anova(object, ...)lm or glm).anova.
  These objects represent analysis-of-variance and analysis-of-deviance tables.
  When given a single argument it produces a table which
  tests whether the model terms are significant.When given a sequence of objects, anova tests
  the models against one another in the order specified.The print method for anova objects prints tables in a
  pretty form.
na.action = na.omit is used.coefficients, effects,
  fitted.values, residuals,
  summary, drop1, add1.