Textbooks often assert that life began with specialized complex molecules, such as RNA, that are capable of making their own copies. This scenario has serious difficulties, but an alternative has remained elusive. Recent research and computer simulations have suggested that the first steps toward life may not have involved biopolymers. Rather, noncovalent protocellular assemblies, generated by catalyzed recruitment of diverse amphiphilic and hydrophobic compounds, could have constituted the first systems capable of information storage, inheritance and selection. A complex chain of evolutionary events, yet to be deciphered, could then have led to the common ancestors of today's free-living cells, and to the appearance of DNA, RNA and protein enzymes.
机构:
Northwestern Univ, Evanston, IL 60208 USA
Roosevelt Univ, Chicago, IL 60605 USA
Univ Illinois, Chicago, IL USA
Depaul Univ, Chicago, IL 60604 USA
Univ Iowa, Iowa City, IA 52242 USANorthwestern Univ, Evanston, IL 60208 USA