Gibraltar’s DNA research offers clues into mankind’s history in Iberia
Gibraltar-based scientists have contributed to a major genetic study of the history of the peoples of the Iberian Peninsula, with the findings to be published today in the online US publication Science.
The study, which includes ancient human DNA from Gibraltar, looks into the Iberian Peninsula population over a period spanning the past 8,000 years.
In Gibraltar, two major discoveries form part of the study including a skull that was found that belonged to a female from the Neolithic era whose ancestry was from Anatolia, now Turkey.
A further three males found in Bray’s Cave in the Upper Rock dated from the Bronze Age.
These remains indicated that the local Iberian Peninsula male chromosomes were completely replaced with those from central Europe during the Bronze Age.
The Gibraltar team participated in this study led by researchers at Harvard Medical School and the Institute of Evolutionary Biology in Barcelona.
Yesterday evening, Professor Clive Finlayson made the announcement at a press conference held in the John Mackintosh Hall.
The research first came to light in July last year and will be published today, which he said is a great achievement for Gibraltar.
“The Strait of Gibraltar and Gibraltar have been at the crossroads in history for obvious reasons,” Mr Finlayson explained.
“Even though Gibraltar is well known for the Neanderthal question, other issues are coming out on the back of that research.”
“This opens the window and we have the technology now to look at all of this, and we are very proud of Gibraltar and the rich history it has.”
“But it also has a rich pre-history that does not start with Tarik, we had the Phoenicians before that, and these people, and it just shows what a long timeline we have and what a wonderful time machine Gibraltar is.”
“As a Doctor Who fan, in the absence of a Tardis, this is the next best thing.”
The research was carried out by a team of 111 individuals, and the local team included Mr Finlayson, Professor Geraldine Finlayson, Stewart Finlayson, and Francisco Giles Guzman, archaeologist and senior scientific officer at the Gibraltar National Museum.
Heritage Minister Dr John Cortes, who said: “I think this research places Gibraltar in context, places history in context and it places society in context.”
“I think it shows us that we are not the people who invented day to day lives.”
“There are other things that happened in our history and in our prehistory which were just as real to the people living then as the people who are living now.”
“This research shows we were citizens of the world for a lot longer than we thought.”
“I think it is quite humbling to think about these things.”
Four samples from Gibraltar formed part of the research, which Mr Finlayson described as “wonderful forensic detective work”.
The first was a skull that belonged to a female that was found in the Europa Point 1 Cave.
The DNA sample dated back to the Neolithic era dating back to 5,400BC.
She was also lactose intolerant, something which most humans from that era were.
Other findings revealed she had Anatolian ancestry, which meant that her ancestors travelled from modern-day Turkey to Gibraltar, which could have taken generations to make the passage across Europe.
This is also the time, Mr Finlayson added, that people stopped hunting and gathering and turned to farming and agriculture for survival, a practice which started in the Middle East.
A further six males were found in Bray’s Cave in the Upper Rock nearly 10 years ago and their remains date back to the Bronze Age in 2000BC.
A small piece of Amber was also found during this discovery, linking them to the Eastern Mediterranean.
DNA sampling was carried out on three males that showed they were not related but they had 60% ancestry from earlier Iberian people from the Copper Age and 40% of ancestry from Central Europe.
“The three Bronze Age individuals from Gibraltar were confirmed males by the genetic analysis,” Mrs Finlayson said.
“It is very likely that they had light skin and dark eyes and that they were lactose intolerant.”
The three males were found in a cave which could have been a mass grave, although there is no evidence of violence.
The study also details genetic variation among ancient hunter-gatherers, documents intermingling of ancient Iberians with people from North Africa and the Mediterranean, and provides an additional explanation for why present-day Basques, who have such a distinctive language and culture, are also ancestrally different from other Iberians.
As far back as 2,500 BC, the researchers found, Iberians began living alongside people who moved in from central Europe and carried recent genetic ancestry from the Russian steppe. Within a few hundred years the two groups had extensively interbred.
To the researchers’ surprise, men and women from the two groups contributed strikingly unequal proportions of DNA to subsequent generations.
Before the central Europeans moved in, Iberians had no detectable recent ancestry from outside the Iberian Peninsula. After 2,000 BC, 40 percent of Iberians' overall ancestors and 100 percent of their patrilineal ancestors—that is, their father and their father’s father and so forth—could be traced to the incoming groups from central Europe.
“The results were astonishing,” said Carles Lalueza-Fox, a regular contributor at the Gibraltar Calpe conferences, principal investigator of the Paleogenomics Lab at the Institute of Evolutionary Biology and co-senior author of the study.
“The data suggest there was a major genetic change that is not obvious from the archaeological record."
What could have instigated such a dramatic turnover is not yet clear.
There is no evidence to suggest that Iberian men were killed or forcibly displaced either, as there is no evidence of violence, Mrs Finlayson added.
One alternative possibility is that local Iberian women preferred the central European newcomers, however genetic data alone will not reveal the whole story, the researchers said.
The team analyzed genomes from 403 ancient Iberians who lived between about 6,000 BC and 1,600 AD, 975 ancient people from outside Iberia and about 2,900 present-day people.
“It is unbelievable what new technology is doing. I would never have guessed, when we were excavating these individuals over ten years ago, that we would be talking about their DNA today,” said Mr Giles Guzman.
Findings from the 271 of ancient Iberian genomes (including those from Gibraltar) had not been published before. Nearly two-thirds came from skeletons no older than 2,000 BC, boosting by 25 times the number of publicly available genomes from this relatively recent period.