Phylogenetic Tree of a Protein (IMAGE) Tokyo Institute of Technology Caption Phylogenetic tree of a protein which is evolutionarily 'mixed' between the archaeal and bacterial domains, precluding assignment in the LUCA. Other proteins separate the domains onto different branches, suggesting they are ancient. Credit Berkemer and McGlynn 2020. CC BY 4.0 Usage Restrictions The image may only be used with appropriate caption and credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.