How Dogs (Eventually) Became Our Best Friends

Summary

In Siberia, the 18,000-year-old remains of a puppy named Dogor raised questions about the early stages of canine domestication. With most of its features preserved, Dogor's discovery might help pinpoint when and where wolves became dogs. The script delves into the genetic journey from ancient wolves to modern dogs, exploring theories of domestication, the role of genetics, and the deep bond humans have shared with dogs throughout history.

Takeaways

• 🐾 In 2018, a well-preserved 18,000-year-old puppy was discovered in Siberia, nicknamed 'Dogor', which may provide clues about canine domestication.
• 🔍 The puppy's species remains uncertain, and determining whether it was a dog, wolf, or something in between could help understand the timing and location of domestication.
• 🧬 Modern dogs belong to the subspecies Canis lupus familiaris, which is thought to have diverged from wolves between 40,000 and 27,000 years ago.
• 🐺 The process of domestication likely involved thousands of years of interactions, with traits like hypersociability being important for early domestication.
• 🍽 The commensal pathway to domestication suggests that early 'proto-dogs' were attracted to human settlements for discarded food and other resources.
• 🦴 A 2020 study differentiated between two types of canids based on tooth wear, indicating a group that likely consumed human leftovers.
• 🛡 Once domesticated, dogs were found to be useful for various tasks such as guarding and assisting with hunting and other livestock.
• 🌾 The spread of agriculture is reflected in dogs' genetic adaptations, such as the AMY2B gene, which helps break down starch, a common component in agricultural diets.
• 🤔 There is ongoing debate about whether dogs were domesticated once or multiple times, with studies suggesting both possibilities.
• 🏺 Archaeological evidence shows a deep bond between humans and dogs, with similar burial practices indicating close companionship even in death.
• 🐕 The diversity of dog breeds is a result of cross-breeding and human needs, with many breeds originating from the Victorian era dog shows.

Q & A

What significant discovery was made in Siberia during the summer of 2018?

In the summer of 2018, a patch of permafrost near the Indigirka River in Siberia melted, revealing the body of a two-month-old puppy that was astonishingly 18,000 years old.

What is the nickname of the 18,000-year-old puppy found in Siberia, and what does it signify?

The puppy was nicknamed 'Dogor,' which is a word for 'friend' in the local language and also a play on words, questioning whether it is a dog or something else.

Why is the species of the ancient puppy, Dogor, significant to scientists?

Dogor's species is significant because it comes from a period when wolves were becoming domesticated. Determining whether it was a wolf or a dog could help scientists understand the specific time and place of domestication.

What is the modern dog's subspecies known as, and what extinct species are they related to?

Modern dogs belong to the subspecies Canis lupus familiaris, and they are related to an extinct species of wolf from the Pleistocene, Canis lupus.

What is the commensal pathway to domestication, and how does it relate to the early relationship between dogs and humans?

The commensal pathway to domestication refers to an animal benefiting from a relationship with humans, with little to no initial benefit for humans. In this case, proto-dogs were attracted to discarded human food, which also attracted other animals they could prey on.

What genetic adaptation in dogs is associated with the spread of agriculture?

The spread of agriculture is associated with a genetic adaptation in dogs involving the AMY2B gene. Domestic dogs have more copies of this gene, which codes for an enzyme that breaks down starch, reflecting an increase in starch consumption with the advent of agriculture.

What debate exists regarding the number of times dogs were domesticated?

There is debate about whether dogs were domesticated once or multiple times. Some studies suggest a single domestication event, while others have indicated the possibility of separate domestication in Europe and Asia.

How do archaeologists interpret the treatment of dogs in burials as evidence of their relationship with humans?

Archaeologists interpret the treatment of dogs in burials, often similar to human burials, as evidence that dogs were seen as close companions to humans, even in death.

What role did the genetic trait of hypersociability play in the domestication of dogs?

Hypersociability, the tendency for adult animals to initiate social contact even with members of other species, is a key genetic trait shared by wolves and modern dogs. This trait, along with other behaviors like scavenging for food, could have made some wolves better candidates for domestication.

What is the significance of the discovery of Dogor's DNA results for understanding dog domestication?

The DNA results of Dogor could potentially shed light on the early days of dog domestication, providing insights into the transition from wolves to dogs and the timeline of this process.

How have new breeds of dogs developed over time?

New breeds of dogs developed to meet a variety of human needs, with coat colors and textures becoming more diverse. Many of these changes can be traced to cross-breeding and hybridization as humans moved around the planet with their canine companions.

Outlines

00:00

🐕 Unearthing Dogor: The 18,000-Year-Old Puppy Mystery

In the summer of 2018, Siberia's melting permafrost near the Indigirka River revealed the remarkably preserved remains of a two-month-old puppy, approximately 18,000 years old. Nicknamed 'Dogor,' which is a play on words for 'friend' in the local language and a question of its species, the puppy's discovery raised questions about whether it was a dog, a wolf, or an intermediate species. This period coincides with the hypothesized domestication of wolves, making Dogor's identification crucial for understanding the timing and location of domestication. The script delves into the genetic divergence between wolves and dogs, estimated to have occurred between 40,000 and 27,000 years ago, and the challenges in pinpointing the exact moment due to rapid genetic changes and interbreeding. It also discusses the commensal pathway to domestication, where early dogs were attracted to human settlements for food, and the genetic trait of hypersociability that may have been a key factor in domestication. The narrative highlights the difficulty in tracing the exact species of the ancestral wolf and the continuous lineage of domesticated dogs, suggesting a single domestication event rather than multiple ones.

05:04

🔍 The Ongoing Debate on Dog Domestication

The script continues to explore the history of dog domestication, addressing the debate on whether dogs were domesticated once or twice. Initially, genetic divergence between European and Asian dogs suggested multiple domestication events, but a 2017 study of ancient dog specimens from Germany proposed a single domestication event dating back 20,000 to 40,000 years. The study found a significant European ancestry in these ancient dogs, aligning with modern dogs and wolves. The archaeological record, featuring dog burials similar to human burials, indicates a deep bond between humans and dogs from early times. Examples include a 9,000-year-old Siberian dog buried with artifacts and showing evidence of being cared for, and the earliest known dog burial in Germany from 16,000 years ago, found alongside humans. The script also touches on the development of new dog breeds due to cross-breeding and human migration, and how dog shows in the Victorian era in Britain contributed to breed diversity. The hope is that the DNA results of Dogor will provide further insights into the early stages of dog domestication, reinforcing the long-standing companionship between humans and dogs.

Keywords

💡Permafrost

Permafrost refers to ground that remains frozen for at least two consecutive years. It is a key concept in the video as it is the condition under which the 18,000-year-old puppy was preserved and later discovered near the Indigirka River in Siberia. The melting of this permafrost unveiled important clues about the history of canine domestication.

💡Domestication

Domestication is the process by which a population of animals becomes accustomed to humans and loses its ability to survive in the wild. In the video, the concept is central to understanding the evolutionary transition of wolves into dogs. The script discusses the debate around when and where this process occurred and how it has shaped the relationship between humans and dogs.

💡Canis lupus familiaris

Canis lupus familiaris is the subspecies to which all modern dogs belong. The term is used in the video to trace the origins of domestic dogs back to an extinct species of wolf from the Pleistocene epoch. It highlights the genetic lineage and the process of speciation that led to the diversity of dog breeds we see today.

💡Genetic Divergence

Genetic divergence refers to the process by which two populations evolve separately, leading to genetic differences. The video discusses this concept in the context of the split between wolves and dogs, which is estimated to have occurred between 40,000 and 27,000 years ago, and the implications it has for understanding the domestication timeline.

💡Hypersociability

Hypersociability is a genetic trait characterized by the tendency of adult animals to initiate social contact, even with members of other species. The video describes this trait as being strongly selected for in modern dogs, suggesting it may have been a key factor in the domestication process, as it would have facilitated interactions with humans.

💡Commensal Pathway

The commensal pathway to domestication refers to a relationship where an animal benefits from being in proximity to humans, even if there is little to no initial benefit to the humans. The video uses this term to describe how early dogs may have been attracted to human settlements for discarded food, leading to a mutualistic relationship that eventually resulted in domestication.

💡AMY2B Gene

The AMY2B gene is associated with the ability to digest starch, which is more prevalent in domestic dogs than in wolves. The video explains that an increase in copies of this gene in dogs is linked to the shift from a carnivorous diet to one that includes starches, reflecting changes in human dietary habits with the advent of agriculture.

💡Archaeological Record

The archaeological record refers to the physical evidence of past human activity, such as artifacts, structures, and burials. The video cites the archaeological record to illustrate the deep bond between humans and dogs, showing that dogs were often buried in ways similar to humans, indicating a close companionship even in death.

💡Taimyr Wolf

The Taimyr wolf is an extinct species of wolf from Northern Siberia. The video mentions it as a potential ancestral species to modern dogs, although genetic analysis has shown that it is not a direct ancestor of Canis lupus familiaris. This highlights the complexity of tracing the exact lineage of domestic dogs.

💡Dogor

Dogor is the nickname given to the 18,000-year-old puppy found in Siberia. The name is significant as it is a play on words in the local language, meaning 'friend' and raising the question of whether the specimen was a dog or something else. The video emphasizes the potential of Dogor's DNA to provide insights into the early stages of canine domestication.

💡Burials

Burials in the context of the video refer to the archaeological practice of interment, specifically the way dogs were buried alongside humans. This practice is indicative of the close relationship between humans and dogs and is used in the video to demonstrate the cultural significance and emotional bond humans had with their canine companions throughout history.

Highlights

In the summer of 2018, Siberia's permafrost revealed an 18,000-year-old puppy named 'Dogor', which could help determine the timing and location of dog domestication.

Dogor's well-preserved remains, including fur, teeth, and nose, raised questions about its species, whether it was a dog, a wolf, or something in between.

The period Dogor comes from is critical for understanding the transition of wolves to domesticated dogs.

Modern dogs, Canis lupus familiaris, trace back to an extinct Pleistocene wolf species, Canis lupus, with the exact ancestor still unknown.

Genetic divergence between wolves and dogs is estimated to have occurred between 40,000 and 27,000 years ago, with interbreeding complicating the timeline.

Hypersociability, a key genetic trait, is strongly selected in modern dogs, possibly facilitating domestication.

The commensal pathway to domestication suggests early 'proto-dogs' were attracted to human settlements for food and resources.

Evidence from a Czech Republic site indicates two types of canids, one possibly more associated with human settlements due to diet.

Domesticated dogs were useful to humans as guards, hunters, and in domesticating other livestock.

A gene adaptation in dogs, AMY2B, indicates a shift from a carnivorous to a starchy diet, aligning with the spread of agriculture.

Debate exists on whether dogs were domesticated once or multiple times, with studies suggesting both possibilities.

Archaeological evidence shows a deep human-dog bond, with similar burial practices for dogs as for humans.

Ancient dog burials reveal a close relationship, with shared diets and care in life, suggesting a communal lifestyle.

The development of dog breeds is relatively recent, emerging from Victorian-era dog shows and human needs.

The origins of the human-dog relationship are complex and continually evolving with new scientific discoveries.

The DNA results of Dogor are anticipated to provide further insights into the early stages of dog domestication.

The human-dog bond is ancient, with evidence of companionship extending beyond life into burial practices.

Transcripts

It was the summer of 2018 in Siberia, and a patch of permafrost near the Indigirka River

had melted enough to uncover the body of a two-month-old puppy..

After its almost perfectly preserved remains were discovered, scientists determined that

the puppy was an astonishing 18,000 years old

The frozen animal was nicknamed “Dogor” - not only the word for ‘friend’ in the

local language, but also a clever play on words: is it a dog, or…?

Something else?

And, despite its age, it still had most of its fur, teeth, and even a cute little nose

preserved.

But while Dogor was in really good condition for a nearly 20,000 year old pup, scientists

were unable to confirm what species it belonged to.

Was it a dog or was it a wolf?

Or was it something in between?

Dogor comes from the period of time when scientists think wolves were becoming domesticated, so

knowing whether it was a wolf or a dog could help us better understand the specific time,

and maybe even the place, that domestication occurred.

Because, there’s still a lot we don’t know about how wolves went from fairy tale

villains to our canine companions.

Like, when did they first become domesticated?

Where did this happen?

And what did the process look like, in terms of genetics and anatomy?

We’re still figuring out the details, but most scientists agree that it took thousands

of years of interactions to develop our deep bond with these good boys and girls.

Modern dogs….like my good friend Abby here….

belong to the subspecies known as Canis lupus familiaris

And we can trace their origins back to a now-extinct species of wolf from the Pleistocene, an ancestor

they share with the modern grey wolf, called Canis lupus.

But the exact species of this ancestor is still unknown.

While some potential ancestral wolf species - like the extinct species from which the

Taimyr wolf, a specimen discovered in Northern Siberia, is from - have been identified, genetic

analysis has shown that they’re not direct ancestors to what would become Canis lupus

familiaris.

What we can say from studies of dog and wolf genomes is that wolves and dogs began to genetically

diverge from each other sometime between about 40,000 and 27,000 years ago.

And figuring out the exact timing is tough, because it looks like the split happened over

a very short period of time, and there was probably interbreeding between domestic dogs

and wild wolves along human migration routes.

So dogs still looked pretty wolf-like at the start of domestication.

It’s also complicated because these two species diverging genetically isn’t necessarily

the same thing as domestication; one’s just a split in the gene pool, while the other’s

the whole behavioral and genetic process that humans were involved in.

But one of the key genetic traits wolves and modern dogs share, that has been really strongly

selected for in modern dogs, seems to be hypersociability, which is the tendency for adult animals to

initiate social contact even with members of other species.

And for some wolves, this tendency, along with other behaviors, like scavenging for

food, could’ve made them a better fit for eventual domestication.

These traits also would’ve been useful as human settlements became more widespread,

with resources that these canines definitely would have wanted.

This is known as the commensal pathway to domestication, where an animal benefits from

a relationship with humans, but there’s little to no benefit for the humans themselves...

well you know at least at first

In this case, proto-dogs were drawn to the discarded human food, which also likely attracted

other animals that they could’ve preyed on, too.

And there seems to be some evidence that this was probably happening around 28,500 years ago.

A new paper published in 2020 was able to distinguish between two different types of

canids from a site in the Czech Republic based on the microscopic wear on their teeth.

One group had wear that better matched a diet with more meat in it, while the other group

had wear that suggested they’d been chomping on harder, more brittle foods - things like

bone.

And the researchers think the difference means that the bone-chewing group was hanging around

this human settlement more and eating their scraps.

Eventually, humans realized that wolves - once domesticated - could be useful: they could

be guards, work with hunters, and even help with domesticating other livestock species.

And after that, wherever humans went, their canine companions followed.

In fact, we can actually track the spread of agriculture through a particular genetic

adaptation in dogs!

In 2013, scientists were able to isolate the gene associated with the change from the carnivorous

diet of wolves to a more starchy diet in dogs.

Domestic dogs have more copies of the gene known as AMY2B than wolves do.

AMY2B codes for an enzyme that’s secreted by the pancreas that breaks down starch.

An increase in starch consumption in people is often associated with agriculture - like

growing wheat and rice.

And domesticated dogs living in human settlements would’ve been fed the kinds of things that

people were eating, too.

Along with the difficulties in figuring out when dogs were domesticated, there’s also

been some debate about whether it happened once or more than once.

Like cats, dogs were once thought to have been domesticated twice, because in 2016 researchers

showed that the genetic divergence between European and Asian dogs seemed to happen after

dogs were found in these areas, suggesting domestication happened in both Europe and

Asia.

However, another study from 2017 suggests that dogs may only have been domesticated

once.

This research on the genomes of two really old dog specimens from Germany shows that

this might’ve happened as far back as 20,000 to 40,000 years ago!

One set of dog remains was 7,200 years old and the other 4,700 years old.

And by comparing them to modern wolves and dogs, scientists were able to find that they both

had between 70-80% of European ancestry within their genetic make-up.

And this study found a much older date for the genetic divergence between European and

Asian dogs than the 2016 study did - old enough to suggest that domestication happened just

the one time.

So it seems there was one continuous lineage of domesticated dogs, instead of two separate

domestication events.

While we’re still figuring out when all of this took place and how it happened, it

didn’t seem to take that long before people were deeply attached to their pups.

And we can see this bond in the archaeological record with burials.

Across Europe, Asia, Africa, and North America, dog burials can be found spanning the Late

Pleistocene to the Mid-Holocene Epoch.

What makes these dog burials special is that many of them were treated and deposited in

ways that are really similar to how humans are buried.

This implies that these dogs were seen as very close companions, even in death.

For example, the remains of a male dog were recovered by archaeologists at the 9,000 or

so years old cemetery in Siberia alongside other artifacts, like a spoon made

from a large antler.

This dog was an older adult, with evidence of wounds that were partially healed by the

time he died, showing that he had been cared for during his life.

An analysis of the chemistry of one of his vertebra showed that his diet included

both terrestrial and aquatic resources, similar to the diets of the people at the site.

This might mean that these dogs and humans lived in close proximity, even sharing food.

We also see mixed burials in some cultures, where both dogs and humans are laid to rest

together.

In fact, the earliest known burial of a dog -- a puppy that was buried around 16,000 years

ago in Germany -- was actually found alongside two human bodies!

Dogs were also buried alongside their humans in Egypt, where dogs were often used in hunting

and guarding.

This may have been the case for a mummified dog found in a tomb at Valley of the Kings, which

may have been a favourite hunting dog of one of the rulers

buried nearby.

Over thousands of years, domestication created both physical and genetic changes in dogs.

While many early dogs looked pretty similar to each other, new breeds were developed to

meet a variety of human needs, and coat colors and textures became more diverse.

Many of these changes can be traced to the cross-breeding and hybridization of individual

dog populations, as humans moved around the planet with their canine companions and came

across new groups of canids.

Today, there are hundreds of dog breeds, and most of them aren’t actually that old.

They came about because of the introduction of dog shows during the Victorian era in Britain.

So dogs were originally drawn to our ancestors for food, but they eventually bonded with

us, working and living alongside us for thousands of years.

And this bond continued even after death, based on the archaeological record of human

and dog burials.

But the origins of this relationship are still more complicated than scientists originally

thought, with new discoveries changing the history of dog domestication all the time.

And we’re still waiting to find out the DNA results of Dogor, that 18,000 year old

puppy from Siberia.

The hope is that it can shed some light on the early days of domestication.

But, at the very least, we can say that dogs have been our species’ best friend, for

a very, very long time.

Gotta give a quick shoutout to David Howe, the ethnocynology guru, for making sure what

had our “pups” in a row.

Big high fives to this month’s Paws-itively awesome  Eontologists: Patrick Seifert, Jake

Hart, Jon Davison Ng, Sean Dennis, Konstantin Haase, and Steve!

All pledge levels have access to our Discord, so come nerd out with us by becoming an Eonite

at patreon.com/eons.

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