Co-Evolution of Dogs and Humans

What Co-Evolution Means

• Simply means the mutual evolutionary influence between species.

• Asks: Why did it benefit both humans and dogs to form a relationship?

Dogs from Wolves

• There is little debate that dogs and wolves share a common ancestry

• Mitochondrial DNA evidence shows us they separated between 100,000 and 135,000 years ago. (Vila et. al, 1997)

Separation of Dogs and Wolves

• Of course we could only associate with wolves who would accept as masters.

• So some wolves hunted and lived with us, some didn’t.

• Simply, this is probably how the species’ separated in to what we now know as wolves and domestic dogs.

Cavemen and Their Pets

• Well if this is true, then dogs were our companions up to 135,000 years ago.

• And we weren’t really us 135,000 years ago.

• Neanderthals and wolves probably initiated the contact then.

• Relationship was probably solely based on hunting together originally.

14,000th, the MilkBone anniversary

• We know that dogs were more than just hunting partners as far back as 14,000 years ago, from evidence of personal decorated burials. This would be a lot of trouble for a simple hunting companion.

• Why were dogs the choice for our first interspecies friendship?

How we became friends.

• Bryan Sykes

• Said that the first ritual was giving out scraps.

• Wolves appreciate the scraps, and humans grow fond of the wolves.

• Sykes gets the idea, but this is too simple.

How we became friends

• Sykes’ idea does make sense on some level.

• The problem is believing that wolves were just happy to pick up our leftovers

• This does not make sense because wolves aren’t scavengers

• They can hunt.• Let’s look first then at why we chose

dogs…

…Why Dogs?

• We both have some sense of altruism;

• We both have a tendency to help people with no guarantee of return, so do dogs and wolves.

• We have similar family setups; in the sense that siblings and grandparents play a role in child-raising, wolves and dogs do the same.

Why Dogs?

• “Dog’s got personality.” – Samuel L. Jackson• No study has been done here, but most theorists

agree that dogs, like people, have notable within-species individual differences.

• This is something I think we all at least assume to be true.

• Hard to say if they learned personality from us, or if they always had it, a comparative study with wolves would tell us that, but unfortunately no such research has been done.

Why Dogs?

• Humans have sharp hunting tools, and the ability to strategize.

• Wolves have sharp teeth, and a keen sense for tracking down prey.

• It makes sense for both species to hunt together, Sykes understood that.

It’s everything.

• It’s the hunting skills.

• It’s the similar traits.

• Over time, selection made those traits even more compatible.

• But still, why would any breed of wolf or dog would accept our scraps, if they were fully accomplished and successful hunters?

Lack of Aggression

• Some weren’t.• Individual differences.• Some wolves weren’t as violent and aggressive• Would be glad to help out humans, who could do the

killing, if they found the prey. • This may be how we achieved the ‘master’ status over

our canine friends. We simply chose weaker ones.• As far as I know this is my personal theory, and one

argument of my paper; I have no scientific evidence of it, yet…

• For now though, let’s just say we’re friends due to personality traits & hunting skills and we’ll move on.

DOGS LEARNING FROM US

Communication Skills in Dogs?

• Communication Studies

• Miklosi, Topal and Csani (2001)

• Replicated 2-way food choice tasks used for children.

• Dogs pay attention to us; understand cues such as pointing, nodding, glancing etc.

• In fact dogs are as good at this as children under 2 and non-human primates.

Human-like social skills

• But how do we know these skills evolved specifically in domestic dogs?

• The Comparative Method• Hare and Tomasello (2005)• Compared dogs and wolves on 2-way food

choice tasks.• Wolves don’t care about us; they search

for food independently, and therefore score no better than chance in such tests.

So dogs are learning from us.

• Probably.

• This certainly leaves the possibility that dogs’ social skills evolved as a by-product of domestication.

• It makes perfect sense that dogs can pick up our cues. (more on that in a moment)

Rico the Social Dog

• Rico is a 12 year old border collie.• Rico has a “vocabulary” of over 200 words.• Can retrieve objects upon request, and bring

them to the appropriate family member.• And it isn’t “clever hans”… cues have been

controlled for.• He can also learn new words in a single trial and

still perform above chance• How???

Rico the Social Dog

• Capacity for words is about as good as language-trained apes, dolphins and parrots.

• This probably isn’t language, as we define it.• It does however show complex cognitive

processes, which is still very amazing.• Rico is only one dog, and the research is not as

extensive as it needs to be, but it is incredible nonetheless.

Rico the Social Dog

• Juliane Kaminski, Josep Call and Julia Fischer tell us how.

• Rico’s performance can be shown as a set of simpler mechanisms.

understanding the principle that objects have labels learning by exclusion ability to store and actively retrieve these labels in reference memory

Rico the Social Dog

• … What that means• Rico can’t understand language, he just has a

complex mechanistic system for retrieving objects.

• What an idiot.• Actually it is still amazing, and something

previously not thought to be possible in dogs.• We will have to wait and see if other dogs can

accomplish this.

How did dogs learn all this?

• Since they aren’t in the wild, we control the domesticated dog’s chances of meeting mates.

• Dogs who do not behave are often put down and given no chance to reproduce

• There’s also that surgery we put them through.

• So they have much to gain by learning our mannerisms.

Artificial Selection

• Darwin The idea that certain traits are bred for intentionally.

May be unintentional, simply controlled by our decisions.

• Basically we control their fitness.

• The better they are at learning tricks, the more food we give them, the more likely it is we will want to breed them.

Artificial Selection

• So we train them (though we are unaware of it) to memorize movements, and be sensitive to our facial cues.

• Is our choice of which dogs breed and which don’t unfair?

• Is this “playing god”?

• Maybe, but this isn’t an ethics course, so I don’t really care.

Moving on… How Dogs Help Us

How Dogs Help Us

• Herding dogs.• Police dogs.• Seeing-eye dogs.• Some dogs still help hunters.• But what have you done for me lately?• Most of us don’t hunt anymore• Many dogs these days don’t fetch or guard much of

anything. (my dog is afraid of the heating vent)• For most of us, they are just a friend. • We adhere to tradition, they previously helped our

fitness, dogs certainly don’t hurt our fitness, so there is no reason to stop associating with dogs.

This dog isn’t protecting anyone.

But he’s somebody’s buddy.

How dogs have effected us.

• In order for it to be co-evolution, dogs must have had an effect on us.

• If they can learn from us, why can’t we learn from them?

• Wolfgang Schleidt and Michael Shalter tell us how they might have…

Schleidt & Shalter

• We get our sense of nobility from dogs.• They hypothesize that dogs had a sense

of altruism before we did.• It’s possible, remember that we were

Neanderthals when we first befriended dogs.

• They said that dogs are not nearly as selfish as we are, and they have taught us to be like them.

Schleidt & Shalter

• No statistical basis.

• Correlational research could be done, comparing altruism scores between dog-owners with non-dog owners, but that wouldn’t prove historical truth.

• We really don’t know if this is true or not. It’s certainly possible though.

Dogs and Autism

• Redefer and Goodman (1989)

• According to them, the low sensory and affective arousal levels of autism are challenged by dogs which present stimuli to engage many senses.

• In other words, dogs present a vivid visual impression, strong clear sounds, a special smell and an innovation of touch.

Dogs and Autism

• Reports showed improved language skills, improvement in social interaction, expression of emotions and greater confidence with physical touch in children with autism.

• A longitudinal study is being carried out currently to show long term effects

• Experts in the field seem to agree that this really does work, especially with autistic children who’s condition is more severe.

How dogs have effected us

• Its possible that dogs have a subtle effect on language, social interaction, expression of emotions and physical touch with all of us, not just autistic children.

• Perhaps autism just amplifies the effects, makes the effects noticeable.

Conclusions

• Humans who could get along with wolves increased chances of survival.

• Wolves who could get along with humans increased chances of survival.

• So it would only make sense that traits to improve co-dependence would be passed on.

• Hence co-evolution.

Where do we go from here?

• This area of study is very new.

• More work will be done, and we will understand it better…

How much do dogs actually contribute to our own altruism?

How well do dogs really understand what we’re thinking? (theory of mind)

Where do we go from here?

Finding evidence that selection acted directly on dog’s social cognition.

Proving the autism hypothesis.

Finally, finding scientific proof that we chose a less aggressive brand of wolf to become our domestic dog. (my theory)

Questions?