Darwin’s changing views on evolution: from centres of origin and teleology to vicariance and incomplete lineage sorting

Abstract

It is a strange fact that in many ways the first edition of Charles Darwin's Origin of Species is closer to modern neodarwinism than the sixth and last edition. Sometimes this is attributed to a decline in the quality of the argument, but the opposite interpretation is given here. It is suggested that Darwin's early work on evolution is naïve and based on the two creationist principles of centre of origin and teleology (panselectionism). This fusion later became the 'modern synthesis'. However, after the first edition of the Origin, Darwin developed a non-teleological synthesis that integrated natural selection with what he called 'laws of growth' -phylogenetic/morphogenetic trends or tendencies. Discussion of Darwin's later, more sophisticated model of evolution has been suppressed in the teleological modern synthesis, but similar ideas are re-emerging in current work on molecular phylogenetics and biogeography. This indicates that the ancestor of a group can be diverse in its morphology and its ecology, that this diversity can be inherited, and that groups usually originate over a broad region and not at a single point.

Taxonomic Considerations on Metastelmatinae (Apocynaceae) Based on Plastid and Nuclear DNA

“…Therefore, this incongruence may be produced by incomplete Uneage sorting, and/or a heterogeneous rate of molecular evolution across the subtribe. Both processes may be caused by periods of rapid diversification, possibly generated by the fragmentation of polymorphic broadly distrib-uted ancestral species giving rise to several small isolated populations, which diverged rapidly from each other (Heads 2009). In these cases, there seems to be a combination of short branches with few synapomorphies followed by long branches with a relatively large number of homoplasies (Rokas and Carroll 2006).…”

A reconstruction of Palaeo-Macaronesia, with particular reference to the long-term biogeography of the Atlantic island laurel forests

“…Winkworth et al, 2002;Särkinen et al, 2007) but not all biogeographers, some of whom regard long-distance dispersal as a generally unsupported inference (e.g. Nelson & Ladiges, 2001;Heads, 2005Heads, , 2009). However, it seems to us that the vicariance-dispersalism controversy becomes more easily resolvable if it is accepted that islands have always been built and destroyed throughout the history of the great oceans, thus extending the time-scale over which such migrations have been possible, and allowing for the operation of 'stepping-stone' dispersal via now vanished islands and terrains (Morley, 2003;Carpenter et al, 2010;Heads, 2010;Renner, 2010).…”

The endemic plant families and the palms of New Caledonia: a biogeographical analysis

“…It would be expected if vicariant groups evolved as recombinations of widespread ancestral characters already distributed over different, broad sectors of the ancestral range before the evolution of the modern groups (cf. Heads, 2009c). It is well known that parallel evolution is ubiquitous and recombination of characters probably takes place by parallel evolution in the populations of a given biogeographical sector.…”