A new viewpoint on antlers reveals the evolutionary history of deer (Cervidae, Mammalia).

Recent molecular phylogeny of deer revealed that the characters of antlers previously focused on are homoplasious, and antlers tend to be considered problematic for classification. However, we think antlers are important tools and reconsidered and analysed the characters and structures to use them for classification. This study developed a method to describe the branching structure of antlers by using antler grooves, which are formed on the antlers by growth, and then projecting the position of the branching directions of tines on the burr circumference. By making diagrams, comparing the branching structure interspecifically, homologous elements (tines, beams, and processes) of the antlers of 25 species of 16 genera were determined. Subsequently, ancestral state reconstruction was performed on the fixed molecular phylogenetic tree. It was revealed that Capreolinae and Cervini gained respective three-pointed antlers independently, and their subclades gained synapomorphous tines. We found new homologous and synapomorphous characters, as the antler of Eld's deer, which has been classified in Rucervus, is structurally close to that of Elaphurus rather than that of Rucervus, consistent with molecular phylogeny. The methods of this study will contribute to the understanding of the branching structure and phylogeny of fossil species and uncover the evolutionary history of Cervidae.

Colonizing the High Arctic: Mitochondrial DNA Reveals Common Origin of Eurasian Archipelagic Reindeer (Rangifer tarandus).

In light of current debates on global climate change it has become important to know more on how large, roaming species have responded to environmental change in the past. Using the highly variable mitochondrial control region, we revisit theories of Rangifer colonization and propose that the High Arctic archipelagos of Svalbard, Franz Josef Land, and Novaia Zemlia were colonized by reindeer from the Eurasian mainland after the last glacial maximum. Comparing mtDNA control region sequences from the three Arctic archipelagos showed a strong genetic connection between the populations, supporting a common origin in the past. A genetic connection between the three archipelagos and two Russian mainland populations was also found, suggesting colonization of the Eurasian high Arctic archipelagos from the Eurasian mainland. The age of the Franz Josef Land material (>2000 years before present) implies that Arctic indigenous reindeer colonized the Eurasian Arctic archipelagos through natural dispersal, before humans approached this region.

Phylogeographical analysis of mtDNA data indicates postglacial expansion from multiple glacial refugia in woodland caribou (Rangifer tarandus caribou).

Glacial refugia considerably shaped the phylogeographical structure of species and may influence intra-specific morphological, genetic, and adaptive differentiation. However, the impact of the Quaternary ice ages on the phylogeographical structure of North American temperate mammalian species is not well-studied. Here, we surveyed ~1600 individuals of the widely distributed woodland caribou (Rangifer tarandus caribou) using mtDNA control region sequences to investigate if glacial refugia contributed to the phylogeographical structure in this subspecies. Phylogenetic tree reconstruction, a median-joining network, and mismatch distributions supported postglacial expansions of woodland caribou from three glacial refugia dating back to 13544-22005 years. These three lineages consisted almost exclusively of woodland caribou mtDNA haplotypes, indicating that phylogeographical structure was mainly shaped by postglacial expansions. The putative centres of these lineages are geographically separated; indicating disconnected glacial refugia in the Rocky Mountains, east of the Mississippi, and the Appalachian Mountains. This is in congruence with the fossil record that caribou were distributed in these areas during the Pleistocene. Our results suggest that the last glacial maximum substantially shaped the phylogeographical structure of this large mammalian North American species that will be affected by climatic change. Therefore, the presented results will be essential for future conservation planning in woodland caribou.

Integrative use of spatial, genetic, and demographic analyses for investigating genetic connectivity between migratory, montane, and sedentary caribou herds.

Genetic differentiation is generally assumed to be low in highly mobile species, but this simplistic view may obscure the complex conditions and mechanisms allowing genetic exchanges between specific populations. Here, we combined data from satellite-tracked migratory caribou (Rangifer tarandus), microsatellite markers, and demographic simulations to investigate gene flow mechanisms between seven caribou herds of eastern Canada. Our study included one montane, two migratory, and four sedentary herds. Satellite-tracking data indicated possibilities of high gene flow between migratory herds: overlap of their rutting ranges averaged 10% across years and 9.4% of females switched calving sites at least once in their lifetime. Some migratory individuals moved into the range of the sedentary herds, suggesting possibilities of gene flow between these herds. Genetic differentiation between herds was weak but significant (FST=0.015): migratory and montane herds were not significantly distinct (FST all9) than vice-versa (4Nm all<5), which suggests migratory herds had a demographic impact on sedentary herds. Demographic simulations showed that an effective immigration rate of 0.0005 was sufficient to obtain the empirical FST of 0.015, while a null immigration rate increased the simulated FST to >0.6. In conclusion, the weak genetic differentiation between herds cannot be obtained without some genetic exchanges among herds, as demonstrated by genetic and spatial data.

Circadian organization in reindeer.

The light/dark cycle of day and night synchronizes an internal 'biological clock' that governs daily rhythms in behaviour, but this form of regulation is denied to polar animals for most of the year. Here we demonstrate that the continuous lighting conditions of summer and of winter at high latitudes cause a loss in daily rhythmic activity in reindeer living far above the Arctic Circle. This seasonal absence of circadian rhythmicity may be a ubiquitous trait among resident polar vertebrates.

Refugial origins of reindeer (Rangifer tarandus L.) inferred from mitochondrial DNA sequences.

The glacial-interglacial cycles of the upper Pleistocene have had a major impact on the recent evolutionary history of Arctic species. To assess the effects of these large-scale climatic fluctuations to a large, migratory Arctic mammal, we assessed the phylogeography of reindeer (Rangifer tarandus) as inferred from mitochondrial DNA (mtDNA) sequence variation in the control region. Phylogenetic relationships among haplotypes seem to reflect historical patterns of fragmentation and colonization rather than clear-cut relationships among extant populations and subspecies. Three major haplogroups were detected, presumably representing three separate populations during the last glacial. The most influential one has contributed to the gene pool of all extant subspecies and seems to represent a large and continuous glacial population extending from Beringia and far into Eurasia. A smaller, more localized refugium was most likely isolated in connection with ice expansion in western Eurasia. A third glacial refugium was presumably located south of the ice sheet in North America, possibly comprising several separate refugial populations. Significant demographic population expansion was detected for the two haplogroups representing the western Eurasian and Beringian glacial populations. The former apparently expanded when the ice cap retreated by the end of the last glacial. The large continuous one, in contrast, seems to have expanded by the end of the last interglacial, indicating that the warm interglacial climate accompanied by marine transgression and forest expansion significantly confined population size on the continental mainland. Our data demonstrate that the current subspecies designation does not reflect the mtDNA phylogeography of the species, which in turn may indicate that morphological differences among subspecies have evolved as adaptive responses to postglacial environmental change.

Reliable noninvasive genotyping based on excremental PCR of nuclear DNA purified with a magnetic bead protocol.

A new protocol for extraction of DNA from faeces is presented. The protocol involves gentle washing of the surface of the faeces followed by a very simple DNA extraction utilizing the wash supernatant as the source of DNA. Unlike most other protocols, it does not involve the use of proteinase K and/or organic extraction, but is instead based on adsorption of the DNA to magnetic beads. The protocol was tested by microsatellite genotyping across six loci for sheep and reindeer faeces. Comparison with DNA extracted from blood demonstrated that the protocol was very reliable, even when used on material stored for a long time. The protocol was compared with another simple, solid-phase DNA-binding protocol, with the result that the bead-based protocol gave a slightly better amplification success and a lower frequency of allelic drop-outs. Furthermore, our experiments showed that the surface wash prior to DNA extraction is a crucial step, not only for our protocol, but for other solid-phase protocols as well.

[2 phases of form development realized during microevolution]. / Dve fazy formoobrazovaniia, realizuiushchiesia v khode mikroévoliutsii.

The general "plan" of animal structure evolves due to the changes both, in body proportions and body size. The method allowing to estimate the level of population differentiation according to these two parameters was considered. In the process of population differentiation two phases of form formation can be discerned. On the first stage of microevolution the morphogenesis mainly proceeds by proportion changes. The next stage is characterised primarily by changes of size. The same phase can be observed at intra-population level. The selection directed to the increase in differentiation of individuals according to their proportions.