About

Kerry L Shaw is a professor in the Department of Neurobiology and Behavior at Cornell University. His research focuses on behavioral genetics, sexual selection and evolution, speciation, genetic architecture of behavior including QTLs, linkage analysis, and genome evolution, with a particular emphasis on orthopteroid insects. He teaches courses such as Speciation: Behavior, Ecology and Genetics, Animal Behavior Journal Club for Undergraduates, and Neurobiology and Behavior I: Introduction to Behavior. Shaw is actively involved in research and academic activities within the department, contributing to the understanding of the genetic and behavioral mechanisms underlying evolution and species differentiation.

Research topics

• Evolutionary biology
• Biology
• Computer Science
• Genetics
• Library science
• Environmental ethics
• Art history
• Ecology
• History
• Philosophy
• Computational biology
• Statistics

Selected publications

• ISLANDS AS CRADLES OF SPECIES DIVERSITY:

  Princeton University Press eBooks · 2026-02-03

  book-chapter1st authorCorresponding
  PublisherDOI

• Sexual isolation maintains species boundaries between Hawaiian crickets in sympatry despite weak habitat isolation

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-09-08

  preprintOpen accessSenior author

  Abstract Understanding the relative importance of different reproductive isolating barriers in maintaining species boundaries is fundamental to understanding how closely related species coexist without hybridizing. Habitat isolation and sexual isolation are often the first barriers between closely related species, yet they are rarely studied together, making their relative contributions to reproductive isolation unclear. We conducted the first comprehensive study of both barriers in Hawaiian swordtail crickets ( Laupala ), focusing on the recently diverged, sympatric species pair Laupala kona and Laupala hualalai . Using genomic data, we confirmed that the two species are genetically distinct, which can only be achieved by strong reproductive isolation through a prolonged time period. Through field surveys, we quantified microhabitat use, spatial distribution, and diets, and found extensive ecological overlap. Both species occupied similar substrates, elevations, and microclimates, and occurred in mixed-species aggregations. They only differ in their diets (inferred from stable isotopes), which might have some implications in reducing encounter rates. Despite this weak habitat isolation, they have divergent sexual traits and exhibit strong sexual isolation in lab assays. The species differ significantly in male pulse rate and cuticular hydrocarbon profiles, and females consistently preferred conspecific song stimuli. Mating trials showed almost complete sexual incompatibility between heterospecific pairs, with very rare interspecies copulations. Together, these results demonstrate that sexual isolation, rather than habitat partitioning, maintains species boundaries between L. hualalai and L. kona in sympatry. Our findings highlight the sufficiency of sexual isolation to prevent hybridization even in the absence of strong ecological divergence, providing rare empirical evidence that sexual barriers alone can maintain reproductive isolation in natural populations.

  PublisherOA PDFDOI

• Genomic data confirms phenotypic predictions of hybridization between cryptic Hawaiian cricket species

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-09-15

  preprintOpen accessSenior author

  Abstract Hybridization is increasingly recognized as an important driver of species radiations, yet its detection in morphologically cryptic taxa remains challenging. The Hawaiian crickets of the genus Laupala represent a rapid non-adaptive radiation in which species are morphologically indistinguishable but differ in acoustic mating signals. Here we report the first discovery of natural hybridization in the Laupala radiation. During field surveys on Maui, we observed crickets with intermediate pulse rates and unusually high acoustic variation at sites where the ranges of Laupala makaio (slow singer) and Laupala orientalis (fast singer) converge. We hypothesized these represented natural hybrids and tested this prediction using genomic data from genotyping-by-sequencing (GBS). Maximum likelihood phylogenetic analysis showed that fast-singing putative hybrids clustered with L. orientalis and the slow-singing ones with L. makaio , yet all putative hybrids formed a cohesive geographic group. Using 9,345 ancestry-informative markers, we calculated hybrid indices and heterozygosity values for triangle plot analysis. All hybrids showed excess L. makaio ancestry (predicted from analysis of pulse rate patterns) and were classified as later-generation hybrids or backcrosses to L. makaio , with no F1 hybrids detected. Critically, we found a strong positive correlation (R = +0.74, p = 4.1×10⁻⁶) between pulse rate and hybrid index at the site with highest pulse rate variation, showing that genomic ancestry predicts pulse rate phenotype. Morphological comparisons confirmed that hybrids were cryptic, reinforcing the difficulty of detecting hybridization without genomic data. Together, our results provide the first demonstration of natural hybridization in Laupala , showing that phenotypic predictions based on acoustic intermediacy can be confirmed with genomic evidence. The discovery of natural hybridization in Laupala opens new avenues for investigating how hybridization contributes to rapid diversification in non-adaptive radiations, paralleling patterns observed in some adaptive radiations.

  PublisherOA PDFDOI

• Mild radiographic abnormalities of thoracolumbar spinous processes are not associated with decreased performance in 100 Warmblood jumping horses in active competition

  Journal of Equine Veterinary Science · 2025-02-11

  article
  PublisherDOI

• Coupling of Barriers to Gene Exchange: Causes and Consequences.

  UNC Libraries · 2024-10-22

  articleOpen access1st authorCorresponding

  Coupling has emerged as a concept to describe the transition from differentiated populations to newly evolved species through the strengthening of reproductive isolation. However, the term has been used in multiple ways, and relevant processes have sometimes not been clearly distinguished. Here, we synthesize existing uses of the concept of coupling and find three main perspectives: (1) coupling as the build-up of linkage disequilibrium among loci underlying barriers to gene exchange, (2) coupling as the build-up of genome-wide linkage disequilibrium, and (3) coupling as the process generating a coincidence of distinct barrier effects. We compare and contrast these views, show the diverse processes involved and the complexity of the relationships among recombination, linkage disequilibrium, and reproductive isolation, and, finally, we emphasize how each perspective can guide new directions in speciation research. Although the importance of coupling for evolutionary divergence and speciation is well established, many theoretical and empirical questions remain unanswered.

  PublisherDOI

• The biogeographic and evolutionary processes shaping population divergence in <i>Laupala</i>

  Molecular Ecology · 2024-07-10 · 7 citations

  articleOpen accessSenior authorCorresponding

  Speciation generates biodiversity and the mechanisms involved are thought to vary across the tree of life and across environments. For example, well-studied adaptive radiations are thought to be fuelled by divergent ecological selection, but additionally are influenced heavily by biogeographic, genomic and demographic factors. Mechanisms of non-adaptive radiations, producing ecologically cryptic taxa, have been less well-studied but should likewise be influenced by these latter factors. Comparing among contexts can help pinpoint universal mechanisms and outcomes, especially if we integrate biogeographic, ecological and evolutionary processes. We investigate population divergence in the swordtail cricket Laupala cerasina, a wide-spread endemic on Hawai'i Island and one of 38 ecologically cryptic Laupala species. The nine sampled populations show striking population genetic structure at small spatio-temporal scales. The rapid differentiation among populations and species of Laupala shows that neither a specific geographical context nor ecological opportunity are pre-requisites for rapid divergence. Spatio-temporal patterns in population divergence, population size change, and gene flow are aligned with the chronosequence of the four volcanoes on which L. cerasina occurs and reveal the composite effects of geological dynamics and Quaternary climate change on population dynamics. Spatio-temporal patterns in genetic variation along the genome reveal the interplay of genetic and genomic architecture in shaping population divergence. In early phases of divergence, we find elevated differentiation in genomic regions harbouring mating song loci. In later stages of divergence, we find a signature of linked selection that interacts with recombination rate variation. Comparing our findings with recent work on complementary systems supports the conclusion that mostly universal factors influence the speciation process.

  PublisherOA PDFDOI

• Coupling of Barriers to Gene Exchange: Causes and Consequences

  Cold Spring Harbor Perspectives in Biology · 2024 · 35 citations

  • Computer Science
  • Biology
  • Library science

  Coupling has emerged as a concept to describe the transition from differentiated populations to newly evolved species through the strengthening of reproductive isolation. However, the term has been used in multiple ways, and relevant processes have sometimes not been clearly distinguished. Here, we synthesize existing uses of the concept of coupling and find three main perspectives: (1) coupling as the build-up of linkage disequilibrium among loci underlying barriers to gene exchange, (2) coupling as the build-up of genome-wide linkage disequilibrium, and (3) coupling as the process generating a coincidence of distinct barrier effects. We compare and contrast these views, show the diverse processes involved and the complexity of the relationships among recombination, linkage disequilibrium, and reproductive isolation, and, finally, we emphasize how each perspective can guide new directions in speciation research. Although the importance of coupling for evolutionary divergence and speciation is well established, many theoretical and empirical questions remain unanswered.

  PublisherOA PDFDOI

• How Important Is Sexual Isolation to Speciation?

  Cold Spring Harbor Perspectives in Biology · 2024-02-12 · 19 citations

  articleOpen access1st authorCorresponding

  A central role for sexual isolation in the formation of new species and establishment of species boundaries has been noticed since Darwin and is frequently emphasized in the modern literature on speciation. However, an objective evaluation of when and how sexual isolation plays a role in speciation has been carried out in few taxa. We discuss three approaches for assessing the importance of sexual isolation relative to other reproductive barriers, including the relative evolutionary rate of sexual trait differentiation, the relative strength of sexual isolation in sympatry, and the role of sexual isolation in the long-term persistence of diverging forms. First, we evaluate evidence as to whether sexual isolation evolves faster than other reproductive barriers during the early stages of divergence. Second, we discuss available evidence as to whether sexual isolation is as strong or stronger than other barriers between closely related sympatric species. Finally, we consider the effect of sexual isolation on long-term species persistence, relative to other reproductive barriers. We highlight challenges to our knowledge of and opportunities to improve upon our understanding of sexual isolation from different phases of the speciation process.

  PublisherOA PDFDOI

• Quantitative trait loci underlying a speciation phenotype

  Insect Molecular Biology · 2023-06-15 · 5 citations

  articleSenior authorCorresponding

  Sexual signalling traits and their associated genetic components play a crucial role in the speciation process, as divergence in these traits can contribute to sexual isolation. Despite their importance, our understanding of the genetic basis of variable sexual signalling traits linked to speciation remains limited. In this study, we present new genetic evidence of Quantitative Trait Loci (QTL) underlying divergent sexual signalling behaviour, specifically pulse rate, in the Hawaiian cricket Laupala. By performing RNA sequencing on the brain and central nervous system of the parental species, we annotate these QTL regions and identify candidate genes associated with pulse rate. Our findings provide insights into the genetic processes driving reproductive isolation during speciation, with implications for understanding the mechanisms underlying species diversity.

  PublisherDOI

• The biogeographic and evolutionary processes shaping population divergence in Laupala

  2022-08-01 · 1 citations

  preprintOpen accessSenior author

  Speciation generates biodiversity, and the mechanisms involved are thought to vary across the tree of life and across environments. For example, well-studied adaptive radiations are thought to be fueled by divergent selection in ecologically variable environments, but additionally are influenced heavily by biogeographic, genomic and demographic factors. Mechanisms of non-adaptive radiations, producing ecologically cryptic taxa, have been less well-studied but should likewise be influenced by these latter factors. Comparing among these contexts can help pinpoint universal mechanisms and outcomes. Here, we investigated the contributions of biogeographic and evolutionary processes to population divergence in Laupala cerasina , a wide-spread endemic on Hawai’i Island and one of 38 ecologically and morphologically cryptic Laupala species. The nine sampled populations showed striking population genetic structure at small spatio-temporal scales, fitting a progression rule pattern where populations have sequentially colonized progressively younger volcanoes on Hawai’i Island. The rapid differentiation among populations and species of Laupala shows that neither a specific geographic context nor ecological opportunity are pre-requisites for rapid divergence. Genomic heterogeneity was strongly dependent on recombination rate and background selection. The genomic landscape was further shaped by elevated divergence in regions harbouring mating song loci in the most recently diverged population pairs. Comparing our findings with recent work on complementary systems supports the influence of mostly universal factors in the speciation process.

  PublisherOA PDFDOI

Recent grants

• The Genetics of Female Acoustic Preference Behavior

  NSF · $471k · 2008–2012

• The Behavioral Genetics and Evolution of Cricket Song

  NSF · $306k · 2004–2008

• Dimensions: Collaborative Research: A community level approach to understanding speciation in Hawaiian lineages

  NSF · $215k · 2013–2018

• The Behavioral Genetics and Evolution of Cricket Song

  NSF · $25k · 2008–2009

• Genomic Architecture Underlying Behavioral Isolation and Speciation

  NSF · $720k · 2013–2018

Frequent coauthors

• Thomas Blankers

  13 shared

• Kevin P. Oh

  Macquarie University

  13 shared

• Tagide deCarvalho

  12 shared

• Tamra C. Mendelson

  University of Maryland, Baltimore

  10 shared

• Alan R. Templeton

  Washington University in St. Louis

  9 shared

• Eric J. Routman

  9 shared

• Scott K. Davis

  9 shared

• Daniel J. Fergus

  North Carolina State University

  8 shared

Education

• PhD, Biology

  Washington University in Saint Louis