Over millions of years, Africa has been the stage for an extraordinary diversity of large herbivores, including elephants, hippos, rhinos, and numerous relatives that are now extinct, which shaped the continent's landscapes. However, this diversity has been progressively declining, and today's large herbivores, such as elephants and hippos, are survivors of an evolutionary lineage that has lost diversity over time.
New research published in the journal Nature reveals that the explanation for this loss of diversity is not, as previously thought, a greater vulnerability to extinction. Instead, the researchers discovered that the problem lies in a much quieter difficulty: the inability to generate new species at the same rate as smaller animals.
According to the study, which traces an evolutionary history of 23 million years, African large herbivores face a fundamental limitation in the speciation process. This inability to adapt and generate new species at the necessary pace is believed to have contributed to the gradual decline of their diversity over geological time.