While they are both members of the Felidae family, domestic cats (Felis catus) didn't directly descend from lions (Panthera leo). Rather, each species descended from a common ancestor, Proailurus, which emerged around 30 million years ago and was closer in size and appearance to the domestic cat than the lion. Although not closely related to each other, cats and lions share many of the same characteristics.
Carnivores called miacids emerged 60 million years ago, during the Eocene epoch, eventually evolving into other animals including Proailurus. Proailurus, a common ancestor of all felids, developed 30 million years ago during the Ogliocene epoch. Later, during the Miocene period around 12 million years ago, Pseudaelurus -- a more modern common felid ancestor -- evolved from Proailurus, according to "Cats of Africa: Behavior, Ecology and Conservation." This common ancestor would soon develop into two distinct branches of felids. One branch became extinct and the other evolved to include both domestic cats and big cats like lions, according to "Rex Cats."
Pseudaelurus evolved into eight distinct lineages, one resulting in domestic felines and one resulting in large wild cats in the Panthera lineage, according to "Cats of Africa." The Panthera lineage includes lions, tigers, jaguars and leopards. The domestic cat lineage includes African and European wildcats, domestic cats, Chinese desert cats, jungle cats, sand cats and black-footed cats. The Felidae family itself, to which all felids belong, consists of three subfamilies: Pantherinae, Felinae and Acinonychinae. Lions belong to the Pantherinae subfamily and domestic cats to the Felinae family, according to Animal Diversity Web. So, while these two species of felids are related, they're each descended separately from their common ancestor, Pseudaelurus.
Cat Family Relations
Currently, there are 40 species in the Felidae family belonging to three subfamilies and 18 genera, according to the Seaworld website. Lions are most closely related to other members of the Pantherinae subfamily and Panthera genus, such as tigers. These species can even successfully mate with each other to form hybrids, according to "Chimeras, Hybrids and Interspecies Research: Politics and Policymaking." On the other hand, small domestic cats are members of the Felinae subfamily and Felis genus, most closely related to the wild cat (Felis sylvestris), from whom they are descended. Domestic cats can mate with them and other members of the genera within the Felinae subfamily, such as the serval (Leptailurus serval) or Asian leopard cat (Prionailurus bengalensis), to form hybrid breeds like the Savannah or Bengal.
Differences and Similarities
Wild lions are only found in sub-Saharan Africa and India's Gir Forest, according to National Geographic. Unlike their lion relatives, domestic cats are found all over the world, where they have traveled with their human companions since their domestication over 10,000 years ago. Although these cats differ in size, they share many of the same characteristics, such as keen senses of smell, sight and hearing. They also both communicate through pheromones and body movements. Both lions and our little house cats are obligate carnivores, meaning these feisty felines need to eat meat to survive. While domestic cats continue to thrive, Asian lions (Panthera leo persica) are endangered and African lions (Panthera leo) are a vulnerable species.