Even in the absence of the oceanic barriers, i.e. within the larger islands, we find evidence of short range endemism124.
The passive margins of the early Paleozoic were partially activated by subduction of oceanic crust (i.e., the forced descent of oceanic crust beneath the leading edge of an overriding continental plate) during late Cambrian to Ordovician times (about 500 to 470 million years ago).
(c) PE in both continental and oceanic crusts, i.e., the combined effect of (a) and (b).
Andesitic magmatism and continent crust-forming processes are caused by the subduction of oceanic plates, i.e., the operation of plate tectonics.
In Figure 4f, we see that the top and bottom of the subducting oceanic crust (i.e., plate interface and oceanic Moho) are defined by strong negative and positive amplitudes of receiver functions, respectively.
If the same oceanic current (i.e. Gulf Stream) conditions were expected to occur in the future as occurred between 1400 and 1650 C.E. in the N.E. USA region, then maybe it is appropriate to incorporate this time period.
Here, we used the observation that the subducting oceanic crust (i.e., SOC2 and SOC3) is mostly aseismic, whereas all subduction seismicity is concentrated inside the slab, which is also subducting the oceanic upper mantle (see, for example, Ito et al., 2005).
Recent research using short-duration tags around oceanic islands (i.e., where deep waters are close to shore) has provided valuable and insightful data on diving behavior, beaked whale echolocation, and identifying beaked whale prey [6], [7], [8].
Another strong signature of positive selection was detected along the lineage leading to oceanic dolphins, i.e., the family Delphinidae (delphinids).
So, while it is tempting to bring together the expansion of atmospheric and oceanic "deserts", I would advise keeping them as separate issues — although I can see how this might be very difficult.
