---
_id: '14787'
abstract:
- lang: eng
  text: Understanding the phenotypic and genetic architecture of reproductive isolation
    is a long‐standing goal of speciation research. In several systems, large‐effect
    loci contributing to barrier phenotypes have been characterized, but such causal
    connections are rarely known for more complex genetic architectures. In this study,
    we combine “top‐down” and “bottom‐up” approaches with demographic modelling toward
    an integrated understanding of speciation across a monkeyflower hybrid zone. Previous
    work suggests that pollinator visitation acts as a primary barrier to gene flow
    between two divergent red‐ and yellow‐flowered ecotypes of<jats:italic>Mimulus
    aurantiacus</jats:italic>. Several candidate isolating traits and anonymous single
    nucleotide polymorphism loci under divergent selection have been identified, but
    their genomic positions remain unknown. Here, we report findings from demographic
    analyses that indicate this hybrid zone formed by secondary contact, but that
    subsequent gene flow was restricted by widespread barrier loci across the genome.
    Using a novel, geographic cline‐based genome scan, we demonstrate that candidate
    barrier loci are broadly distributed across the genome, rather than mapping to
    one or a few “islands of speciation.” Quantitative trait locus (QTL) mapping reveals
    that most floral traits are highly polygenic, with little evidence that QTL colocalize,
    indicating that most traits are genetically independent. Finally, we find little
    evidence that QTL and candidate barrier loci overlap, suggesting that some loci
    contribute to other forms of reproductive isolation. Our findings highlight the
    challenges of understanding the genetic architecture of reproductive isolation
    and reveal that barriers to gene flow other than pollinator isolation may play
    an important role in this system.
acknowledgement: We thank Julian Catchen for making modifications to Stacks to aid
  this project. Peter L. Ralph, Thomas Nelson, Roger K. Butlin, Anja M. Westram and
  Nicholas H. Barton provided advice, stimulating discussion and critical feedback.
  The project was supported by National Science Foundation grant DEB-1258199.
article_processing_charge: No
article_type: original
author:
- first_name: Sean
  full_name: Stankowski, Sean
  id: 43161670-5719-11EA-8025-FABC3DDC885E
  last_name: Stankowski
- first_name: Madeline A.
  full_name: Chase, Madeline A.
  last_name: Chase
- first_name: Hanna
  full_name: McIntosh, Hanna
  last_name: McIntosh
- first_name: Matthew A.
  full_name: Streisfeld, Matthew A.
  last_name: Streisfeld
citation:
  ama: Stankowski S, Chase MA, McIntosh H, Streisfeld MA. Integrating top‐down and
    bottom‐up approaches to understand the genetic architecture of speciation across
    a monkeyflower hybrid zone. <i>Molecular Ecology</i>. 2023;32(8):2041-2054. doi:<a
    href="https://doi.org/10.1111/mec.16849">10.1111/mec.16849</a>
  apa: Stankowski, S., Chase, M. A., McIntosh, H., &#38; Streisfeld, M. A. (2023).
    Integrating top‐down and bottom‐up approaches to understand the genetic architecture
    of speciation across a monkeyflower hybrid zone. <i>Molecular Ecology</i>. Wiley.
    <a href="https://doi.org/10.1111/mec.16849">https://doi.org/10.1111/mec.16849</a>
  chicago: Stankowski, Sean, Madeline A. Chase, Hanna McIntosh, and Matthew A. Streisfeld.
    “Integrating Top‐down and Bottom‐up Approaches to Understand the Genetic Architecture
    of Speciation across a Monkeyflower Hybrid Zone.” <i>Molecular Ecology</i>. Wiley,
    2023. <a href="https://doi.org/10.1111/mec.16849">https://doi.org/10.1111/mec.16849</a>.
  ieee: S. Stankowski, M. A. Chase, H. McIntosh, and M. A. Streisfeld, “Integrating
    top‐down and bottom‐up approaches to understand the genetic architecture of speciation
    across a monkeyflower hybrid zone,” <i>Molecular Ecology</i>, vol. 32, no. 8.
    Wiley, pp. 2041–2054, 2023.
  ista: Stankowski S, Chase MA, McIntosh H, Streisfeld MA. 2023. Integrating top‐down
    and bottom‐up approaches to understand the genetic architecture of speciation
    across a monkeyflower hybrid zone. Molecular Ecology. 32(8), 2041–2054.
  mla: Stankowski, Sean, et al. “Integrating Top‐down and Bottom‐up Approaches to
    Understand the Genetic Architecture of Speciation across a Monkeyflower Hybrid
    Zone.” <i>Molecular Ecology</i>, vol. 32, no. 8, Wiley, 2023, pp. 2041–54, doi:<a
    href="https://doi.org/10.1111/mec.16849">10.1111/mec.16849</a>.
  short: S. Stankowski, M.A. Chase, H. McIntosh, M.A. Streisfeld, Molecular Ecology
    32 (2023) 2041–2054.
date_created: 2024-01-10T10:44:45Z
date_published: 2023-04-01T00:00:00Z
date_updated: 2024-01-16T10:10:00Z
day: '01'
department:
- _id: NiBa
doi: 10.1111/mec.16849
external_id:
  isi:
  - '000919244600001'
  pmid:
  - '36651268'
fulldoi: https://doi.org/10.1111/mec.16849
intvolume: '        32'
isi: 1
issue: '8'
keyword:
- Genetics
- Ecology
- Evolution
- Behavior and Systematics
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.1101/2022.01.28.478139
month: '04'
oa: 1
oa_version: Preprint
page: 2041-2054
pmid: 1
publication: Molecular Ecology
publication_identifier:
  eissn:
  - 1365-294X
  issn:
  - 0962-1083
publication_status: published
publisher: Wiley
quality_controlled: '1'
status: public
title: Integrating top‐down and bottom‐up approaches to understand the genetic architecture
  of speciation across a monkeyflower hybrid zone
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 32
year: '2023'
...