| Popis: |
This chapter considers the origin of the coconut in four perspectives—time of origin, place of origin, mode of origin, and the species/taxon from which the coconut has originated. The information available on these aspects from various sources—history, prehistory, paleobotany, genetics, botany including palynology, botany phylogeny, and biogeography has been considered. They indicate that the present-day cultivated coconut is wild in nature. It is because they show all the characteristics of a wild and weedy plant for all its attributes—percent setting of inflorescence, percent fruit setting within an inflorescence, opportunistic pollination system, prevalence of seed dormancy, staggered germination, and so on. These characteristics have been identified as typical of wild and weedy taxa by well-known specialists as Stebbins, Baker, Harlan, De Wet, etc. The coconut has no near relatives. They may have been lost due to extinctions. The place of origin is diffuse in nature, because the characterization of the standard landraces/morphotypes of a global collection of coconut germplasm attests to this conclusion with some forms in different regions showing marginal characteristics of ennoblement for various characters. Some of the extant variability for fruit and nut characters observed in certain remote regions like Nicobar and Laccadive Islands match with the fossil coconuts observed in Deccan traps (India), Queensland (Australia), and Colombia. They may indicate that there has been a progression in domestication in some regions of the world for large fruit and nut size. Regarding the time of origin, the molecular phylogenetic studies have shown that the subtribe Attaleinae (to which the coconut belongs) had differentiated in South America; it then possibly dispersed to the Indian and Pacific Oceans in the last 20–30 Mya. There are suggestions that large-scale extinctions took place in the eastern Indian Ocean–western Pacific Ocean regions during the large-scale geological turmoil that followed the collision of the Australian plate with the Southeast Asia plate 15–30 Mya. This may also explain the absence of any closely related forms to Cocos, because the strong possibility exists that they may have suffered extinctions. In view of the position that the present-day coconut is fundamentally wild in nature, and there are only faint traces of nobilizations in certain characters such as larger fruit and nut size, etc., the question of mode of evolution of the coconut does not arise. |
