Alkaloid Profiling and Anti-Cholinesterase Potential of Three Different Genera of Amaryllidaceae Collected in Ecuador: Rchb., Herb. and Herb.

Ecuador is an important center of biodiversity for the plant subfamily Amaryllidoideae, known for its important bioactive molecules. This study aimed to assess the chemical and biological potential of four different Amaryllidoideae species collected in Ecuador: , , , and . Twenty-six alkaloids were identified in the bulb extracts of these species using GC-MS.

 (Alstroemeriaceae), an exceptionally small new species from the eastern Andean slopes of Ecuador.

Recent field research on the eastern slopes of the Andes resulted in the discovery of a new species of from the Cerro Candelaria Reserve in the Tungurahua province of Ecuador. 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).

A spectacular new species of (Anura: Hylidae) from the Cordillera de Los Llanganates in the eastern Andes of Ecuador.

We have discovered a spectacular new species of frog in the genus , belonging to the species group. The adult female is characterized by a mostly black body with large bright red spots on the dorsal and ventral surface, extremities, and toe pads. The adult male is unknown.

Strong differentiation between amphibian communities on two adjacent mountains in the Upper Rio Pastaza watershed of Ecuador, with descriptions of two new species of terrestrial frogs.

We present the results of herpetological surveys in two adjacent mountains where the EcoMinga Foundation protects the cloud forest in the Upper Rio Pastaza watershed, in the Llanganates Sangay Ecological Corridor in Ecuador. A rapid assessment of the amphibian communities of the study sites reveals a diverse and heterogeneous composition, dominated by terrestrial frogs from the genus . We also identify a cryptic diversity with a significant number of candidate new species.

New circumscriptions add two northern Andean species to (Gesneriaceae).

Recent studies of type specimens and exploratory research expeditions in the northern Andes have resulted in an updated circumscription and recognition for two species of (Gesneriaceae) in Ecuador and Colombia. A change in the rank from a variety to species is recognized for (Fritsch) Wiehler. The combination (Fritsch) J.

Diversity from genes to ecosystems: A unifying framework to study variation across biological metrics and scales.

Biological diversity is a key concept in the life sciences and plays a fundamental role in many ecological and evolutionary processes. Although biodiversity is inherently a hierarchical concept covering different levels of organization (genes, population, species, ecological communities and ecosystems), a diversity index that behaves consistently across these different levels has so far been lacking, hindering the development of truly integrative biodiversity studies. To fill this important knowledge gap, we present a unifying framework for the measurement of biodiversity across hierarchical levels of organization.

Differentiation measures for conservation genetics.

We compare the two main classes of measures of population structure in genetics: (i) fixation measures such as ,, and θ and (ii) allelic differentiation measures such as Jost's 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.

Expected Shannon Entropy and Shannon Differentiation between Subpopulations for Neutral Genes under the Finite Island Model.

Shannon entropy H and related measures are increasingly used in molecular ecology and population genetics because (1) unlike measures based on heterozygosity or allele number, these measures weigh alleles in proportion to their population fraction, thus capturing a previously-ignored aspect of allele frequency distributions that may be important in many applications; (2) these measures connect directly to the rich predictive mathematics of information theory; (3) Shannon entropy is completely additive and has an explicitly hierarchical nature; and (4) Shannon entropy-based differentiation measures obey strong monotonicity properties that heterozygosity-based measures lack. We derive simple new expressions for the expected values of the Shannon entropy of the equilibrium allele distribution at a neutral locus in a single isolated population under two models of mutation: the infinite allele model and the stepwise mutation model. Surprisingly, this complex stochastic system for each model has an entropy expressable as a simple combination of well-known mathematical functions.

Two new species of endemic Ecuadorean Amaryllidaceae (Asparagales, Amaryllidaceae, Amarylloideae, Eucharideae).

New species of the genera Stenomesson and Eucharis (Amaryllidaceae) are described from Ecuador. Stenomessonecuadorense is the second species of the genus reported from that country, and the only endemic one. It is related to Stenomessonminiatum and Stenomessoncampanulatum, both from Peru, with which it shares orange flower color and the fusion of the staminal corona to the perianth tube.

Coverage-based rarefaction and extrapolation: standardizing samples by completeness rather than size.

We propose an integrated sampling, rarefaction, and extrapolation methodology to compare species richness of a set of communities based on samples of equal completeness (as measured by sample coverage) instead of equal size. Traditional rarefaction or extrapolation to equal-sized samples can misrepresent the relationships between the richnesses of the communities being compared because a sample of a given size may be sufficient to fully characterize the lower diversity community, but insufficient to characterize the richer community. Thus, the traditional method systematically biases the degree of differences between community richnesses.

Phylogenetic diversity measures based on Hill numbers.

We propose a parametric class of phylogenetic diversity (PD) measures that are sensitive to both species abundance and species taxonomic or phylogenetic distances. This work extends the conventional parametric species-neutral approach (based on 'effective number of species' or Hill numbers) to take into account species relatedness, and also generalizes the traditional phylogenetic approach (based on 'total phylogenetic length') to incorporate species abundances. The proposed measure quantifies 'the mean effective number of species' over any time interval of interest, or the 'effective number of maximally distinct lineages' over that time interval.

G(ST) and its relatives do not measure differentiation.

G(ST) and its relatives are often interpreted as measures of differentiation between subpopulations, with values near zero supposedly indicating low differentiation. However, G(ST) necessarily approaches zero when gene diversity is high, even if subpopulations are completely differentiated, and it is not monotonic with increasing differentiation. Likewise, when diversity is equated with heterozygosity, standard similarity measures formed by taking the ratio of mean within-subpopulation diversity to total diversity necessarily approach unity when diversity is high, even if the subpopulations are completely dissimilar (no shared alleles).

A two-stage probabilistic approach to multiple-community similarity indices.

A traditional approach for assessing similarity among N (N > 2) communities is to use multiple pairwise comparisons. However, pairwise similarity indices do not completely characterize multiple-community similarity because the information shared by at least three communities is ignored. We propose a new and intuitive two-stage probabilistic approach, which leads to a general framework to simultaneously compare multiple communities based on abundance data.

Partitioning diversity into independent alpha and beta components.

Existing general definitions of beta diversity often produce a beta with a hidden dependence on alpha. Such a beta cannot be used to compare regions that differ in alpha diversity. To avoid misinterpretation, existing definitions of alpha and beta must be replaced by a definition that partitions diversity into independent alpha and beta components.