Cancer as a Microevolutionary Process

The body of an animal operates as a society or ecosystem whose individual members are cells, reproducing by cell division and organized into collaborative assemblies or tissues. In our earlier discussion of the maintenance of tissues (Chapter 22), our interests were similar to those of the ecologist: cell births, deaths, habitats, territorial limitations, and the maintenance of population sizes. The one ecological topic conspicuously absent was that of natural selection: we said nothing of co...

 How Plants and Animals Survive in Their Environment

Plants and animals are separated by about 1.5 billion years of evolutionary history. They have evolved their multicellular organization independently but using the same initial tool kit the set of genes inherited from their common unicellular eucaryotic ancestor. Most of the contrasts in their developmental strategies spring from two basic peculiarities of plants. First, they get their energy from sunlight, not by ingesting other organisms. This dictates a body plan different from that of ani...