are journals. Don't know Public Library of Science as an organization,so I don't know how good the peer reviewers are.

It is an axiom that you can get any article published, if you shop it around enough. PLOS is probably not NEJM nor the Tasmanian Journal of Obscure results. As with all "epidemiological" studies, it needs to be repeated in a different cohort (probably several times) to confirm its findings.

PLOS is a pretty decent journal. A colleague of mine just published a paper there, so I know the peer review process is fairly rigorous. However, they publish a number of editions on various scientific fields, so they accept a large number of papers each month. More prestigious journals publish few papers and are more selective. Thus, the fact that this paper is in PLOS suggests that it is good science, but not great science.

Reading through it, it seems that what holds the study back from being great and getting into a more prestigeous journal is the sample size of data they test each model with. If the sample size was larger, they might have been able to narrow the number of possible theories down further. As it is, they propose either two X-linked genes or one X-linked gene and one autosomal gene as the causitive agents for homosexuality. They can't disprove one in favor of the other with the evidence they have. This isn't to say that their sample size isn't large enough to be useful; just that it isn't large enough to answer the question completely.

and browsed my little corner of the world, and the articles fell into the category of "so what else is new?" or extremely esoteric. The article itself frequently cited the author's prior research (so you wonder how often he's recycling the same data.)