En este artículo se analiza la variabilidad fenotípica del maíz en el sitio ... more En este artículo se analiza la variabilidad fenotípica del maíz en el sitio Caserones-1, comparando siete caracteres entre ejemplares pertenecientes a dos períodos: Formativo e Intermedio Tardío (cal. 20-1.020 d.C.). Considerando la antigua relación entre esta especie y diversos grupos humanos en América (ca. 7.500 AP), así como la tendencia generalizada a la disminución de la variabilidad genética como resultado de los procesos de selección y domesticación, es que aquí ponemos a prueba la hipótesis de disminución de la variabilidad fenotípica desde el Formativo al Período IntermedioTardío como consecuencia del manejo antrópico. Los resultados aquí mostrados refutan la hipótesis anterior, describiendo un panorama inverso: de acuerdo al Análisis de Componentes Principales, la longitud es el atributo que presenta la transformaci&oacu...
A new fossil cycad species, Sueria laxinervis, is described from the Upper Cretaceous (Maastricht... more A new fossil cycad species, Sueria laxinervis, is described from the Upper Cretaceous (Maastrichtian) Quiriquina Formation in Cocholgüe, Bíobío Region, Chile. The generic assignment is supported by the taeniopterid-type leaf with haplocheilic stomata and sinuate anticlinal walls of leaf epidermal cells, while S. laxinervis clearly differs from the other two described Sueria species in its sparse veins and large epidermal cells. The vascular bundles of the midrib are arranged in an inverted-omega shape, supporting the placement of Sueria in Cycadales.
The current relationship between leaf traits and environmental variables has been widely used as ... more The current relationship between leaf traits and environmental variables has been widely used as a proxy for climate estimates. However, it has been observed that the phylogenetic relationships between taxa also influence the evolution of climatic related leaf traits, implying that the direct use of the physiognomy-climate relation should be corrected by their ancestor-descendant relations. Here, we analyze the variation of 20 leaf traits during the evolution of 27 species in the Gondwana family Nothofagaceae. We evaluate whether the evolution of these traits is exclusively associated with past climate variations or whether they are restricted by phylogenetic relationships. Our results indicate that four leaf traits, associated with size and shape, had consistently a phylogenetic independent evolution, suggesting adaptive variation with the environment. While three of the traits, presented consistently phylogenetic signal and fit a Brownian motion or Ornstein-Uhlenbeck model of evol...
Several studies have demonstrated the contribution of northern immigrants to the flora of the tro... more Several studies have demonstrated the contribution of northern immigrants to the flora of the tropical Andes-the world's richest and most diverse biodiversity hotspot. However, much less is known about the biogeographic history and diversification of Andean groups with southern origins, although it has been suggested that northern and southern groups have contributed roughly equally to the high Andean (i.e., páramo) flora. Here we infer the evolutionary history of the southern hemisphere plant genus , a lineage with a rich fossil history and an important ecological role as an early colonising species characteristic of wet, montane environments. Our results show striking contrasts in species diversification, where some species may have persisted for some 90 million years, and whereas others date to less than 2 Ma since origination. The outstanding longevity of the group is likely linked to a high degree of niche conservatism across its highly disjunct range, whereby tracks damp a...
En este artículo se analiza la variabilidad fenotípica del maíz en el sitio ... more En este artículo se analiza la variabilidad fenotípica del maíz en el sitio Caserones-1, comparando siete caracteres entre ejemplares pertenecientes a dos períodos: Formativo e Intermedio Tardío (cal. 20-1.020 d.C.). Considerando la antigua relación entre esta especie y diversos grupos humanos en América (ca. 7.500 AP), así como la tendencia generalizada a la disminución de la variabilidad genética como resultado de los procesos de selección y domesticación, es que aquí ponemos a prueba la hipótesis de disminución de la variabilidad fenotípica desde el Formativo al Período IntermedioTardío como consecuencia del manejo antrópico. Los resultados aquí mostrados refutan la hipótesis anterior, describiendo un panorama inverso: de acuerdo al Análisis de Componentes Principales, la longitud es el atributo que presenta la transformaci&oacu...
A new fossil cycad species, Sueria laxinervis, is described from the Upper Cretaceous (Maastricht... more A new fossil cycad species, Sueria laxinervis, is described from the Upper Cretaceous (Maastrichtian) Quiriquina Formation in Cocholgüe, Bíobío Region, Chile. The generic assignment is supported by the taeniopterid-type leaf with haplocheilic stomata and sinuate anticlinal walls of leaf epidermal cells, while S. laxinervis clearly differs from the other two described Sueria species in its sparse veins and large epidermal cells. The vascular bundles of the midrib are arranged in an inverted-omega shape, supporting the placement of Sueria in Cycadales.
The current relationship between leaf traits and environmental variables has been widely used as ... more The current relationship between leaf traits and environmental variables has been widely used as a proxy for climate estimates. However, it has been observed that the phylogenetic relationships between taxa also influence the evolution of climatic related leaf traits, implying that the direct use of the physiognomy-climate relation should be corrected by their ancestor-descendant relations. Here, we analyze the variation of 20 leaf traits during the evolution of 27 species in the Gondwana family Nothofagaceae. We evaluate whether the evolution of these traits is exclusively associated with past climate variations or whether they are restricted by phylogenetic relationships. Our results indicate that four leaf traits, associated with size and shape, had consistently a phylogenetic independent evolution, suggesting adaptive variation with the environment. While three of the traits, presented consistently phylogenetic signal and fit a Brownian motion or Ornstein-Uhlenbeck model of evol...
Several studies have demonstrated the contribution of northern immigrants to the flora of the tro... more Several studies have demonstrated the contribution of northern immigrants to the flora of the tropical Andes-the world's richest and most diverse biodiversity hotspot. However, much less is known about the biogeographic history and diversification of Andean groups with southern origins, although it has been suggested that northern and southern groups have contributed roughly equally to the high Andean (i.e., páramo) flora. Here we infer the evolutionary history of the southern hemisphere plant genus , a lineage with a rich fossil history and an important ecological role as an early colonising species characteristic of wet, montane environments. Our results show striking contrasts in species diversification, where some species may have persisted for some 90 million years, and whereas others date to less than 2 Ma since origination. The outstanding longevity of the group is likely linked to a high degree of niche conservatism across its highly disjunct range, whereby tracks damp a...
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