Hot and Cold spots of selection: Parasitoid attack of fungus-growing ants
Abstract: It is known that fungus-growing ants, and their integral mutualism with fungus, allowed for their exploitation of new niches; which resulted in diversified lineages. However, there may have been other factors that refined these lineages into the resulting clades and species we see today. Diapriidae wasps are extremely common in the Neotropics; and poorly understood phylogenetically and ecologically. However, Diapriidae parasitoids in the same genera are known to parasitize both Cyphomyrmex and Trachymyrmex (Formicidae: Attini). The parasite wedge theory suggests speciation occurred in parapatric populations from parasitoid pressures. This theory is rooted in the geographic mosaic theory of coevolution, which has shown that populations of species interacting with other species, can lead to the coevolution of the interacting species. Using these theories, it may be …show more content…
In this theory, parasites act as selective pressures. Populations of host-parasites are patchy, and unevenly distributed as in the geographic mosaic theory 3,4. As hosts and parasites interact, they adapt in response to each other in an evolutionary arms race 5. Populations with higher proportions of parasites may have reduced dispersal and gene flow compared to populations with low parasite pressure 3,4. Alternatively, individuals with unique alleles or behaviors will arise that would be adaptive against the parasites, or provide a means for escape from them. Over time, these alleles or behaviors of parasite escape accrue and eventually lead to reproductive isolation 3,4. When parts of a host-parasite population diverge from their ancestral population, cryptic species can emerge parapatricaly 6. There are good examples of cryptic species, coevolution 7, and parasitism found in Fungus-Growing ants in the tribe Attini (Hymenoptera:
Abstract: It is known that fungus-growing ants, and their integral mutualism with fungus, allowed for their exploitation of new niches; which resulted in diversified lineages. However, there may have been other factors that refined these lineages into the resulting clades and species we see today. Diapriidae wasps are extremely common in the Neotropics; and poorly understood phylogenetically and ecologically. However, Diapriidae parasitoids in the same genera are known to parasitize both Cyphomyrmex and Trachymyrmex (Formicidae: Attini). The parasite wedge theory suggests speciation occurred in parapatric populations from parasitoid pressures. This theory is rooted in the geographic mosaic theory of coevolution, which has shown that populations of species interacting with other species, can lead to the coevolution of the interacting species. Using these theories, it may be …show more content…
In this theory, parasites act as selective pressures. Populations of host-parasites are patchy, and unevenly distributed as in the geographic mosaic theory 3,4. As hosts and parasites interact, they adapt in response to each other in an evolutionary arms race 5. Populations with higher proportions of parasites may have reduced dispersal and gene flow compared to populations with low parasite pressure 3,4. Alternatively, individuals with unique alleles or behaviors will arise that would be adaptive against the parasites, or provide a means for escape from them. Over time, these alleles or behaviors of parasite escape accrue and eventually lead to reproductive isolation 3,4. When parts of a host-parasite population diverge from their ancestral population, cryptic species can emerge parapatricaly 6. There are good examples of cryptic species, coevolution 7, and parasitism found in Fungus-Growing ants in the tribe Attini (Hymenoptera: