dream, or see what they’re daydreaming about. Surely this is only possible in science fiction? Well actually, it is (probably) possible in real life too, and the technology needed to do it may be around in just a few decades.

Scientists at Stanford University have published new Human eye | Image: Wikipediaresearch in which they could ‘see’ what someone else was seeing. OK, the scientists didn’t physically ‘see’ an image of what the participant was viewing, but they could work out what sort of picture the participant was looking at.

It’s basically like giving someone a book with a few hundred pictures in, then telling them to open to a random page, and being able to work out which image the person is looking at. Very cool.

MRI scan of a human brain | Image: National Geographic How? I wondered that too, and it’s a lot less complicated than you might think.

The scientists started by showing a series of images to the participants, and tracking the different oxygen levels in the brain associated with each image – different pictures will trigger different amounts of oxygen in different parts of the brain. They repeated this several hundred times, putting the results into a computer program that could ‘learn’ which oxygen levels were associated with each type of picture.

Then, when an unknown image was shown to the participant, the computer program would look at the person’s brain oxygen level and figure out what sort of image they are looking at.

So what about seeing dreams? It’s certainly a long way off yet, but I think this new research is a vital first step to a massive number of possible applications. Of course, it also raises the issue of whether people want to have their brains read… I’d be interested to hear your thoughts – post a comment below.

Japan: Where robots have emotions

Is this what we'll be living with in 15 years? | Image: Wikipedia Imagine a robot that doesn’t just respond to human emotions, but actually has its own emotions. In just a few years time we may not have to imagine any longer, thanks to the astonishing recent rate of progress in robotics in Japan.

Already robots are being programmed to respond to human emotions – they might smile when they hear people laughing, or ‘cry’ when they hear about murders. And in Japan, 15% or the entire workforce is expected to be robot by as soon as 2025 – that’s just a little over 15 years.

I must admit that I had no idea that robot development is so far ahead in Japan – some hospitals have walking, talking humanoid robots that greet patients while cleaning the floors. Humanoid robots are actually expected to become a key part in care for the elderly as Japan realizes that it has far more old people to look after than young people to work, thanks to the post-war baby boom.

Map image

I think robots have really great potential, and hopefully over the next few years the rest of the world will start following Japan’s example. I’ve said this before and I’ll say it again: we really are living in an exciting time for exploration, discovery and research – it’ll be interesting reading this post 10 years to see how much progress we’ve made.

Or maybe I’ll get my robot to read it for me.

Check out an excellent article from MSNBC on Japan’s robotic future here

Preserving seeds for 10,000 years: New doomsday vault opens

The entrance to the 'doomsday' vault | Image: National Geographic

I don’t plan to be around 10,000 years in the future, but what would I do if I woke up in the year 12,008 and wanted something to eat? It would probably be a good idea to go to Norway.

- Svalbard Archipelago

Why? A new facility has just opened on a remote Svalbard island which aims to collect millions of seeds, preserving the genetic diversity of our crops in case humanity has a disaster like nuclear war or extreme global warming. Even if there was a major earthquake nearby or a direct hit by a nuclear missile, the new storage facility has been built so strongly that it would be able to withstand the destruction. (Click here for images of the doomsday vault)

Within a few years, the target is to have a few hundred samples of each of 4.5 million different varieties of crops, coming to a grand total of 2 billion individual seeds. So far only 100 million seeds have been added, but even they weighed a massive 10 tons, meaning that when the facility is full it will contain hundreds of tons of seeds.

Shelves inside the seed vault | Image: CNN As if it wasn’t cold enough in Svalbard already – it never goes above freezing point – special air conditioning systems have been added to reduce the temperature to a frozen 0F (-18C). The low temperature is essential if the seeds are to last for thousands of years, and fortunately the ice around the seed bank won’t be melting anytime soon – it is located deep inside a remote frozen mountain.

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So when I wake up in 10,000 years, I’ll be able to eat whatever I want – maize, wheat, rice… I just hope I’ll manage to figure out how to get there…

How did the first humans get to America?

A Neanderthal, the species that homo sapiens would eventually drive to extinction | Image: Wikipedia We all know that the first humans on our planet lived in Africa. It’s simple enough to explain how they got to the Middle East, then Europe, then Asia, but how on Earth did they get all the way to America?

A major new genetic study has given massive support to the theory that the first Americans got to the continent by traveling from Siberia, across the Bering Strait on a land bridge that is now covered in water. There were two separate influxes – one around 30,00 years ago, and one after the end of the last Ice Age, 12,000 years ago.

So how is it possible to tell which direction humans migrated tens of thousands of years ago? The new research (published in the jornal Science) collected information on ‘genetic markers’ from about 1000 people from all over the world. By comparing who has which markers, it is possible to tell which populations are most closely related to each other. (Click here for an extensive interactive guide detailing human migration)

Map of human migration | Image: National Geographic

Other interesting finds from the research include the fact that the further you go from Africa, the less diverse human genetic code becomes. This is because only a relatively small number of pioneering humans actually came out of Africa, and so all the rest of the world is descended from only a small pool of genetic variation.

And one fascinating fact that should forever put an end to racism: over 90% of all genetic variation in humans occurs in populations themselves, rather than between different populations and races. So there may be more genetic difference between two white Americans than between a Hispanic and an Aborigine. Now that’s something to think about.

If you think this research is interesting, why not join the Genographic Project, a new genetic survey aiming to be the biggest of its kind ever undertaken. It’s co-sponsored by IBM and National Geographic. Please note that the Genographic Project is completely unrelated to the research detailed above.