Disadvantages of domestication

The number of domestic animals greatly exceed the number of wild or related species. In some cases, their wild ancestors have been completely exterminated. The breeding of domestic animals has provided people with many indisputable advantages, but it has its downside. The grazing of large livestock herds diminishes food and water resources of local wild Domesticated cats have helped people keep homes free of rodents for many thousands of years. Photo by Ernest A. James. Bruce Coleman, Inc....

Claws nails and hooves

Gas Exchange Lions

The distal ends of mammal digits possess keratinized sheaths or plates that are epidermal derivatives forming claws, nails, or hooves. Only the members of the whale and sirenia seacows families lack these structures. Claws are usually sharp, curved, and pointed. In many cases mammal claws are very similar to the claws found in other vertebrates. A claw consists of a dorsal plate called the unguis and a ventral plate called the subunguis. The unguis is curved both in length and width and...