This will be based on thetiming of your goals and thetiming of development opportunities (if a key conference is being held now, that may be a deciding factor even if you would prefer to take a class).
The most likely contest remains between Simon Thomas and Elin Jones (and never rule out Dafydd Elis-Thomas) - but there's a wider dimension where timing, not the successful candidate iskey.
By analysing where these differences occur in the animals' genomes, it is possible to get an insight into the two species' histories - thetiming of key events in their evolution.