Hunting the first hominid

“ Hunting the First Hominid Summary. The origins of the human species remains of great interest to man. The basic characteristics of hominids are conjectured to be thinking, tool-making, talking, hunting, scavenging and bipedalism. However, the First Hominid is yet to be definitively identified. Genetically, man is only marginally different from the apes (gorillas, chimps, orang-utans and gibbons). The time of divergence of each ape and hominid lineage from the common stem may be generally represented in a “ sort of hairy Y diagram, with multiple branches instead of simply two as is usual on a Y.” The explicit pathway of evolution can be traced only through fossil records of extinct species located by paleoanthropologists, who track hominids backward in time. The emergence of the first hominid is confirmed by radiometric dates to be a period between 5 million and 7 million years ago. As all early hominids are African, it is also accepted that the First Hominid lived in Africa. However, finding out the definitive new adaptation that transformed a particular primitive species into the First Hominid is difficult.
Based on essential hominid adaptation, it may be assumed that the identification of the First Hominid may be founded on the following unique hominid characteristics, which are key features that differentiate apes from hominids : hominids are essentially bipedal; hominids are apelike creatures that have lost their sexual dimorphism; hominids have thick dental enamel; Hominids are hand-graspers or manipulators, with long, opposable thumbs and big toes that are closely aligned with the remaining short, straight toes. On this basis, a description of the First Hominid may read like this: “ An ape-brained and small-canined creature, with dental enamel of unknown thickness. Large if male but smaller if female. May be spotted climbing adeptly in trees or walking bipedally on the ground. Last seen in Africa between 5 million and 7 million years ago.”
There are two contenders for the title of First Hominid. In 2001, Yohannes Haile-Selassie of the University of California, Berkeley, discovered a specimen in Ethiopian sediments between 5. 2 million and 5. 8 million years old, named Ardipithecus ramidus kadabba, which means “ root ape.” The specimen includes more than 20 teeth, pieces of two left humeri, a partial ulna, a partial clavicle, a half of one finger bone and a complete toe bone. The second contender is the 6 million-year-old Orrorin tugenensis, or “ original man,” found by a joint French-Kenyan team headed by Brigitte Senut of the Centre Nationale de la Recherche Scientifique, in Kenya. The Orrorin fossils include a few teeth, a jaw fragment; a partial humerus; a finger bone; and substantial parts of three femurs.
The single toe bone in the Ardipithecus specimen suggests bipedality. In Orrorin evidence for bipedality lies in the large head of the femur. The bones from the upper limbs of Orrorin and Ardipithecus both show tree-climbing and grasping adaptations. Neither relative brain size nor body size dimorphism can be evaluated in either specimen. Orrorin appears to have thick enamel, like a hominid or an orang-utan, and Ardipithecus seems to have thin enamel, like other apes. However, Orrorins canine is sizable and pointed like an apes canine, while of Ardipithecus’ canines are all small-crowned and flat-wearing, like a hominids canines.
Essentially, Ardipithecus and Orrorin show different mosaics of hominid and ape features. In this scenario, it has to be admitted that “ we cant tell the ape from the hominid even though we have teeth, jaws, and arm and leg bones.” This is a clear call for paleoanthropologists to revise the guidelines used to list the defining attributes of apes and hominids. It is also a testament to the vast complexity of evolution.
Works Cited.
Shipman, Pat. “ Hunting the First Hominid.” American Scientist. Jan.-Feb. 2002. Web. Mar. 2014
http://www. americanscientist. org/issues/num2/hunting-the-first-hominid/1