Kingdom Animalia:  the zoological malaise from a microbial perspective.
Pain and cognitive dissonance abounds amongst biologists:  the plant-animal, botany-zoology wound has nearly healed and the new gash--revealed by department and budget reorganizations--is "molecular" vs. "organismic" biology.  Here I contend that resolution of these tensions within zoology requires that an autopoietic-gaian view replace a mechanical-neodarwinian perspective; in the interest of brevity and since many points have been discussed elsewhere, rather than develop detailed arguments I must make staccato statements and refer to a burgeoning literature.  The first central concept is that animals, all organisms developing from blastular embryos, evolved from single protist cells that were unable to reproduce their undulipodia.  The second points to the usefulness of recognizing the analogy between cyclically established symbioses and meiotic sexuality.
Margulis
L
L
Department of Botany, University of Massachusetts, Amherst 01003, USA.
D000828:Animal Population Groups; D000818:Animals; D001419:Bacteria; D005075:Biological Evolution; D018534:Earth, Planet; D004783:Environmental Microbiology; D005057:Eukaryotic Cells; D019143:Evolution, Molecular; D008540:Meiosis; D010163:Paleontology; D010802:Phylogeny; D013559:Symbiosis; D015046:Zoology