TY - JOUR

T1 - Echoes of ancient introgression punctuate stable genomic lineages in the evolution of figs

AU - Gardner, Elliot M.

AU - Bruun-Lund, Sam

AU - Niissalo, Matti

AU - Chantarasuwan, Bhanumas

AU - Clement, Wendy L.

AU - Geri, Connie

AU - Harrison, Rhett D.

AU - Hipp, Andrew L.

AU - Holvoet, Maxime

AU - Khew, Gillian

AU - Kjellberg, Finn

AU - Liao, Shuai

AU - Pederneiras, Leandro Cardoso

AU - Peng, Yan-Qiong

AU - Pereira, Joan T.

AU - Phillipps, Quentin

AU - Puad, Aida Shafreena Ahmad

AU - Rasplus, Jean-Yves

AU - Sang, Julia

AU - Schou, Sverre Juul

AU - Velautham, Elango

AU - Weiblen, George D.

AU - Zerega, Nyree J. C.

AU - Zhang, Qian

AU - Zhang, Zhen

AU - Baraloto, Christopher

AU - Rønsted, Nina

N1 - Publisher Copyright: Copyright © 2023 the Author(s).

PY - 2023

Y1 - 2023

N2 - Studies investigating the evolution of flowering plants have long focused on isolating mechanisms such as pollinator specificity. Some recent studies have proposed a role for introgressive hybridization between species, recognizing that isolating processes such as pollinator specialization may not be complete barriers to hybridization. Occasional hybridization may therefore lead to distinct yet reproductively connected lineages. We investigate the balance between introgression and reproductive isolation in a diverse clade using a densely sampled phylogenomic study of fig trees (Ficus, Moraceae). Codiversification with specialized pollinating wasps (Agaonidae) is recognized as a major engine of fig diversity, leading to about 850 species. Nevertheless, some studies have focused on the importance of hybridization in Ficus, highlighting the consequences of pollinator sharing. Here, we employ dense taxon sampling (520 species) throughout Moraceae and 1,751 loci to investigate phylogenetic relationships and the prevalence of introgression among species throughout the history of Ficus. We present a well-resolved phylogenomic backbone for Ficus, providing a solid foundation for an updated classification. Our results paint a picture of phylogenetically stable evolution within lineages punctuated by occasional local introgression events likely mediated by local pollinator sharing, illustrated by clear cases of cytoplasmic introgression that have been nearly drowned out of the nuclear genome through subsequent lineage fidelity. The phylogenetic history of figs thus highlights that while hybridization is an important process in plant evolution, the mere ability of species to hybridize locally does not necessarily translate into ongoing introgression between distant lineages, particularly in the presence of obligate plant–pollinator relationships.

AB - Studies investigating the evolution of flowering plants have long focused on isolating mechanisms such as pollinator specificity. Some recent studies have proposed a role for introgressive hybridization between species, recognizing that isolating processes such as pollinator specialization may not be complete barriers to hybridization. Occasional hybridization may therefore lead to distinct yet reproductively connected lineages. We investigate the balance between introgression and reproductive isolation in a diverse clade using a densely sampled phylogenomic study of fig trees (Ficus, Moraceae). Codiversification with specialized pollinating wasps (Agaonidae) is recognized as a major engine of fig diversity, leading to about 850 species. Nevertheless, some studies have focused on the importance of hybridization in Ficus, highlighting the consequences of pollinator sharing. Here, we employ dense taxon sampling (520 species) throughout Moraceae and 1,751 loci to investigate phylogenetic relationships and the prevalence of introgression among species throughout the history of Ficus. We present a well-resolved phylogenomic backbone for Ficus, providing a solid foundation for an updated classification. Our results paint a picture of phylogenetically stable evolution within lineages punctuated by occasional local introgression events likely mediated by local pollinator sharing, illustrated by clear cases of cytoplasmic introgression that have been nearly drowned out of the nuclear genome through subsequent lineage fidelity. The phylogenetic history of figs thus highlights that while hybridization is an important process in plant evolution, the mere ability of species to hybridize locally does not necessarily translate into ongoing introgression between distant lineages, particularly in the presence of obligate plant–pollinator relationships.

KW - Ficus

KW - hybridization

KW - Moraceae

KW - phylogenomics

U2 - 10.1073/pnas.2222035120

DO - 10.1073/pnas.2222035120

M3 - Journal article

C2 - 37399402

AN - SCOPUS:85161602541

VL - 120

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

SN - 0027-8424

IS - 28

M1 - e2222035120

ER -