Washington, D.C. -- Over the last half century, researchers have found that mineral surfaces may have played critical roles organizing, or activating, molecules that would become essential ingredients to all life--such as amino acids (the building blocks of proteins) and nucleic acids (the essence of DNA). But which of the countless possible combinations of biomolecules and mineral surfaces were key to this evolution? This vexing question has stumped scientists for years because of the sheer volume of possibilities. Now an interdisciplinary team of researchers led by Robert Hazen, of the Carnegie Institution's Geophysical Laboratory and former president of the Mineralogical Society of America, has developed new protocols and procedures for adapting DNA microarray technology to rapidly identify promising molecule/mineral pairs.
Hazen's Presidential Address in the November/December issue of American Mineralogist describes this work. It sets out a first-of-its-kind comprehensive survey into research that has identified processes by which minerals may have prompted the transition from a geochemical world to a biological one almost four billion years ago.
Scientists understand several probable steps in the origin of life, notably how the first organic molecules could have formed. In fact, prebiotic synthesis processes are now thought to have been so productive that the ancient Earth must have had far more different kinds of molecules than could have been used by early life. One of the biggest questions in origins research, therefore, is how just the right blend of critical biomolecules was selected, concentrated, and organized from the diverse primordial "soup." Previous research by the Carnegie team and others has shown that many molecules, including amino acids, can adhere to mineral surfaces, prompting further organic reactions. These findings have made surface/molecule interactions the subject of intense study.