Volume 24, Issue 2, Pages R60-R61 (January 2014) Trade-offs  Theodore Garland  Current Biology  Volume 24, Issue 2, Pages R60-R61 (January 2014) DOI: 10.1016/j.cub.2013.11.036 Copyright © 2014 Elsevier Ltd Terms and Conditions

Figure 1 Grade shifts. Two traits may be positively related among a phylogenetically diverse collection of species (left) (such as vertebrates), but (middle) negatively related when comparisons are made within sets of more closely related species (right) (subclades, such as salmonid fishes or passerine birds). Current Biology 2014 24, R60-R61DOI: (10.1016/j.cub.2013.11.036) Copyright © 2014 Elsevier Ltd Terms and Conditions