Worldwide genetic structure of albacore thunnus alalunga revealed by microsatellite dna markers

One of the most common problems in fisheries is the definition of management units. Albacore Thunnus alalunga is an important species for commercial fisheries. Its population structure is still partially unknown; however, on the basis of fisheries data, tagging experiments, and morpho-ecological studies, 6 management units are currently accepted for this species. The main objective of this study was to define genetic entities within T. alalunga and to discuss the appropriateness of current management units. For this purpose, 13 microsatellite loci were applied to 551 albacore samples collected worldwide, and the population genetic structure was assessed. The most relevant differences between management and genetic units were that (1) Atlantic and Indian Ocean samples are genetically indistinguishable, and (2) possible differentiation exists within the Pacific Ocean and also within the Mediterranean Sea. Thus, this study provides genetic information to clarify albacore population delimitation, which is a key factor to reach the demanded sustainable management of this resource

Worldwide genetic structure of albacore thunnus alalunga revealed by microsatellite dna markers

One of the most common problems in fisheries is the definition of management units. Albacore Thunnus alalunga is an important species for commercial fisheries. Its population structure is still partially unknown; however, on the basis of fisheries data, tagging experiments, and morpho-ecological studies, 6 management units are currently accepted for this species. The main objective of this study was to define genetic entities within T. alalunga and to discuss the appropriateness of current management units. For this purpose, 13 microsatellite loci were applied to 551 albacore samples collected worldwide, and the population genetic structure was assessed. The most relevant differences between management and genetic units were that (1) Atlantic and Indian Ocean samples are genetically indistinguishable, and (2) possible differentiation exists within the Pacific Ocean and also within the Mediterranean Sea. Thus, this study provides genetic information to clarify albacore population delimitation, which is a key factor to reach the demanded sustainable management of this resource

Population dynamics during the Neolithic transition and the onset of megalithism in Portugal according to summed probability distribution of radiocarbon determinations

As field data accumulates, the study of Neolithic Portugal has been receiving increasing attention recently, from material culture and subsistence to ideology. However, little is known about population dynamics. In this paper, we use a judicious selection of radiocarbon determinations to evaluate demographic phenomena within the 9.500-5.000 cal BP range (thus, starting in the Late Mesolithic) making use of "summed probability distribution" analysis. In greater Portugal, results show a negative deviation (i.e. demographic decrease) at 6.400-6.300 cal BP and a positive deviation (i.e. demographic increase) at 5.350-4.950 cal BP. These can be explained, respectively, by the impact of farming about one millennium after its introduction (confirming the "Neolithic demographic transition" model) and by the full establishment of the "secondary products revolution" in the Late Neolithic. However, individual analyses of the northern and southern halves of the country-i.e. using the Mondego river valley as an ecological-geographical divide-show rather contrasting trajectories, with scarce Mesolithic populations and a demographic increase in the megalithism in the North, whereas in the South a demographic crisis occurred at the onset of megalithism (which remains to be fully explained) being followed in the Late Neolithic by a sharp demographic increase. Further summed probability distribution analyses of radiocarbon determinations, particularly if combined with other populational proxies, will be able in the future to detect other demographic events taking place in space and time.Juan de la Cierva postdoctoral grant [FJCI-2016-30588]Catalonian government [PGC2018-096943-B-C21]Spanish governmentSpanish GovernmentEuropean Commission [2017-SGR-1302]APOSTD Postdoctoral grant by the Valencian government [APOST/2019/179]info:eu-repo/semantics/publishedVersio