In its purest form (with no extra debris), liquid water can exist as a liquid until -40°C if left still (unmoving). In order to actually freeze this water below 0°C, there must be something (a “template”) to provide the exact arrangements of molecules necessary for ice to form. Some bacteria have developed proteins that do this; thus, these bacteria represent the most effective biological ice-forming agents in nature. Researchers now have determined that the same ice-forming capability may exist within certain fungi species. However, the evolution of this fungal ability is very surprising. This presents a resolution to an age-old question about these fungi regarding how and why they possess such an extraordinary method for initiating ice formation compared to other living organisms, including bacteria. Schematic domain map of MoINpro, EnINpro, PPoINpro, and PsINpro, highlighting conserved and variable regions. (CREDIT: Science Advances) How Fungi Obtain Their Ice-Nucleating Ability This answer is the result of the transfer of genetic information across kingdoms, possibly hundreds of millions of years ago. The genetic blueprint for the production of …