The vast expanse of Africa’s wilderness is a treasure trove of biodiversity, housing thousands of distinct species. Among these, you’ll find creatures with close evolutionary ties, each adapting subtly to carve their niche in the ecosystem.
Consider the antelope family, a diverse ensemble featuring reedbucks and impalas. Reedbucks, denizens of lush forests and marshes, have evolved powerful hindquarters for quick sprints through wetlands, small horns to navigate thick foliage, and solitary or monogamous social structures ideal for secluded forest habitats. Impalas, on the other hand, are more adapted to open plains with their less developed hindquarters for sustained running, larger horns suited to the vast expanses, and the formation of larger, polygynous social groups.
These antelope species exemplify nature’s remarkable diversity, especially in Kenya, where you can encounter between 20 to 35 antelope species, including the world’s rarest antelope species, the Hirola. However, this profusion of species isn’t mirrored in the world of elephants, largely due to their incredible adaptability and remarkable intelligence, which has led to relatively low species diversity. So what are elephant’s closest relatives and where can we find them?
African elephant evolution: two species or one?
For many years, the scientific consensus leaned toward the existence of a single elephant species in Africa. It wasn’t until 1900 when German zoologist Paul Matschie proposed the notion of distinct African savannah and forest elephants. African forest elephants, dwelling in the dense forests of West and Central Africa, differ notably from their savannah cousins, who roam the more open, arid African landscapes.
A whole century after Matschie’s original hypothesis, researchers conducted a study involving 295 African elephant skulls, unveiling clear distinctions between forest and savannah elephants. Forest elephants exhibited smaller sizes, unique tusk shapes, and oval-shaped ears, setting them apart from their savannah relatives. In 2001, a genomic study corroborated these differences, estimating their divergence around 2.5-5 million years ago. This scientific consensus officially categorized African elephants into two distinct species: African savannah and African forest elephants. However, an ongoing debate continues as both species can interbreed where their territories overlap, giving rise to fertile hybrids.
Regardless of this taxonomic debate, both species play vital roles in their respective ecosystems, significantly influencing their environments. From a conservation standpoint, considering them as separate species enables tailored protective measures, which can be crucial for safeguarding specific populations. Studies have underscored that forest elephants have a slower reproductive rate compared to savannah elephants, rendering their populations more vulnerable and perhaps more in need of urgent protection.
Asian elephants: close kin with distinct traits
The Asian elephant stands as African elephant’s closest relative, although they bear some intriguing distinctions. Asian elephants sport smaller ears, an adaptation to cooler climates where the same level of heat dissipation isn’t required. Their trunks also exhibit differences, featuring a single finger-like protrusion compared to the African elephant’s two “fingers.”
Researchers have observed that Asian elephants display superior muscle coordination and a capacity for more complex tasks compared to their African counterparts. Notably, not all Asian elephant males grow tusks, unlike African elephants, where tusks are frequently found in both genders.
Due to geographical separation, these two species never naturally cross paths. However, an exceptional case emerged in 1978 at Chester Zoo when an Asian elephant cow named Sheba was impregnated by an African bull elephant named Jumbolino, resulting in a calf that, unfortunately, succumbed to stomach complications shortly after birth.
Beyond the pachyderm: unusual relatives of the elephant
Beyond the realms of elephants, their family tree takes a surprising twist. Two marine herbivores, dugongs and manatees, share a remarkable kinship with elephants and are elephants closest relatives. These aquatic mammals boast impressively lengthy lifespans of up to 70 years and employ prehensile lips, akin to an elephant’s trunk, to forage on the sea floor.
Moreover, the elephant family’s most astonishing relatives can be found much closer in geographical terms to the African elephant. Enter the hyrax, a small mammal resembling a sizable guinea pig. These furry creatures diverged from elephants around the same era as dugongs and manatees, around 60 million years ago. Hyraxes are widespread across Africa, inhabiting trees and rocky outcrops. They share numerous striking similarities with their colossal cousins, from similar teeth and toe structures to skull shapes. In a remarkable parallel, hyraxes have even developed small “tusks” stemming from their incisors. Both species exhibit internal testes, experience extended gestation periods, and boast highly developed long-term memory.
In the grand tapestry of life on Earth, the African elephant stands as a highly adaptable species, thriving across various environments. Their adaptability has minimized the evolutionary pressure for diversification, resulting in only three distinct elephant species alive today. The African forest elephant is an example of adaptation for thriving in dense jungles, differentiating itself from its savannah counterpart. The Asian elephant, occupying its own distinct niche, bears its unique set of traits.