Eighteen years later, pregnant with my first child, I started eating fish. Oily fish in particular contains plenty of long-chain omega-3 fatty acids, essential for neural development.

I was a fairly strict vegetarian - I ate eggs and dairy products but nothing that would involve killing an animal to furnish the food on my plate.

I gave up meat when I was 18, and it was an ethical decision. I loved the taste, and went on holiday to Greece, fairly gorging myself on lamb souvlaki before taking the plunge into a meatless existence.

If a group of humans began to run regularly, perhaps allowing them to hunt or scavenge more effectively, anatomical changes would follow, especially among the still-developing youngsters.

In our evolutionary narratives, the organism itself often seems to play a passive role: a powerless victim, almost, of changes to its environment or mutations in its genes.

Always attempting to tame and subjugate nature is not the solution. But the latest science is helping us to map out a path across this shifting landscape in uncertain times, showing us how to work with natural forces, not against them.

While planting woodlands along rivers has been shown to work in small areas, it has been unclear whether it would be effective on a larger scale. But computer modelling indicates that restoring forests on floodplains could slow floodwaters and reduce the height of the flood downstream.

Science offers us the possibility of understanding natural rhythms and events that must have seemed like the work of angry and unpredictable gods to our ancestors.

Around 4000BC, the Mesolithic, hunter-gatherer way of life here gave way to a more settled, farming existence. Those Neolithic people built wooden trackways across the salt marshes and reed beds.

Stonehenge is famously aligned with midsummer sunrise, and possibly also intentionally with midwinter sunset.

Pagan Romans started their midwinter celebrations with the feast of Saturnalia on 17 December, ending them with a new year festival, the Kalendae Januariae, at the start of January - both were celebrated with parties and the exchange of gifts.

In Luke, shepherds go to find Jesus. In Matthew, an unspecified number of wise men, sometimes portrayed as kings, arrive. Nativity plays usually throw all the elements together, with kings and shepherds beating a path to the stable.

I love Christmas. At this very special time of year, when the sun appears only fleetingly to those of us living in the northern hemisphere, I feel a deep connection with ancient ancestors.

I’m slightly obsessed with Moomins. They were my specialist subject on BBC’s 'Celebrity Mastermind' a few years ago!

I’ve always loved the seaside and I used to be a fairly keen surfer, but it’s a solitary activity so when my husband and I had children, we bought sit-on-top kayaks. Whenever possible, we escape to the coast or explore rivers with them.

My mum was an art teacher, so we used to have fantastic dressing-up costumes when we were little.

I’m a firm believer in teaching children to manage risk.

Of course 'Horizon' had made an impact on me from a young age, but it was also humbling to meet and interview eminent scientists, and hear their high opinion of the series and of the science presented on the BBC more generally.

Science plays a huge role in our lives. We're surrounded by technology, we depend on it.

Look what consumer power has done with organic food; we can do the same with clothes.

I was a goth in my student days. I dyed my hair black, but it came out grey, with a blue scalp. Then I dyed it red and it came out fuschia pink.

When I started doing television, I was very aware my clothes would be obvious and it was a great opportunity to promote brands which are made with respect to people and the environment.

The real hallmarks of humanity are: curiosity and an amazing ability to cooperate.

I find humanism to be the most rational and positive philosophy for life. And it’s not a new thing at all - the history of humanist thought is deep and inspiring.