Humans have a lot of diseases we don’t want. The problem is a lot of diseases are caused by bacteria or viruses that, just like us, want to survive and multiply! Our main weapons against bacteria are antibiotics. These are drugs that act a bit like your body does in response to bacteria. They latch on to the outside of the bacteria and recruit our body’s killer cells to come along and eat the bacteria.

But many bacteria have evolved to avoid the antibiotics, which then become a bit useless really! So lots of people who are sick with things like colds, or even worse, can’t be helped. Understanding how the bacteria evolve is really important if we want to avoid being completely helpless to fight back against them!

What about viruses? Viruses evolve really, really quickly. It’s their main way of evading our defences! That’s why there’s nothing really like antibiotics for viruses. One way we can help ourselves is to vaccinate vulnerable people, like the sick or old. Vaccines are dead versions of the virus which teach our body how to fight them. To be useful the vaccine has to be made from a similar virus to the one that is infecting people.

So how do you choose the vaccine? Scientists in Cambridge help to make the decision for the Flu virus. They study family trees of the virus to make informed predictions about what the next virus to infect people will look like. This is really important. Flu kills tens of thousands of people every year! The scientists can also tell where the virus comes from, so can help stop it spreading.

Our planet is in a state of change. All the pollution that we produce with our cars, power plants and aeroplanes is changing our climate. At the same time, we’re cutting down lots of forests and moving animals and plants from one part of the world to another. This is causing chaos in the natural world!

Climate change is a big issue; temperatures are predicted to rise rapidly over the next hundred years. This might sound quite nice but it will have lots of bad effects. Sea levels will rise and all the different weather systems will change. Lots of animals and plants are now found where they weren’t before. Their presence is causing lots of problems for local wildlife – they’re messing up all the food webs! The UK has lots of new species which have either been accidently introduced or are taking advantage of the warming weather: cannibalistic ladybirds, rampant crayfish and exotic spiders to name a few!

The changing weather has also confused many birds which migrate. They rely on clues from the weather to time their migrations. Because the temperature is changing so quickly they’re starting to get it wrong and they can leave too early and arrive at their destination when there’s no food, or leave too late and face the same problem!

In many tropical regions people are cutting down the rainforests to use the trees as timber, or to make the land good for farming. Unfortunately half the world's species live in the rainforest! Their habitats are being destroyed or cut up into chunks, isolating small groups from each other and making them more vulnerable.

We have to tackle these problems otherwise we’ll get ourselves into lots of trouble! But how? Part of the way we can do this is to understand how these changes will affect animals and plants. To do that we need to understand evolution! We can use our modern knowledge to help us conserve species, and cope with invasive species and climate change.

So, Darwin and evolution are proving very useful right now!

Written by Stephen Montgomery