Or How the Common Cat Has Shaped the Evolution of Human Ancestors

It has often been said that the dog was the first animal domesticated by humans. The date of this has long been placed at 14,000 to 20,000 years before present. Recent analysis of mitochondrial DNA of dogs, wolves, and other canines show that dogs had actually split off from wolves 135,000 years ago. I purpose that not only have paleontologists been mistaken about the date of the domestication of dogs, dogs were not even the first animals to be domesticated. This place of honor belongs to the ancestors of the common house cat, Felis catus.

Not only was the cat the first to be domesticated, it was done so over 4 million years ago, long before the genus Homo evolved. And in fact it was the cat, or rather the loss of cats, that molded and shaped the evolution of Homo. (If “domestication” doesn’t sit well with you when applied to the relationship between a prehuman primate and a cat, think of it as a quasi-symbiotic relationship.)

There are many unexplained matters in the early history of hominines. How could the australopithecines survive in Pliocene Africa? No tools for hunting, too small and weak to complete with other scavengers, teeth (in the gracile form) unadapted for plant eating, they seem to have been unable to even feed themselves. And the slow and small australopithecines would have been easy prey the first large carnivore to come along. Where did they spend the night? In spite of these drawbacks, australopithecines managed to survive almost unchanged for 2 million years. How? And why did these survivors suddenly evolve into a new genus, Homo, just then the large carnivores were dying out? The answer to all these questions: the Pliocene Pussy Cat.

There are five sections to the Pliocene
Pussy Cat Theory (PPCT).
Subsistence, defense, shelter, extinction and evolution. But first some background.


Modern domestic cats are descendants of the African wild cat, a species which hominines have always co-existed with. Compare this with the dog. Modern dogs are descendants of the European Gray Wolf, a species that early hominines had no contact with. This by itself means that it is more likely that cats were domesticated first.

There are several cases of modern apes adopting cats as pets. One classic example that we will examine later is Koko the gorilla. Cases of apes adopting any other species are far rarer. The recent case in Osaka, Japan of a wild macaque monkey stealing a kitten shows that this is not limited to captive primates

Stray cats are far more likely to move into a human’s home, and by doing so becoming self domesticated, then any other species.

Cats, unlike any other domestic animal, will hunt on its own and then bring its prey back to its home and drop it in its master’s lap.

Few feline fossils have been found at australopithecine living sites. However, sick cats tend to go off and die by themselves. Any fossils found would be mistaken for wild cats. Even today, it is near impossible to tell a domestic cat’s skeleton from that of an African Wild Cat.

We do know that cats and primates were in close association in the past as cats are known to have acquired a primate virogene some 5 to 10 million years ago.

Subsistence; or what the cat dragged in:

How did the australopithecines find food given that they had no natural adaptations for hunting, no tools and (in the case of the gracile form) teeth unadapted for a vegetarian diet? Their cats fed them. Anyone who has owned modern cats know that there is nothing cats love more then to bring presents of food home to their masters. Based on the amount of mice, birds, lizards, toads, frogs and large insects that my cats bring me, I first developed my theory regarding the early (4 million years before present) domestication of the ancestors of the African wild cat. Australopithecines massed from 29 to 45 Kg. They would have required about 1000 to 2000 calories per day. A nice juicy mouse has between 200 and 400 calories. So at worse case, an australopithecine would need ten mice or their equivalent each day. As a cat, in a mouse (or prey equivalent) rich environment, can easily catch far more then they can eat, it would not take many cats to support an australopithecine. Five cats per hominine, each bringing in an average of two extra mice (or prey equivalent) each day, together with what little the hominine could find for itself, would easily support an australopithecine. Based on the above points, it seems clear that the best way for australopithecines to have fed themselves was not by hunting, not by scavenging carnivore kills, not by gathering plant food, but by having their pet cats bring them small game.

Defense; or Cat Throwing as a Martial Art:

Question: How did the early hominines protect themselves from the many large predators with which they coexisted, without any weapons? Answer: They did have a weapon. The cat. Imagine that you have an angry tomcat thrown at your face. That would discourage even a lion or a hyena, at least long enough for the thrower to make his escape. Hard on the cat, but they breed replacements quickly. Male cats would be the primary weapon. The australopithecine may not have been able to conceptualize that they were preserving females for future breeding, however it doesn’t take much thought to know that the slightly larger tomcats would make a better weapon. Two million years of being carried around as a defensive weapon may account for the modern cat’s desire to be held. This carrying of cats, while almost certainly is not the cause of bipedalism, it would certainly have reinforced a bipedal posture. I’m surprised that people don’t still carry cats as an anti-mugging defense. It works better then mace.

Experimental proof:

After obtaining a number of cats and human volunteers, perform the following steps:

1. Have volunteer attack you.

2. Throw cat at head of attacker.

3. Call ambulance for attacker.

4. Repeat steps 1 through 3 until volunteers decline to attack.

As you will see, cats can be very effective in both fighting off an attack and in preventing future attacks.

Shelter; or The Static Cling Theory:

Nights on the African savanna can be a savage and dangerous place even today. During the time of ouraustralopithecine ancestors it was far more dangerous then it is now. It is hard to see how a small and defenseless animal like an australopithecine could survive it on the ground. It has often been said that the australopithecines, with their feet and legs well adapted to bipedalism, could not climb trees very well, and would have a very hard time spending an entire night in a tree hanging on with just its hands. Females with young would be especially vulnerable. Other explanations of how they spent the night (such as brush fences) have their own problems. But what if they had “help” to stay in the trees?

I have already demonstrated how australopithecines could have met their food needs by use of the cat and how they could have used cats for defense, now I will show how they could have used cats for night time shelter.

As anyone who has ever petted a cat during dry weather (like that on the African savanna) knows, cat fur has the potential for producing enormous amounts of static electricity. Rub a child’s balloon on a cat and it will stick to the ceiling, sometimes for days. I purpose that australopithecines used this static producing property of cats to help them spend the nights safely in the trees, out of the reach of the many large carnivores that roamed the African savanna. If an australopithecine rubbed itself briskly with one or more cats, it might be able to build up a large enough electro-static charge for it to stick to the branches of the tree just like the balloon sticks to the ceiling. It’s possible they had to wait for the coming of the morning dew to discharge the static charge and allow the australopithecines to drop to the ground. More likely they discharged themselves by urinating – a stream of urine is a good conductor. You may test this by peeing on an electric fence. This may explain why humans have such a disproportional large penis, the largest penis of any primate. The males would use the better aim their long penis gave them to “shoot down” the females and young.

The australopithecines may not have needed to rub the cats against their bodies themselves, but that the cats did it automatically. A few hundred generations of selective breeding of cats could easily have produced this behavior and is a wink of an eye in evolutionary terms. Millions of years later, modern cats still show vestiges of this behavior.

Experimental proof:

I attempted to duplicate the australopithecine’s static cling on a test subject (myself), however at over 100 Kg, the test subject was far heavier then an australopithecine and not quite as hairy as they are generally believed to have been. Also only two cats were available for the experiment and they were not at all cooperative. For these reasons the experiment failed. There was a weight loss of several tens of grams noted, but as this was due to blood loss, it was not considered pertinent to the experiment. However, valuable data was gathered on the use of cats as weapons, so the experiment was not a total loss.

Perhaps somebody else would like to try the experiment. If anyone out there has access to a young chimpanzee of a weight of 45 Kg or less and a large number of cats, just rub the chimp briskly with the cats until the chimp sticks to the ceiling. In order to get it back down, do what an australopithecine would do and piss on it. Just make sure the chimp does not have a full bladder during the test or you may find the experiment over before it starts.

Extinction; or Killer Kitties:

It is curious that during the time of the australopithecines, many species of very large and very dangerous carnivores became extinct. The hominines could not have done this directly, so it must have been their cats. But how could a little pussy cat kill a giant hyena or a sabertooth lion? I have been giving this question a lot of thought and I have come up with a scenario in which the Pliocene pussy cats could cause the extinction of large carnivores. It came to me in a Darwinian flash of inspiration while thinking of Farley Mowat’s classic book Never Cry Wolf. In this book he tells about the wolves which everyone had believed lived solely on big game prey. He found that the wolves really lived on mice for most of the year. Let us purpose that the large African carnivores lived in a similar manner. They would feed heavily on large prey animals at certain times of the year, i.e. during grazing animal migration, but for most of the year they would feed exclusively on mice or other rodents. When the Pliocene pussy cat population boomed due to their association with hominids, they simply out competed the larger carnivores by eating all of the mice. Most of the large carnivores died out, leaving only those few species present today who did not feed on rodents. We see a similar situation today in Australia and New Zealand where imported Holocene pussy cats are in the process of causing mass extinction of the native animals. We need a study of five million year old hyena scats. I am confidence that they have a lot of rodent bones and hair in them compared to modern hyena scats.

Evolution; or The Making of Mankind:

As australopithecines remained more or less unchanged for two million years, this shows that they were very well adapted to their environment. So what forced their evolution into Homo? Australopithecines were successful only because of their association with cats. The lost of the use of cats would force australopithecines as a species to change or die. Cats also remained unchanged during this period which shows that they too were well adapted. I believe that cats were so successful due to their association with australopithecines that their population increased beyond the environment’s carrying capability. The end of the Pliocene is marked by the Malthusian collapse of the cat population.

This may have been due to disease caused by overcrowding, but there is evidence that it was due to overhunting. Henry Wesselman has done research that shows that the micro-mammal fauna, rodents and other small mammals, under went a sudden population collapse and shift in species types. Cats ate themselves out of business.

No longer able to obtain food, shelter or protection from cats, most australopithecines died out. Only the bigger and the smartest managed to survive. Some entire species of cat using australopithecines were unable to adapt and so Australopithecus africanus quickly went extinct. The plant eating robust australopithicenes were not as dependent on cats as the graciles, as so were able to hold on longer, but in the end, A. robustus and A. boisei met their doom. Only a small group of gracile australopithecines in East Africa were able to adapt and change. The chaotic morphologies of Homo rudolfensis, H. habilis, H. microcranous, H. ergaster and other hominines of this period so odd that they can not be assigned to a species show a creature under severe evolutionary pressure.

Eventfully, out of this transitional period, Homo erectus emerged, a species fully adapted to life without cats. With its larger size, stone weapons and most of all fire, H. erectus could have provided for their own food and defense; and would have no need to sleep in trees. Indeed, its large size would no doubt have prevented erectus from taking advantage of static cling. H. erectus had no need for cats.

A living model for a cat using hominid.

One way to find out how primates get along with cats is to ask one. Koko, the famous sign language using gorilla, has long had pet cats. Many films of Koko show her playing with her pet kitten with a great deal of love and tenderness. Koko often talks about her first cat, All Ball, which was killed by a car years ago. Koko’s “Mom” and translator, Dr. Francine “Penny” Patterson reports that Koko still mourns for this long dead cat. I am sure that if Koko’s present cat is allowed to roam free, it will be bringing home mice and other prey, just as almost all free roaming house cats do. As a gorilla has about the same mental capability as an australopithecine, Koko and her kitten can serve as a model for the early domestication of the ancestors of the modern cat by members of genus Australopithecus and/or Ardipithecus over four million years ago.

No other hominine evolutionary theory can present a living model. There is no ape living in the savanna. There is no ape living in an aquatic environment. But there is an ape living with a cat. As a gorilla, Koko would not think of eating a mouse that her cat brought her, but there is little doubt that human ancestors were not so choosy. As famed writer Farley Mowat once proved while on a field trip as a student biologist, even modern humans can survive quite well on a diet of nothing but mice.

Two questions remain:

How did it all start?

The Aquatic Ape Theory (AAT) states that the very early hominines had a semi-aquatic phase in which they lived in a littoral area and fed largely on fish and shellfish. PPCT is fully compatible with AAT. We all know that cats love fish. It could be that during our semi-aquatic phase, when we were eating a lot of fish, cats first came into contact with human ancestors, by stealing leftover fish heads. A bond was formed between feline and hominine, with the hominine supplying most of the food at first, and then after moving out into the savanna, cats supplying most of the food.

What did the cats get out of it?

Basically the same thing they get out of humans today, minus the canned cat food. Protection for their kittens would have been the most important, but the cats would have also appreciated a warm body to curl up next to at night, and something that only a hominine can provide, fingers to scratch that spot on the neck that can’t be gotten to any other way. As any cat owner will tell you, the bond between cat and human is a deep one that goes beyond physical needs.

I propose the following timeline:

4.4 mya Ardipithecus ramidus, a non-cat using woodland biped makes first contact with Felis attica, the ancestor of all modern small cats, which was about the same size as a modern house cat.

4.2 to 3.9 mya Australopithecus anamensis, a transitional species, learns to make full use of the cat which enabled it’s move onto the savanna.

3.9 to 2.4 mya Australopithecus afarensis is fully adapted to life on the savanna using cats for subsistence, defense and shelter. Those Felis attica’s in association with hominines evolve into Felis lunensis. Wild Felis attica’s evolve into various species of small wild cats.

2.4 to 1.8 mya Homo habilis, another transitional species, loses the use of cats and is forced to find other means of support. During this period, other cat using hominines such a A. africanus and the robust australopithecines failed to make the transition to non-cat life and go extinct. This population crash of Felis lunensis forces the evolution of Felis silvestris, the modern African Wild Cat, as the surviving cats return to the wild.

1.8 mya Homo erectus is now fully adapted to life without cats. Felis silvestris is fully adapted to life without hominines.

4000 years ago Homo sapiens re-domesticate the cat. Felis silvestris evolves into Felis catus, the modern domestic cat.

I am looking forward to having my Pliocene Pussy Cat Theory receiving the same respect and consideration that the Aquatic Ape Theory has received.

Lorenzo L. Love

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