The assembly of regional biotas and organismal responses to anthropogenic climate change both depend on the capacity of organisms to adapt to novel ecological conditions. Here we demonstrate the concept of evolutionary lag time, the time between when a climatic regime or habitat develops in a region and when it is colonized by a given clade. We analyzed the time of colonization of four clades (three plant genera and one lizard genus) into the Atacama–Sechura Desert of South America, one of Earth’s driest and oldest deserts. We reconstructed time-calibrated phylogenies for each clade and analyzed the timing of shifts in climatic distributions and biogeography and compared these estimates to independent geological estimates of the time of origin of these deserts.ChaetantheraandMalesherbia(plants) andLiolaemus(animal) invaded arid regions of the Atacama–Sechura Desert in the last 10 million years, some 20 million years after the initial onset of aridity in the region. There are also major lag times between when these clades colonized the region and when they invaded arid habitats within the region (typically 4–14 million years). Similarly, hyperarid climates developed ∼8 million years ago, but the most diverse plant clade in these habitats (Nolana) only colonized them ∼2 million years ago. Similar evolutionary lag times may occur in other organisms and habitats, but these results are important in suggesting that many lineages may require very long time scales to adapt to modern desertification and climatic change.

Background and Aims Grapevine introduction into South America occurred after Spanish colonisation during the 16th century. In Chile, some vines were established in small villages and oases along the Atacama Desert. Considering that these plants have survived harsh environmental conditions, we explored and collected naturalised vines from 18°34′LS (close to the Peruvian border) to 31°53′LS, in order to understand their genetic nature and preserve this germplasm. Methods and Results Over 150 grapevine accessions were collected and characterised using 11 Simple Sequence Repeats (SSR) markers, to determine the genetic diversity and to propose a population structuring. SSR diversity was high, with observed heterozygosity (Ho = 0.87) greater than expected heterozygosity (He = 0.70). Three discrete genetic groups were identified, which did not show any association with geographical distribution. Groups 1 (G1) and G3 had a higher level of genetic diversity and also an important level of heterozygosity. Conclusions The gene pool of naturalised grapevines from the Atacama Desert had a significant genetic diversity and exhibited an important level of heterozygote excess. Clustering of this diversity suggested that this naturalised grapevine germplasm would represent a novel source of allelic variants. Significance of the Study Naturalised and admixed genotypes are potential sources of new alleles, and are a unique source of diversity for grapevine breeding cultivars and/or rootstocks better adapted to the prospect of climate change.

Populations of the columnar cactus genus Eulychnia (Cactaceae) are an iconic sight in the Chilean Atacama Desert. The most recent taxonomic treatment of the genus suggested to accept up to seven taxa at species level based on morphological data. To date, species boundaries and infrageneric relationships in Eulychnia have not been investigated using a molecular approach. In this study, sequence data were generated for six chloroplast markers (rpl32-trnL, trnH-psbA, trnL-trnF, trnQ-rps16, trnS-trnG, and ycf1) for the seven species. Where possible, samples were collected from the south and north of the distribution range of widely distributed species, as well as plants from two morphologically distinct populations in the Atacama and Coquimbo Regions. Evolutionary trends of morphological characters were investigated using ancestral state reconstruction, and the habitat of the Chilean taxa was taken into account based on latitudinal and altitudinal distribution, precipitation regime, and vegetation zones. Two major clades were retrieved in the molecular phylogenetic hypotheses, a northern clade and a southern clade, which can easily be distinguished morphologically by differences in rib shape and type of the indumentum of the pericarpel and the hypanthium. The only Eulychnia taxon found outside Chile is most commonly accepted as Eulychnia iquiquensis subsp. ritteri. However, its isolated geographic distribution and the fact that this taxon is not most closely related to E. iquiquensis but was retrieved as sister to the rest of the northern clade in our molecular phylogenetic results support the recognition of E. ritteri at species level. Our results also provide some support for the two recently published species, E. chorosensis (previously placed in E. acida s.l.) and E. taltalensis (previously considered to be part of E. breviflora s.l.). The relationships in the southern clade need further study.

Alstroemeria L. (Alstroemeriaceae) represents one of the most diverse genera of vascular plants in Chile. It contains approximately 54 taxa, 40 of which are endemic. The “complex” Alstroemeria magnifica is endemic to Chile, and it comprises four varieties: A. magnifica var. magenta, A. magnifica var. magnifica, A. magnifica var. sierrae, and A. magnifica var. tofoensis. It is distributed from Coquimbo to the Valparaíso Region. We analyzed karyotypes of 10 populations along its natural distribution. All the populations presented an asymmetric karyotype, with 2n = 16 chromosomes but with three different karyotypic formulae. Alstroemeria magnifica var. magnifica and A. magnifica var. sierrae presented the same karyotypic fomula, and A. magnifica var. magenta, and A. magnifica var. tofoensis each had a different formula. The scatter plot among CV_CL vs. M_CA shows different groupings between populations of the four varieties. Based on the results, it is possible to consider raising Alstroemeria magnifica var. magenta to species level (A. magenta) and A. magnifica var. tofoensis to subspecies level (A. magnifica subsp. tofoensis); A. magnifica var. magnifica and A. magnifica var. sierrae should each remain as varieties. Nevertheless, these taxonomic changes should be considered tentative, as additional sources of evidence become available.

Alstroemeria L. es uno de los géneros de plantas chilenas más diversos y con un enorme potencial ornamental. Está representado por 35 especies, la mayoría distribuida entre los 28-38° S en la zona mediterránea de Chile central. Se reconocen 24 complejos, de los cuales 18 presentan problemas de conservación. Uno de estos complejos es Alstroemeria diluta E. Bayer. con dos subespecies: subsp. diluta y subsp. chrysantha Bayer. Alstroemeria diluta crece sólo en Chile; la subsp. diluta se distribuye desde los 34º15'S, en la Región de O'Higgins, hasta Cauquenes (36º00'S), en la Región del Maule y la subsp. chrysantha desde los 28º08'S, en la Región de Atacama, hasta Punta Curaumilla (33º05'S), en la Región de Valparaíso. Se realizó un studio comparativo del cariotipo de cuatro poblaciones de A. diluta subsp. diluta y tres poblaciones de A. diluta subsp. chrysantha. Las siete poblaciones analizadas presentaron un cariotipo asimétrico, con un 2n = 2x = 16 cromosomas, y con la misma fórmula cariotípica: 3m + 1sm + 1st + 3 t. La arquitectura del cariotipo entre las subespecies es la misma. El diagrama de dispersión MCA vs CVCL mostró diferentes grupos entre las poblaciones de las dos subespecies y la longitud total diploide de los cromosomas (LTC) fue mayor en las poblaciones de la subsp. chrysantha. Los resultados obtenidos sugieren que las poblaciones distribuidas en la V Región de Valparaíso pertenecen a la subsp. diluta.