For many primates, insects are an important part of the diet, but until recently the exoskeletons of insects have been thought indigestible for most mammals.
Recent research has discovered that both mice and insectivorous bats produce ‘acidic mammalian chitinase’ (AMCase), an enzyme which digests insect exoskeletons. This enzyme is also found in modern insectivorous primates due to the presence of CHIA genes.
Today, most insectivorous primates have only one CHIA gene, with a few exceptions including the Tarsius syrichta (pictured), which has a total of five. Earlier on in the evolutionary process, many primates had multiple CHIA genes, including our own primate ancestors, meaning that insects were a key part of our ancestors’ diet.
Image credit: Tarsius syrichta by Plerzelwupp. CC BY-SA 3.0 via Wikimedia Commons.