Global transport of organisms by humans provides novel

Last updated: 1/30/2023

Global transport of organisms by humans provides novel resources to wild species which often respond maladaptively Native herbivorous insects have been killed feeding on toxic exotic plants which acted as ecological traps 4 We document a novel eco evolutionary trap stemming from the opposite effect that is high fitness on an exotic resource despite lack of adaptation to it Plantago lanceolata was introduced to western North America by cattle ranching Feeding on this exotic plant released a large isolated population of the native butterfly Euphydryas editha from a longstanding trade off between maternal fecundity and offspring mortality Because of this release and despite a reduced insect developmental rate when feeding on this exotic Plantago immediately supported higher larval survival than did the insects traditional host Collinsia parviflora Previous work from the 1980s documented an evolving preference for Plantago by ovipositing adults We predicted that if this trend continued the insects could endanger themselves because the availability of Plantago to butterflies is controlled by humans who change land management practices faster than butterflies evolve Here we report the fulfilment of this prediction The butterflies abandoned Collinsia and evolved total dependence on Plantago The trap was set In 2005 humans withdrew their cattle springing the trap Grasses grew around the Plantago cooling the thermophilic insects which then went extinct This local extinction could have been prevented if the population had retained partial use of Collinsia which occupied drier microhabitats unaffected by cattle removal The flush of grasses abated quickly rendering the meadow once again suitable for Euphydryas feeding on either host but no butterflies were observed from 2008 to 2012 In 2013 2014 the site was naturally recolonized by Euphydryas feeding exclusively on Collinsia returning the system to its starting point and setting the stage for a repeat of the anthropogenic evolutionary cycle In his 1999 address to the Ecological Society of America Gary Polis described Homo sapiens as a ubiquitous keystone pest and so we have proven to be Although adaptation to human activities enables some wild species to coexist with us many fail to adapt to human land man agement and suffer in consequence An example of this is the setting by humans of ecological traps9 10 which are defined as follows in an environment altered suddenly by human activities an organism makes maladaptive habitat choices based on formerly reliable environmental cues despite availability of higher quality habitat 0 Most ecological traps result from preference by wild organisms for novel resources that are unsuitable or toxic Australian monitor lizards suffered population crashes after feeding on toxic exotic cane toads Bees have maladaptively preferred crops grown from seed treated with neonicotinoid insecticides 2 2 Several examples have involved insect her bivores feeding on exotic host plants that reduced insect fitness 4 but