We compare the two main classes of measures of population structure in genetics: (i) fixation measures such as F_ST, G_ST, and θ and (ii) allelic differentiation measures such as Jost's D and entropy differentiation. These two groups of measures quantify complementary aspects of population structure, which have no necessary relationship with each other. We focus especially on empirical aspects of population structure relevant to conservation analyses. At the empirical level, the first set of measures quantify nearness to fixation, while the second set of measures quantify relative degree of allelic differentiation. The two sets of measures do not compete with each other. Fixation measures are often misinterpreted as measures of allelic differentiation in conservation applications; we give examples and theoretical explanations showing why this interpretation can mislead. This misinterpretation has led to the mistaken belief that the absolute number of migrants determines allelic differentiation between demes when mutation rate is low; we show that in the finite island model, the absolute number of migrants determines nearness to fixation, not allelic differentiation. We show that a different quantity, the factor that controls Jost's D, is a good predictor of the evolution of the actual genetic divergence between demes at equilibrium in this model. We also show that when conservation decisions require judgments about differences in genetic composition between demes, allelic differentiation measures should be used instead of fixation measures. Allelic differentiation of fast‐mutating markers can be used to rank pairs or sets of demes according to their differentiation, but the allelic differentiation at coding loci of interest should be directly measured in order to judge its actual magnitude at these loci.

El género Teagueia, una vez considerado como un género menor con muy pocas especies, ha experimentado una sorprendente radiación evolutiva de alta diversidad en la cuenca alta del Río Pastaza ubicada en los Andes orientales del Ecuador. Todos los miembros de esta radiación local comparten un habito largo-reptante, en contraste con el resto de las especies del género. Seis especies de esta radiación local fueron descritas anteriormente; aqui se describe cuatro especies adicionales. Cada una de las cuatro especies nuevas se distingue por la forma particular de sus labelo, diferencias en los tamaños de sus flores, y diferencias en las textura de sus hojas. Todas las especies nuevas, al igual que las otras de esta radiación, tienen distribuciones extremadamente reducidas.

Recent field research on the eastern slopes of the Andes resulted in the discovery of a new species of Bomarea from the Cerro Candelaria Reserve in the Tungurahua province of Ecuador. Bomarea pastazensis is the second smallest species in the genus and differs from the smallest by the presence of glutinous trichomes on the ovary, glabrous sepals, and greenish-yellow petals with purple spots. Based on IUCN guidelines, a preliminary conservation status is assigned as Vulnerable (VU).

Se describen e ilustran dos nuevas especies del género Teagueia, T. barbeliana y T. puroana. Se discuten sus afinidades, su importancia para la ciencia, y su conservación. Las especies más cercanamente emparentadas con las nuevas son T. alyssana, T. sancheziae, T. cymbisepala, y T. jostii, que al igual que las nuevas, son endémicas a las alturas (>3100m) de la cuenca alta del Río Pastaza en los Andes Orientales del Ecuador. Teagueia barbeliana se distingue por sus sépalos y pétalos redondos, sus sépalos laterales unidos hasta la mitad de su longitud, y las alas en el ápice de la columna. Teagueia puroana se distingue por sus pétalos y sépalos con colas largas.