Deep ancestral introgression shapes evolutionary history of dragonflies and damselflies

Abstract

exchange of inter-specific genetic information via various biological processes. In particular, 51 lateral gene transfer, incomplete lineage sorting (ILS) and introgression can result in gene trees 52 that are discordant with the species tree [3, 4]. Lateral transfer and introgression both involve 53 gene flow following speciation, thereby producing "reticulate" phylogenies. Incomplete lineage 54 sorting (ILS), on the other hand, occurs when three or more lineages coalesce in their ancestral 55 population. This often arises in an order that conflicts with that of the true species tree, and thus 56 involves no post-speciation gene flow and therefore does not contribute to reticulate evolution. 57 Thus, phylogenetic species-gene tree incongruence observed in empirical data can provide 58 insight into underlying biological factors that shape the evolutionary trajectories of a set of taxa. 59The major source of reticulate evolution for eukaryotes is introgression where it affects 60 approximately 25% of flowering plant and 10% of animal species [1, 5]. Introgressed alleles can 61 be fitness-neutral, deleterious [6] or adaptive. For example, adaptive introgression has been 62 shown to provide an evolutionary rescue from polluted habitats in gulf killifish (Fundulus 63 grandis) [7], yielded mimicry adaptations among Heliconius butterflies [8] and archaic 64 introgression has facilitated adaptive evolution of altitude tolerance [9], immunity and 65 metabolism in modern humans [10]. Additionally, hybridization and introgression are important 66 and often overlooked mechanisms of invasive species establishment and spread [11]. 67Odonata, the insect order that contains dragonflies and damselflies, lacks a strongly 68 supported backbone tree to clearly resolve higher-level phylogenetic relationships [12, 13]. 69 Current evidence places odonates together with Ephemeroptera (mayflies) as the living 70 representatives of the most ancient insect lineages to have evolved wings and active flight [14]. 71Odonates possess unique anatomical and morphological features such as a specialized body 72 form, specialized wing venation, a distinctive form of muscle attachment to the wing base [15] 73 allowing for direct flight and accessory (secondary) male genitalia that support certain unique 74 behaviors (e.g., sperm competition). They are among the most adept flyers of all animals and are 75 exclusively carnivorous insects relying primarily on vision [16, 17] to capture prey. They spend 76 much of their adult life in flight [18]. Biogeographically, odonates exhibit worldwide dispersal 77[19] and play crucial ecological roles in local freshwater communities, being a top invertebrate 78 predator [20]. Due to this combination of characteristics, odonates are quickly becoming model 79 organisms to study specific questions in ecology, physiology and evolution [21, 22]. However, 80 the extent of introgression at the genomic scale within Odonata remains primarily unknown. 81Two early attempts to tackle introgression/hybridization patterns wi...

Field evidence for colour mimicry overshadowing morphological mimicry

“…Therefore, we studied the nanoarchitecture of the wing colour patches in the model butterfly G. andromica and the local mimic damselfly E. fasciata. We also in- (Suvorov et al, 2020).…”

“…The genus Cora belongs to the damselfly family Polythoridae, similar to Euthore . The genus Hetaerina belongs to the family Calopterygidae: Calopterygidae and Polythoridae are part of two sister clades under the Superfamily Calopterygoidea (Suvorov et al, 2020).…”

Tropical Origin, Global Diversification and Dispersal in the Pond Damselflies (Coenagrionoidea) Revealed by a New Molecular Phylogeny

“…We specified a General Time-Reversible (GTR) model of molecular evolution for each partition, and accounted for rate heterogeneity among sites by assuming gamma-distributed rate heterogeneity. Finally, we used a topological constraint to enforce the monophyly of each of the two families within Coenagrionoidea (Coenagrionidae and Platycnemididae), as supported by recent large-scale studies (Kohli et al ., 2020; Bybee et al ., 2021; Suvorov et al ., 2021). The maximum a posteriori probability (MAP) tree was used to summarize phylogenetic inference.…”

“…We include over 35% of the approximately 1,805 species, and thereby substantially increase the phylogenetic coverage of sampled taxa compared to previous studies (Dijkstra et al ., 2014; Waller & Svensson, 2017). Recent phylogenomic studies have produced a robust and dated backbone for the order Odonata, which we used to inform the origin time of the most recent common ancestor of pond damselflies and featherlegs (Kohli et al ., 2020; Suvorov et al ., 2021). We combine this root age prior with an empirical paleogeographic model (Landis, 2017), genetic data and distribution range data of extant taxa, to simultaneously infer the divergence times and geographic distribution of ancestral lineages.…”

Genome sequences of the five Sitopsis species of Aegilops and the origin of polyploid wheat B-subgenome

“…In addition, we also estimated pair-wise branch length and genetic similarity using DendroPy module 61 in Python. Genetic introgression among the A-, B- and D-lineages were estimated using a combination of the D-statistic, fd, hybrid index (γ) and χ 2 good ness of fit test 62–64 . Introgressed variants among the four D-lineage Sitopsis species were identified based on the shared-specific SNPs for each species pair compared to the other species.…”