As humans continue to encroach on our planet, we are driving a mass extinction that some experts call a "biological holocaust." Since more and more species are dying, it creates an increasing number of genetic bottlenecks, which make animal and plant survival even more difficult.
Take for example the white rhinoceros (Ceratotherium simum), which can be divided into two sub-species that are genetically very similar — but one is relatively thriving while the other is on the brink of extinction.
