Characteristics of Model Organisms

small

easy to breed specific individuals

easily raised in a lab setting without costing a lot of money

the more we already know, the better

one we have already sequenced or know a lot about

armadillos: identical tetrads; xenopus: huge oocytes

not a long generation time; something we can easily observe

the closer the "model" gets to humans or having humanlike characteristics, the more problems society will have with being used for scientific research

the fewer the better: do not want anything that will cause havoc in lab, disease, cost a lot of money to raise, keep alive, study, etc