The notion that shifts to new hosts can initiate insect speciation is more than 150 years old, yet widespread conflation with paradigms of sympatric speciation has led to confusion about how much support exists for this hypothesis. Here, we review 85 insect systems and evaluate the relationship between host shifting, reproductive isolation, and speciation. We sort insects into five categories: (1) systems in which a host shift has initiated speciation; (2) systems in which a host shift has made a contribution to speciation; (3) systems in which a host shift has caused the evolution of new reproductive isolating barriers; (4) systems with host-associated genetic differences; and (5) systems with no evidence of host-associated genetic differences. We find host-associated genetic structure in 65 systems, 43 of which show that host shifts have resulted in the evolution of new reproductive barriers. Twenty-six of the latter also support a role for host shifts in speciation, including eight studies that definitively support the hypothesis that a host shift has initiated speciation. While this review is agnostic as to the fraction of all insect speciation events to which host shifts have contributed, it clarifies that host shifts absolutely can and do initiate speciation.
|Number of pages||12|
|State||Published - May 2017|
Bibliographical noteFunding Information:
The authors would like to acknowledge G. Hood for reading and providing valuable comments on an early version of this manuscript; M. Neiman for setting a good example for intralaboratory collaborative manuscript writing; and several of Binghamton University's Ecology, Evolution, and Behavior Program's faculty and graduate students for engaging with some of the ideas and data described herein. Comments from two editors and two anonymous reviewers substantially improved the clarity and flow of the manuscript. Projects funded by the NSF to AAF (DEB 1145355 and 1542269) led directly to the discussions that motivated this review. The authors declare that they have no conflicts of interest.
© 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.
- Ecological speciation
- habitat isolation
- immigrant inviability
- plant–insect interactions
- reproductive isolation
- sympatric speciation
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Agricultural and Biological Sciences (all)