In addition to the references to papers by Hansen and Bartoszek, and by Ives,
Midford and Garland, I would biasedly suggest this paper:
Felsenstein, J. 2008. Comparative methods with sampling error and
within-species variation: contrasts revisited and revised. American Naturalist
171: 713-725.
Hi,
I could also suggest that you look at Hansen and Bartoszek (2012) Interpreting
the Evolutionary Regression: The Interplay Between Observational and Biological
Errors in Phylogenetic Comparative Studies. Systematic Biology. 61(3), s 413-
425 where we discuss bias effects of measurement error
