Results from both divergence dating methods implemented herein indicate that most diversification within Melanohalea occurred during the Miocene and Pliocene, and was likely the result of habitat changes due to mountain uplift, major climatic changes (aridification) and associated shifts in vegetation patterns.
Fluctuating climatic conditions and aridification during that time may have promoted speciation in African lacertids through ecological displacement.
It has been proposed that diversification of African ungulates was strongly influenced by the climatic fluctuations causing cyclic aridification [ 28].
The radiation in drier lowland habitats associated with the decrease of body size is much younger, occurred mainly in a single lineage (called the minutoides group, and especially within the species M. minutoides), and was probably linked to aridification and climatic fluctuations in middle Pliocene/Pleistocene.
During the Miocene, Iberian landscapes were drastically modified due to geographic and climatic changes (mainly cooling and aridification) changes.
Previous studies suggest that global climate change did not have a profound affect on South American climate during the time period in question, but rather that the growth of Andean topography reinforced the preexisting climatic regime and promoted further aridification within the AP and along the Pacific cost18,19.
Examples are aridification and desertification, climatic changes from meteorite strikes and volcanic eruptions, local water drawdown, and availability and use of local and locally appropriate building materials.
Our study uses phylogenies representing 20% of the extant angiosperm flora of the Cape of South Africa (1800 of the 8900 species), a biodiversity hotspot that has experienced climatic changes associated with strong seasonal aridification since the Neogene (ca. 2-14 million years ago), likely in several different episodes [ 14].
However, the upward sedimentologic variation in the Atacama Gravels evidences a progressive aridification of the climate.
The disappearance of the river has been explained as a consequence of river diversion related to tectonic activity12, or aridification due to climate change39.
