Situated at the northernmost Neotropics, Mesoamerica possess one of the highest levels of endemism and species diversity, but also one of the most globally threatened biota and high rates of deforestation. However, a relatively lesser effort has been dedicated to provide robust biogeographic hypotheses seeking to explain shared distributional patterns, even when it may be expected that species sharing geographic areas should show congruent spatio-temporal patterns of differentiation. Several phylogeographic studies of individual bird species have shown that genetic structure is frequently associated to discontinuous ranges and geographical barriers that restrict admixture between populations, leading to genetic differentiation (see ) which may have proceeded independently or jointly with the divergence in morphological, behavioral or ecological traits (see ). Our study provides a framework for understanding the evolutionary origins and historical factors enhancing speciation in well-defined regions within Mesoamerica, indicating that the evolutionary history of extant biota inhabiting montane forests is complex and often idiosyncratic.Ĭomparison of phylogeographic patterns across co-distributed species provides valuable insights on the probable congruence of processes that may have driven intraspecific diversification in particular regions. Nevertheless, dating analyses and divergence patterns observed were consistent with the hypothesis of broad vicariance across Mesoamerica derived from mechanisms operating at distinct times across taxa in the SMS. Our analyses suggested shared phylogeographic breaks in areas corresponding to the SMS populations, and between the main montane systems in Mesoamerica, with the Central Valley of Oaxaca and the Nicaragua Depression being the most frequently shared breaks among analyzed taxa. We assessed genetic structure, demographic history, and defined a framework for the coalescent simulations used in biogeographic hypothesis testing temporal and spatial co-variance. We gathered mitochondrial DNA sequences for at least one locus from 177 individuals across all species. Selected species include endemic and differentiated populations across the montane forests of Mesoamerica, and particularly within the SMS. Herein, we searched for spatially and temporally concordant phylogeographic patterns, in four bird genera from three distinct avian orders co-distributed across Mesoamerica and investigated their causes through hypothesis testing regarding historical processes. Within northern Mesoamerica, the biotic province of the Sierra Madre del Sur (SMS) in southwestern Mexico harbors exceptionally high avian endemism and diversity. To determine which one will be administered next.Mesoamerica is a remarkable region with a high geological and ecological complexity. Please consult your child's most recently returned test Natalie will be administered during the weeks listed below. Thank you for your support with this great enrichment program! The first study guide will be available on October 25th with the first challenge being due November 15th. If you are interested in being the parent volunteer in your child’s classroom to collect and grade the geography tests, please complete the form attached and return back to the school to the attention of Natalie Decatur, care of Annalisa Decatur in Mrs. Support and encouragement from you can make this a great learning experience for the whole family. It is also a great opportunity for families to discuss personal connections with places around our country and around the world. However, as part of the district-wide geography program, Hawley’s Unite the States Geography Program prepares our students for success in geography in future grades. It is important to remember that scores on the Geography tests do not have an impact on your child’s grades and will not appear on his/her report cards.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |