Researchers dissected the evolutionary history of the Italians for the first time, revealing that their extraordinary diversity dates back 19,000 years.
The study shows that northern and southern Italians have evolved differently over time due to contrasting environmental and ecological circumstances that have led to the peculiarities of their gene pools.
The results help explain the differences in health of the two groups, as well as their predisposition to certain diseases.
the The team sequenced the entire genome of participants from the two sites, resulting in over 17 million genetic variants that were compared to 600 human remains from the Upper Paleolithic to the Bronze Age.
The team identified traces of post-glacial migrations among residents of northern Italy, who also had a close relationship with ancient European cultures such as the Magdalenian and Epigravettian – these groups were mainly located in what today is France and Spain.
On the other hand, southern Italians have been found to have a close relationship with the Neolithic human remains of Anatolia, modern Turkey and the Middle East, and with the Bronze Age vestiges of the South Caucasus – a region that extends to Africa
Researchers also discovered features that characterize people living in the north and south who have evolved due to different environments that help reduce the risk of kidney inflammation and skin cancer, as well as the risk of diabetes and d obesity, promoting a longer lifespan.
Scroll down for video
Researchers have dissected the evolutionary history of the Italians for the first time, revealing that their extraordinary diversity dates back 19,000 years ago. Results showed an exact crop that had an impact on the northern and southern regions of the country
Marco Sazzini, one of the principal investigators of this study and professor of molecular anthropology at the University of Bologna, said: “ Understanding the evolutionary history of the ancestors of Italians allows us to better understand the demographic processes and those of environmental interactions that shaped the complex mosaic of ancestry elements of today’s European populations. “
“This survey provides valuable information in order to fully appreciate the biological characteristics of the current Italian population.”
“In addition, it allowed us to understand the root causes that can have an impact on the health of this population or on their predisposition to a certain number of diseases.”
For this study, published in BMC Biology, the team sequenced the entire genome of 40 participants, resulting in 17,495,290 single nucleotide variants (SNV).
Researchers were able to map the location of ancient civilizations that influenced genetic diversity among the two groups of Italians
After analyzing the genomes of participants from southern Italy, the researchers discovered that traces of post-glacial migrations were not present and noted that more recent events had significantly reshaped their genetic makeup.
Scientists then compared SNVs to genetic variants observed in 35 other populations in Europe and the Mediterranean, and then to those found near 600 human remains dating from the Upper Paleolithic (40,000 years ago) in the Bronze Age ( 4000 years ago).
“These comparisons have reached such high levels of precision that it has been possible to extend the investigation to very distant periods compared to those obtained by previous studies,” the team said in a statement.
Following these investigations, the team determined the traces left in the genetic heritage by the events which followed the last glaciation which ended about 19,000 years ago.
The earliest events that left their mark on Italian DNA were the migrations that occurred during the Neolithic and Bronze Age, which took place between 7,000 and 4,000 years ago.
“The results of this study show, on the contrary, that the first biological adaptations to the environment and the migrations that underlie the extraordinary genetic diversity of Italians are much older than previously thought,” said l ‘team.
The team also assessed and measured the differences between the gene pools of participants from northern and southern Italy.
Stefania Sarno, researcher at the University of Bologna and one of the co-first authors of the article, said: “ We observe demographic trends that partially overlap among the ancestors of these two groups of 30,000 years and for the remaining years of the Upper Paleolithic. ‘
“However, we observed a significant variation between their gene pools from the late ice age, therefore a few thousand years before these great migrations that occurred in Italy from the Neolithic.”
The DNA of people living in northern Italy shows traces of these post-glacial migrations.
They also have ties to the ancient European cultures which lived mainly in what is now France and Spain.
In addition to having traces of different cultures, the study also revealed distinct features in the gene pools of two groups. The metabolism of northern Italians has adjusted to digest a diet high in calories and fat, which makes them less at risk for diabetes. The pigment of southern Italians that gives skin color has been changed, which is why they are less likely to get skin cancer.
However, the team discovered elements of even older ancestry from Eastern European hunter-gatherers who roamed Earth between 36,000 and 26,000 years ago.
This group then spread to Western Europe with migratory movements of “glacial refuges” during the late ice age.
After analyzing the genomes of participants from southern Italy, the researchers found that traces of post-glacial migrations were not present and noted that more recent events had considerably reshaped their genetic heritage.
This group has closer genetic relationships with Neolithic human remains from what is today Turkey and the Middle East.
There are also traces with the remains of the Bronze Age which were discovered in the northern parts of Africa.
“ Unlike northern Italy, the south was a main hub for migratory movements, which first spread agriculture in the Mediterranean region during the Neolithic transition, then during the Bronze Age , fostered a new ancestry component, ” said the team.
In addition to having traces of different cultures, the study also revealed distinct features in the gene pools of two groups.
Those migrating north have experienced abrupt climate change and environmental pressures similar to those of the last glacial maximum, which has forced biological adaptations.
For example, their metabolism has changed so that they digest a diet high in calories and fat.
Study shows that northern and southern Italians have evolved differently over time due to contrasting environmental and ecological circumstances that have resulted in the peculiarities of their gene pools
Paolo Garagnani, professor of experimental medicine and pathophysiology at the University of Bologna: “ In subjects from northern Italy, we observed changes in the gene networks regulating the production of insulin and body heat as well than in those responsible for the metabolism of adipose tissue. “
“These changes could have resulted in key factors reducing susceptibility to diseases like diabetes and obesity.”
Southern Italians, however, bask in a warmer climate than their counterparts.
This environment has caused changes in the genes coding for mucins, which are proteins found in the mucous membranes of the respiratory and gastrointestinal systems that prevent pathogens from attacking tissue.
Paolo Abondio, Ph.D. student at the University of Bologna and another co-first author of this study, said: “These genetic adaptations may have evolved in response to ancient microorganisms.
“Some researchers have linked some of these genetic variants to reduced susceptibility to Berger disease, which is a common inflammation affecting the kidneys and which is indeed less common in the south than in northern Italy.”
Regarding the peculiarities of southern Italy, the researchers found the genes that modify the production of melanin, which is the pigment that gives skin color.
They believe that this happened due to more intense sunshine and a higher number of sunny days in the Mediterranean regions.
These changes may also have contributed to a lower incidence of skin cancer among southern Italians.
Claudio Franceschi, professor emeritus at the University of Bologna, said: “We have observed that some of these genetic variants are also linked to a longer lifespan.”
“This also applies to other genetic modifications characteristic of southern Italians.”
“These are found on genes involved in the metabolism of arachidonic acid and on those encoding the FoxO transcription factors.”