In any case, our subsequent analyses of body and range size influences on diversification depend on relative, not absolute age of nodes, and thus are independent from possible inaccuracies that may remain in our estimates of absolute ages of diversification events.
Despite intensive investigation in the last 15 years, absolute age and rate of diversification are poorly known for the flora of Macaronesia.
Figure 1 shows that irrespective of the clustering algorithm used, the age of this diversification varies between about 8 MY with two clocks, to an age less than half this figure with more than 15 clocks.
Interestingly, the estimated age of the diversification of the lacustrine species overlaps significantly with and is likely to have been driven by orogenic movements and monsoon changes occurring that time.
The estimated age of the diversification of the Central-Eastern, Western, and Southern clades is 6.2 MYA (7.8-4.7 MYA).
Assuming that after each extinction event, colonization was initiated from a nearby island hosting derived haplotypes, the apparent age of species diversification in the archipelago would be moved closer to the present after each extinction recolonization cycle.
This is the age-old story of diversification: It raises your expected return while simultaneously reducing risk.
Consistent with these studies, a meta-analysis [33] revealed that species of reptiles and amphibians from temperate-zone areas of the Northern Hemisphere tend to be younger (in term of the age of earliest intraspecific diversification) than are taxa found at similar latitudes in the Southern Hemisphere.
Since the Zaprionus genus and the melanogaster subgroup seem to share the same age of origin and diversification in tropical Africa, as well as ecological features, our data suggest that they passed through a permissive period of transposable element invasion during the diversification period.
Unfortunately the crown age and subsequent timing of diversification of angiosperms remains one of the most vexing questions in evolutionary biology, with some molecular estimates [ 42, 49, 61] substantially older (~100 Myr) than the oldest reported crown angiosperm fossils [ 29].
