Invader immunology: invasion history alters immune system function in cane toads (Rhinella marina) in tropical Australia.

Because an individual's investment into the immune system may modify its dispersal rate, immune function may evolve rapidly in an invader. We collected cane toads (Rhinella marina) from sites spanning their 75-year invasion history in Australia, bred them, and raised their progeny in standard conditions. Evolved shifts in immune function should manifest as differences in immune responses among the progeny of parents collected in different locations. Parental location did not affect the offspring's cell-mediated immune response or stress response, but blood from the offspring of invasion-front toads had more neutrophils, and was more effective at phagocytosis and killing bacteria. These latter measures of immune function are negatively correlated with rate of dispersal in free-ranging toads. Our results suggest that the invasion of tropical Australia by cane toads has resulted in rapid genetically based compensatory shifts in the aspects of immune responses that are most compromised by the rigours of long-distance dispersal.

Tugan-Baranovsky on Socialism: From Utopia to the Economic Plan

Tugan-Baranovsky's ideas on socialism are reconstructed with an emphasis on the relation between political economy and utopia. Utopia enters the stage after the critique of capitalism, in the definition of the realm of possibilities in the world of ideas. With the help of ethics, the notion of ideal socialism, unreachable by definition, is defined in the sphere of utopia. Thus, the task of political economy is first to show which of these possible worlds are reachable in the real world, and second to choose the one that conforms better to ideal socialism: this is socialism in practice through the economic plan. Thus, far from considering utopia and science as contradictory, Tugan-Baranovsky saw them as complementary, and his socialism is the result of the dialogue he instituted between them.

Global invasion history of the fire ant Solenopsis invicta.

The fire ant Solenopsis invicta is a significant pest that was inadvertently introduced into the southern United States almost a century ago and more recently into California and other regions of the world. An assessment of genetic variation at a diverse set of molecular markers in 2144 fire ant colonies from 75 geographic sites worldwide revealed that at least nine separate introductions of S. invicta have occurred into newly invaded areas and that the main southern U.S. population is probably the source of all but one of these introductions. The sole exception involves a putative serial invasion from the southern United States to California to Taiwan. These results illustrate in stark fashion a severe negative consequence of an increasingly massive and interconnected global trade and travel system.