Formation of the Isthmus of Panama
نویسندگان
چکیده
The formation of the Isthmus of Panama stands as one of the greatest natural events of the Cenozoic, driving profound biotic transformations on land and in the oceans. Some recent studies suggest that the Isthmus formed many millions of years earlier than the widely recognized age of approximately 3 million years ago (Ma), a result that if true would revolutionize our understanding of environmental, ecological, and evolutionary change across the Americas. To bring clarity to the question of when the Isthmus of Panama formed, we provide an exhaustive review and reanalysis of geological, paleontological, and molecular records. These independent lines of evidence converge upon a cohesive narrative of gradually emerging land and constricting seaways, with formation of the Isthmus of Panama sensu stricto around 2.8 Ma. The evidence used to support an older isthmus is inconclusive, and we caution against the uncritical acceptance of an isthmus before the Pliocene.
منابع مشابه
Comment (2) on “Formation of the Isthmus of Panama” by O’Dea et al.
O'Dea et al. challenged the inference that the Isthmus of Panama has been in place for the last 10 million years or more and from "an exhaustive review and reanalysis of geological, paleontological, and molecular records," they argued for a "formation of the Isthmus of Panama sensu stricto around 2.8 Ma." I review environmental changes since ~5 Ma throughout Earth, and I argue that environmenta...
متن کاملTesting geological models of evolution of the Isthmus of Panama in a phylogenetic framework
The emergence and closure of the Isthmus of Panama had regional and global impacts that were rivalled by few other Cenozoic geological events. The closure of the Central American Seaway and the rise of the Isthmus had dramatic affects on climate and air and oceanic currents worldwide. Formation of the Isthmus also drove terrestrial biotic interchange, ending the isolation of South America by pe...
متن کاملFracturing of the Panamanian Isthmus during initial collision with South
Tectonic collision between South America and Panama began at 23–25 Ma. The collision is signifi cant because it ultimately led to development of the Panamanian Isthmus, which in turn had wide-ranging oceanic, climatic, biologic, and tectonic implications. Within the Panama Canal Zone, volcanic activity transitioned from hydrous mantle-wedge−derived arc magmatism to localized extensional arc mag...
متن کاملComment (1) on “Formation of the Isthmus of Panama” by O’Dea et al.
A review and reanalysis of geological, molecular, and paleontological data led O'Dea et al. (1) to propose (i) that reports by Montes et al. (2) and Bacon et al. (3) regarding a middle Miocene closure of the Central American Seaway (CAS) are unsupported, and (ii) a new age of the formation of the Isthmus at 2.8 million years ago (Ma). Here, we reject both of these conclusions.
متن کاملCaribbean and Pacific moisture sources on the Isthmus of Panama revealed from stalagmite and surface water dO gradients
[1] We test the hypothesis that the Pacific Ocean contributes moisture to the Intertropical Convergence Zone (ITCZ) over southern Central America, by spatial analysis of surface water dO values from Panama and Costa Rica. The dO values decrease with distance from the Caribbean Sea to the isthmian divide then gradually increase from the divide toward the Pacific slope, which suggests a contribut...
متن کامل