Why do so many men, despite hair colour, have ginger beards?

Wednesday 22nd July 2009
Submitted by Luis Villazon
Ricky Gellatly, Oxford

Beard hair is quite different to head hair; it is coarser, curlier and doesn't fall out as we get older. Comparatively little work has been done on the genetics of human hair colour, but it is believed that in order to have a ginger beard you must be a carrier for the recessive gene on chromosome 4. With two copies of this gene you will have ginger hair all over, but with just one, the hair on your head will be brown or auburn and your beard will be ginger.

Why hasn't anyone built a diesel motorbike?
previous qanda Article
Why do old men go bald, but get hairy nostrils?
next qanda Article
Q&A Tabs

It depends on the temperature of the water. In cold water, the bacterial action that causes a body to bloat with gas may be so slowed that the body stays on the seabed. The skin will absorb water...

Lobsters and other shellfish have harmful bacteria naturally present in their flesh. Once the lobster is dead, these bacteria can rapidly multiply and release toxins that may not be destroyed by...

Phlegm is the mucous secretion of the respiratory passages. The cilia cells that line these passages are continually driving the phlegm upward to the throat, where it triggers the swallow reflex...

 When a nuclear bomb explodes on Earth, the huge release of radiation triggers the rapid expansion of air around it, causing the intense blast wave that wreaks so much destruction. In the...

Galaxies are certainly ‘born’ and ‘evolve’, but they don’t have a clearly defined ‘life cycle’ like stars do, for example. In the early Universe, ‘...

All female mammals have a clitoris, the sole purpose of which is to react to sexual stimulation, and presumably this stimulation has evolved to be pleasurable for most species. But establishing...

To create a sound, we have to set matter - whether it's a gas like air, a liquid or even a solid material - in regular motion, creating a wave of specific frequencies, which we hear as a sound of...

Mirrors don’t reverse left and right either – that’s just our interpretation of what happens. Your reflection in the mirror is actually reversed front to back – if you have...

Discovered by an American student named Gary Flandro in the mid-1960s, the slingshot manoeuvre usually involves spacecraft briefly 'coat-tailing' a planet orbiting the Sun, extracting some of the...

The ice disappears because the wind blows away water molecules that have evaporated or 'sublimed' from the ice, so the ice slowly shrinks in size. The molecules that escape are those with the...