Old thread reawakened! Science has at length retracted its publication of this study: Widely panned arsenic life paper gets retracted—15 years after brouhaha - Ars Technica == If this could get readers to download a periodic table of the elements and see where phosphorus and arsenic are, it would be very good. There is a lot of there there. Phosphate (H3PO4 as protonated acid) is a big deal in biology. Arsenate (H3AsO4) isn't, and apparently its larger ionic size is a deal breaker. Yet their similarity means chemicals containing the bigger one must be carefully purified to remove the smaller one, in lab research. Doing that seems not to have been done, and here we are. I suppose that other researchers went to California's Mono Lake to expand this idea. Nothing of which has been published even though it would be sparkly. So here we are. There is no reason to doubt that life beyond Earth could have different architecture at that scale allowing arsenate ion to do things like phosphate. But it is vexing to study with Earth microbes as they have been on team phosphate for billions of years. Stuck in their ways. == It may be beyond hope that readers see Chemistry including Biochemistry for what it is. Arrange for electrons to move between molecules, and nuclei (atoms) will follow. Got 'em by the short hairs if I may be crude. We are allowed to expect more from exobiologists.