scholarly journals Hybridization drives genetic erosion in sympatric desert fishes of western North America

2019 ◽  
Author(s):  
Tyler K. Chafin ◽  
Marlis R. Douglas ◽  
Bradley T. Martin ◽  
Michael E. Douglas
Keyword(s):  
Reproductive Isolation ◽  
Extinction Risk ◽  
Genetic Erosion ◽  
Sympatric Species ◽  
Habitat Modification ◽  
Genetic Purity ◽  
Hybrid Swarm ◽  
Desert Fishes ◽  
Differential Adaptation ◽  
Anthropogenic Habitat

AbstractMany species have evolved or currently coexist in sympatry due to differential adaptation in a heterogeneous environment. However, anthropogenic habitat modifications can either disrupt reproductive barriers or obscure environmental conditions which underlie fitness gradients. In this study, we evaluated the potential for an anthropogenically-mediated shift in reproductive boundaries that separate two historically sympatric fish species (Gila cypha and G. robusta) endemic to the Colorado River Basin using ddRAD sequencing of 368 individuals. We first examined the integrity of reproductive isolation while in sympatry and allopatry, then characterized hybrid ancestries using genealogical assignment tests. We tested for localized erosion of reproductive isolation by comparing site-wise genomic clines against global patterns and identified a breakdown in the drainage-wide pattern of selection against interspecific heterozygotes. This, in turn, allowed for the formation of a hybrid swarm in one tributary, and asymmetric introgression where species co-occur. We also detected a weak but significant relationship between genetic purity and degree of consumptive water removal, suggesting a role for anthropogenic habitat modifications in undermining species boundaries. In addition, results from basin-wide genomic clines suggested that hybrids and parental forms are adaptively non-equivalent. If so, then a failure to manage for hybridization will exacerbate the long-term extinction risk in parental populations. These results reinforce the role of anthropogenic habitat modification in promoting interspecific introgression in sympatric species by relaxing divergent selection. This, in turn, underscores a broader role for hybridization in decreasing global biodiversity within rapidly deteriorating environments.

scholarly journals Genome-wide patterns of divergence and introgression after secondary contact between Pungitius sticklebacks

2020 ◽  
Vol 375 (1806) ◽  
pp. 20190548 ◽  
Author(s):  
Yo Y. Yamasaki ◽  
Ryo Kakioka ◽  
Hiroshi Takahashi ◽  
Atsushi Toyoda ◽  
Atsushi J. Nagano ◽  
...  
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Sequence Data ◽  
Continuous Process ◽  
Sympatric Species ◽  
Whole Genome Sequence ◽  
Secondary Contact ◽  
Pungitius Pungitius ◽  
Hybrid Male ◽  
Differential Adaptation

Speciation is a continuous process. Although it is known that differential adaptation can initiate divergence even in the face of gene flow, we know relatively little about the mechanisms driving complete reproductive isolation and the genomic patterns of divergence and introgression at the later stages of speciation. Sticklebacks contain many pairs of sympatric species differing in levels of reproductive isolation and divergence history. Nevertheless, most previous studies have focused on young species pairs. Here, we investigated two sympatric stickleback species, Pungitius pungitius and P. sinensis , whose habitats overlap in eastern Hokkaido; these species show hybrid male sterility, suggesting that they may be at a late stage of speciation. Our demographic analysis using whole-genome sequence data showed that these species split 1.73 Ma and came into secondary contact 37 200 years ago after a period of allopatry. This long period of allopatry might have promoted the evolution of intrinsic incompatibility. Although we detected on-going gene flow and signatures of introgression, overall genomic divergence was high, with considerable heterogeneity across the genome. The heterogeneity was significantly associated with variation in recombination rate. This sympatric pair provides new avenues to investigate the late stages of the stickleback speciation continuum. This article is part of the theme issue ‘Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers’.

LINEATIN ENANTIOMER PREFERENCE, FLIGHT PERIODS, AND EFFECT OF PHEROMONE CONCENTRATION AND TRAP LENGTH ON THREE SYMPATRIC SPECIES OF TRYPODENDRON (COLEOPTERA: SCOLYTIDAE)

2000 ◽  
Vol 132 (6) ◽  
pp. 877-887 ◽  
Author(s):  
B.S. Lindgren ◽  
S.E.R. Hoover ◽  
A.M. MacIsaac ◽  
C.I. Keeling ◽  
K.N. Slessor
Keyword(s):  
Sex Ratio ◽  
Reproductive Isolation ◽  
Release Rate ◽  
Sympatric Species ◽  
Ambrosia Beetle ◽  
Flight Period ◽  
Trypodendron Lineatum ◽  
Temporal Separation ◽  
Baited Traps ◽  
Pheromone Concentration

AbstractThe effects of lineatin enantiomer ratios, lineatin release rate, and trap length on catches and the flight periods of three sympatric species of Trypodendron Stephens were investigated in field bioassays using multiple-funnel traps. The ambrosia beetle, Trypodendron betulae Swaine, was caught in similar numbers in baited traps and blank control traps, showing that this species does not respond to lineatin. Our results confirmed that Trypodendron lineatum (Olivier) is attracted only to (+)-lineatin. Trypodendron rufitarsus (Kirby) and Trypodendron retusum (LeConte) were shown to utilize lineatin and like T. lineatum were caught only when (+)-lineatin was present. These results indicate that lineatin does not govern reproductive isolation among these three species. There was no effect by (+)-lineatin release rate within the range tested. The flight of T. rufitarsus commenced earlier and ceased before the peak of the T. lineatum flight, suggesting that temporal separation may be an important component of reproductive isolation between these two species. The flight period of T. retusum was similar to that of T. lineatum. Host odours may aid in reproductive isolation of these two species. Enantiomer blend did not significantly affect sex ratio in any species; however, sex ratio differed among species, indicating that different species responded differently to the traps or that natural sex ratios differ. Catches of T. rufitarsus and T. retusum increased with trap length when pheromone release per trap was held constant and when release was held constant relative to trap length. Trap length and release rate did not affect sex ratio.

Quantitative Trait Loci Affecting Differences in Floral Morphology Between Two Species of Monkeyflower (Mimulus)

Genetics ◽  
1998 ◽  
Vol 149 (1) ◽  
pp. 367-382 ◽  
Author(s):  
H D Bradshaw ◽  
Kevin G Otto ◽  
Barbara E Frewen ◽  
John K McKay ◽  
Douglas W Schemske
Keyword(s):  
Quantitative Trait Loci ◽  
Reproductive Isolation ◽  
Quantitative Trait ◽  
Floral Morphology ◽  
Cumulative Effect ◽  
Sympatric Species ◽  
Accurate Estimate ◽  
Phenotypic Variance ◽  
Trait Loci ◽  
Morphological Differences

Abstract Conspicuous differences in floral morphology are partly responsible for reproductive isolation between two sympatric species of monkeyflower because of their effect on visitation of the flowers by different pollinators. Mimulus lewisii flowers are visited primarily by bumblebees, whereas M. cardinalis flowers are visited mostly by hummingbirds. The genetic control of 12 morphological differences between the flowers of M. lewisii and M. cardinalis was explored in a large linkage mapping population of F2 plants (n = 465) to provide an accurate estimate of the number and magnitude of effect of quantitative trait loci (QTLs) governing each character. Between one and six QTLs were identified for each trait. Most (9/12) traits appear to be controlled in part by at least one major QTL explaining ≥25% of the total phenotypic variance. This implies that either single genes of individually large effect or linked clusters of genes with a large cumulative effect can play a role in the evolution of reproductive isolation and speciation.

Comparative morphology of two sympatric Pareledone species from South Georgia

1994 ◽  
Vol 6 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Heather I. Daly ◽  
Paul G. Rodhouse
Keyword(s):  
Reproductive Isolation ◽  
Body Mass ◽  
Comparative Morphology ◽  
Sympatric Species ◽  
Morphometric Data ◽  
South Georgia ◽  
Buccal Mass ◽  
Significant Difference ◽  
Sharp Point ◽  
Trophic Niches

Morphometric data were collected for 410 specimens of Pareledone turqueti and P. polymorpha caught around South Georgia. The two species differ in beak morphology and in the male hectocotylus. The species have similar appearances although there is a small but significant difference in the mantle length/body mass relationship for females, with P. polymorpha having a relatively longer mantle. There is no significant difference in the arm length/body mass relationship between species or sexes (p>0.05), except in the case of arm IV of females. There is an interspecific significant difference between sucker number on arms I and II of males, arms I–IV of females, and between hood length and mass of the buccal mass (p<0.05), with P. turqueti having relatively lower sucker numbers, a longer hood length and greater buccal mass mass. The beak of P. turqueti is similar to that of Eledone spp. but P. polymorpha has a small, fine beak with the rostral tip ending in an elongated, sharp point. Differences in beak and buccal mass suggest that these sympatric species occupy distinct trophic niches and that the differing morphology of the male hectocotylus is a factor in reproductive isolation.

Reproductive Isolation in Sympatric Species of Dayflying Moths (Hemileuca: Saturniidae)

Evolution ◽  
1979 ◽  
Vol 33 (2) ◽  
pp. 728 ◽  
Author(s):  
Michael M. Collins ◽  
Paul M. Tuskes
Keyword(s):  
Reproductive Isolation ◽  
Sympatric Species

scholarly journals Urbanization and Population Genetic Structure of the Panama City crayfish (Procambarus econfinae)

2019 ◽  
Vol 111 (2) ◽  
pp. 204-215
Author(s):  
Sarah I Duncan ◽  
Ellen P Robertson ◽  
Robert J Fletcher ◽  
James D Austin
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Habitat Loss ◽  
Legal Protection ◽  
Habitat Modification ◽  
Panama City ◽  
Habitat Patches ◽  
Anthropogenic Habitat ◽  
Habitat Loss And Fragmentation

Abstract For species with geographically restricted distributions, the impacts of habitat loss and fragmentation on long-term persistence may be particularly pronounced. We examined the genetic structure of Panama City crayfish (PCC), Procambarus econfinae, whose historical distribution is limited to an area approximately 145 km2, largely within the limits of Panama City and eastern Bay County, FL. Currently, PCC occupy approximately 28% of its historical range, with suitable habitat composed of fragmented patches in the highly urbanized western portion of the range and managed plantations in the more contiguous eastern portion of the range. We used 1640 anonymous single-nucleotide polymorphisms to evaluate the effects of anthropogenic habitat modification on the genetic diversity and population structure of 161 PCC sampled from across its known distribution. First, we examined urban habitat patches in the west compared with less-developed habitat patches in the east. Second, we used approximate Bayesian computation to model inferences on the demographic history of eastern and western populations. We found anthropogenic habitat modifications explain the genetic structure of PCC range-wide. Clustering analyses revealed significant genetic structure between and within eastern and western regions. Estimates of divergence between east and west were consistent with urban growth in the mid-20th century. PCC have low genetic diversity and high levels of inbreeding and relatedness, indicating populations are small and isolated. Our results suggest that PCC have been strongly affected by habitat loss and fragmentation and management strategies, including legal protection, translocations, or reintroductions, may be necessary to ensure long-term persistence.

scholarly journals Limited intrinsic postzygotic reproductive isolation despite chromosomal rearrangements between closely related sympatric species of small ermine moths (Lepidoptera: Yponomeutidae)

2019 ◽  
Vol 128 (1) ◽  
pp. 44-58 ◽  
Author(s):  
Katerina H Hora ◽  
František Marec ◽  
Peter Roessingh ◽  
Steph B J Menken
Keyword(s):  
Reproductive Isolation ◽  
Parental Species ◽  
Meiotic Chromosome ◽  
Chromosomal Rearrangements ◽  
Sympatric Species ◽  
Hybrid Fitness ◽  
New Host ◽  
Closely Related Species ◽  
Postzygotic Reproductive Isolation

Abstract In evolutionarily young species and sympatric host races of phytophagous insects, postzygotic incompatibility is often not yet fully developed, but reduced fitness of hybrids is thought to facilitate further divergence. However, empirical evidence supporting this hypothesis is limited. To assess the role of reduced hybrid fitness, we studied meiosis and fertility in hybrids of two closely related small ermine moths, Yponomeuta padella and Yponomeuta cagnagella, and determined the extent of intrinsic postzygotic reproductive isolation. We found extensive rearrangements between the karyotypes of the two species and irregularities in meiotic chromosome pairing in their hybrids. The fertility of reciprocal F1 and, surprisingly, also of backcrosses with both parental species was not significantly decreased compared with intraspecific offspring. The results indicate that intrinsic postzygotic reproductive isolation between these closely related species is limited. We conclude that the observed chromosomal rearrangements are probably not the result of an accumulation of postzygotic incompatibilities preventing hybridization. Alternative explanations, such as adaptation to new host plants, are discussed.

scholarly journals Recent and rapid anthropogenic habitat fragmentation increases extinction risk for freshwater biodiversity

2020 ◽  
Vol 13 (10) ◽  
pp. 2857-2869
Author(s):  
Chris J. Brauer ◽  
Luciano B. Beheregaray
Keyword(s):  
Habitat Fragmentation ◽  
Extinction Risk ◽  
Freshwater Biodiversity ◽  
Anthropogenic Habitat

Reptile responses to anthropogenic habitat modification: A global meta‐analysis

2020 ◽  
Vol 29 (7) ◽  
pp. 1265-1279 ◽  
Author(s):  
Tim S. Doherty ◽  
Sara Balouch ◽  
Kristian Bell ◽  
Thomas J. Burns ◽  
Anat Feldman ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Habitat Modification ◽  
Anthropogenic Habitat
Sign in / Sign up

Export Citation Format

Share Document