The three studies differ in the strength of inference with respect to the genetic nature of the changes, as well as to the degree in which global warming has been demonstrated to be the selective agent behind the shifts.
Yet, although the observations are in line with expectations based on common sense, in A. albopictus, it is not entirely sure that global warming was the selective agent (Urbanski et al. 2012).
One of these new agents is the selective factor Xa inhibitor rivaroxaban (Xarelto®) which was approved for the prevention of VTE in adult patients undergoing elective hip or knee replacement surgery in 2008 [ 5].
However, a major limitation to this system is that the selective agent must provide a specific growth advantage or disadvantage.
In these situations, experimental evolution experiments are a good alternative, since the selective agent is known and can be manipulated, adequate controls can be set up, replication is possible, multidimensional phenotype data can be acquired, and allele-frequency changes can be followed, allowing for direct estimates of selection coefficients of any given trait.
Bialaphos was used as the selective agent.
Allyl alcohol was used as the selective agent in the medium with methanol as sole carbon and energy source.
Of obvious importance in the evolution of coloration is the third party, which is the actual selective agent involved in the relationship between the organism and its background.
Second, in related, historical experiments in which a selection was removed and after time reapplied, the rate at which cells lost sufficient EBV-derived plasmids to become sensitive to being killed by reapplication of the selective agent has been found to be 3 5% per generation (Yates et al, 1984; Kirchmaier and Sugden, 1995).
Unlike other parts of the skull that harbour different functions (protecting the brain and sensory organs), the mandible's main functional demands are related to feeding, and dietary changes are expected to be the main selective agent for this structure.
