No abstract

Conservation translocation using captive‐bred individuals has become increasingly important for species restoration. Despite advancements in technologies for captive‐breeding, such as gamete cryopreservation, it remains largely unknown if these artificially‐produced offspring can be used to establish a viable wild population. Using an amphibian species with a stable conservation status (Anaxyrus fowleri), we measured the post‐release growth and survivorship of offspring produced from frozen/thawed sperm and projected fecundity and population differences. Cryo‐derived tadpoles and post‐metamorphic toadlets were smaller than their natural counterparts. Model projections show that early‐life differences in growth can scale up to substantial differences in final life fecundity and population trends. Our findings call for greater attention towards the differences between captive‐bred and cryo‐derived individuals compared to their natural counterparts, and the need for more investment into developing cryopreservation technologies that are viable at the population level for conservation translocation.

Summary In all domains of life, mechanisms exist that protect cooperating groups from exploitation by cheaters. Recent observations with the bacterium Pseudomonas aeruginosa have suggested a paradigmatic cheater control mechanism in which cooperator cells punish or “police” cheater cells by cyanide poisoning. These cheater cells are deficient in a pleiotropic quorum-sensing regulator that controls the production of cooperative secretions including cyanide, and presumably also cyanide resistance. In this study, we directly tested and refuted the cyanide policing model. Contrary to the hypothesis, cheater fitness was unaffected by the presence of cyanide. Cheater mutants grew equally well in co-cultures with either cyanide-proficient or cyanide-deficient cooperators, and they were as resistant to exogenous cyanide as wild-type cells. We show that these behaviors are the result of quorum-sensing-independent and cyanide-responsive resistance gene regulation. Our results highlight the role of genetic architecture in the evolution of cooperative behavior.