> model <- glm(sig ~  expression + log(length), data=retained_genes,  family=binomial(link="logit"))
> print(anova(model, test="Chisq"))

Analysis of Deviance Table

Model: binomial, link: logit

Response: sig

Terms added sequentially (first to last)


            Df Deviance Resid. Df Resid. Dev  Pr(>Chi)
NULL                         6676     4507.1
expression   1   115.00      6675     4392.1 < 2.2e-16 ***
log(length)  1   102.55      6674     4289.5 < 2.2e-16 ***
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1