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Humans Didn't Make Dogs Weird - Video học tiếng Anh
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Humans Didn't Make Dogs Weird
Humans Didn't Make Dogs Weird
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0:00
The best thing about dogs –
0:01
besides what wonderfully good boys and girls they all are –
0:05
is their sheer variety.
0:06
From enormous great danes to tiny chihuahuas, flat-faced pugs and
0:11
long-snouted borzois, there’s a size and shape of dog for everyone.
0:15
Even our unofficial SciShow dog Perry. Whatever he is.
0:19
Conventional wisdom holds that this smorgasbord of doggy designs is
0:24
all thanks to the breeding efforts of Victorian kennel clubs in the 1800s.
0:28
But now, scientists have raised some doubts about that.
0:31
It seems like dogs have always been weird –
0:35
or at least for a very long time.
0:39
[♪INTRO]
0:41
In September 1865, the latest edition of Field magazine
0:45
featured an illustration of a very good boy named Major.
0:49
Major was a pointer, a breed of dog used to help hunters find game.
0:54
But Major wasn’t just any pointer. He was the pointer.
0:59
In that issue, English sports writer John Henry Walsh wrote detailed
1:03
descriptions of Major, enumerating all the specs and stats that made
1:07
this dog the standard against which all pointers could be judged.
1:12
Walsh didn’t stop there.
1:13
He outlined standards for many dog breeds,
1:16
as did other dog-enthusiasts of the time.
1:19
This was the beginning of dog breeds as we know them.
1:21
Dog breeders have been following the path of these
1:24
formalized breed standards for the past two hundred years.
1:28
With that history in mind, you might assume that all dogs
1:31
before the 1800s were kind of the same,
1:34
a mish-mash of doggy traits without distinct shapes and sizes.
1:38
If true, that would be a long history of same-ness,
1:41
at least 10,000 years.
1:43
Dogs were the first species that we humans successfully domesticated.
1:48
Before horses, chickens, cats, or even crop plants, we had dogs.
1:53
They really are man’s best friend, aren’t they?
1:55
The oldest dog that has been genetically identified as a true domestic
1:59
dog comes from an archaeological site called Veretye in Russia,
2:04
just under 11,000 years old.
2:06
Even older than that, a site called Bonn-Oberkassel
2:09
in Germany features a grave, around 15,000 years old,
2:13
where two very dog-like skeletons were buried alongside a human.
2:17
They really are man’s best friend.
2:19
Not just for life. For forever.
2:22
The fact that these pups were intentionally buried
2:24
with a human suggests they might have been part of the family.
2:27
Meanwhile, some studies comparing the DNA of dogs and
2:30
wolves have concluded that domestic dogs split from
2:33
their wolf-y ancestors around 30,000 years ago.
2:37
So, that’s our timeline.
2:38
Somewhere between 30,000 and 11,000 years ago,
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at least one lineage of wolves made the transition – with human help –
2:46
from wild animals to pets and partners.
2:49
Trying to identify the first ancient dogs is a real challenge because
2:53
the earliest dogs would have looked a whole lot like their wolf cousins.
2:56
On top of that, large carnivores are pretty rare to begin with in the fossil
3:00
and archaeological record, especially compared to large herbivores.
3:04
And skull bones – which are some of the most informative
3:07
parts of an ancient dog – are pretty fragile and tend
3:10
to crumble before they can ever be dug up and studied.
3:13
Furthermore, an early dog that died near humans
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was pretty likely to become dinner, which can
3:18
also be a hindrance to long-term preservation.
3:21
So, we don’t know for sure when dogs were domesticated,
3:24
but certainly by around 11,000 years ago,
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ancient humans were living alongside doggy pals.
3:29
Did we make dogs? Or did they make us?
3:33
Just something to think about.
3:34
Since modern dog breeds didn’t come about until the 1800s,
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those early dogs are generally assumed to have been missing
3:41
most of the anatomical diversity that we see in modern dogs.
3:45
But you never know until you look closely.
3:48
Which we will take a close look,
3:50
right after we go to this quick break!
3:53
This SciShow video is supported by JMP:
3:55
the statistical analysis software trusted by data scientists.
3:59
JMP isn’t your average statistical discovery company.
4:02
They get that understanding data is a journey.
4:05
And JMP is with you the whole way.
4:07
JMP offers opportunities for statisticians
4:09
to meet with developers and discuss their ideal products.
4:13
That’s not something that all companies do.
4:15
One data scientist who relies on JMP said that
4:17
she has not only used JMP for years, but also influenced
4:20
the development of new functionalities JMP now has.
4:24
She said JMP developers and even
4:26
executives listen to “ordinary users.”
4:29
And that kind of relationship between tool developer
4:31
and end user isn’t found just anywhere.
4:35
To reap the benefits of visual statistics for yourself
4:37
and get a 30-day free trial, visit jmp.com/scishow.
4:44
So, a 2025 study looked closely at over 600 skulls of modern dogs,
4:50
modern wolves, and ancient canines as old as 50,000 years.
4:54
They used a technique called morphometrics
4:56
to quantify the size and shape of these skulls.
4:59
Essentially, they created a dataset of measurements and
5:02
coordinates of features which could be compared from skull to skull.
5:05
Then, they fed that data into statistical software
5:08
designed to identify patterns of differences.
5:11
The first thing this analysis was able to do
5:13
was distinguish dog skulls from wolf skulls.
5:16
Not perfectly, of course.
5:17
There’s a lot of physical overlap between dogs and wolves.
5:21
Even among modern breeds, a lot of dogs are very wolf-like.
5:24
But the analysis identified more than 80 ancient skulls that were
5:28
more anatomically similar to modern dogs versus modern wolves.
5:32
The study classified these,
5:34
along with modern dog skulls, as morphological dogs.
5:38
The oldest of these morphological dogs was that
5:40
11,000-year-old Russian specimen that had previously
5:43
been genetically identified as a domestic dog.
5:46
But beyond that, the study found that early
5:48
dogs came in more varieties than expected.
5:51
None of the ancient skulls were quite
5:53
as long-snouted as borzois or as flat-faced as pugs,
5:57
but they came in a surprisingly wide array of shapes and sizes.
6:01
In fact, the skulls of the 43 oldest morphological dogs
6:05
exhibited about half as much physical diversity as modern dogs,
6:10
and twice as much as earlier skulls.
6:12
These ancient skulls even included shapes
6:15
similar to modern breeds like whippets and dachshunds.
6:18
Or… dah-shin? Da-shuhn? Dock-sin? Dachshund.
6:25
Dachshund.
6:25
Those early dogs didn’t have quite the same range of sizes as
6:29
modern breeds, and since this study only looked at the cranium,
6:33
we can’t say for sure if any of them had weiner-dog bodies.
6:36
But the evidence is clear that early domestic dogs already
6:39
came in a range of shapes, several thousand years ago.
6:43
This variability was probably a result of
6:45
differences in the dogs’ environments and diets,
6:48
plus the preferences of humans they lived with.
6:50
These dogs weren’t being bred to win Best in Show,
6:53
but the wants and needs of their humans influenced their
6:57
reproductive habits and had tangible effects on their doggy bodies.
7:01
This physical diversity lines up with genetic evidence that has
7:04
found that multiple genetic lineages of domestic dogs had already
7:08
diverged across Europe and Asia before 5,000 years ago.
7:12
But it’s not just human influence that was shaping these dogs.
7:15
Some of this diversity was probably
7:17
inherited directly from their wolf ancestors.
7:19
The study found that ancient wolf skulls,
7:22
while not nearly as variable as dogs,
7:24
were more diverse in their shape than modern wolves.
7:27
This is probably thanks to major declines in
7:29
wolf populations over the past few centuries.
7:32
Sadly, that’s our fault.
7:34
So, rather than being all the same until the Victorians tinkered with
7:38
their pedigrees, dogs have been a glorious assortment of shapes and
7:41
sizes for thousands of years, and probably from the very start.
7:46
Of course, this makes the search for
7:47
the earliest dogs even more complicated.
7:50
Not only would the first domestic dogs have looked a lot like wild
7:53
wolves, they might have already been pretty anatomically diverse.
7:57
Hopefully, there are more ancient dogs waiting
7:59
to be uncovered at even older archaeological sites.
8:02
Who knows, maybe someday we’ll
8:03
discover the ancient equivalent of a corgi!
8:10
[♪OUTRO]
