A Comparison of the Mating Behaviour Between Populations of the Reptile Ticks Aponomma Hydrosauri and Amblyomma Albolimbatum.

1982 ◽  
Vol 30 (4) ◽  
pp. 635 ◽  
Author(s):  
RH Andrews ◽  
CM Bull
Keyword(s):  
Reproductive Isolation ◽  
Tick Species ◽  
Mating Behaviour ◽  
Geographical Isolation ◽  
Rapid Speciation ◽  
Different Populations

Tests were conducted in Australia to determine the levels of reproductive isolation between geographically separated populations of reptile ticks. Mating behaviour was observed both on and off hosts in the laboratory when males were placed with females of their own or different populations. There was no evidence for reproductive isolation between South Australian populations of Aponomma hydrosauri (Denny) collected from the host lizard Trachydosaurus rugosus, despite one area of geographical isolation. Males of Amblyomma albolimbatum Neum. showed no discrimination between females from populations more than 2000 km apart. This contrasts with earlier reports of reproductive isolation between reptile tick species and contradicts hypotheses of rapid speciation in parasitic taxa.

scholarly journals Differences in offspring size predict the direction of isolation asymmetry between populations of a placental fish

2013 ◽  
Vol 9 (5) ◽  
pp. 20130327 ◽  
Author(s):  
Matthew Schrader ◽  
Rebecca C. Fuller ◽  
Joseph Travis
Keyword(s):  
Reproductive Isolation ◽  
Offspring Size ◽  
Hybrid Inviability ◽  
Haldane’S Rule ◽  
Haldane's Rule ◽  
Asymmetric Pattern ◽  
Heterandria Formosa ◽  
Different Populations ◽  
Selection For

Crosses between populations or species often display an asymmetry in the fitness of reciprocal F 1 hybrids. This pattern, referred to as isolation asymmetry or Darwin's Corollary to Haldane's Rule, has been observed in taxa from plants to vertebrates, yet we still know little about which factors determine its magnitude and direction. Here, we show that differences in offspring size predict the direction of isolation asymmetry observed in crosses between populations of a placental fish, Heterandria formosa . In crosses between populations with differences in offspring size, high rates of hybrid inviability occur only when the mother is from a population characterized by small offspring. Crosses between populations that display similarly sized offspring, whether large or small, do not result in high levels of hybrid inviability in either direction. We suggest this asymmetric pattern of reproductive isolation is due to a disruption of parent–offspring coadaptation that emerges from selection for differently sized offspring in different populations.

DEVELOPMENTAL RATES AND DIAPAUSE IN ACHETA PENNSYLVANICUS (BURMEISTER) AND ACHETA VELETIS ALEXANDER AND BIGELOW (ORTHOPTERA:GRYLLIDAE)

1960 ◽  
Vol 38 (5) ◽  
pp. 973-988 ◽  
Author(s):  
R. S. Bigelow
Keyword(s):  
Reproductive Isolation ◽  
High Temperatures ◽  
Cold Hardiness ◽  
Embryonic Diapause ◽  
Geographical Isolation ◽  
Laboratory Rearing ◽  
Nymphal Development ◽  
Developmental Physiology ◽  
Developmental Rates ◽  
Genetically Determined

Tendencies to diapause were not observed in nymphs of Acheta pennsylvanicus (Burmeister), but diapause was noted in a high proportion of the nymphs of Acheta veletis Alexander and Bigelow. On the average, nymphal development was more rapid in pennsylvanicus than it was in veletis nymphs. Embryonic diapause always occurred in pennsylvanicus but never in veletis eggs. These differences in developmental physiology are genetically determined and the failure of the two species to produce hybrids may be due to conflicting lethal interactions of the two genotypes in hybrid embryos. Both species die out after several generations of laboratory rearing at continuous high temperatures, and the evolution of cold hardiness has apparently involved a reduction in tolerance to constant high temperatures. Reproductive isolation may have been achieved by these two species without geographical isolation. Nymphal development is more rapid in northern than in southern veletis populations.

scholarly journals First passage time to allopatric speciation

2013 ◽  
Vol 3 (6) ◽  
pp. 20130026 ◽  
Author(s):  
Ryo Yamaguchi ◽  
Yoh Iwasa
Keyword(s):  
Genetic Distance ◽  
First Passage Time ◽  
Passage Time ◽  
Allopatric Speciation ◽  
Geographical Isolation ◽  
Different Populations ◽  
Two Populations ◽  
Simple Stochastic Model ◽  
Migration Event ◽  
Large Diffusion

Allopatric speciation is a mechanism to evolve reproductive isolation; it is caused by the accumulation of genetic differences between populations while they are geographically isolated. Here, we studied a simple stochastic model for the time until speciation caused by geographical isolation in fragmented populations that experience recurrent but infrequent migration between subpopulations. We assumed that mating incompatibility is controlled by a number of loci that behave as neutral characters in the accumulation of novel mutations within each population. Genetic distance between populations was defined as the number of incompatibility-controlling loci that differ between them. Genetic distance increases through the separate accumulation of mutations in different populations, but decreases after a successful migration event followed by genetic mixing between migrants and residents. We calculated the time to allopatric speciation, which occurs when the genetic distance exceeds a specified threshold. If the number of invasive individuals relative to the resident population is not very large, diffusion approximation provides an accurate prediction. There is an intermediate optimal rate of migration that maximizes the rate of species creation by recurrent invasion and diversification. We also examined cases that involved more than two populations.

The potential for rapid speciation in plants

Genome ◽  
1989 ◽  
Vol 31 (1) ◽  
pp. 203-210 ◽  
Author(s):  
Mark R. Macnair
Keyword(s):  
Reproductive Isolation ◽  
Genetic Architecture ◽  
Genetic Basis ◽  
Natural Populations ◽  
Direct Result ◽  
Epistatic Interactions ◽  
Genetic Changes ◽  
Rapid Speciation ◽  
Genetic Revolution ◽  
Self Fertilization

Speciation involves both ecological adaptation and reproductive isolation. This paper reviews various ways in which plants could achieve reproductive isolation as a direct result of adaptation to prevailing conditions, particularly through changes in flowering time, the adoption of self-fertilization, and changes in flower morphology so that different pollinators are attracted. These characters are likely to have a relatively simple genetic architecture, and there must frequently be genetic variance for them in natural populations. It is argued that speciation could thus be initiated swiftly in plants, without any need for a "genetic revolution" or the fixation of genes with strongly epistatic interactions. Postmating barriers also often have a simple genetic basis in plants, and so could also evolve swiftly if associated with an adaptive response. The nature of the genetic changes associated with speciation in a number of recent speciation events in Layia, Stephanomeria, and Mimulus is reviewed.Key words: Speciation, adaptation, reproductive isolation.

Ecological speciation! Or the lack thereof?This Perspective is based on the author’s J.C. Stevenson Memorial Lecture delivered at the Canadian Conference for Fisheries Research in Halifax, Nova Scotia, January 2008.

2009 ◽  
Vol 66 (8) ◽  
pp. 1383-1398 ◽  
Author(s):  
Andrew P. Hendry
Keyword(s):  
Nova Scotia ◽  
Reproductive Isolation ◽  
Biological Diversity ◽  
Ecological Speciation ◽  
Divergent Selection ◽  
Adaptive Divergence ◽  
Memorial Lecture ◽  
Darwin’S Finches ◽  
Apparent Deviation ◽  
Different Populations

Ecological speciation occurs when adaptation to different environments or resources causes the evolution of reproductive isolation. This process is now thought to be very important in the evolution of biological diversity. Indeed, support for ecological speciation is so often asserted in the literature that one can get the impression of ubiquity. Eager to ride on the coattails of this exciting work, my own research has investigated ecological speciation in guppies, sticklebacks, and Darwin’s finches. Much to my initial dismay, I failed to find simple and strong signatures of ecological speciation in the first two of these systems. Setting aside the possibility of personal incompetence, my apparent deviation from ubiquity might simply reflect an existing literature bias. This bias seems obvious in retrospect given that essentially all published studies of ecological speciation purport to be confirmatory, whereas many cases of divergent selection and adaptive divergence are associated with only weak to modest levels of reproductive isolation. In short, different populations can be arrayed along a continuum from panmixia to complete reproductive isolation. Variation along this continuum might profitably be used for studying factors, outlined herein, that can promote or constrain “progress” toward ecological speciation.

Cross-mating between Chinese population of Neoseiulus californicus (Acari: Phytoseiidae) and that from the commercial one from USA 

2020 ◽  
Vol 25 (4) ◽  
pp. 728-734
Author(s):  
Jie Ji ◽  
Zi-wei Song ◽  
Shi-yong Xie ◽  
Zhi-qiang Zhang
Keyword(s):  
Reproductive Isolation ◽  
Chinese Population ◽  
Southern China ◽  
Neoseiulus Californicus ◽  
Biological Features ◽  
Commercial Population ◽  
Different Populations ◽  
Reproductive Compatibility ◽  
Reproductive Rates ◽  
Molecular Characters

Based on morphological and molecular characters, a Neoseiulus species collected from southern China was identified as Neoseiulus californicus (McGregor), which was not recorded in China before 2012. However, the Chinese population of N. californicus has some unique biological features and its morphology is also somewhat different from those populations from outside China. In order to clarify if there was reproductive isolation or reduction in the reproductive rates between Chinese population and the commercial population of N. californicus (originated from California, USA), reproductive compatibility between the specimens of two different populations was evaluated under laboratory conditions to ascertain their conspecificity. Inter-population crosses showed there was no reproductive isolation between the Chinese population and the commercial population. The results confirmed that these two belong to the same species, in agreement with the results based on morphological and molecular identifications of the Chinese N. californicus.

scholarly journals Intrinsic pre-zygotic reproductive isolation of distantly related pea aphid host races

2018 ◽  
Vol 14 (11) ◽  
pp. 20180332 ◽  
Author(s):  
Varvara Fazalova ◽  
Bruno Nevado ◽  
Ailsa McLean ◽  
H. Charles J. Godfray
Keyword(s):  
Reproductive Isolation ◽  
Host Plant ◽  
Broad Bean ◽  
Mating Behaviour ◽  
Habitat Choice ◽  
Pea Aphid ◽  
Drastic Reduction ◽  
Host Races ◽  
Female Survival ◽  
Aphid Host

Human activities may weaken or destroy reproductive isolation between young taxa, leading to their fusion with consequences for population and community ecology. Pea aphid host races are adapted to different legume taxa, providing a degree of pre-mating isolation mediated by habitat choice. Yet, all races can feed and reproduce on the broad bean ( Vicia faba ), a major crop which represents a ‘universal host plant’, which can promote hybridization between races. Here, we ask if pea aphid host races have reproductive barriers which prevent or reduce gene flow when they co-occur on the universal host plant. We observed mating behaviour, female survival, number of eggs and egg fertilization rates for three types of crosses: among individuals of the same host race, between closely related host races and between distantly related host races. We did not find significant differences in mating behaviour and female survival among the three types of crosses. However, we observed a drastic reduction in the number of eggs laid, and in the number of fertilized eggs, in distant crosses. We conclude that widespread broad bean cultivation in agriculture may predispose closely related—but not distantly related—host races to hybridize, disrupting reproductive isolation between incipient species.

scholarly journals Extraordinarily rapid speciation in a marine fish

2017 ◽  
Vol 114 (23) ◽  
pp. 6074-6079 ◽  
Author(s):  
Paolo Momigliano ◽  
Henri Jokinen ◽  
Antoine Fraimout ◽  
Ann-Britt Florin ◽  
Alf Norkko ◽  
...  
Keyword(s):  
Reproductive Isolation ◽  
Ecological Speciation ◽  
Neutral Buoyancy ◽  
Reproductive Behaviors ◽  
Low Salinity ◽  
Ecological Selection ◽  
Rapid Speciation ◽  
Speciation Event ◽  
Approximate Bayesian ◽  
The Baltic

Divergent selection may initiate ecological speciation extremely rapidly. How often and at what pace ecological speciation proceeds to yield strong reproductive isolation is more uncertain. Here, we document a case of extraordinarily rapid speciation associated with ecological selection in the postglacial Baltic Sea. European flounders (Platichthys flesus) in the Baltic exhibit two contrasting reproductive behaviors: pelagic and demersal spawning. Demersal spawning enables flounders to thrive in the low salinity of the Northern Baltic, where eggs cannot achieve neutral buoyancy. We show that demersal and pelagic flounders are a species pair arising from a recent event of speciation. Despite having a parapatric distribution with extensive overlap, the two species are reciprocally monophyletic and show strongly bimodal genotypic clustering and no evidence of contemporary migration, suggesting strong reproductive isolation. Divergence across the genome is weak but shows strong signatures of selection, a pattern suggestive of a recent ecological speciation event. We propose that spawning behavior in Baltic flounders is the trait under ecologically based selection causing reproductive isolation, directly implicating a process of ecological speciation. We evaluated different possible evolutionary scenarios under the approximate Bayesian computation framework and estimate that the speciation process started in allopatry ∼2,400 generations ago, following the colonization of the Baltic by the demersal lineage. This is faster than most known cases of ecological speciation and represents the most rapid event of speciation ever reported for any marine vertebrate.

scholarly journals Detecting level of genetic differentiation in two closely related species of Drosophila: D. bipectinata and D. malerkotliana

Genetika ◽  
2016 ◽  
Vol 48 (3) ◽  
pp. 963-970
Author(s):  
A.K. Singh ◽  
Sanjay Kumar ◽  
Neha Singh
Keyword(s):  
Genetic Differentiation ◽  
Reproductive Isolation ◽  
Related Species ◽  
Species Complex ◽  
Allozyme Variation ◽  
Sympatric Species ◽  
Drosophila Species ◽  
Allozyme Polymorphism ◽  
Closely Related Species ◽  
Different Populations

A considerable amount of allozyme variation exists among different populations of a Drosophila species. Such allozyme variation can also be observed between two closely related species of Drosophila which show reproductive isolation but experience mating under laboratory conditions and produce hybrids. D. bipectinata and D. malerkotliana are two closely related sympatric species and belong to bipectinata species complex. Allozyme polymorphism studies conducted with them and their hybrids reveal that these two species have enough genetic differentiation due to allozyme variation at three enzyme coding loci; however, their hybrids exhibit common allozyme variants of both the species. The hybrids exhibit very little genetic differentiation from either of their parents.

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