Showing posts with label genetics. Show all posts
Showing posts with label genetics. Show all posts

Friday, March 08, 2013

We are indeed all Jock Tamson's bairns

With every generation you (nearly) double your number of ancestors because every individual has two parents – going back just 10 generations (200-300 years) you are likely to have around a thousand ancestors.

"When genetics researchers talk about common ancestry between people they usually mean that they are tracing the inheritance of particular sections of DNA or genes.And we know that different sections of our DNA have different patterns of genetic ancestry. This means that researchers can get very different estimates of how recently we share ancestors, depending on what they are looking at...
...look at mtDNA to follow ancestry passed along the female line. For mtDNA, everyone alive today shares a common ancestor who lived between 160,000 and 200,000 years ago.everyone alive today shares a common ancestor who lived between 160,000 and 200,000 years ago....
...look at Y chromosome DNA to follow ancestry through the male line, the most recent estimate is of a common ancestor who lived between 240,000 and 580,000 years ago...
...If, however, you look for the most recent person that everyone alive today is descended from, the best current estimate is that the individual lived only 3,500 years ago"

"Genetic ancestry testing presents a simplified view of the world where everyone belongs to a group with a label, such as ‘Viking’ or ‘Zulu’. But people’s genetics don’t reflect discrete groups. Even strong cultural boundaries, such as between the Germanic and Romance language groups in Europe, do not have very noticeable genetic differences. The more remote and less-populated parts of the UK, such as the Scottish Highlands, do have some genetic differences from the bulk of the population, but they are not big. There is no such thing as a ‘Scottish gene’. Instead groups show a story of gradual genetic change and mixing...
...Researchers use the genetic differences between Y chromosomes or mtDNA among a set of individuals to infer possible trees of relatedness. We can estimate the times of common ancestors on those trees, although these estimates lack precision. But it is not reasonable to make a leap from these DNA trees to mapping your ancestors onto geographical locations or past migrations. For example, a man in Scotland might have a type of Y chromosome that has been found more often in North Africa than elsewhere. However, this is based on populations in North Africa now, not in the past, and people have moved over the centuries. And, the same Y type may be found in other parts of the world – he could equally have inherited it from one of these. And even if some of his ancestors did come from North Africa, it does not show when they came to Scotland or how many of his millions of ancestors came from that region."

Prof Steve Jones, from University College London and author of some of the seminal books on genetics and evolution, said: "On a long trudge through history - two parents, four great-grandparents, and so on - very soon everyone runs out of ancestors and has to share them. "As a result, almost every Briton is a descendant of Viking hordes, Roman legions, African migrants, Indian Brahmins, or anyone else they fancy."

Sunday, May 13, 2012

Scots - the mongrel "race"

According to recent DNA research, the human species came very close to extinction during the last Ice Age. We know this because there ought to be far greater DNA variations than there actually are and providing evidence to suggest the total population of mankind towards the close of the Ice Age could have been as few as ten thousand people or less. More recently, DNA research from Leicester University and published in 2010, goes further and where eighty per cent of Caucasian males in Europe may have had ancestors who lived in regions known today as Iraq and Syria

Around 1,000 people have been tested in the past four months as part of the Scotland’s DNA project, and the preliminary results reveal the “astonishing” diversity of our genetic origins.

Almost 100 different groups of male ancestry have been found so far from all over Europe, and further afield, and 157 types of female DNA from Europe, Asia and Africa.

One per cent of Scotsmen, around 26,000 individuals, are descended from the Berber and Tuareg tribesmen of the Sahara, with a lineage going back 5,600 years.

 The project has also found a lost tribe, the Maeatae, who fought the Roman legions in 208AD and seemed to disapper from recorded history in the 8th century. The latest DNA techniques re-discovered them – concentrated in their historic homelands around Stirling.

 The Royal Stewart DNA is  found in 15 per cent of men with the "Stewart" surname, which means there are thousands of Scots wandering the streets with a “smidgen of royal blood in their veins”, the genetic marker also suggests that the Stewarts were originally Cornishmen.

  A team from Oxford University has discovered that the Celts are descended from a tribe of Iberian fishermen who crossed the Bay of Biscay 6,000 years ago. DNA analysis reveals they have an almost identical genetic "fingerprint" to the inhabitants of coastal regions of Spain, whose own ancestors migrated north between 4,000 and 5,000BC. "Although Celtic countries have previously thought of themselves as being genetically different from the English, this is emphatically not the case," Professor Sykes said. "...from a genetic point of view, Britain is emphatically not a divided nation."  The Celtic cultural myth “is very entrenched and has a lot to do with the Scottish, Welsh and Irish identity; their main identifying feature is that they are not English,” said Dr. Sykes

Dr. Oppenheimer, author of , “The Origins of the British: A Genetic Detective Story”,  said genes “have no bearing on cultural history.” There is no significant genetic difference between the people of Northern Ireland, yet they have been fighting with each other for 400 years, he said.

 "...We all came here after the last ice age and perhaps because it is impossible to go further north-west, Scotland has been the final destination for many journeys over 11,000 years. The basic lineage is the same for Scotland and England, the ice moved north and everybody came from the south. We have a lot more Vikings, and we have more early Irish, but the basic recipe is similar.”explained Alistair Moffat

Wednesday, December 19, 2007

Horse Sense

Millions of pounds spent each year on the sperm of race-winning horses. The owner of one superstar stud can earn £25 million a year. British breeders can typically expect to pay more than £500 a time in stud fees, with some American horses commanding fees of up to £10,000. Stallions reputed for producing good quality offspring come at a premium, and can fetch far higher fees.

Research published today will cast doubt on the rationale that bringing champion horses together will produce potentially race-winning foals. a horse's lineage is far less important than was previously thought. Genes account for only 10% of the prize money a horse wins in its lifetime

"The offspring of expensive stallions might tend to win more money, but not necessarily because they have inherited the best genes . It is likely those breeders best able to pay high stud fees are also those who are able to spend more on care of the horse, how it is trained, and who rides it - all of which will contribute more to how much it will win."

We in the socialist movement have been arguing that what genes determine in humans are the physical characteristics and the capacities of the brain, but not the actual behaviour and behaviour patterns . In other words, human nature is one thing, human behaviour another.

It makes horse sense .