Luis Letelier

Relationships and genetic consequences of contrasting modes of speciation among endemic species of Robinsonia (Asteraceae, Senecioneae) of the Juan Fernández Archipelago, Chile, based on AFLPs and SSRs

This study analyses and compares the genetic signatures of anagenetic and cladogenetic speciation in six species of the genus Robinsonia (Asteraceae, Senecioneae), endemic to the Juan Fernández Islands, Chile. Population genetic structure was analyzed by amplified fragment length polymorphism (AFLP) and microsatellite (simple sequence repeat, SSR) markers from 286 and 320 individuals, respectively, in 28 populations. Each species is genetically distinct. Previous hypotheses of classification among these species into subgenera and sections, via morphological, phytochemical, isozymic and internal transcribed spacer (ITS) data, have been confirmed, except that R. saxatilis appears to be related to R. gayana rather than R. evenia. Analysis of phylogenetic results and biogeographic context suggests that five of these species have originated by cladogenesis and adaptive radiation on the older Robinson Crusoe Island. The sixth species, R. masafuerae, restricted to the younger Alejandro Selkirk Island, is closely related to and an anagenetic derivative of R. evenia from Robinson Crusoe. Microsatellite and AFLP data reveal considerable genetic variation among the cladogenetically derived species of Robinsonia, but within each the genetic variation is lower, highlighting presumptive genetic isolation and rapid radiation. The anagenetically derived R. masafuerae harbors a level of genetic variation similar to that of its progenitor, R. evenia. This is the first direct comparison of the genetic consequences of anagenetic and cladogenetic speciation in plants of an oceanic archipelago.

Progressive migration and anagenesis in Drimys confertifolia of the Juan Fernandez Archipelago, Chile

A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity. We investigate speciation in Drimys confertifolia, endemic to the two major islands of the Juan Fernández Archipelago, Chile, to determine genetic consequences of anagenesis, to examine relationships among populations of D. confertifolia and the continental species D. winteri and D. andina, and to test probable migration routes between the major islands. Population genetic analyses were conducted using AFLPs and nuclear microsatellites of 421 individuals from 42 populations from the Juan Fernández islands and the continent. Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor. The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape. Analysis of the probability of migration within the archipelago confirms colonization from the older island, Robinson Crusoe, to the younger island Alejandro Selkirk.

Genetic variation (AFLPs and nuclear microsatellites) in two anagenetically derived endemic species of Myrceugenia (Myrtaceae) on the Juan Fernández Islands, Chile

PREMISE OF THE STUDY Anagenesis (or phyletic evolution) is one mode of speciation that occurs in the evolution of plants on oceanic islands. Of two endemic species on the Juan Fernández Islands (Chile), Myrceugenia fernandeziana and M. schulzei (Myrtaceae), believed to have originated anagenetically from different continental progenitors, the first is endemic to Robinson Crusoe Island and has no clear tie to continental relatives; the last is endemic to the younger island, Alejandro Selkirk Island, and has close affinity to M. colchaguensis in mainland Chile. METHODS Using AFLPs and six nuclear microsatellites from 381 individuals representing 33 populations, we determined patterns of genetic variation within and among populations on both islands and between those of the islands and mainland. KEY RESULTS Considerable genetic variation was found within populations on both islands. The level of gene diversity within M. schulzei was equivalent to that of its close continental relative M. colchaguensis. Genetic diversity was not partitioned geographically in M. fernandeziana and was weakly so and nonsignificantly in M. schulzei. CONCLUSIONS The high genetic variation in both taxa is most likely due to anagenetic speciation. Subsidence of the older island Robinson Crusoe, landscape erosion, and restructuring of communities have severely reduced the overall island population to a single panmictic system. On the younger and less modified Alejandro Selkirk Island, slightly stronger patterns of genetic divergence are seen in M. schulzei. Because both species are genetically diverse and number in the thousands of individuals, neither is presently endangered in the archipelago.

The ecology, distribution and conservation status of Myrcianthes coquimbensis: a globally endangered endemic shrub of the Chilean Coastal Desert

Background: Myrcianthes coquimbensis is an endangered shrub endemic to Chile. No published account is known about its biology, ecology or threats to its continued existence. Aims: To document the current state of knowledge of M. coquimbensis regarding its geographic distribution, and population and reproductive parameters, and to evaluate threats in its distribution range. Methods: Historical records and recent survey data of 110 localities were used to characterise its known distribution. Plots were established in seven localities to determine the proportion of flowering individuals, recruitment and estimate population size and structure. Finally, levels of post-dispersal seed predation were determined in one locality. Results: The current distribution of M. coquimbensis extends along 82.8 km of the Chilean coast, where the species is mainly threatened by habitat loss. Only 13% of the individuals flowered during 2010, and 66% of these plants lost their entire flower crop due to desiccation. Few seeds (7.5%) were lost to post-dispersal seed predation. The populations are composed mainly of adult plants (70% of the individuals), and little to no recruitment was observed. Conclusions: M. coquimbensis populations are threatened by habitat loss and are not naturally recruiting through sexual reproduction. This exemplifies a case where studies on the ecology of a species are urgently needed to be able to design effective conservation and management plans.

Genetic variability and structure of Gomortega keule (Molina) Baillon (Gomortegaceae) relict populations: geographical and genetic fragmentation and its implications for conservation

Gomortega keule (Molina) Baillon is a rare Chilean species classified as endangered and currently under conser- vation. Currently, conservation of this species is carried out by private companies and government agencies, but is done so based more on pragmatic criteria than scientifically based strategies. In this context, information concerning the genetic variability of the species among the different populations over its entire distribution range is incomplete, making it difficult to coordinate management and conservation strategies. Here we report a study to evaluate the genetic variability and popu- lation structure of G. keule over its entire distribution in Chile. Twenty-five ISSR primers for 223 individuals from 11 geo- graphical populations were tested to evaluate genetic variability. Results showed a high level of genetic diversity for the species. A high level of genetic differentiation among populations was found, while genetic structure of the geographic populations was also shown by using STRUCTURE 2.1 software. Despite the fact that this species has been highly af- fected by human intervention and habitat destruction, a high level of genetic diversity was present. A likely explanation for this is that it reflects the previous distribution of this long-lived species and the current lack of sexual regeneration. Ge- netic diversity data must be considered in the development of a management strategy for further developing the protected areas, for identifying isolated small populations for conservation, and using larger populations with higher genetic diversity as seed sources for ex situ propagation and replanting.

Genetic consequences of cladogenetic vs. anagenetic speciation in endemic plants of oceanic islands

This paper presents for the first time a comparison of the genetic consequences of two different types of speciation in plants of an oceanic island. Genetic data, using two different DNA methods, were obtained from more than 4,000 plants from the two major islands of the Juan Fernández Archipelago (Chile). Results show that some immigrant populations undergo major splitting events and harbor limited genetic diversity within each evolving line. In contrast, other immigrant populations establish and enlarge, but they never split, hence accumulating higher levels of genetic diversity.

Distribución geográfica de los ortópteros (Insecta: Orthoptera) presentes en las provincias biogeográficas de Atacama y Coquimbo (Chile)

By means of reference material and literature reviews, as well as entomological surveys, we documented the taxonomic composition of the order Orthoptera within the biogeographic provinces of Atacama and Coquimbo, and identifi ed the relationships between the spatial distribution of species and the plant formations described from these provinces. We recorded the presence of 68 species, 37 genera, and 9 families. The most diverse family was Tettigoniidae, followed by Proscopiidae and Acrididae. High species richness was observed in only 4 of the 23 plant formations analyzed. The areas with the highest number of species were

Isolation and Characterization of 12 Microsatellite Loci in Soapbark, Quillaja saponaria (Quillajaceae)

Premise of the study: Microsatellite primers were developed for the endemic Chilean tree Quillaja saponaria (Quillajaceae), a common member of the sclerophyllous Mediterranean forest, to investigate intraspecific patterns of genetic diversity and structure. Methods and Results: Using an enriched library, 12 polymorphic microsatellite loci were developed in Q. saponaria. All loci consisted of dinucleotide repeats. The average number of alleles per locus was 5.3 (2–13), with a total of 64 alleles recorded in 39 individuals from three populations. Conclusions: The microsatellite markers described here are the first characterized for Q. saponaria. The polymorphic loci will be useful in studies of genetic diversity and genetic population differentiation in natural populations of this species.

Biogeography and genetic consequences of anagenetic speciation of R haphithamnus venustus (Verbenaceae) in the Juan Fernández archipelago, Chile: insights from AFLP and SSR markers

The genus R haphithamnus (Verbenaceae) consists of two species, one in South America and another endemic to the Juan Fernandez archipelago, Chile. The genus represents an example of anagenetic speciation in which the island populations have diverged from their colonizing ancestors to the point where they are recognized as a distinct species. The island species R haphithamnus venustus differs from the continental R . spinosus primarily by floral traits associated with adaptation to hummingbird pollination. Two molecular markers, amplified fragment length polymorphisms (AFLPs) and microsatellites, were used to estimate divergence between the continental and insular species, and to compare diversity in the two species. The comparable or greater diversity in the insular species observed in some diversity indices of AFLPs would support the hypothesis that during the course of anagenetic speciation it has recovered from any reduction of genetic diversity associated with colonization of the archipelago. This pattern of comparable or higher diversity in insular species is seen with other instances of anagenetic speciation in the Juan Fernandez archipelago. By contrast, the lower genetic diversity in the insular R . venustus found in microsatellites is likely to be the result of a founder effect from the original colonization of the archipelago; prior molecular studies suggest recent colonization of the Juan Fernandez archipelago by R haphithamnus . The seeming non-concordance between the present results and the widely accepted biogeography of R haphithamnus inferred from other data is discussed and an explanation is presented.

Distribution and Conservation Status of Gyriosomus granulipennis Pizarro-Araya and Flores, 2004 (Coleoptera: Tenebrionidae)

In the last decade, several expeditions were conducted in desert insular ecosystems in the transitional coastal desert of Chile (Alfaro et al. 2009, 2014, 2016). One of the taxonomic contributions of these expeditions is the newly described species Gyriosomus granulipennis Pizarro-Araya and Flores, 2004 (Coleoptera: Tenebrionidae), which was described based on material collected on Choros Island (PizarroAraya and Flores 2004). In this paper, we 1) analyze the distribution and conservation status of G. granulipennis and 2) propose actions to monitor and ensure the preservation of the species’ populations. Our study was conducted on Choros Island, which belongs to the archipelago of Los Choros and located near the northwestern border of Punta de Choros, 114 km north of La Serena (Coquimbo Region, Chile) (Castro and Brignardello 2005) (Fig. 1). The island is part of the Pingüino de Humboldt National Reserve (PHNR), which is under the administration of the National System of Protected Wild Areas (SNASPE by its Spanish acronym) and includes three islands: Choros (322 ha), Damas (56 ha), and Cha~naral (507.3 ha). The reserve is located in the transitional coastal desert of Chile (25–32° S), encompassing the southern limit of the biodiversity hotspot for Chile (Gaston 2000), and possesses a very unique plant diversity and endemicity (Armesto et al. 1993; Cavieres et al. 2002). The island has a Mediterranean-type climate (di Castri and Hajek 1976) with low daily and annual temperature ranges as a result of oceanic influence (Armesto et al. 1993). The mean annual precipitation in the area is ;90 mm; dry and rainy years occur in irregular cycles that are linked to the El Ni~no-Southern Oscillation event (Novoa and Villaseca 1989). To analyze the data about the distribution and conservation status of G. granulipennis, we reviewed the available literature and the list of endangered species of the Chilean Ministry of Environment (Ministerio de Medio Ambiente 2011). The data included literature records from 2002 (Pizarro-Araya and Flores 2004) and 2006 (Alfaro et al. 2009), in addition to records from