Placental invasiveness mediates the evolution of hybrid inviability in mammals

Michael G. Elliot*, Bernard J. Crespi

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

41 Citations (Scopus)

Abstract

A central question in evolutionary biology is why animal lineages differ strikingly in rates and patterns of the evolution of reproductive isolation. Here, we show that the maximum genetic distance at which interspecific mammalian pregnancies yield viable neonates is significantly greater in clades with invasive (hemochorial) placentation than in clades with noninvasive (epitheliochorial or endotheliochorial) placentation. Moreover, sister species with invasive placentation exhibit higher allopatry in their geographic ranges, suggesting that formerly separated populations in mammals with this placental type fuse more readily on recontact. These differences are apparently driven by the stronger downregulation of maternal immune responses under invasive placentation, where fetal antigens directly contact the maternal bloodstream. Our results suggest that placental invasiveness mediates a major component of reproductive isolation in mammals.

Original languageEnglish
Pages (from-to)114-120
Number of pages7
JournalAmerican Naturalist
Volume168
Issue number1
DOIs
Publication statusPublished - Jul-2006
Externally publishedYes

Keywords

  • reproductive isolation
  • mammals
  • placentation
  • hybrid inviability
  • immunology
  • MOLECULAR EVOLUTION
  • REPRODUCTIVE MODE
  • FETAL MEMBRANES
  • PREGNANCY
  • SPECIATION
  • PHYLOGENIES
  • CHIROPTERA
  • RESPONSES
  • CONFLICT
  • PRIMATES

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