Sean Ryan

Exponent · Ecological and Biological Sciences

The small cabbage white butterfly, Pieris rapae , is a major agricultural pest of cruciferous crops and has been introduced to every continent except South America and Antarctica as a result of human activities. In an effort to reconstruct the near-global invasion history of P. rapae , we developed a citizen science project, the “Pieris Project,” a...

A major goal of invasion and climate change biology research is to understand the ecological and evolutionary responses of organisms to anthropogenic disturbance, especially over large spatial and temporal scales. One significant, and sometimes unattainable, challenge of these studies is garnering sufficient numbers of relevant specimens, especiall...

The power of citizen science to contribute to both science and society is gaining increased recognition, particularly in physics and biology. Although there is a long history of public engagement in agriculture and food science, the term 'citizen science' has rarely been applied to these efforts. Similarly, in the emerging field of citizen science,...

Significance The biological consequences of climate change are determined by the responses of individual species and interactions among species. Hybridization, or interbreeding between related species, is an interaction that affects how species evolve in response to environmental change. Here we provide evidence that climatic warming has caused a g...

Hybrid zones are a valuable tool for studying the process of speciation and for identifying the genomic regions undergoing divergence and the ecological (extrinsic) and non-ecological (intrinsic) factors involved. Here, we explored the genomic and geographic landscape of divergence in a hybrid zone between Papilio glaucus and Papilio canadensis. Us...

Hybrid zones are a valuable tool for studying the process of speciation and for identifying the genomic regions undergoing divergence and the ecological (extrinsic) and non-ecological (intrinsic) factors involved. Here, we explored the genomic and geographic landscape of divergence in a hybrid zone between Papilio glaucus and Papilio canadensis . U...

A key adaptation in insects for dealing with variable environmental conditions is the ability to diapause. The tiger swallowtail butterflies, Papilio glaucus and P. canadensis are ideal species to explore the genetic causes and population genetic consequences of diapause because divergence in this trait is believed to be a salient factor in maintai...

Citizen science has advanced science for hundreds of years, contributed to many peer-reviewed articles, and informed land management decisions and policies across the United States. Over the last 10 years, citizen science has grown immensely in the United States and many other countries. Here, we show how citizen science is a powerful tool for tack...

The goal of this report is to help government agencies and other organizations involved in natural resource management, environmental protection, and policymaking related to both to make informed decisions about investing in citizen science. In this report, we explore the current use of citizen science in natural resource and environmental science...

Background/Question/Methods Theory predicts that hybrid zones are capable of shifting and that these shifts can have substantial evolutionary impacts. However, empirical examples of hybrid zone movement are rare due to the lack of long-term datasets and difficulties in detection due to inadequate sampling of molecular markers. Consequently, our u...

Background/Question/Methods For many insect populations, phenology—the timing of life cycle events—and voltinism—the number of generations a population has in a given year—are both greatly influenced by climate. While the consequences of climate induced changes in phenology and voltinism could substantially impact insect populations, it remains u...

Despite no obvious barriers to gene flow in the marine realm, environmental variation and ecological specializations can lead to genetic differentiation in highly mobile predators. Here, we investigated the genetic structure of the harbor porpoise over the entire species distribution range in western Palearctic waters. Combined analyses of ten micr...

Background/Question/Methods Clinal variation in species traits that correspond with climatic gradients are predicted to shift as climate change alters this underlying gradient. However, despite considerable effort, surprisingly few studies have documented such changes. Using historically (1980s) and recently (2010s) collected specimens from a but...

Background/Question/Methods In response to a changing climate many species are predicted to undergo shifts in their geographic range and many such cases have already been documented. However, species traits may also change in response to climate change via evolution and plasticity, but studies demonstrating changes in species traits to climate ch...

Background/Question/Methods It is well known that many phytophagous insects use plant chemistry in the process of host selection. For example, it has been shown that plants from the family Brassicaceae contain glucosinolates (secondary metabolites) that can act as attractants or deterrents to insect herbivores either in their intact form or when...