The role of the Southern Hemisphere in the evolutionary history of Apiaceae, a mostly north temperate plant family

CALVIÑO, C. I.; TERUEL, F. E.; DOWNIE, S. R.

JOURNAL OF BIOGEOGRAPHY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016 vol. 43 p. 398 - 409

0305-0270

Aim To estimate the most likely pathways of expansion of the first diverginglineages of the angiosperm family Apiaceae across the Southern Hemisphereand to Eurasia by reconstructing the biogeographical history of the familythrough space and time.Location Southern Hemisphere, with emphasis on Africa.Methods Divergence times were assessed under a penalized-likelihood method(r8s) and a data set of 129 cpDNA rps16 intron sequences. Confidence intervalswere estimated using ABCq, BCa, bootstrap-t and standard normal methods.Biogeographical distributions were reconstructed using DEC analyses overrps16 intron and/or nrDNA ITS trees.Results Crown Apiaceae likely originated by the Late Cretaceous in Australasia.Apiaceae subfamilies diverged between 45.9 and 71.2 Ma in the Southern Hemisphere,specifically, Mackinlayoideae in Australasia, Azorelloideae in SouthAmerica and Apioideae and Saniculoideae in southern Africa. From the Palaeoceneto Oligocene, Africa showed connections via transoceanic dispersals as a sinkcontinent with Australasia and as a source continent with South America andEurasia. These dispersals explain the present intercontinental disjunctions of thesubfamilies. The first diverging lineages of Apioideae and Saniculoideae likelyoriginated in Africa and diversified in situ since the Palaeocene, with no inputfrom newcomers until the Miocene. Subsequently, several dispersals mainly fromEurasia are estimated back to northern and eastern Africa.Main conclusions The Southern Hemisphere has played a key role in theorigin and early diversification of Apiaceae, currently a mostly north temperatefamily. African Apiaceae was likely assembled by Palaeocene lineages thatdiversified in situ and are now restricted mainly to southern Africa and postMiocene newcomers mostly restricted to northern and eastern Africa byeffective environmental barriers.