December 10, 2014 For curious minds who are keen on ancient Egyptian history and culture, have you ever wondered how much work can take to conserved a human mummy? Here is a recent example! Conservation process of Minirdis, a 2,500 years-old mummy of 14 years-old Egyptian boy, who was the son of a priest, has been recently conducted at Chicago´s Field Museum. This mummy has been part of the museum since 1920, along with a collection of 30 complete human mummies from Egypt. The scientists who opened the coffe few weeks ago, are eager to stabilize the mummy and coffin, so they can travel in the exhibit "Mummies: Images of the Afterline", which is expected to open in Los Angeles in September. To do so, conservators are already working hard; creatingwood pieces to repair broken sections of the coffin and using new linen to fill holes and gaps in the death mask. Have a look to this short video if you want to gain a deeper insight into the world of conserving Egyptian mummies!
Among the most controversial topics in paleoanthropology the following question
arise:
Were Neanderthals a different species from
modern humans or just a subspecies?
New evidence supported that our close relatives, Neanderthals, were a distinct species separate from Homo sapiens and not a subspecies of them. This has been demonstrate by looking at the complete morphological pattern of the whole nasal complex in Neanderthals fossil remains and comparing them with modern humans data. This comparison has revealed clear species- level differences in nasal structure and function.
Furthermore, the research has indicated that the Neanderthal nasal complex was not adaptively inferior to that of modern humans, and thet Neanderthal´s extinction was likely due to competition from modern humans and not an ability of the Neanderthal nose to process a colder and drier climate. IN fact, it seems that previous works about Neanderthals nose, have approached this anatomical enigma from the wrong perspective; comparing nasal dimensions of Neanderthals to modern humans populations (Inuit and Europeans whose nasal complex is adapt to cold and mild climates).
However, the results of the current study suggests that the upper airways of this extinct group worked through a different set of rules as a result of their evolutionary history separate from modern humans. Modern Homini also stated in its different overall cranial structure of ours, all resulting in a mosaic of features not found among any population of Homo sapiens.
The archeologist Andrew Smith, discovered a skeleton in St
Helena´s baith in 2010, near the place where some human tracks from 117.000
years ago, appeared. Those prints were called Eva´s prints. That skeleton
belongs to a man that lived in southern Africa 2.330 years ago, and the finding
of it gives us more information about human´s origins and our common ancestor.
The mitocondrial or matern DNA extracted from a teeth and a
rib was analyzed and it has aported the
first proof of our origin: we all come from Africa (from a lineage that is,
presumably, extinct). Besides, it can be used to develop the human geneological
tree with all the branches derivated from a common mitocondrial Eva.
The genetic information found in those bones are the oldest
ones that diverged from the genetic profile made about some modern human
appeared 200000 years ago.
Lactose which is the main carbohydrate of
the milk, is a disaccharide sugar derived from galactose and glucose. To be
able to digest it, lactase enzyme is required. In mammals, after the period of breast
breeding, the expression of this enzyme drops considerably, until it disappears.
In general, during adulthood mammals feel sick whenever they try to digest this
sugar .However, a mutation responsible for lactose tolerance aroused randomly
years ago. This change in the regulatory region of the lactose gene, turned out
to provide additional sustenance and source of water to ancient individuals that
depend on dairying. As is showed a distinct advantage in this kind of
population, the trait of lactase persistence during adulthood was eventually favored
by natural selection, first in Europeans. Still today, is considered one of the
strongest signals of selection within human genome variation.
Latest findings, October 21
We encourage you to watch the video!
Published in Nature Communications by the University College of Dublin (Ireland)
Researches from the University College and Trinity College of Dublin have revealed that our Eiropean ancestors remained lactose intolerance for 5000 years. This occurred after they began practicing agriculture and 4000 years after they started to make cheese among Central European Neolithic farmers. The study has analyzed DNA extracted from the petrous bones of 13 individuals skulls from different eras, all of hem found buried in archaelogical sites in the Great Hungarian Plain. Regarding the results, the authors sugest that from the Neolithic to the Bronze and Iron age might have occurred significant changes in the genetics of these populations. What is more, it took several years of experimentation with different bones of varying density and DNA preservation to discover that the inner ear region of the petrous bone in the skull, which is the hardest bone and well protected from damage, is ideal fro ancient DNA analysis in humans and any other mammals. For the first time, the percentage for the DNA yiels in the petrous bones was 183 times higher than in other bones, such as those from the teeth, fingers or ribs. The exceptionally high percentage of DNA yield made it possible to scientists to check for known genetic markers, including lactose intolerance. Thus, they found that in all that time human pigmentation was modified, as transformed from hunters to farmers, but instead, they did not acquired lactose tolerance. This means that thses ancient Europeans would have had domesticated animals like cows, goats and sheeps, but they would not yet have genetically develoved a tolerance for drinking large quantities of milk from mammals.
The FOXP2 gene which is
implicated in human speech and language proficiency does exists in both humans
and chimps. But the version of this gene in each of the speciesnot only looks different but functions
differently too. A mutation that happened over half million years ago (a substitutions
of two amino-acids) was theresponsable
of distinguishing the human FOXP2 protein from
that found in chimpanzees. Evidence from genetically manipulated mice and human
neuronal cell models suggests that these changes affect the neural functions of
FOXP2.
Last findings, raise the possibility that the humanized FOXP2 phenotype reflects a different tuning of corticostriatal systems involved in declarative and procedural learning, a capacity potentially contributing to adapting the human brain for speech and lenguage acquisition.
Genetic and archaeological research in the last 10 years has revealed
that almost all present-day Europeans descend from the mixing of two ancestral
groups: indigenous hunter-gatherers and early European farmers.
However,researchers at
Harvard Medical School and the University of Tübingen in Germany have now
documented a genetic contribution from a third ancestor: Ancient North
Eurasians. This group appears to have contributed DNA to present-day Europeans
as well as to the people who travelled across the Bering Strait into the
Americas more than 15,000 years ago.
This explains the recently
discovered genetic connection between Europeans and Native Americans as the
same Ancient North Eurasian group contributed to both of them. What is more,
the research team also discovered that ancient Near Eastern farmers and their
European descendants can trace much of their ancestry to a previously unknown,
even older lineage called the Basal Eurasians. To prove Europeans ancestry, the researchers collected and sequenced the
DNA of more than 2,300 present-day people from around the world and of nine
ancient humans from Sweden, Luxembourg and Germany.But even if ancient DNA sequencing was
considered to be a powerful technology to learn about human history, as they
were limited number of DNA ancient samples, the team think there could easily
be more than three ancient groups who contributed to today's European genetic
profile. In fact, they havefound that the
three-way model doesn't tell the whole story for certain regions of Europe. That
is why only more genetic data from ancient human remains will allow the
scientific community to fully unravel our prehistoric past.
Despite
some people's insistence humans are no longer subject to natural selection, the
anthropologyst John Hawks of the University of Wisconsin suggests that we have evolved
dramatically in the last 30,000 years and will continue to do so into the
future. To prove a recent human evolution he makes reference to how Tibetans
have adapted to living at very high altitudes.
In fact,
Millions of Tibetans spend their days at average elevations of nearly 15,000
feet and even if , up there the air has 40 percent less oxygen than at sea
level as well as a lack of O2 Tibetans seem to breathe easy. The last finding which
is described in the journal Nature Genetics, compared the DNA of 90 Tibetans to
that of people who are not altitude adapted. Furthermore, they discovered a mutation in the EGLN1 gene that prevents
Tibetans’ blood from becoming dangerously clogged with red blood cells—a
response that can be deadly for non-native mountaineers.
This
mutation appears to have originated just 8,000 years ago. But it’s so advantageous
that today, according to the last
research, nearly 90 percent of Tibetans have it. While it’s virtually
absent in even closely related lowland neighbors.
You can learn more about the finding at this link:
