Sexy Farmers

5 03 2010

Burly farmer with dirty fingernails seeks like minded companion for long days toiling in the fields.  Enjoys pig breeding and whittling tools. GSOH.

Now then, girls, try to contain yourselves.  Does this conjure up an image of your perfect man? No?  Well, it may have been a different matter for eligible young maidens living in Britain 10,000 years ago.

At this time farming was a revolutionary new concept.  Until then, humans had been content with hunting for animals and gathering wild plants from the land around them.  Farmers first appeared in the Near East but soon began to spread west across Europe, eventually reaching the shores of Britain.  As they travelled, they seduced the local ladies, breeding with women who chose them over the local hunter gatherers.

The farmer

So, how on earth do scientists know this? Well, they have been taking a look at the DNA of people all over Europe, including here in Britain.  This has revealed hidden clues about the identity of our ancient ancestors.

To find out about the male members of the family they scrutinised the Y chromosome, as this can only be passed down from father to son.  Males have XY chromosomes, whereas females have XX.

It turns out that a particular type of Y chromosome very common in Europe originates from the Near East, where farming first started.  Scientists took DNA samples from more than 2,500 men, and could clearly see that this genetic type had spread across the continent, travelling to the west.  More than 60% of British men, and almost all Irish men, have this version of the Y chromosome.

The farmer’s wife

But what about our female ancestors? Well, this is where the story comes together.

Other scientists have been delving into something called mitochondrial DNA, or mt DNA. This is genetic information that we all have (male or female), but it is only passed down maternally – we all got our mt DNA from our mothers, and they from their mothers.

Studies fail to find evidence for waves of ladies flooding into Europe in the last 10,000 years. It would seem that women were less likely to be intrepid adventurers, preferring instead to stay in familiar surroundings.  Unlike the males who migrated from distant lands, bringing with them their farming skills and their Y chromosomes, the females bearing the next generation were local hunter gatherer women.

What were our ancient ancestors up to?

These discoveries shed light on who fancied whom as the agricultural revolution took hold between 5,000 and 10,000 years ago. As Patricia Balaresque, an author of the study, puts it:

“Maybe back then, it was just sexier to be a farmer.”

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References

Scrutiny of the boys was published in PLoS Biology:

Balaresque P, Bowden GR, Adams SM, Leung H-Y, King TE, et al. (2010) A Predominantly Neolithic Origin for European Paternal Lineages. PLoS Biol 8(1): e1000285

Scrutiny of the girls was part of the following study:

Richards M, Macaulay V, Hickey E, Vega E, Sykes B, et al. (2000) Tracing European founder lineages in the near eastern mtDNA pool. Am J Hum Genet 67: 1251–1276