This work also led to the production of his PhD thesis entitled " On the molecular basis of the two signal hypothesis of T cell activation : Signaling by CD3 and CD28 ".
12.
Despite the lack of empirical evidence for this hypothesis being the sole evolutionary function for exaggerated sexual swelling, it has been suggested that the reliable indicator hypothesis may work together with the graded-signals hypothesis.
13.
In line with this ideal, the most recent account regarding the function of sexual swellings ( the graded-signals hypothesis ) combines several existing theories in the attempt to provide a more comprehensive account of sexual swellings.
14.
Meanwhile, Archetti and Brown hope they can stimulate more experiments to test the leaf-signal hypothesis . " There are a series of steps you'd want to investigate on the tree side and the insect side, " Brown said.
15.
Another student, Sam Brown, tested the leaf-signal hypothesis against real data about trees and insects . " It was a first stab to see what was out there, " said Brown, now an evolutionary biologist the University of Texas.
16.
Many plant physiologists see the protection provided by pigments as so important that there is not much left over for Hamilton's leaf-signal hypothesis to explain . " You may have a few instances where insects have some sort of relationship to color changes, " Hoch said, " but it's almost certainly not a broad-based explanation.
