Can boron isotopes be used as a palaeodietary proxy?

The stable isotope and trace element biogeochemistry of fossil tooth enamel has provided
many insights into the dietary and behavioural ecology of extinct mammals, including early
hominins, especially carbon isotopes as a proxy for C4 (savannah) grasses (Lee-Thorp et
al., 2012). Boron isotopes in marine microfossils reflect the pH of the ocean environment, but research in terrestrial ecosystems is limited.
Boron is an essential micronutrient in plants (O'Neill et al., 2004), and is digested and
incorporated into the tissues of mammals. Measurements of boron isotopes can be obtained from tooth
enamel (He et al., 2015), which is resistant to alteration during fossilisation.
Given the large mass difference in boron isotopes, boron isotope fractionation may occur during the
preparation or consumption of food. A broader understanding of the transfer and isotopic
fractionation of boron within an ecosystem could facilitate the development of boron as a
new and informative dietary proxy, with implications for our understanding of the dietary
habits of primate and human ancestors.