The Evolution of the Cat

Cats are some of the most ubiquitous and widespread animals alive today. Found in the wild on every continent except Australia and Antarctica and domesticated practically everywhere, these animals are incredibly diverse. They thrive in numerous different environments from deserts, jungles, mountains to grasslands and come in all shapes and sizes. They find themselves among the top predators wherever they are and are highly adaptable. Their success can be traced back to a history of evolutionary advantages that date back to the earliest Cenozoic. Cats are part of a group known as Carnivora, a group that contains all large mammalian land predators. Carnivorans rose from the grouping Carnivoromorpha, tree-dwelling carnivores that evolved around 66 million years ago. This family shared some of the key traits of carnivorans such as carnassials, modified shearing teeth meant to consume flesh. It was originally believed that a superfamily inside Carnivoromorpha known as Myacoidea was the origin of our modern carnivorans. This family included the Miocys, dog-like carnivores as well as Viveravidae, civet-like carnivores. There was a thought among scientists that these two groups were ancestral to the two major groups of carnivorans, those being Caniformia, which contains dogs, bears and their relatives, and Filiformia, containing cats, hyenas and their relatives. Some evidence supporting this came in morphological similarities such as the parallels in how there are more teeth and myocides in Caniforms compared to the Viveravids in Filiforms, but this is highly debated and not widely supported. Nowadays Viveravidae is seen as a more basal group of Myacoidea and the branch point of the dog and cat lineages occurred later on in the Eocene. Early Filiforms retained an arboreal lifestyle, setting them apart from the more mobile and ground-dwelling Caniforms. In addition, Filiforms also stuck to a more carnivorous diet as opposed to Caniforms like bears which could leave a more omnivorous lifestyle. In addition to these general lifestyle changes, they could also be morphologically differentiated from Caniforms by having shorter snouts, more specialized carnassial teeth, and the presence of a double-chambered auditory bole, bony capsules found within the ear. Filiformia consists of seven extant families with cats being listed under the family Filidae. Their closest living carnivore and relatives are the members of Prionodontidae, the Asiatic Linsangs. These small animals give us a decent look at how earlier Filids may have looked like. The earliest known Filid was the Laetolegacine genus Proailurus. Comparing this small cat directly to an Asiatic Linsang, we can see some remarkable similarities. They both had long, slender bodies with tails that were proportionally longer compared to those of cats. They also shared a similar tree-dwelling lifestyle as well. Following Proailurus, however, came a period of time known as the Cat Gap, where for seven million years since the emergence of this animal, there was a lack of any new Filid fossils, a problem especially prominent to North America. What's more, many of the old Filiforms present on the continent, such as the Nimirvid, showed a sharp decline as well. There are many reasons given for why this gap could have occurred, such as an increase in hypercarnivorous behavior of some species paired with an increase in body size, meaning that any absence or decline of a large prey species would be extremely detrimental to these carnivores. In addition, habitat loss is also brought up as a valid reason for why the Cat Gap could have occurred. That being said, what I find to be a very interesting reason that some people posit for this gap was that dogs and their caniform relatives began evolving many cat-like characteristics. This would have had them take the place of Filiforms in North America. A good example of this is that some dogs and their relatives during the Miocene had specialized elbows that would have made it easier to pounce on prey when hunting, similar to cats. That being said, scientists have yet to find any caniforms during this gap that directly occupied former Filiform niches and ecosystems, so this theory is still shaky. The Cat Gap came to an end after the cat genus Pseudolurus entered North America 18.5 million years ago after having evolved one and a half million years prior. Pseudolurus is seen to be a direct descendant of Proiolurus. Although given the length of time between the animals, there are likely other genera connecting the two. This cat, which could grow to be as large as a puma, rapidly spread and diversified into many different branches of cats. Pseudolurus is notable for being ancestral to all other modern cat groups, as well as several extinct groups like the Mycridontinae. This is a line of cats home to powerful saber-toothed predators like Smilodon and Homotherium. It's a group we've already covered on this channel in greater detail, so I recommend you watch that video as well. What should be noted, however, was that Mycridontinae was not the only line of saber-toothed predators in Filiformia. It's also worth bringing up two former groups inside Filiformia, the Nimravidae, which is a far more basal filiform group, as well as a sister group even more closely related to the Felids than the Asiatic Linsangs, the Barbora Felidae. These lines of carnivores were also known for having many false saber-toothed cats. For now, however, I'll dive into one group in particular that came from Pseudolurus, the Felidae. This family evolved in Asia sometime during the Miocene Epoch. Felids possessed several physical traits such as great eyesight and hearing, rough tongues to help extract meat from prey, cushioned feet, and with the exception of a few cats such as the cheetah, retractable claws with sheaths to protect them. These adaptations all helped them become efficient predators, and their more unique features such as retractable claws set them apart from other carnivores. This has led to the cats outcompeting many old branches of carnivorans in places they migrate to, such as North America, where they became especially prominent. Felidae today consist of two major branches, those being Pantherinae and Felinae, which split off around 10 million years ago. Pantherinae consists of two closely related genera, those being Neophilus and Panthera. These two groups split off from one another about 6.4 million years ago. The Neophilus genus contains the Clouded Leopard and the Sunda Clouded Leopard, cats found in Southeast Asia with several defining characteristics, such as a cloudy pattern on their fur and elongated canines similar to those found Panthera, on the other hand, contains what people colloquially refer to as the Big Cats. Our understanding of Pantherinae evolution is still a little fuzzy, with the earliest member of Panthera, the Miocene Panthera Blytheae, sharing more in common with Snow Leopards than with all other Big Cats. As a result, we can safely assume that Panthera must trace back its evolution a little bit further. Among Panthera, the Snow Leopard and the Tiger, as well as its close relatives such as the Long Don Tiger, is seen as sister groups. In addition, the Jaguar, Lion, and Extinct Species like the American Lion, Cave Lion, and European Jaguar are more closely related to one another than the prior two Big Cats, separated from them by about 3.5 million years of evolution. Pantherines all share very similar morphology and almost all of them have the ability to roar. The one exception to this is the Snow Leopard, which is unable to roar due to its shorter vocal folds. Despite their many similarities, however, the lifestyles of the Pantherines can differ immensely. Some members of Panthera, such as the Tiger, are solitary hunters, and others, like the Lions, are incredibly social animals that work in groups. When we think about Big Cats, people also often lump in animals like the Cheetah, Puma, Lynx, and many other large felid predators. However, those animals belong to the second extant branch of Felidae, the Felinae. Felinae is the most widespread group of cats alive today. They're differentiated from Pantherines in their ability to purr, a trait they possess due to their shorter vocal cords. Felinae can be broken up into seven different lineages of cats. The first of these lineages diverged 9.4 million years ago and contains the Bay Cat and Asian Golden Cat under the genus named Catopuma. These two cats split off from one another roughly 5 million years ago when Borneo was connected to the nearby archipelago. This line also contains the Marbled Cat listed under the genus Pardophilus. These cats are found from the Himalayas in South Asia to islands such as Borneo in Southeast Asia. The next branch of Felinae diverged 8.5 million years ago and consists of several medium-sized African and Asian cats. This group contains the Savannah Roaming Caracal and its rainforest cousin the African Golden Cat, as well as the genus Leptilurus which contains the Serval. Also, fun fact for me at least, but apparently the Caracal is present as far east as India, which I had no idea since I always associated this cat with the Zoo Tycoon 2 African expansion. The third lineage contains numerous different elusive South American cat species. This group first evolved 8 million years ago in North America, migrating over to South America when the Panama Land Bridge connected the two continents around 3 million years ago. These are all listed under the genus Leopardus, which ranges from Central to South America. These include the Jefferies Cat, the Northern Tiger Cat, the Southern Tiger Cat, the Cod Cod, the Onsilla, the Pampas Cat, the Andean Mountain Cat, the Ocelot, and the Margay. Given South and Central America contain a diverse set of biomes and ecosystems, Leopardus could be found in all sorts of regions. The rainforests were home to ocelots, the grasslands were home to the Pampas Cat, and at the high altitudes of the Andes you could find the Andean Mountain Cat. Similarly to Leopards and Jaguars, these cats all had spotted coats to help with camouflage. Fourth up is a branch made up of cats under the genus Lynx, which split off 7.2 million years ago. These are the Eurasian Lynx, the Iberian Lynx, the Canada Lynx, and the Bobcat, which is also a Lynx. Just like with the Leopardus branch, these cats evolved in North America but later spread to Eurasia where they evolved into newer forms. Today, these cats are found in colder northern regions and as their names give away, they're found all the way from Canada and the US to where there have been major efforts to reintroduce them to their former habitats. The fifth lineage, diverging 6.7 million years ago, contains cats which we typically associate with the big cats, those being the Cheetah under the genus Acinonyx and the Puma or Cougar under the genus Puma. This genus is also home to the smaller relative of both these animals, the Jaguarundi under the genus Herpailurus found in South and Central America. The Puma and Jaguarundi are more closely related to one another than to the Cheetah and evolved in North America, but recent studies indicate that the ancestors of Cheetahs also evolved in North America, later crossing the Bering Land Bridge into Eurasia and finally to Africa. However, while Cheetah ancestors evolved in North America, the genus of the Cheetah itself, Acinonyx, evolved and spread only throughout the Old World. Extinct quote-unquote Cheetahs such as the American Cheetah are more closely related to the Puma than their African cousins. One more note about the Cheetah and that's regarding their lack of retractable claws. This adaptation is mainly to help the Cheetah maintain its composure and The sixth lineage contains some of the smallest of all cat species, diverging 6.2 million years ago. These are listed under the genus Prionailurus, containing the Sunda Leopard Cat, the Fishing Cat, the Leopard Cat, the Flat-Headed Cat, and the Rusty Spotted Cat, the smallest wild cat in the world. These cats are found all over South and Southeast Asia. In addition, the branch also contains the Palace Cat under the genus named Otocolobus found throughout Central Asia. The last group in Felinae is the Felis lineage, which diverged This includes the Jungle Cat, the Chinese Mountain Cat, the European Wild Cat, the African Wild Cat, the Sand Cat, and the Black-Footed Cat. The African Wild Cat, Felis libica, used to be separated into two separate species, those being the African and Asian Wild Cat. However, they're now grouped together under one species. The African Wild Cat is also the closest relative and likely ancestor of the last cat we'll discuss today, the domesticated cat, Felis caddis. The earliest evidence of cat domestication dates back to 9,500 years ago in Cyprus, but there's evidence to suggest that it occurred earlier in regions such as Egypt and the Fertile Crescent 10,000 years ago. Compared to the taming of wolves, the domestication of cats followed a different path, wherein cats were attracted to human settlements due to rodents that would feed on their grain. Over time, humans and cats grew closer, leading to their eventual domestication. Domestic cats have since been a staple across human households throughout the world, and they've even managed to hybridize with several wild species. Some hybrids such as Bengal, which are crossbreeds between domestic cats and Asian leopard cats, as well as savannas. Crosses between domestic cats and servals are quite popular. Others, such as the Caracat, a domestic cat and caracal hybrid, are less well-known and honestly pretty creepy looking. From their origins as small tree-dwelling creatures, cats have diversified and expanded their reach across the world. Their specialized adaptations over these millions of years of evolution have led to all kinds of unique cats, from large predators like tigers and lions, to extremely fast runners like cheetahs, to more specialized smaller carnivores. Their domestication has only led to their continued success as an overall group, and made them one of the most popular animals on earth.