We're All Homos

     A Homo is defined as a member of the genus Homo which includes both extinct and extant species of humans (2).  In looking for the origins of Homo, one finds an extremely interesting and often controversial scientific story.  Indeed, many people view the story of human evolution through various spectrums and new observations are constantly arising which challenge and expand this topic.  The New York Times article “Lost in a Million- Year Gao, Solid Clues to Human Origins,” by John Noble Wilford presents a new piece of evidence to the mounting pile.  Overall, Wilford approaches the topic in an enlightening, open-minded manner.  His compilation of observations provides the reader with new knowledge on the emergence of Homo; significantly, this knowledge crosses disclipines and therefore applies not only to science, but also to the fields of history, anthropology, and geology.  Additionally, Wilfred’s thoughts create new sets of questions that ultimately lead to deeper understanding, and thus, more interesting, provactive evolutionary stories. 

            Wilford begins his exploration of Homo with the story that during the “million- year dark age,” primitive hominids (human ancestors and their close kin) walked upright on the fields of Africa.  In gauging a time frame, these primitive hominids, who are considered larger members of the genus Australopithecus, lived up to three millions years ago.  Moving along the timeline, 2.6 million years ago, “clever” hominids were “knapping stone tools.”  Scientists suggest that the first Homo appeared some time after, though there is no solid evidence of this moment (1). 

            From here, subsequent finds suggest an early Homo called Homo habilis.  Wilford describes habilis as a species with a somewhat larger brain and a more humanlike face.  Homo erectus followed and then evolved to Homo sapiens, or modern humans (1). Outside of Wilford’s article, there are other classifications of Homo, including Homo ergaster, Homo antecessor, etc (3). Still, overall the variations between Homo species appear to arise from characteristics of the face and bone structure found in scattered fossils and also, in the case of erectus, use of fire and stone tools (3).

            Using this story as its basis, researchers continue to look for clues in hope of adding, or changing, its groundwork.   Though lack of evidence is a persistent limitation, some new evidence does suggest revisions.  For instance, most researchers of Homo agree that the jaw is the “earliest direct evidence” of Homo.  Hence, the recent discovery of teeth and fossil fragments in Kenya and Malawi may suggest that habilis and erectus lived amongst one another for almost a half a million years.  Even more, both species may have originated more than two millions years ago (1). Consequently, the succession of hominids is a fuzy area within the story of evolution.  The paleoanthropologist Eric Delson states, “It’s always difficult to know what is the earliest specimen of any lineage.  One always finds something older” (1).

            Thus, interest in this article arises not only from its explosive topic, but from the new questions it poses.  Wilford’s opening statement reflects this sentiment.  He writes, “Sometimes the maturity of a field of science can be measured by the heft of its ambition in the face of the next daunting unknown, the mystery yet to be cracked” (1).  Right from the start then, his methodology consists of viewing science as a set of stories that generates further mysteries.  

            Likewise, by examining Wildford’s scientific technique used in this article, one finds various instances of a critical, yet open-minded approach.  For instance, Wilford compiles an array of observations on the topic of habilis.  He looks at two summaries of observations, and from each, draws more observations and more questions.  Specifically, the “theory” that erectus sprang from habilis generates questions of common ancestry, intermediate Homo species before habilis, or change in external habitat.  Similarly, a question of diversity also arises.  Writes Wilford, “Is habilis really one, two, possibly three species?” (1).  From this, one may speculate that there was more diversity during the time period than previously thought, and more evidence may later expand (or diminish) this story.  Finally, a more subtle question throughout the article is “how one knows what they know.” In other words, researchers continue to dig for new answers and new pieces of evidence.  These pieces provide insight into past time periods.  As new developments unfold, new pieces fit together to reveal additional information.  Yet, each addition also broadens the number and range of new, pertinent questions.

            Thus, for the student of science, Wilford’s article serves two main purposes. It provides students with knowledge on the species and evolution of Homo.  At the same time, it employs the scientific method of story telling.  Together, the reader not only learns, but is able to delve deeper and ponder further questions. 

References

1)     http://www.nytimes.com/2007/09/18/science/18evol.html?_r=1&oref=slogin; New York Times Article, Lost in A Million- Year Gap, Solid Clues to Human Origins

2)     http://www.m-w.com; Dictionary

3)     http://www.talkorigins.org/faqs/homs/species.html; site on Hominids