0:00
slon's mouth dropped open as she stared
0:02
at the sample on screen there had to
0:05
have been a mistake she repeated the
0:07
experiment over and over and over again
0:10
but each time she arrived at the same
0:12
conclusion the mysterious girl showed
0:14
Slan the answers she had always looked
0:16
for and showed the world our own
0:17
forgotten past the unsettling discovery
0:20
was truly significant but before we
0:22
start smash the like button and make
0:24
sure to subscribe if you haven't and hit
0:26
that notification bell so that you won't
0:28
miss any new stories when Vivian Slan
0:31
began her career as a paleogeneticist
0:34
she never could have imagined she'd find
0:36
something as extraordinary as she did on
0:38
that fateful day in the laboratory in
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Leipig Germany vivian always had a keen
0:43
interest in where we came from her
0:45
curiosity into answering this question
0:47
led her to become a scientist to reckon
0:50
with in 2012 researchers discovered a
0:53
fragment of ancient bone in a cave in
0:56
Siberia the unremarkable bone was tossed
0:58
in a research pile of the other animal
1:00
fossils that were discovered along with
1:02
it at the time researchers thought it
1:04
was just another sample of an early
1:06
human species Denisova that was
1:08
discovered at the site 2 years before
1:11
but that was far from the truth the
1:13
existence of the Dennisova was
1:15
discovered when scientists analyzed a
1:18
tooth and finger bone found in the Altai
1:20
Mountains and identified it as a
1:22
completely new species of early human or
1:25
hominin a term that means all the
1:27
species regarded as human there are a
1:30
number of hominins recorded to date the
1:33
earliest known human ancestors date back
1:35
to more than 4 million years ago the
1:37
orolopiththesines are the first human
1:39
ancestor recorded who could climb and
1:42
walk upright on two legs these distant
1:45
relatives first emerged in Africa way
1:47
before modern humans appeared on Earth
1:49
for context Homo sapiens first emerged
1:52
approximately 200 to 300
1:56
years ago and Slan wanted to find out
1:59
more about what happened during that
2:01
time the fragment of bone lay forgotten
2:03
beside the animal fossils in Slan's
2:06
laboratory at the Max Plank Institute
2:08
for Evolutionary Anthropology until she
2:10
directed one of her colleagues to look
2:12
closer at the old specimens to update
2:14
their filing system it was that simple
2:18
request that changed the world's entire
2:20
understanding of our human history
2:22
slan's mouth dropped open as she stared
2:24
at the sample on screen there had to
2:27
have been a mistake for years of working
2:29
and studying the samples of DNA that
2:31
came to her lab Slan thought she had
2:33
seen it all she had studied numerous
2:35
different species of early humans that
2:37
were discovered before her and loved to
2:39
imagine their lives and the world as she
2:41
did her work she especially loved to
2:43
study the species known as Homohidal
2:46
Brigensis who emerged about 700 years
2:49
ago the Homohidlebergensus came from
2:51
Africa and Eurasia and were much more
2:54
like modern people in their appearance
2:56
they were particularly interesting to
2:58
Slan as they laid the foundation for how
3:00
their descendants would evolve but they
3:02
acted pretty differently from their
3:03
predecessors too just like another
3:06
species Slan was fascinated by the
3:08
Neanderthalss are widely known in
3:10
today's society as they only emerged 40
3:13
years ago their DNA still remains in
3:16
most people of European and Asian
3:18
descent and that's because they mated
3:20
with Homo sapiens slan was fascinated by
3:23
what the world looked like at that time
3:25
and how all the species interacted with
3:27
each other to result in the world and
3:30
people we have today but she could have
3:32
never imagined she'd find a real life
3:34
clue slan's colleague studied the bone
3:37
fragment as instructed and immediately
3:39
asked for her help the sequence in the
3:41
DNA wasn't like the Dennisova sample she
3:44
was expecting she stared at the sample
3:46
puzzled over what went wrong that's when
3:48
Slan came to lend her expertise and help
3:51
her colleague understand what was
3:52
occurring in the DNA or more aptly to
3:55
discover what secret the DNA was hiding
3:58
when Slan analyzed the DNA present in
4:00
the bone's mitochondria she had no idea
4:03
what was waiting for her the bone
4:05
fragment was just 1 in in size but she
4:08
could already tell something for certain
4:09
the DNA indicated that it belonged to a
4:11
teenage girl who was about 15 years old
4:14
at first the bone looked like it
4:16
belonged to Dennisova but something
4:18
didn't quite add up slan grabbed more
4:21
equipment and began to analyze the
4:22
nuclear DNA "this was already very
4:25
exciting," Slan told National Geographic
4:28
"it only got more exciting when we
4:30
started looking at the nuclear DNA
4:32
that's when we realized there was
4:34
something a bit funky about this bone,"
4:36
Slan continued slan's knowledge of
4:38
genetics told her that material is
4:40
passed down by both the mom and dad it
4:43
wasn't enough to know who this bone
4:44
belonged to but where she came from and
4:47
who her parents were slan excitedly got
4:50
to work but nothing could have prepared
4:51
her for the shock of making a monumental
4:54
scientific discovery when she studied
4:56
the results at first she thought she had
4:58
made a mistake she redid the analysis
5:00
again and again before coming to the
5:02
realization that she had stumbled upon
5:05
something extraordinary while studying
5:07
the bone fragment she realized that the
5:09
ancient girl's genetic makeup was
5:11
incredibly diverse her hetererozygosity
5:14
was incredibly high for relatives
5:17
hetererozygosity would present in DNA as
5:20
relatively meager for unrelated but same
5:23
species it would present higher but
5:25
still relatively small but in this
5:27
ancient girl the presence of
5:29
hetererozygosity at an alarmingly high
5:32
rate could only mean one thing slan's
5:35
eyes grew wide as she looked at the test
5:37
analysis for the final time she had
5:39
discovered one of the holy grails in
5:41
human evolution slan discovered that
5:43
this bone fragment belonged to a firstg
5:46
generation child of interbreeding
5:48
between two different species who were
5:51
her parents the analysis showed that
5:53
this girl was the love child of a dad
5:55
who was a Dennis and a mom who was a
5:58
Neanderthal but how was it even possible
6:01
we knew from previous studies that
6:03
Neanderthalss and Denisvens must have
6:06
occasionally had children together Slan
6:08
told London newspaper the Evening
6:09
Standard but I never thought we would be
6:11
so lucky as to find an actual offspring
6:14
of the two groups geneticist David Reich
6:17
who worked at Harvard University agreed
6:19
it's amazing to be able to find
6:21
something like this Rich said to
6:22
National Geographic it seemed unlikely
6:25
that we would be able to catch it
6:27
happening in the act an individual
6:29
that's really the product of a first
6:30
generation hybrid however how is
6:33
interbreeding possible without resulting
6:35
in deformities in the offspring although
6:37
a mule which is bred by a donkey and a
6:40
horse can be born relatively healthy it
6:42
will always be infertile preventing it
6:45
from producing young of its own but
6:47
there are other species that defy the
6:48
deformities science of interbreeding and
6:51
one such case is seen in big cats have
6:54
you ever heard of a liger scientists
6:55
took a peek into the DNA of 144 Gwen
6:59
monkeys the idea was to find out why the
7:02
two groups had such distinct features
7:05
they found that the unique evolution was
7:07
not because of separate breeding within
7:09
the two distinct species of ape in fact
7:12
the red monkeys and blue ones were
7:14
naturally creating hybrid babies and not
7:17
in the confines of the zoo looking
7:19
further into this interesting group
7:21
researchers found that the original
7:23
inhabitants were the red monkeys the
7:25
area was later invaded by the blue one
7:28
both sides didn't seem to mind the stark
7:30
differences in appearance this brings
7:32
the first key that's vital to
7:34
understanding where we came from habitat
7:37
changes that force migration the cross
7:39
between a grizzly bear and a polar bear
7:42
is also called a prizly cute right the
7:45
hybrids were first found in the wild
7:47
then the zoos decided to try and breed
7:49
the new pairing in captivity the reason
7:52
however is quite sad to the point where
7:54
they shouldn't have existed at all the
7:56
new species bred out of desperation due
7:59
to the melting ice shelves the polar
8:01
bears were forced to migrate anywhere
8:03
with solid land also both sides had
8:06
their habitats destroyed to the point
8:08
where they couldn't find food so the
8:11
second factor is climate change this
8:14
crossbreed comes from a male wolf and
8:16
female coyotes the interesting thing is
8:18
that the offspring remains fertile so
8:21
it's not like a mule they babies grow up
8:23
to look larger than their mothers but
8:25
with features less like the father
8:28
they're also adept at survival but this
8:31
comes with a prince because both sides
8:34
roaming grounds have got smaller they've
8:37
started to invade each other's territory
8:39
they breed so much that scientists had
8:42
to go out and sterilize some of the
8:44
females because they were worried the
8:46
pure strain of wolf DNA would be
8:48
irreversibly diluted pulfins come from a
8:51
female dolphin tercops truncatus and a
8:54
male false killer whales sudorca
8:57
cedidins these hybrids however are
9:00
incredibly rare more so than the other
9:02
examples on this list the first recorded
9:05
one was in Tokyo SeaWorld in 1,981
9:09
but he died after 200 days it was first
9:13
believed the pairing would end up with
9:14
infertile offspring years later they
9:17
found out it wasn't the case the mother
9:20
and babies had a really hard time either
9:23
the calves wouldn't live very long or
9:25
the mother wouldn't feed them some
9:27
specialists think it's because the
9:29
female gave birth too early in life the
9:32
last example is unbelievable these
9:34
amazing hybrids actually are a
9:36
combination of female land iguana and
9:39
male marine iguanas that's right water
9:42
and land have finally come together the
9:44
babies have distinct features from both
9:46
parents but the reason why they managed
9:48
to join comes from a delicate balance of
9:51
conditions in this case mother nature
9:53
gave the green light to these boys and
9:55
girls because it was a better way to
9:57
survive the harsh conditions surrounding
9:59
the Galapagos Islands the marine iguanas
10:02
couldn't find enough seaweed their
10:04
staple food but even though there was
10:06
plenty of food on land it was too hard
10:08
for them to traverse the rocky shores so
10:11
they made children that had the best of
10:13
both worlds this all brings us back to
10:16
our story of the two humanoids between
10:19
harsh conditions climate alterations and
10:21
habitat changes we see that nature can
10:24
usually find a way to adapt or to quote
10:26
the famous Jurassic Park life finds a
10:29
way one can only imagine what happened
10:31
long ago to bring Denisven and
10:33
Neanderthal together as for Slan it was
10:36
a groundbreaking breadcrumb of human
10:38
history and discovery she will never