Essay Sample about Hominin Family Tree
Throughout evolution, there has been a lot of various species. With every new generation, comes new changes and these changes are what made us who we are today. By looking into our Hominin family tree, we can see how our early ancestors lived, developed, and spread throughout the world.
Discovered in 2001 in West-Central Africa, Sahelanthropus tchadensis is one of the oldest species to be related to humankind. Between 6 and 7 million years ago, these creatures inhabited the land of West-Central Africa, now known as Chad. By looking at their skeletal structure and the location of their foramen magnum, we know Sahelanthropus tchadensis walked upright through terrain ranging from forested regions to flat grasslands in hopes to find fruit, leaves, nuts, and seeds to eat with their small canine teeth to sustain their plant-based diet (The Smithsonian Institution, 2021).
Next in line, discovered within the same year as Sahelanthropus tchadensis is Orrorin tugenensis. Orrorin lived and was discovered in central Kenya within the Tugen Hills region. Nicknamed the Millenium Man, Orrorin tegenesis lived between 6.2 and 5.8 million years ago and had a smaller-sized body, similar to a chimpanzee (The Smithsonian Institution, 2021). With this, they had smaller rounded teeth and thick enamel which they used to eat a diet comprised of mostly plants. They also had longer femurs and climbed in trees, but also walked on their two feet which is their main characteristic tying them to humans.
After Orrorin came Ardipithecus kadabba living 5.8 and 5.2 million years ago in Eastern Africa where we know today as Ethiopia. In 1997, paleontologists uncovered the remains of this species dating back to 5.6 to 5.8 million years ago (The Smithsonian Institution, 2021). From these bones, scientists were able to piece together that Ardipithecus kadabba walked upright, and had a similar brain and body size to a modern chimpanzee. They inhabited land comprised of plenty of water sources within woodlands and grasslands. Within these biomes, they ate more fibrous foods compared to earlier species. With their narrower front teeth and larger back teeth, they are believed to have chewed their food in the back of their mouth meaning they were eating harder foods such as nuts.
The next species to come into existence is Ardipithecus ramidus, or Ardi, living about 4.4 million years ago. Discovered in 1994 in Eastern Africa, specifically in today’s Middle Awash and Gona, Ethiopia, scientists uncovered that Ardi lived in a particularly wooded area, and traveled around by both bipedalism and tree climbing. By looking at the thickness of the enamel on the uncovered teeth, as well as the abrasion and teeth size, it is concluded their diet consisted of meat, plants, and fruit making them omnivores. Also by looking at their teeth, it is clear that males and females within this species share a very similar size. One feature on Ardipithecus ramidus that stands out is the feet; they have a rigid foot with a dissimilar large toe (The Smithsonian Institution, 2021).
Moving onto the next branch of the family tree, we have Australopithecus anamensis. They lived in Eastern Africa, or Lake Turkana, Kenya, and Middle Awash, Ethiopia, between 4.2 and 3.8 million years ago (The Smithsonian Institution, 2021). This species has a human-like ankle joint, allowing them to walk on their two feet. They also had long forearms suggesting that they probably swung in trees as well. Their facial features more closely resemble past ancestors. In 1995, Australopithecus anamensis remains were discovered in forests and woodlands surrounding lakes. With their strong narrow jaws being comprised of consistent rows of heavily enameled teeth, it is believed they ate abrasive and tough foods such as nuts.
Further up the tree, about 3.85 to 2.95 million years ago, we have Lucy’s species, scientifically known as Australopithecus afarensis. These individuals were discovered in 1974 and were found to have lived in Ethiopia, Kenya, and Tanzania. Australopithecus afarensis reached maturity at a much faster pace than modern humans, with males reaching about 4’11 and 92 pounds, and females reaching 3’5 and about 64 pounds (The Smithsonian Institution, 2021) Like others before them, they had mostly ape-like features with protruding lower jaws, small brain, and smaller canine teeth. Their arms were strong and long, with curved fingers for climbing in trees, and hips structured to support walking on two legs. This species survived off mostly a plant-based diet, making an exception for small vertebrates during off-seasons where fruit availability was low.
Discovered 16 years later, is the next of kin, Australopithecus Garhi. Within this species, longer strides were being made with bipedalism known by the discovery of a longer femur (The Smithsonian Institution, 2021). Australopithecus garhi lived about 2.5 million years ago in Eastern Africa, specifically Middle Awash, Ethiopia. This species of hominin is especially interesting because of its tie to some of the oldest known stone, and bone tools which were used for survival and potentially to eat meat and bone marrow from larger animals.
Living next, between 3.3 and 2.1 million years ago in South Africa was Australopithecus africanus (The Smithsonian Institution, 2021). These individuals had a diet comparable to modern chimpanzees of plants, nuts, seeds, eggs, and small insects. This species, discovered in 1924, had a rounder cranium capable of holding a larger brain. They also had smaller teeth and pelvis, femur, and foot bones allowing them to walk on two legs and long strong arms for climbing in trees.
Starting the last group of species before the ones most similar to humans is Paranthropus aethiopicus, discovered in 1967. Paranthropus aethiopicus lived in Eastern Africa about 2.7 to 2.3 million years ago. They have a very strong jaw, huge chewing muscles, which they used for a vegetarian diet, and a protruding face (The Smithsonian Institution, 2021).
Paranthropus boisei comes next with the discovery of this species in 1959 with their existence dating back between 2.3 and 1.2 million years ago. In Eastern Africa (Ethiopia, Kenya, Tanzania, Malawi), this species lived in grassland-dominated areas that also included wetter habitats with rivers, lakes, and streams (The Smithsonian Institution, 2021). Within these environments, they ate roots and nuts in times of food scarcity with their strong powerful jaws and chewing muscles. Along with this they also ate plants, fruits, and other diverse foods. Paranthropus boisei had larger brains and teeth.
Last on the Hominin family tree before the homo group is Paranthropus robustus. This species lived in South Africa about 1.8 to 1.2 million years ago. First discovered in 1938, it was easy to notice their dish-shaped face. They had large zygomatic arches, thick enamel, and large chewing muscles that anchored to the skull. These features allowed them to chew more fibrous foods, such as nuts, seeds, roots, and termites in the back of their jaw. The females were slightly smaller, standing at about 3’3 and weighing about 88 pounds in comparison to the males who were about 3’9 and 119 pounds.
