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up until the recent past our
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understanding of our own Evolution was
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limited to the fossils and artifacts
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left behind but with the Advent of
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ancient DNA analysis A Whole New World
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has opened up offering access to the
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genetic secrets of our distant
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past welcome to anrom media in this
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video we will understand denisovans and
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how ancient DNA analysis has helped us
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in understanding them the denans were an
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ancient human population that once roam
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the Earth alongside the Neanderthals and
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sapiens however nobody knew about them
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up until a pathbreaking discovery in the
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Siberia in 2010 an analysis of
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mitochondrial DNA extracted from a
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finger bone found in the denova cave in
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the Russian alai revealed the existence
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of a new homon and taxon this newly
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described group was found to be
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genetically distinct from both homo
1:01
neanderthalensis the bone dating back to
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the initial upper Paleolithic opened up
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a whole new chapter in our understanding
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evolution but it did not stop
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there thanks to the power of ancient DNA
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analysis researchers have been able to
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piece together the story of the Denise
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ens their migration patterns and even
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their interactions with other human
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species the Denis Soven DNA has revealed
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fascinating insights into our own
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genetic makeup such as their
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contributions to our immune system
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metabolism and even the ability to adapt
1:36
altitudes since the early 1980s
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researchers have been conducting
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excavations in the alai region
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unearthing several stratified
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Paleolithic sites these excavations have
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revealed multiple habitation layers
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covering the last 2 million years of
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Evolution the most significant findings
1:55
came from denisova cave in Siberia where
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13 habitation layers with Paleolithic
2:02
identified the Cave's unusually complete
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stratagraph sequence has allowed
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researchers to trace the evolution of
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the cave dwellers material culture deep
2:12
prehistory the small bone fragment from
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a girl's little finger discovered from
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the dinova cave was sent to Sante Pabo
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the head of the Department of genetics
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at the max plank Institute of
2:25
anthropology through genetic analysis it
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was revealed that the bone belonged to a
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previously unknown homin which was named
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denovan after the cave subsequent
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analysis of a tooth from the cave also
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confirmed its denovan
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origin in total only five small and
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highly fragmented fossils found in
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denisov cave have been identified as
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denisovans based on DNA
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analysis these fossils include molers
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named as denova 2 denova 4 and denova 8
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partial fanges named denisova 3 and bone
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chips named denova 11 whole genome
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sequencing has been successfully
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conducted on denisova 3 specimen while
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poor DNA preservation and modern
3:08
contamination have hindered nuclear
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genome analysis of the
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others outside of denova cave a mandible
3:16
found in Bia cave in China was
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tentatively attributed to Denise ens
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based on proteomic evidence sediment DNA
3:23
extracted from the site also confirmed
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the presence of Denise
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ens these limited fossil findings
3:29
suggest that denisovans may have been
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widespread across Continental Asia
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Island Southeast Asia and near
3:37
Oceania some layers of the denisovan
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cave also evidence appearance of early
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upper Paleolithic blade industry as well
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as numerous bone implements and
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ornaments made before 40,000 years ago
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this suggests that the upper Paleolithic
3:51
emerged earlier in the alai region
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compared to Europe or
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Africa the appearance of upper
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Paleolithic blade technology is seen in
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other parts of the world only with
4:02
latter migrations of early modern humans
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ago the denisovans were identified as a
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distinct group based on analysis of
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mitochondrial DNA sequences which showed
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Hypes outside the range of variation of
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neanderthals Hypes are sets of genetic
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variants located on a single stretch of
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the genome and they can be used to
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differentiate groups and determine their
4:29
the mitochondrial DNA sequence of
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denisovans called lineage X indicated
4:35
that they diverge from modern humans in
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neanderthals around 1 million years
4:39
ago however analysis of nuclear genome
4:42
showed that denisovans are actually a
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sister group to neanderthals suggesting
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a closer relationship than indicated by
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the mitochondrial DNA
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data the conflicting data between
4:53
mitochondrial DNA and nuclear DNA arose
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because they have different patterns of
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inheritance and can provide different
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information about the relationships
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groups the mitochondrial DNA sequence of
5:05
denisovans is thought to be derived from
5:06
an ancient homin group that hybridized
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with denisovans and introduced the
5:14
sequence molecular data suggests that
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the split between neanderthals and
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denisovans occurred between 380 to
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470,000 years ago while the branch
5:24
leading to Denise ens in modern humans
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diverged around 800,000 years ago
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the denisovans are also more closely
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related to another set of fossils found
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in the SEMA deusas cave in Spain dated
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to 480,000 years ago indicating that the
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split between neanderthals and
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denisovans must have occurred before
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time the study of ancient DNA has
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revealed significant genetic differences
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between Denise ens and modern humans
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denisen genomes differ from the standard
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11.7% while the difference between
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neanderthals and modern humans is
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12.2% denisovans and Neanderthals are
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closely related but distinct from Homo
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sapiens modern non-africans have about 2
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to 4% Neanderthal ancestry while Dennis
6:12
ens did not contribute to the
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Neanderthal humid mixture however
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denisovan ancestry makes up 3 to 6% of
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the gene pool in Southeast Asia
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Oceania denisovans show higher genetic
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diversity than neanderthals but lower
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diversity than modern humans indicating
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a larger and more diverse population
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their geographic distribution ranged
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from North Asia to Southeast
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Asia during the late middle to early
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upper Pline early modern humans emerged
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in Africa neanderthals in Europe and
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denisovans in Asia hybridization events
6:48
occurred between these groups suggesting
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a metap population that includes all
6:53
taxa the alai region where denisova cave
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is located was occupied by neanderthal
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denisovans and modern humans although
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the precise timing and coexistence of
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these groups remain uncertain the
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denisova 11 girl represents an example
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of hybridization with a neanderthal
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mother and a denisovan
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father denisovans carry genetic traits
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associated with dark skin brown hair and
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brown eyes which are also present in
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humans the denisova 3 individuals genome
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revealed a genetic component inherited
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from an unknown homant ancestor that
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separated from neander paals denisovans
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and modern humans around 1 to 4 million
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ago denisovans likely played a role in
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adaptive introgression where early Homo
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sapiens acquired genes from denisovans
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that enhanced adaptation disease
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resistance and immune systems the
7:47
presence of human Lucy antigens in
7:49
modern humans inherited from denisovans
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hypothesis for example there are
7:56
evidences that adaptation to high
8:00
among modern-day Tibetans is a result of
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introgression from Dennis
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ens the populations of Eastern
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Indonesians papuans Philippine Negros
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Siberians South Asians and East Asians
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are among the few existing groups that
8:14
exhibit substantial traces of genetic
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ens it is worth noting that the region
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of Island Southeast Asia and Papua which
8:23
consists of numerous densely inhabited
8:25
archipelagos holds some of the earliest
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evidence of early archaic humans outside
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Africa additionally it is believed that
8:33
archaic honin like homo florensis
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coexisted with modern humans in this
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region modern Australian abinal and
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papuans have the highest proportion of
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around 5 to 6% of denisovan ancestry
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while American and Mainland Asian
8:48
populations have a smaller proportion
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0.2% this suggests interbreeding between
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denisovans and early modern humans
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during the early dispersal of humans in
9:01
Recent research has focused on using
9:03
modern human DNA as a primary source of
9:06
information to understand the
9:07
substructure and geographic distribution
9:10
honin new genomes from Island Southeast
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Asia and Papua have been analyzed
9:16
leading to the identification of two
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previously unknown groups of denisovans
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referred to as D1 and D2 these subgroups
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diverge from the Alti denisovan lineage
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approximately 280,000 and 360,000 years
9:30
respectively both D1 and D2 groups
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interbred with modern humans as
9:35
indicated by genomes of modern day
9:38
papuans some of the genetic mixing with
9:40
D1 Denise ens appears to be restricted
9:43
to New Guinea and nearby islands and may
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have occurred as recently as the end of
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the pene epoch making them among the
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last surviving archaic homins in the
9:53
world the genetic diversity observed
9:55
within the denisovan lineage suggests
9:57
their deep Divergence and separation in
9:59
to three distinct branches across
10:01
different regions Branch D2 contributed
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to the introgression signal in Oceania
10:06
and to a lesser extent in
10:09
Asia Branch D1 appears to be primarily
10:12
confined to new guinia and nearby
10:14
Islands while branch d0 is found in East
10:17
Asia and Siberia this indicates that
10:19
denisovans were capable of Crossing
10:21
significant geographical barriers
10:23
inhabiting a wide range of
10:26
environments The evolutionary history of
10:28
modern homo can be divided into three
10:31
stages around 800 to 900,000 years ago
10:34
Homo erectus gave rise to a new species
10:37
possibly homo heidelbergensis or homo
10:40
rensis associated with the spread of the
10:44
Eurasia this species is considered the
10:46
ancestor of homo sapiens neanderthals
10:50
denisovans Homo heidleberg anes migrated
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to Eurasia around 800,000 years ago as
10:56
indicated by the sites in Israel in the
10:58
lent region around 700,000 to 600,000
11:01
years ago homo he highle binus with
11:03
auline Industries migrated to Europe
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encountering late Homo erectus
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members between 600,000 and 200,000
11:11
years ago Europe had around 10 different
11:14
homon and populations with variations in
11:16
biology culture and lithic industries
11:20
Gene exchange between them resulted in
11:21
the emergence of Neanderthals around
11:24
200,000 to 150,000 years
11:27
ago around 4 50,000 to 350,000 years ago
11:32
certain homo heidleberg inses from the
11:34
lent migrated to the Iranian plateau and
11:36
further to Central and North Asia
11:39
including denova cave in southern
11:41
Siberia gave rise to
11:43
denisovans this migration marked
11:45
splitting of L of homo heidelbergensis
11:47
into neanderthals and
11:50
denisovans the stone tools of denisovans
11:52
and denisova Cave shows similarities to
11:55
those found in the lent region
11:56
specifically in Israel and Syria it
11:59
represents a transitional period between
12:01
the lower and middle Paleolithic
12:03
Industries during the interval of
12:05
450,000 to 350,000 years ago late homo
12:09
heidleberg insis migrated Eastward from
12:11
the Levant to Regions such as turkia
12:14
Kazakhstan and Mongolia as indicated by
12:16
the appearance of aelan Industries in
12:19
areas their likely route was north of
12:21
the Himalayas in Tibet the mandible
12:24
found in bashia cave in the northeastern
12:26
Tibetan Plateau dates back to at least
12:31
ago the presence of din sovans in the
12:33
region is also supported by the
12:35
adaptation of Tibetans to high altitudes
12:38
possibly through introgression from
12:41
denisovans late homo H highle binus
12:44
following an Eastward migration from the
12:46
lent hybridized with late Asian Homo
12:48
erectus and acquired a small portion of
12:50
archaic ancestry through adaptive
12:53
introgression this may explain the
12:55
presence of erectus likee features in
12:57
the late ploen skull cap found in Sait
13:02
Mongolia homo rodisian is and archaic
13:05
Homo Sapien remained in Africa and
13:08
became the ancestor of anatomically
13:10
modern humans the transition from homo
13:12
rodisian to Homo sapiens occurred
13:15
gradually between 800 and 200,000 years
13:18
ago the transition from archaic to early
13:21
Homo sapiens is documented by fossils
13:23
finds from different regions of Africa
13:26
such as omo herto and Jer houd early
13:29
modern humans appeared in southern
13:31
Africa around caz's River mouth and the
13:34
West Asia in skull and C at the
13:37
beginning of the upper PTO
13:39
scene as early anatomically modern
13:42
humans migrated Out of Africa between
13:44
80,000 and 40,000 years ago they
13:47
encountered neanderthals and denisovans
13:49
and intermixed with them this
13:51
interbreeding resulted in the transfer
13:53
of genes that enhanced the immune system
13:55
and facilitated adaptation to new
13:59
overall the discovery of Denise ens has
14:01
expanded our understanding of human
14:03
evolutionary history highlighting the
14:05
complexity of our ancestral past the
14:08
diversity of homine groups and the
14:10
dynamic interactions that shaped our
14:12
species it has emphasized the importance
14:15
of genetic and archaeological research
14:17
in unraveling the intricacies of human