Abstract

1. Being an Animal Human beings are animals: phylum: chordata, class: mammalia, order: primates, family: hominids, species: homo sapiens, subspecies: homo sapiens sapiens. According to current scientific opinion, we evolved approximately 200,000 years ago in Africa from ancestors whom we share with the other great apes. What does it mean that we are animals? Scientifically speaking, an animal is essentially a complex, multicellular organism that feeds on other life forms. But what we share with the other animals is not just a definition: it is a history – that is, it is a story – and a resulting set of attributes and circumstances, and an ecosystem, and a planet. What is the story? Living things are homeostatic systems – they maintain themselves through a process of nutrition that enables them to work constantly at replacing the fragile materials of which they are composed. Living things also work at reproducing, or contributing to the reproduction, of other living things that maintain themselves in essentially the same way. To engage in those activities is essentially what it means to be alive. And in order to engage in those activities, a living thing must be, in some way, responsive to conditions in its environment. Plants, for instance, respond to dryness, by growing deeper roots, or to sunshine, by turning their leaves in its direction. Even a unicellular organism is drawn to some things and recoils from others