title: How to compare a model with no random effects to a model with a random effect using lme4?
body: <p>I can use gls() from the nlme package to build mod1 with no random effects.
  I can then compare mod1 using AIC to mod2 built using lme() which does include a random effect.</p>
  
  <pre><code>mod1 = gls(response ~ fixed1 + fixed2, method="REML", data)
  mod2 = lme(response ~ fixed1 + fixed2, random = ~1 | random1, method="REML",data)
  AIC(mod1,mod2)
  </code></pre>
  
  <p>Is there something similar to gls() for the lme4 package which would allow me to build mod3 with no random effects and compare it to mod4 built using lmer() which does include a random effect?</p>
  
  <pre><code>mod3 = ???(response ~ fixed1 + fixed2, REML=T, data)
  mod4 = lmer(response ~ fixed1 + fixed2 + (1|random1), REML=T, data)
  AIC(mod3,mod4)
  </code></pre>