Introduction - Where Did We Come From?
Humans have not always been around. Compelling evidence from numerous scientific disciplines tell us that our species, like all others, has changed over time. We have evolved. Evolution is the underlying principle of biology. One conclusion drawn by evolutionary theory is profound- the human animal shares common ancestry with every living creature on this planet.
Anatomical and physiological comparisons to other living animals, behavioral analyses of living primates, genetic comparisons, and a wealth of fossil evidence has clearly indicated that humans are most closely related to chimpanzees, and share a common ancestor with chimps as recently as 6 million-years-ago. We did not evolve from chimpanzees (they have their own evolutionary history), but share a common ancestor. Although genetic analysis can suggest when this animal existed, only the fossil evidence can tell us what it looked like, how it moved, and perhaps even how it behaved.
We could devote a web site to each of the lines of evidence mentioned in the previous paragraph, but we will focus our efforts on paleoanthropology- the study of human evolution through the fossil record. We hope to provide teachers and parents with resources to address this topic in the classroom and at home, while suggesting methods of using paleoanthropology to teach about the nature of science.
There are three major issues we will address:
· With any scientific discovery come facts and interpretations. It is important to distinguish what is a fact and what is an interpretation and how evidence plays a role in each case. It is important to recognize that scientific interpretations are very often supported by a wealth of evidence, and are not just wild guesses.
Fact: K. Kimeu discovered the individual who is represented by skull KNM-WT 15000 in East Africa in 1984.
Interpretation: This skull is of an 8-year old Homo erectus who lived 1.6 million years ago.
· Science is not a belief system; it is rooted in doubt. Science embraces and thrives on skepticism, challenge, and debate. We present on this web site three different interpretations of the human family tree (or phylogeny). These are fiercely debated in the scientific community. We suggest that this scrutiny is a healthy part of science and should not be avoided in the classroom. What is important to teach students is why scientists disagree (or agree) about particular interpretations of the human fossil record.
· Science is dynamic and incorporates new discoveries into what is already known about the world. Every year, new hominid discoveries complicate our understanding of human evolution and force scientists to readdress hypotheses about our ancestry. Keep visiting this site to see how new discoveries alter our family tree.
Enjoy this exploration into who you are and where you came from.