This is not a &quot;jump&quot;. This is ongoing research in a relatively young field (about 20 years old), with multiple views. But you can read <a href="http:&#x2F;&#x2F;www.geology.wisc.edu&#x2F;outcrop&#x2F;05&#x2F;05_pdfs&#x2F;11%20Iron%20Isotopes.pdf" rel="nofollow">http:&#x2F;&#x2F;www.geology.wisc.edu&#x2F;outcrop&#x2F;05&#x2F;05_pdfs&#x2F;11%20Iron%20I...</a> concerning work being done in 2005 on the topic, which shows that the New Yorker is no distant leap beyond what people in that field have been saying for over a decade, and with efforts to fill in the details.