Domestication and fitness in the wild: A multivariate view

Abstract

Domesticated species continually escaping and interbreeding with wild relatives impose a migration load on wild populations. As domesticated stocks become increasingly different as a result of artificial and natural selection in captivity, fitness of escapees in the wild is expected to decline, reducing the effective rate of migration into wild populations. Recent theory suggest that this may alleviate and eventually eliminate the resulting migration load. I develop a multivariate model of trait and wild fitness evolution resulting from the joint effects of artificial and natural selection in the captive environment. Initially, the evolutionary trajectory is dominated by the effects of artificial selection causing a fast initial decline in fitness of escapees in the wild. In later phases, through the counteracting effects of correlational multivariate natural selection in captivity, the mean phenotype is pushed in directions of weak stabilizing selection, allowing a sustained response in the trait subject to artificial selection. Provided that there is some alignment between the adaptive landscapes in the wild and in captivity, these phases are associated with slower rates of decline in wild fitness of the domesticated stock, suggesting that detrimental effects on wild populations are likely to remain a concern in the foreseeable future.

Identifying hybrids & the genomics of hybridization: Mallards & American black ducks of Eastern North America

“…Watterson's θ Aut = 0.0082, Watterson's θ Z = 0.0029; Supporting Information Table ). In general, the lower genetic diversity coupled with the positive shift in Tajima's D values in non‐western mallards are likely signatures of bottlenecking that is often experienced during domestication (Innan & Kim, ; Makino et al, ; Tufto, ). Together, these results strongly support these non‐western mallards to be of alternative stock, and likely the result of a century of releasing game‐farm mallards in Eastern North America.…”

“…These samples suggest that feral female mallards are successfully surviving on the landscape. How gene flow from these non‐western, putatively feral birds affect fitness of wild populations remains to be determined; however, if unabated, the chance of negative impact(s) on wild populations may be significant and requires careful consideration (Randi, ; Tufto, ).…”

“…however, if unabated, the chance of negative impact(s) on wild populations may be significant and requires careful consideration (Randi, 2008;Tufto, 2017).…”

Assessing changes in genomic divergence following a century of human‐mediated secondary contact among wild and captive‐bred ducks

“…Natural or anthropogenically induced changes in species' ranges (expansion, contraction, or shifts) have recently brought many closely related species into secondary contact, raising concern over the possibility of extinction by introgressive hybridization in various taxa (Abbott, Barton, & Good, ; Payseur & Rieseberg, ; Todesco et al, ; Wayne & Shaffer, ). Such interactions are further complicated when artificially selected‐on domesticated forms come into contact with their wild congeners (Domyan et al, ; Kidd, Bowman, Lesbarreres, & Schulte‐Hostedde, ; Makino et al, ; Skoglund, Ersmark, Palkopoulou, & Dalén, ; Tufto, ; Wu et al, ). Where the release of domesticated stocks is common and intensive, interbreeding with released or feral conspecifics can cause a decrease in genetic variation, leading to a loss of adaptive potential and overall fitness within the wild population (Frankham, ; Laikre, Schwartz, Waples, & Ryman, ).…”

Modeling fitness changes in wild Atlantic salmon populations faced by spawning intrusion of domesticated escapees

“…A range of models and modeling scenarios have been published in the past decade or so for investigating genetic changes in salmon populations following gene‐flow from maladapted domesticated salmon, or similar evolutionary scenarios (Baskett, Burgess, & Waples, ; Baskett & Waples, ; Besnier, Glover, & Skaala, ; Castellani et al., ; Hindar, Fleming, McGinnity, & Diserud, ; Huisman & Tufto, ; Piou & Prevost, ; Tufto, ). However, no study has thus far modeled potential phenotypic changes in life‐history traits (e.g., size at age and age of maturation) in wild populations that are subject to spawning intrusion from domesticated escapees.…”