Just before this BBC podcast gets underway, here's something you may not know.

My name's Linda Davies and I Commission Podcasts for BBC Sounds.

As you'd expect, at the BBC we make podcasts of the very highest quality featuring the most knowledgeable

experts and genuinely engaging voices. What you may not know is that the BBC

makes podcasts about all kinds of things like pop stars,

poltergeist, cricket, and conspiracy theories and that's just a few examples.

If you'd like to discover something a little bit unexpected, find your next podcast over at BBC Sounds.

Hello and welcome to more or less on the BBC World Service.

We're the program that sidles up to statistics, buys them a drink and asks them where they're from, and I'm Tim Harford.

As you know, we're lucky to have lots of listeners, and our proprietary more or less algorithm has determined that 87.3% of them are loyal, 7.3%

Lacedacical and 5.4% are crafty.

We received an email from one of the loyal ones, Paul.

Dear more or less, can you help me unravel an apparent inconsistency

between how percentages of human DNA in other species are reported. Fact one, humans and chimps share 96% of their DNA, no surprise there.

Fact two, at least 20% of Neanderthal DNA is in humans.

How are these two facts reconciled?

To help with a befuddlement, we need to define what DNA actually is.

DNA.

DNA, full name,

dioxy ribonucleic acid, found in the chromosomes in the cells of living things.

DNA determines the functions of each cell and is responsible

for characteristics such as eye color, hair color.

...