Panda
The giant panda represents one of evolution's more perplexing decisions. A bear that abandoned the carnivorous lifestyle of its ancestors to subsist almost entirely on bamboo—a plant providing so little nutrition that pandas must consume 12 to 38 kilograms daily merely to survive. Their digestive system remains that of a carnivore, profoundly unsuited to processing cellulose. This dietary commitment restricts pandas to elevations between 1,200 and 3,400 metres in a handful of Chinese provinces. When bamboo forests experience periodic die-offs, pandas cannot simply relocate or switch food sources; they starve.
The species' reproductive rate compounds these limitations. Female pandas are fertile for approximately 24 to 36 hours annually. Cubs are born blind, weighing merely 100 grams—roughly 1/900th of their mother's weight. This combination of dietary inflexibility and reproductive inefficiency has rendered the panda entirely dependent upon human conservation efforts for survival.