Ferocious Felids: The Evolutionary Biology of Cats

In the past many people, maybe even yourself, have mistaken prehistoric or living organisms as 'true cats' that are in fact very different to felids, genetically and morphologically. These false cats are the result of convergent evolution and did not evolve from Proailurus . But the prehistoric mammals mentioned here were obligate carnivores, typically only hunting live prey and so they developed similar attributes to capture and kill animals. As previously mentioned felids appeared quite recently on the evolutionary time scale, while the first sabre-toothed mammals resembling cats appeared approximately 50 mya, long before the Felidae family emerged (van den Hoek Ostendel et.al 2006). The Machaeroidinae family included the very first sabre-toothed cat-like organism. Around 44mya the Nimravids appeared followed by the Barbourofelids (23mya) the name itself contains the misleading suffix 'felid'. At first the Barbourofelids were considered a subfamily of Nimravidae but i

The Acinonyx genus is undoubtedly the most unique felid alive today, instigating many heated debates on the subject of genetic variation and cladistic analysis. There was once 4 species that belonged to the Acinonyx genus, but now A. jubatus or the modern cheetah (see figure 1) is the only existent species left. Unlike most felids A. jubatus is principally crepuscular, distinct from nocturnal felids, and instead of using a short range ambush approach to hunting, cheetahs chase down their prey at high speeds (up to 103km/hr) over several hundred metres (Krausman & Morales 2005). Morphology and behaviour are related, thus to increase traction cheetahs have a diminished degree of retraction in the claws and possess longer forelimb bones for more cursorial movement, characteristics shared by canids but not other felids. Cheetah morphology is highly autapomorphic in the Felidae family, which makes it difficult to place them accurately within the Felidae family tree, and the s

The small to medium sized cats of the Felinae subfamily are the most successful and species diverse group of felids in the present age, with their habitat spanning from the couch in your house to the jungles of South America and the savannahs of Africa.There are a total of 8 lineages within the existent felid phylogenetic tree, 7 belonging to the Felinae subfamily (As seen in Figure 1). After the split from the Pantherines, there was a series of rapid divergence events within the Felinae lineage leading to the radiation of 7 other cat groups, with the Bay Cat lineage being the first to evolve in Eurasia and the last known branch being the Domestic Cat lineage which evolved in Eurasia and Africa. Within the felid phylogeny, 21 of the 36 divergences occurred within just 1 million years (Johnson et.al. 2006). At approximately 8.5-8 MYA and 6.7-6.2 MYA, the migration of felids between Eurasia and North America (M2 and M4 in Figure 1) was most likely due to low sea levels, introducing a new

The majestic Pantherinae subfamily or the 'big cats' are the largest and most robust felids in existence, sometimes classified as the roaring cats compared to the purring cats of the Felinae subfamily (Christiansen 2008). Approximately 10.8 million years ago, the Felidae lineage began to diverge into the Felinae and the Pantherinae subfamilies. The radiation of the Pantherinae subfamily resulted in the emergence of 7 modern extant species and all members of the subfamily have the genus Panthera , with the exception of the Neofelis sp. (Johnson et.al. 2006). Three species of Panthera are shown below (Figure 1), exhibiting the similarities in the craniomandibular structures. By about 300 thousand years ago the big cats had populated the majority of the northern hemisphere with the lions extending from Africa into Europe and north-east Asia while competition with the largest extant felids, tigers, may have kept them out of south-east Asia and southern China. Leopards inhabi