The combination of factors that account for present-day distributions of organisms is unique to individual lineages and varies over time. An observation relevant to some lineages at some point in their history is that hurricane frequency and intensity appears to be increasing with global warming. If so, then directional winds from Africa to the Caribbean region (the trade winds), from South America to Africa (the westerlies), the ocean currents they induce, and the transport of the floating islands they carry, were likely more intense during the generally warmer-than-present Tertiary Period and especially at peaks of exceptional warmth. These peaks occurred in the Paleocene/Eocene (65–45 Ma), in the early to middle Miocene (broadly between ∼23–12 Ma), in the middle Pliocene (3–4 Ma), and probably extended slightly later in the lower latitudes. The Paleocene/Eocene interval includes the time when the distance between Africa and South America was one-half to two-thirds that of the present, and when the Greater Antilles island arc was first becoming emergent as increasing target areas for propagules. The second and third intervals of warming include the times when molecular evidence suggests divergence between several African and New World lineages. Thus, wind and ocean transport of organisms and propagules throughout the Tertiary, and especially at peaks of warmth, was likely a more important means of dispersal than would seem plausible under present conditions.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 93 • No. 2