it can be said that the precise origin of the domestic cat
may never be fully known, unless some unexpected archaelogical
discoveries are made, it is nonetheless possible to draft
a broad outline of the probable domestication of the animal
and its subsequent evolution. The cat has managed to fill
a unique socioecological niche opened by the rise of civilized
hundreds of thousands of years man was a hunter-gatherer,
nomadic or semi-nomadic in behaviour. This existence slowly
changed, probably as a consequence of several factors, such
as, climatic change, increase in population density, slow
exhaustion of game and cultural evolution. In round figures,
modern civilization in terms of an agricultural-based economy,
domestication of animals and the appearance of towns began
approximately 10,000 BC.
of the most successful, as judged by achievement, was that
arising in the Middle East , in a region around the eastern
shores of the Mediterranean and extending as far as the Caspian
Sea and Persian Gulf . The earliest remains of almost all
of the major domesticates (cattle, dogs, goats, pigs and sheep)
are to be found in the region. It is usually assumed, with
some justification, that the young of likely species would
be confined, and only those amenable to confinement, adaptable
to close proximity of others of the species and of man would
survive. In effect, this means species with strong social
tendencies (herd or pack-forming species). The motive of the
early domestication was the provision of meat. Later, the
whole animal was utilised in one way or another.
is almost impossible to assess if the cat featured in the
early period of domestication. Probably not in any deliberate
sense, yet a biological niche had been created by early civilisation.
Settled farming and stock keeping implied granaries and barns,
and the mouse, Mus musculus, quickly adapted itself. Aboriginal
mice became the commensal house mouse about this time. Protected
from its usual predators, the house mouse could have been
a troublesome pest, as judged by the masses of skeletons recovered
from the basements of dwellings of Middle East archaeological
sites. It is not unreasonable to postulate that the cat may
have followed the mouse and become a scavenger around farms
and villages. The relationship between cat and man would have
been uneasy initially but tolerated by the latter as a means
of curbing the ravages of mice.
murine researcher has suggested that the cat may have been
domesticated in order to combat epidemics of mice. This could
be the case but it may imply more purposeful behaviour on
the part of man than that which probably occurred. It is conceivable
that young kittens could be reared in captivity but much would
depend on how far the cat had adapted to man. It would be
easy to postulate that the tamer of these cats would stay
while the wilder would depart, in this manner the cat may
have entered domestication. It would be impossible to assign
dates to the event but the above concept would indicate that
it would be desultory and probably extended over a long period.
Even a semi-wild cat shut in a granary could curb the activities
of the mouse population.
development now occurred which transformed the situation,
the Egyptians were emerging as influential people in the Middle
East who were greatly interested in animal life. They had
a penchant to associate gods with specific animals. In particular,
the male cat was depicted as sacred to the sun god Ra and
the female cat to the fertility goddess Bast, two potent deities
of the age. This was approximately 4,000 BC and, about this
time, the cat had attained an important position in religious
life, so much so that the animal itself became deified. Since
it was desirable to show respect to the gods, the keeping
of cats became common throughout Egypt . Not only were they
carefully tended during life but the cadaver was preserved
in special cat cemeteries covering many acres.
high point of cat keeping for the region was about 3,000 BC,
the species was so abundant that it was being depicted in
countries beyond the borders of Egypt . For example, in Crete
(2,900 BC), mainland Greece (2,500 BC), Libya (2,500 BC),
India (2,300 BC) and China (2,200 BC). Note the dates which
roughly chronicle the spread of the cat throughout the extent
of the world which had attained a level of culture able to
support an aesthetically pleasing household pet. The invasion
and subduing of Egypt by the Romans and the rise of Christianity
freed the cat from religious connotations and allowed the
animal to become a domestic pet. The Romans are held responsible
for the cat reaching Europe ( Italy , 1,900 BC, Switzerland
, 1,800 BC, Germany , 1,000 BC and Britain , 1,600 BC). Again
there is evidence of a slow migration.
domestication of the cat, with special regard to Egypt is
summarised as follows:
Period of competition (prior c.7,000 BC), characterised by
wild cats competing with man (hunter/gatherer) for birds and
Period of commensality (c.7,000 to 4,000 BC), characterised
by 'semi-domestic' cats feeding on vermin around and within
the early villages.
Period of early domestication (c.4,000 to 3,000 BC), characterised
by the confinement of cats for cult purposes.
Period of full domestication (c.3,000 BC onwards), characterised
by the great popularisation of cat keeping within Egypt and
the earliest diffusion of the animal from Egypt.
summary calls for two comments from a genetical viewpoint.
First, the period of commensality would indicate variability
of fearsome behaviour (to man at least) for certain individuals
to venture into the villages. Second, the capture of these
animals would induce intense selection for cats which could
adapt to confinement, tolerate close proximity of man and
rear kittens in such an environment. Puberty in the species
depends partly on the month of birth of the kitten, but if
a period of one year is assumed, the difference in numbers
of years will give a good approximation to the number of generations
involved. Therefore, the periods can be reckoned in terms
of thousands of generations. These would be ample for the
observed genetic changes to have occurred.
there is a long tradition of carrying cats aboard ships as
charms for a safe voyage, as companions and to combat vermin.
By this, man has unwittingly aided the migration of the animal,
thus, expanses of water are not a barrier, as is the case
for most land animals. On the contrary, busy sea lanes are
veritable highways for the cat, especially with the progressive
increase in maritime travel and commerce over the centuries.
The expansion into the New World and Australia was by sea
as a direct consequence of the rise of ocean-going ships and
human colonisation. This aspect will be further discussed
biological route by which the cat was domesticated would seem
to be one or more of three possibilities. These are (1) by
a form of neotony by which juvenile characteristics persist
into the adult, particularly behavioural which encourage dependency,
(2) modification of hormonal balance, mainly by reduction
in size of the adrenals and their secretions, and (3) reduction
of brain size, thereby impairing the animal's sensitivity
to uncongenial stimuli. Routes (1) and (3) may be correlated,
as indeed all three may be to some extent.
the races of silvestris , the European had the largest brain,
followed by the steppe cats of central Asia and lybica of
north-east Africa . A group of mummified Egyptian cats possessed
a brain identical in size to lybica. However, skulls from
mediaeval Russian cities showed a fall in brain size, a trend
which was continued by a stock of Siamese. Hemmer (1976b)
suggests that the main decline was of the order of 10 and
15 per cent respectively. Two groups of domestics (normal
and feral) exhibited a wide range of brain sizes, from that
of lybica to beyond that of the Siamese. Very few of the domestics
approached the brain size of European silvestris . It would
seem that the contribution of silvestris to the modern day
cat is either lacking or negligible. Also, it is probable
that there has been a reduction in brain size as a concomitant
of domestication. It is questionable whether the reduction
can explain all of the present day docility, but it may be
is difficult to speculate that some interbreeding between
wild cats and domestics took place, given the unconfinement
of the latter. European silvestris has the reputation of being
a shy, reclusive animal, at least in regard to man. This is
not necessarily a universal trait, of course, and populations
may vary in this respect. Popular reports of wild cat kittens
being timid yet tamable should be regarded with some disbelief.
These could be feral domestics because even the kittens of
the household females must be socialised with man at an early
age if these are not to display some fearful behaviour as
adults. Even if the kittens are wild cats, it is possible
for them to have some domestic ancestry, thus explaining their
lybica form is common in Rhodesia and can be domesticated,
perhaps more easily today than in the past. Many now slink
about in semi-urban areas, interbreeding freely with the domesticated
form. Such populations would be an 'in between' form of the
true wild cat and feral cats (domestics which have returned
to the wild) but for the most practicable purposes being indistinguishable
from the former. If the process has been underway for some
time, a new type of cat would be evolving, wild in appearance
but more adaptable to an emerging environment of mixed farming
and cultivated land, with some admixture of semi-urbanisation.
wild ancestor of the cat must be sought in the Middle East
and is almost certainly the subspecies Felis lybica of the
F. silvestris species complex. These constitute a group of
small wild cats inhabiting Europe , Asia and North Africa
, all of which are similar in appearance and size. At one
time it was thought that the two forms, ( silvestris and lybica
) were distinct species but this opinion is no longer tenable.
They will interbreed with each other and with the domestic
cat and produce fertile offspring. Their karyotypes are identical.
Both species are phenotypically mackerel striped tabby and
such differences as exist are due to adaptation to different
has been suggested that the domestic cat may have a polyphyletic
origin or, more precisely, polyspecific. This seems unlikely.
The only species worthy of consideration in this connection
is F.chaus and for two reasons. While the majority of European
mummified skulls examined could be attributed to a race of
F.lybica, a small proportion could be attributed to F.chaus.
The karyotype of F.chaus is identical to F.lybica, hence hybridisation
is possible and has been realised on occasion. However, the
existence of mummified chaus skulls merely means that the
species was kept in captivity, not necessarily that it was
domesticated. F.chaus is a larger animal than lybica and the
two species would probably not normally copulate. Unless observations
are biased by accidents of sampling, the low proportion of
chaus skulls (3/192=0.016) would imply that the species was
rare and any contribution it may have made to the cat gene
pool would have been swamped by the lybica influence.
of the more plausible arguments for ancient hybridisation
is that chaus has a vestigial tabby pattern and it has been
conjectured that chaus might be responsible for the Abyssinian
pattern. However, this view will not withstand critical examination.
The Abyssinian pattern is inherited as an allele at the tabby
locus and almost certainly arose by mutation, not by hybridisation.
Also, probably at a much later date since preliminary censuses
of mutant phenotypes in modern Egypt and Sudan have failed
to detect the Abyssinian pattern.
world-wide census of cat coat colours which has been in progress
for over a decade has revealed a number of interesting features.
Most of the observed mutants must be of ancient origin, as
evinced by their global distribution. Those mutants which
fall into this category are non-agouti (a), blue dilution
(d), long hair (l), sex-linked orange (O), piebald (S), blotched
tabby (tb) and dominant white (W). These are the most common
mutants used in the surveys but there are others (to be considered
later). That man was the main preserving agent is difficult
to prove directly but there are two points in this direction.
The brighter the colour or the more obvious the effect (eg.
long hair), the more likely the preference. The second is
that mutant phenotypes are often regarded as hallmarks of
frequency distribution of individual mutants is not uniform
throughout the world. Some alleles have a low or moderate
frequency of occurrence in most geographical regions, such
as d and S. The l allele was thought to be similarly distributed
but recent observations suggest that it may occur with elevated
frequency in Turkey , possible Iran , but particularly in
Russia. One can only surmise at present that the long hair
may offer some protection from the cold.
a allele is remarkable because it occurs at a high frequency
in all parts of the world, in some regions at especially high
frequencies. The reason for this is not directly known but
a possible explanation is that all-black phenotypes may be
less fearful than wild type. A gene conferring a degree of
placidity would possess an advantage under conditions of domesticity,
particularly if it arose early in domestication. At this time,
all phenotypes in the cat are docile, due to the accumulation
of 'taming' genes, hence the advantage may be less now than
O allele occurs at its highest frequencies in the East, (India
, South-east Asia and Japan). It has been proposed that the
allele may have arisen in the East and is diffusing westwards.
This could be the case since the orange phenotype is attractive.
However, the allele also displays an inverse relationship
with the dark phenotypes produced by a and tb, as if environments
favouring these latter two alleles are not altogether congenial
to O. This relationship complicates a simple explanation for
explanation for the high frequency of t b in Britain is obscure,
It is tempting to postulate that the mutant occurred in Britain
and is subsequently spreading around the world, aided by the
fact that Britain is a maritime nation. This is possible but
by no means certain. In any event, the apparent advantage
of t b remains unresolved. The only hard evidence is that
the allele may have increased relatively rapidly in Britain
over the last few centuries. It coincides with the growth
in human population density (and that means cat population
density) and this may be the clue. The advantage of t b may
be density dependent and be linked to the suggestion that
melanotic mutants are less fearful. If t b is density dependent,
this may explain why the allele has not increased in the former
British colonies to the same level as found in modern Britain
. The allele could be increasing but only after a time-lag
representing the period between the initial colonisation and
the growth of population density to the stage where the density
dependent advantage can be effective.
is difficult to imagine that the exceptionally high values
of tb in Britain are due solely to human preference. If this
was so, it would be expected that tb would have increased
correspondingly in the former British colonies. All in all,
it is difficult to assess the strength of human preference.
In fact, it may not be very strong and possibly erratic. The
W mutant illustrates the case where human preference cannot
prevail against adverse effects of a gene. The W allele produces
an all-white phenotype which many people admire. Yet, although
the allele occurs in most regions of the world, it occurs
at a frequency of only a few percent. The reason appears to
be that the allele confers deafness and lowered viability
upon its recipients.
two colour mutants which display geographical restrictions
are Siamese (c s ) and Abyssinian (T a ). The former occurs
in South-east Asia and probably generally in that region but
is either unknown or exists at a very low frequency elsewhere.
The latter occurs in South-east Asia and parts of Russia .
The frequency of either mutant is not particularly high. The
restricted distribution and low frequency could imply that
these mutants are of relatively recent occurrence. Since the
discovery of mutant alleles is a function of population size
by number of generations, this could support the historical
evidence that the domestic cat was thriving in the Far East
long before Europe.
other mutants which excite interest and occur at low frequency
are Manx anury (M) and polydactyl (Pd). It is easy to understand
why M will never attain a high frequency because the homozygote
is a pre-natal lethal and the heterozygote suffers mortality
from a variety of skeletal and soft tissue abnormalities.
Why Pd has not increased is not apparent for polydactous cats
are not obviously handicapped nor defective although no serious
studies have been performed on these aspects. Perhaps the
interest is not translated into active preferences.
recently, all of the analyses of cat populations have concentrated
upon the inter-sample frequencies of individual alleles. However,
it is advantageous to study the whole array of allelic frequencies
between samples - the genetic profile as it has been termed.
Individual alleles may change in a given environment but the
movement of populations involves all of the alleles. A recent
study has considered the cats of cities in central, southern
and eastern USSR , and has revealed that the southern and
eastern populations are more similar than those of central
provinces . This is taken to indicate that the domestic cat
travelled eastwards from the Middle East as far as China before
making any significant inroads northwards. In other words,
the cat was following civilisation of a certain level of culture
or prosperity and did not spread outwards until the social
infrastructure permitted it. Admittedly, this conclusion is
prompted by the concepts of earlier paragraphs but the data
is not in conflict with these.
tabby domestic cat found in Britain and Europe is more sombre
coloured, is somewhat more clearly striped and has a more
stocky body conformation than the more lissom lybica . Indeed,
the phenotype more closely resembles silvestris . Two reasons
may be advanced for this. Transporting the cat to Europe meant
a sharp change of environment, for which a silvestris type
cat is more suited. It is conceivable that the domestics would
mate with wild silvestris , thus introducing a trickle of
silvestris genes. However, the hybrids would doubtless show
various degrees of wildness and most would become feral, if
not eventually indistinguishable from wild silvestris . Two
two processes could be complementary, of course, with the
former being the more important. It may be noted that most
cat populations are variable for body conformation, ranging
from compactly built animals to those of a more sinuous nature.
This implies persisting variability for body type.
breeds of cats fall into two distinct classes, British, European
or American (according to country), which are of stocky conformation,
and foreign, which are of sinuous form. This is an exaggerated
reflection of the difference noted above. The concept of breeds
in the cat dates from the middle of the nineteenth century
(notably in Britain ) at which time names and standards of
excellence were adopted. The early breeders adapted such material
to hand, choosing the most likely specimens of the basic phenotypes.
Such 'native' breeds were of the cold climate compact conformation.
About this time, the Siamese were imported and the colour
and sleek conformation caused a sensation. Henceforth, all
'foreign' or non-native breeds had to be of the sinuous form.