Assessing the Cryptic Invasion of a Domestic Conspecific: American Mink in Their Native Range.
Assessing the cryptic invasion of a domestic conspecific: American mink in their native range.
Ecol Evol. 2013 Jul; 3(7): 2296-309
Beauclerc KB, Bowman J, Schulte-Hostedde AI
Control of invasions is facilitated by their early detection, but this may be difficult when invasions are cryptic due to similarity between invaders and native species. Domesticated conspecifics offer an interesting example of cryptic invasions because they have the ability to hybridize with their native counterparts, and can thus facilitate the introgression of maladaptive genes. We assessed the cryptic invasion of escaped domestic American mink (Neovison vison) within their native range. Feral mink are a known alien invader in many parts of the world, but invasion of their native range is not well understood. We genetically profiled 233 captive domestic mink from different farms in Ontario, Canada and 299 free-ranging mink from Ontario, and used assignments tests to ascertain genetic ancestries of free-ranging animals. We found that 18% of free-ranging mink were either escaped domestic animals or hybrids, and a tree regression showed that these domestic genotypes were most likely to occur south of a latitude of 43.13°N, within the distribution of mink farms in Ontario. Thus, domestic mink appear not to have established populations in Ontario in locations without fur farms. We suspect that maladaptation of domestic mink and outbreeding depression of hybrid and introgressed mink have limited their spread. Mink farm density and proximity to mink farms were not important predictors of domestic genotypes but rather, certain mink farms appeared to be important sources of escaped domestic animals. Our results show that not all mink farms are equal with respect to biosecurity, and thus that the spread of domestic genotypes can be mitigated by improved biosecurity. HubMed – depression
Inbreeding reveals mode of past selection on male reproductive characters in Drosophila melanogaster.
Ecol Evol. 2013 Jul; 3(7): 2089-102
Ala-Honkola O, Hosken DJ, Manier MK, Lüpold S, Droge-Young EM, Berben KS, Collins WF, Belote JM, Pitnick S
Directional dominance is a prerequisite of inbreeding depression. Directionality arises when selection drives alleles that increase fitness to fixation and eliminates dominant deleterious alleles, while deleterious recessives are hidden from it and maintained at low frequencies. Traits under directional selection (i.e., fitness traits) are expected to show directional dominance and therefore an increased susceptibility to inbreeding depression. In contrast, traits under stabilizing selection or weakly linked to fitness are predicted to exhibit little-to-no inbreeding depression. Here, we quantify the extent of inbreeding depression in a range of male reproductive characters and then infer the mode of past selection on them. The use of transgenic populations of Drosophila melanogaster with red or green fluorescent-tagged sperm heads permitted in vivo discrimination of sperm from competing males and quantification of characteristics of ejaculate composition, performance, and fate. We found that male attractiveness (mating latency) and competitive fertilization success (P2) both show some inbreeding depression, suggesting they may have been under directional selection, whereas sperm length showed no inbreeding depression suggesting a history of stabilizing selection. However, despite having measured several sperm quality and quantity traits, our data did not allow us to discern the mechanism underlying the lowered competitive fertilization success of inbred (f = 0.50) males. HubMed – depression
Rapid Changes in American Family Life: Consequences for Child Health and Pediatric Practice.
Pediatrics. 2013 Aug 5;
Fiese BH, Rhodes HG, Beardslee WR
Pediatricians are in the unique position of being on the front line of care for children and having access to their families. This article presents both a rationale and the evidence base for identifying the family characteristics and processes that affect child health and suggests approaches that pediatricians can implement to improve the care of children, using data from 3 recent reports of the Institute of Medicine and National Research Council, as well as other recent family research. Evidence regarding the impact on child health of 3 family factors in particular (family composition and living arrangements, family routines, and parental depression) is highlighted, and implications for pediatric practice are described. HubMed – depression