You highlight social-media activity following publication of our papers on Homo floresiensis (dubbed hobbits), quoting a tweet that dismisses our conclusions as “based seemingly on zilch” (see Nature 512, 235; 2014). Critics of our findings, which question the taxonomic validity of H. floresiensis as a separate species, should have at least read the papers and checked the facts.

Our first report (R. B. Eckhardt et al. Proc. Natl Acad. Sci. USA 111, 11961–11966; 2014) shows that specimen LB1, the individual originally designated as representing H. floresiensis, is developmentally abnormal; the second (M. Henneberg et al. Proc. Natl Acad. Sci. USA 111, 11967–11972; 2014) presents a diagnosis of Down's syndrome for LB1.

These interpretations are based on detailed comparative skeletal morphology (see the papers' supplementary information) and on earlier diagnoses of Down's syndrome from skeletons (see, for example, A. Czarnetzki et al. Lancet 362, 1000; 2003; and M. Rivollat et al. Intl J. Paleopathol. 7, 8–14; 2014).

Objectivity is key in controversial fields, particularly when the evidence is so hard-won. Crucial evidence in this case would come from radiocarbon dating of tissue from LB1 and from unrestricted access to the skeletal remains of the other 14 H. floresiensis individuals so that their details can be studied independently.