Evolution of Behaviour and Influencing Factors
In this report I am going to be explaining the
evolutionary development of behaviour in dogs and discussing how internal and
external factors can influence these behaviours. All dogs descended from wolves
around 135,000 years ago; the domestic dog emerged through selective breeding,
and there are some breeds which are much more closely related to wolves than
other breeds are. Due to all of the selective breeding and human influences
this has caused the behaviour of dogs to change dramatically compared to its
ancestors, wolves behaviour.
The link between environment and behaviour -
First of all I’m
going to talk about morphological adaptations which are how an animal has
changed to suit the changing environment gradually, over a period of time. As
the dogs have become more adapted to the human environment some species have
lost most of their predatory instincts and no species of domesticated dog has
the predatory drive of a wolf anymore. Over time they have also become a lot
more docile and affectionate than wolves. Other differences in their behaviours
due to the environment are the domestic dog’s excessive need to scent mark, a
difference in fighting styles due to domestic dogs becoming adapted to having to
fight alone whereas wolves are pack animals, the domestic dog’s acceptance and
tolerance to strangers etc. Dogs have also adapted to bark and communicate much
more frequently than wolves as wolves do not bark.
Another way in
which a domestic dogs environment has changed from that of a wolf is the
competition for resources; dogs do not have to compete for food or territory
etc. anymore because humans provide them with everything they need, whereas
wolves compete for everything. This has caused a massive change in the
independence of the dog, wolves are becoming more and more intelligent and
independent as time goes on and the evolution of the domestic dog is doing the
complete opposite. Their brains have become smaller compared to the wolves because
they do not need/ use their senses as
acutely because they are human commanded whereas wolves are becoming more and
more skilled in these areas because they need these senses to survive. Wolves
are also more independent in the sense of solving their own problems because
during the domestication process dogs have suffered a reduction in their
intellectual capacity because they do not need to think as much for themselves
anymore.
Heredity of behaviour
-
The next thing that I
am going to talk about the heredity of behaviour. This is how behaviours have
been passed on in genes even as dogs and wolves have evolved. This is mainly
instinctive behaviours in domestic dogs which have been passed down in the genes
from wolves; one example is the pack instinct. This is evident when you have
more than one dog in your home, one of the dogs will be in control of the
other/others for example controlling who can drink or eat first and being able
to stop the other dogs playing in an instant. This is a behaviour that is
commonly shown in wolf packs and is known as the hierarchy; also the leader is
not necessarily the oldest or biggest. There is only so much an owner can do to
try and change heredity behaviour.
Another example of a
dog behaviour which has been passed on in genes from the wolf is a dogs search
for freedom. Dogs can escape the most secure of gardens; can jump over fences
and digs holes under them. This is because like a wolf they like to be able to
run free and they associate this with being safe. This can also explain why
some dogs rebel against leads and things because they don’t like the feeling of
being restricted and their instinct is to fight it.
Sex is also a
hereditary behaviour because there is an ingrown sense in all dogs to reproduce
and establish a future for its breed. This can be seen in domestic dogs when
they mark their territory with urine as you take them for walks and around the
garden because this is to let other males know that you’re the alpha male in
the area and to let other dogs of the opposite sex know that they’re willing to
mate.
Another good
example of hereditary behaviour which has been passed down from the wolf in the
dog’s genes is a dog’s instinct to guard and steal food. This comes from when
dogs used to be in the wild and they had to hunt and protect their own food
otherwise they would starve because they could never guarantee when the next
meal would be.
The last example of a
hereditary behaviour in dogs is the ability to swim. This has been passed on in
the genes because it is in a dog’s instinct to survive and being able to swim
gives them a big advantage in escaping from other predators etc.
Internal factors
influencing behaviour –
One internal factor
which influences behaviour is hormones; this is less so in domestic dogs than
it is in wolves because people tend to interfere and reduce the hormones in
their dogs so that they are calmer and easier to handle. Examples of behaviours
caused by hormones are scent marking mainly in male dogs and false pregnancies
in female dogs.
Another
internal behaviour which affects behaviour is illness or pain. If a dog or wolf
is in physical pain they both tend to act overly aggressive; this is to keep
other animals and people away from them because they are vulnerable. One
difference that has occurred between wolves and dogs when they’re in physical
pain is that domestic dogs are a lot more vocal about it and will howl and cry
and try and alert humans that they are in pain whereas wolves would most likely
try and get on with it. Also if a dog or wolf has a disease some of the
symptoms could be changes in behaviour such as brain tumours will cause a dog
or wolf to change its temperament and it can also cause a dog to walk in
circles a lot and to sleep a lot or be very active.
Fear can also cause a
dog or a wolf to behave in a certain way. It can cause both to become a lot
more aggressive towards what they are fearful of. One difference between dogs
and wolves in this aspect is that dogs are more likely to hide and cower from
fear, sometimes behind their owner whereas wolves are a lot less likely to run
away.
Another internal
factor that affects behaviour is stress. Wolves are more use to certain types
of stress than dogs and vice versa. Most domestic dogs have become use to being
confined spaces whereas if you were to put a wolf in this situation it would
probably become increasingly aggressive, pace a lot and not eat etc. Both dogs
and wolves become stressed when they feel threatened which can cause them to
run or to become extremely aggressive.
External factors
influencing behaviour –
One external
factor which affects the behaviour of both dogs and wolves is the presence of
other animals. This can cause different reactions in both dogs and wolves but
it can also cause similar behaviours. In the presence of another dog, a dog’s
behaviour would change because the dog may become defensive, they could become
aggressive (especially if it was two males) and if it was a female in season
then a male may be affectionate towards her or try and mate with her. This is
the same for when wolves meet other wolves. One difference which shows how dogs
have evolved is that sometimes a domestic dog will be fearful of other dogs and
see humans as their family and protection whereas this never happens with
wolves because their family is their own kind. Dogs behaviour can also change
when they encounter other types of animal; dogs are much more likely to except
other animals such as cats, rabbits or birds and see them as companions whereas
wolves will see these animals as prey or competition and so will be aggressive
towards them and their will be constant conflict. Domestic dogs easily adapt
and learn to accept other animals whereas wolves are unlikely to ever be able
to do that because they have to be so competitive to survive.
Seasons can also
affect a dogs behaviour, for example in winter most domestic dogs have evolved
to grow a thick coat of fur and then to shed it in the summer. This changes
their behaviour because this means that they can be active all year round
whereas with wolves such as the grey wolf which has thick fur are only active
during the winter, in the summer they become irritated and sleep and spend more
time in the shade. This also applies for different breeds of dog because some
dogs have been selectively bred to have very short, fine fur and others have
been bred to have long, thick fur. Seasons can also affect a dogs behaviour
because of breeding, in the breeding seasons females come into heat and males
are looking for a mate and so therefore scent mark more etc. This applies for
both wolves and dogs but less so for domestic dogs now due to human
interference.
Another
external factor which can affect dog behaviour is daylight. Domestic dogs are a
lot more active during the daytime because they have evolved to be awake when
humans are awake and to sleep when we sleep. On the other hand wolves are most
active at dusk and at night because this is the best time for them to hunt
because they can hide easily and be more camouflaged.
Weather can affect a
dog’s behaviour because wolves survive outside and so they can deal with
extreme weather conditions and are used to them whereas domestic dogs are
mostly indoor animals. They can be especially fearful of stormy weather such as
thunder and lightning and this can cause them to become aggressive or to hide.
Lastly, humans can
affect dog and wolf behaviour but in completely opposite ways. Wolves are
fearful or humans and tend to stay away from them most of the time but can also
be aggressive towards us because they see us as an enemy. On the other hand
domestic dogs see humans as their friends, protectors and leaders and they are
a lot friendlier towards us and accept us.
Overall, dog behaviour has evolved massively
compared to wolves now; there are many distinct differences between the two.
Some of this is good such as how domestic dogs trust humans now and some of it
can be seen as bad for example how their brain has shrunk compared to the wolves.
Even though dogs have evolved they still have their instinctive behaviours from
their wolf ancestors which have survived through generations of selective
breeding. This is the reason we know that dogs have evolved from wolves.
