Brainy Babies!

Breast milk varies hugely from mother to mother but researchers now think that different milk is produced for boys and girls. Kate Lamble spoke to Katie Hinde from Harvard University to find out more.

Last week a young, physically healthy giraffe called Marius in a zoo in Copenhagen was put down, amidst an uproar from animal lovers. The zoo argued that it had to be done to prevent inbreeding, and produce a healthier population of giraffes. Here's your Quick Fire Science on the subject....

- Last week a young, physically healthy giraffe called Marius in a zoo in Copenhagen was put down, amidst an uproar from animal lovers. The zoo argued that it had to be done to prevent inbreeding, and produce a healthier population of girraffes.

- Inbreeding is when genetically closely related animals mate and bare offspring together.

- This raises the chance of harmful traits being passed down the generations, so reduces the fitness of a population.

- The European Association of Zoos and Aquaria (EAZA) runs a breeding programme for giraffes, which has been very successful. They supported the decision to put Marius down.

- Giraffes live in groups with one male and a number of females- young males have to be removed when they reach sexual maturity to prevent fighting

- The giraffe in questions was genetically similar to others in the breeding programme, so it was decided that for the health of the population it was best for him not to breed.

- Castration and contraception were decided not to be feasible alternatives as both require sedation, which is dangerous for giraffes.

- Yorkshire Wildlife Park in the UK, offered to take Marius, but because Marius' older brother lives there Copenhagen Zoo decided the space would be better off given to a genetically different giraffe.

- There has been public outcry and controversy over Marius' fate - this case raises a lot of questions over the right humans have to control an animal's life, are zoos ethical and how should species conservation programmes be managed.

- Inbreeding can happen in the wild if a population becomes isolated, for example on an island. These populations are then very susceptible to disease

- In humans due to the desirability of royals marrying other royals, some dynasties became very inbred, and suffered health problems.

We may think it's cold and miserable here in the UK in winter, but it's nothing compared to what polar bears have to put up with in the Arctic.

Although their black and brown bear cousins hibernate for the winter, and pregnant female polar bears hide out in dens during the coldest months, other polar bears brave the Arctic winter.

So how do these bears cope? New research from scientists, led by a team at the University at Buffalo in the US, suggests that the answer lies in their genes - specifically genetic adaptations that control the production of a chemical in the body called nitric oxide, which cells use to convert the nutrients in food into energy and heat.

Comparing DNA from 23 polar bears, three brown bears and a black bear, the researchers discovered key differences between polar bears and their cousins in the genes that control nitric oxide production.

The chemical is thought to help cells switch between generating energy from food, to keeping warm, or storing energy as fat, suggesting that this is helping the polar bears adapt to life in the freezer.

But what about animals living in other types of extreme climates? Interestingly, a related story was published this week from a team of Chinese, US and Canadian researchers who've been looking at Tibetan Mastiffs - dogs that are adapted to living up in the mountains at very high altitudes, which were originally domesticated from native dogs living on the Chinese plains.

Led by Dong-Dong Wu, the researchers scanned through the genomes of 32 Tibetan Mastiffs, and compared them to 20 Chinese native dogs and 14 grey wolves.

They identified 16 key gene variations that seemed to be particular to the mastiffs, and found that around 12 of them were relevant to life at high altitude.

While the genes identified in the polar bear were involved in keeping the animals warm, the dog genes seem to be focused on how to generate energy in the low oxygen conditions you get up at high altitude.

Similar gene signatures have been found in other high-altitude animals, suggesting that similar gene pathways evolve independently to cope with the extreme conditions.

Intriguingly, one gene found in the Tibetan Mastiffs, called EPAS1, has also been implicated in adaptation to low oxygen by Tibetans themselves. So maybe the dogs and their owners have evolved together to cope with life up the mountains, although this needs to be explored further to be sure.

Brainy babies now, and what makes for a child prodigy? Should you raise your baby to be bilingual? And are video games rotting, or rejuvenating, childrens' brains? Hannah Critchlow was joined by Professor Usha Goswami from Department of Psychology, Cambridge University...

When we want our children to learn we might give them books, take them on trips or even just help them do their homework - but what about getting them to play a action packed shooting based video game?

It might not be the first thing to spring to mind but Daphne Bavilier from the University of Rochester believes that these specific types of games can help attention, multitasking and even eyesight. Kate Lamble met up with her at the AAAS conference in Chicago.

Transcript to follow...

Transcript to follow...