Transcript Co-Evolution of Dogs and Humans

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 dogowners 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?