With advances in genetics and the decryption of the human genome, many people are taking the time to sit back and ponder the questions of what humanity is and where it comes from.1 Will techniques such as gene therapy eventually create people who aren't quite human? If humanity is a flexible and ever-changing concept, then how do people know if they are human? Does some standard measure of humanity seem likely in our future, and is it even ethically proper to impose such a standard?
Philosophy offers the most satisfying definition of humanity: a human person is a conscious individual who interacts with an outside world. The details of the various philosophical debates on the exact nature of personhood would be enough to fill a library, but the main ideas can be summarized as follows: a person is self-aware, having the ability to think about thinking. Nothing in this definition of humanity involves matters of genetics or quantitative analyses of specific traits, which makes this definition applicable to people who may not be human in the way science tries to define the term.
Defining humanity in a scientific sense, however, is a nettled endeavor. Many "strictly human" traits can be found in animals. Wolves have a complex social structure. Bonobos, a subspecies of chimpanzee, can learn an abstract symbol-language and show the ability to understand grammar and syntax.2 In other experiments dolphins-who are genetically more distant from humans than bonobos-learned a type of sign language showing that they, too, are able to grasp complex rules of language.3 One only has to yell at the family dog to see that animals can express emotion and empathy. What, then, is left to humans?
Many point to our advanced technology as proof of our uniqueness, but it is well known that chimpanzees use tools on a regular basis. The only difference in this instance is that chimpanzees don't need to have very many advanced tools-they are more suited to their environment than the researchers who must carry around thirty pounds of gear to study them.
Despite evidence to the contrary, many people still cling to the belief that humans are somehow superior to all other organisms-this innate superiority being the essence of humanity. Humans are, after all, the most successful large animals on the planet, having spread to every continent and taken control of the ecosystems there. However, it could be argued that certain kinds of bacteria are more highly evolved than people-their genomes do not contain long stretches of "junk DNA" and their genes are organized into related groups more efficiently than the genes of most eukaryotes, like humans.4
The fallacy in the idea of human superiority is that most people assume that evolution is some sort of race: organisms compete with each other to be the most successful species of all, an "ultimate organism." "Evolution has no pinnacle and there is no such thing as evolutionary process."5 The truth of the matter is that...