Thoughts in understanding ancestry DNA

Above image.  My Global 10 Genetic Map coordinates:  PC1,PC2,PC3,PC4,PC5,PC6,PC7,PC8,PC9,PC10 ,0.019,0.0272,0.0002,-0.0275,-0.0055,0.0242,0.0241,-0.0033,-0.0029,0.0015.  The cross marks my position on a genetic map by David Wesolowski, of the Eurogenes Blog

The above map shows genetic distances between different human populations around the planet.  Look how tightly the Europeans cluster.  Razib Kahn recently blogged on just this subject.  The fact of the matter is that the greatest diversity exists between populations outside of Europe, particularly within Africa, and between African and non-African populations.  However, we obsess over tiny differences within European populations, when in truth, most Western Eurasians are very closely related.  We share ancient ancestry from slightly varied mixes of only three base ancestral groups, with the last layer arriving only 4,300 years ago.  This obsession in the Market drives DNA to the consumer businesses to largely ignore non-European diversity, and to focus too closely on differences that blur into each other.

The above image is from CARTA lecture. 2016. Johannes Krause of the Max Planck Institute. It shows the currently three known founder populations of Europeans and their average percentages.

However, at the same time the new Living DNA service seeks to zoom in closer on British populations, attempting to detect ancestry percentages from such tiny zones as "East Anglia".  They appear to be having a level of success with it as well, although that blurriness, that overlap and closeness of populations in Europe gives problems.  Germans are given false percentages of British, Some Scottish appear as Northern Irish, and the Irish dilute into false British areas.  However, I've seen enough results now to suggest that it is far from genetic astrology.  They get it correct to a certain level, particularly for us with English ancestry.  Ancestry DNA customers expect perfection.  I don't think that we will ever get that from such closely related populations at this resolution, but it does provide a new genealogical tool that can point us into some revealing directions.

Above image.  My Living DNA Map.  Based on my recorded genealogy, I estimate 77% to 85% East Anglian ancestry over the past 250 years or so.  Living DNA at Standard Mode gave me 39%.  I'm impressed by that.  That a DNA test can recognise even at a 50% success, my recent ancestry in such a tiny zone of the planet.  I have doubts though that this sort of test will ever be free of errors, and mistakes.  The safest DNA test for ancestry is still one that is based on more distinct populations, and outside of Africa, that can be as wide as "European".  23andMe for example in their "Standard Mode" (75% confidence), assign me 97.3% European, and 0.3% Unassigned.  That is a pretty safe result.

Autosomal DNA tests for ancestry, particularly for West Eurasian (European and Western Asia) descendants, are not reliable at high resolution.  If you want to get really local, then sure - do it.  However, only use the results as an indication, not as a truth.  Populations in Western Eurasia are closely related, and share recent common descent.  There has been a high degree of mobility and admixture ever since.  Some modern populations tested do not have a high level of deep rooted local ancestry in that region.  They overlap with each other.  Keep researching and meander through different perspectives of what your older pre-recorded ancestry could have been.

Above image by Anthrogenica board member Tolan.  Based on 23andMe AC results.  My results skew away from British, and towards North French.  He generated this map, plotting myself (marked as Norfolk in red), and my Normand Ancestral DNA twin Helge in yellow.  My results fall in the overlap with French.  Helge is Normand but in AC appears more British than myself.  I am East Anglian yet in this test appear more French than he does.

The Paleo Diet. A critique

The above photograph seems to illustrate how many modern people eat.  I took it in a Wisbech back street, using the 50p camera, Olympus XA2, loaded with Ilford HP5+ film, which I developed in Kodak D76.

Eat like a Caveman?

What prompted this post?  I was shopping in a local discount store today, and I spotted their range of Paleo and Atkins diet aids - ketosis pills, high protein this, high protein that, and a ... Paleo Protein Bar.  I just cannot imagine a palaeolithic hunter-forager unwrapping and then biting into factory produced "protein bar".  The ketosis pills were ridiculous enough.  Still, it reminded me of why I turned my back onto the Paleo diet crowd years ago.

The Paleo-Diet is based on the assumption that humans have not had time to adapt towards a modern diet.  This they might argue, is why we grow overweight, unfit, and suffer many illnesses.  They suggest that humans evolved to a hunter-gatherer diet over many thousands of years.  In order to replicate some of our "natural" food groups, Paleo-dieters do not eat: junk food, fast food, bread, cereals, any wheat or flour products, refined sugar, beans, legumes (including peanuts), potatoes, processed vegetable oils, or any dairy produce.  Some Paleo-dieters with European heritage, also avoid certain foods, that originated in the New World, including for example, tomatoes, avocados, and peppers.  Although this proscription does not appear in the mainstream, there are some Paleo-dieters that believe that people without a long New World heritage, have a genetic based conflict with such food groups.  On my recent excursion into genetic profiling, I've seen posts from some individuals actively looking for New World food intolerant genes. I know where they are coming from.

Before I launch my critique, I should just start with what I do agree with the Paleo-Diet.

  • I fully agree that we have not had time to adapt to the modern diet.  However, I refer to the massive changes to our diet over the past 100 years, not over the past 10,000 years.  I agree that we should avoid junk food, fast food, processed meat, sugary foods, and processed oils.  I feel that we should also reduce our consumption of refined white wheat flour products.
  • I do like how the more sensible paleo-dieters seek out and eat a variety of vegetables, fruits, and nuts.  By avoiding starchy foods (rice, pasta, and potatoes), they sometimes consume more portions of vegetables.
  • It might encourage people to think like a hunter forager. Foraging at the local farmshops, markets and stores for more variety of natural wholesome foods. To consume mindfully. Avoid cheap meats.

Now what I disagree with:

  • It is based on bad science, bad anthropology.  10,000 years represents lots of generations for us to adapt to an agricultural diet.  Lactose tolerance is evidence of that evolution.  The book The 10,000 year Explosion: How civilization accelerated human evolution. 2009.  Cochran and Harpending, explores these issues, and revealed that human evolution, in terms of deviations within our population alleles, has actually accelerated.  One of the pressures behind this acceleration has been identified as the agricultural diet.  Anthropologists can also point to farming populations, for example, some dairy farmers in Africa, that are particularly tall and strong.  The past 100 years, yes, I can agree, we have not had time to biologically adapt to the profusion of refined sugars and processed fats that surround us daily.  However, you cannot tell me that agricultural foods are all bad.  What are Paleo-dieters actually eating?  Those fruits, vegetables, grass-fed beef, and even nuts, are all agriculturally produced.  I don't see many Paleo-dieters living on whatever they forage or hunt from the wild alone.
  • The truth is that hunter-foragers were highly adaptable to different diets.  As they spread across the planet, so they encountered different resources.  They adapted partly by human culture, by lifestyle, but humans are also great omnivores  and opportunists.  I once saw a British TV documentary about a a woman with an eating disorder, that restricted her diet to one flavour and brand of corn snacks.  Okay, her skin looked a bit pasty, but she was not noticeably overweight, and her disorder had not prevented her from surviving to adulthood, and from raising her own children.  What I hate about the Paleo-diet, particularly about some of it's more extreme schools, is that it is restrictive.  It prohibits the consumption at least of legumes, potatoes, even whole grains cereals, and beans.  Some of it's followers also avoid tomatoes!  Come on people.
  • Again, I'm not criticising the mainstream Paleo.  But some of it's followers  really go for the meat, even processed meats!  They treat it as a high protein diet.  In their eyes, hunter-gatherers ate largely what they hunted.  Although some hunter-gatherer communities did eat a lot of fish and whale meat for example, most of them in reality more likely resourced most of their calorific requirements with foraged foods.  For example, humans have an enzyme that converts starches from plant roots and tubers, into useful sugars.  Other species of apes lack this enzyme.  This would suggest that at some point of our ancestry, the ability to eat and digest roots was pretty essential for survival.  The prized tool of many bush women in SW Africa until recently (it's now most likely a smartphone), was the digging stick.  Expertly used to dig up edible roots for the pot.  Hunted meat was culturally more valued - but foraged foods provided most of the calories.  I've seen Paleo-dieters praising American bacon and tinned ham as a good food source.  I've seen the same people wince at the idea of eating fresh liver or sprats.  I'm pretty sure that fresh tomatoes, rolled oats, and even local potatoes (in the right proportion), are healthier than fried processed bacon.  But that's just my opinion.
  • Any focus on diet, is only half the equation when it comes to living well.  The other half is activity.  Do we exercise?  How often do we get out of breath?  Are we really happy, Do we push our muscles to the limit?  Do we take time out, to stroll through green, clean air areas, do we relax properly?

That's today's sermon.  Eat more vegetables and fruit, and you don't need to avoid oats or tomatoes.  Consume mindfully. Get moving.  Enjoy life.