A specialized deceptive pollination system based on elaborate mushroom mimicry

AbstractDespite its potential effectiveness for outcrossing, few examples of pollination via mushroom mimicry have been reported. This may be because the conditions under which the strategy can evolve are limited and/or because demonstrating it is challenging. Arisaema is a plant genus that has been suggested to adopt mushroom mimicry for pollination, although no compelling evidence for this has yet been demonstrated. Here, we report that Arisaema sikokianum utilizes mostly a single genus of obligate mycophagous flies (Mycodrosophila) as pollinators, and that the insect community dominated by Mycodrosophila is strikingly similar to those found on some species of wood-decaying fungi. Comparative chemical analyses of Arisaema spp. and various mushrooms further revealed that only A. sikokianum emits a set of volatile compounds shared with some mushroom species utilized by Mycodrosophila. Meanwhile, other closely related and often sympatric Arisaema species do not possess such typical traits of mushroom mimicry or attract Mycodrosophila, thereby likely achieving substantial reproductive isolation from A. sikokianum. Our finding indicates that mushroom mimicry is an exceptional and derived state in the genus Arisaema, thus providing an unprecedented opportunity to study the mechanisms underlying the coordinated acquisition of mimicry traits that occurred during a recent speciation event.

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What is gradualism? Cryptic speciation in globorotaliid foraminifera

Paleobiology ◽

10.1017/s0094837300016341 ◽

1996 ◽

Vol 22 (3) ◽

pp. 386-405 ◽

Cited By ~ 42

Author(s):

Richard D. Norris ◽

Richard M. Corfield ◽

Julie Cartlidge

Keyword(s):

Reproductive Isolation ◽

Morphological Changes ◽

Morphological Evolution ◽

Reproductive Ecology ◽

Shell Growth ◽

Shell Shape ◽

Planktic Foraminifera ◽

Near Surface ◽

Surface Ocean ◽

Speciation Event

Analysis of the evolution of the Globorotalia (Fohsella) lineage of planktic foraminifera suggests that reproductive ecology and shell shape have evolved independently in this group. The silhouette of fohsellid shells displays a nearly unbroken anagenetic trend, yet isotopic data show that the fohsellids changed their depth of reproduction during the anagenetic evolution of their skeletons. Remarkably, there are no correlations between anagenesis in skeletal shape and the establishment of reproductive isolation. Apparently, anagenesis masks at least one speciation event that is apparent only in the isotopic evidence for a change in reproductive ecology. Although anagenetic trends have been widely cited as evidence for gradual speciation in planktic foraminifera and other microfossil groups, our data suggest that they should not always be considered to record either the tempo or mode of speciation.Speciation was apparently uncoupled from morphological evolution in fohsellids because these evolutionary phenomena occurred in different phases of ontogeny. Gradual morphological changes were associated with the main phase of shell growth of both the ancestor and descendant species in the near-surface ocean. Reproductive isolation occurred when ancestral and descendant populations became established at different depths near the end of the life cycle. Morphological evolution may also be uncoupled from reproductive isolation in other organisms that experience very different selection pressures over the duration of their ontogenies, such as parasites with many hosts, species with multiple phases of metamorphosis, and organisms that broadcast their gametes.

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Chemical caressess: geographical variation of male sexual signals in a Neotropical scorpion

Behaviour ◽

10.1163/1568539x-00003302 ◽

2015 ◽

Vol 152 (12-13) ◽

pp. 1745-1763 ◽

Cited By ~ 9

Author(s):

Paola A. Olivero ◽

Andrés González ◽

Camilo I. Mattoni ◽

Alfredo V. Peretti

Keyword(s):

Reproductive Isolation ◽

Mate Selection ◽

Geographical Variation ◽

Sexual Isolation ◽

Mate Recognition ◽

Dorsal Side ◽

Sexual Signals ◽

Chemical Analyses ◽

Sexual Behaviours ◽

Two Populations

Differences in sexual signals among species are common, and may influence mate recognition and reproductive isolation. In scorpions, behavioural mechanisms and other sexual signals involved in mate selection and reproductive isolation have been scarcely studied. In this paper, we compare different male sexual signals between two distant populations of the scorpionBothriurus bonariensis, one located in Uruguay and the other in Central Argentina. We compare sexual behaviours from intra-populations and inter-populations matings. In addition, we extent this comparison to the secreted compounds and morphology of the exocrine glands located on the dorsal side of the telson in this species. Males ofB. bonariensisperformed stimulatory behaviours to the female with different frequency of occurrence and duration in the two populations. Chemical analyses of the glandular extracts showed that Uruguayan males present compounds which are absent in males of Argentinian population. In addition, we observed that in inter-population matings, stimulatory behaviours had intermediate patterns to intra-population matings. However, males failed to achieve a successful sperm transfer with females of different population. Mechanisms of sexual isolation between these two distant populations ofB. bonariensisapparently seem to have evolved due to divergence in allopatry. The differences in stimulatory levels during courtship between the two populations studied here give evidence for an early behavioural divergence promoted by sexual selection.

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Extraordinarily rapid speciation in a marine fish

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1615109114 ◽

2017 ◽

Vol 114 (23) ◽

pp. 6074-6079 ◽

Cited By ~ 46

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.

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Seven new species of Trichodorus (Diphtherophorina, Trichodoridae) from Spain, an apparent centre of speciation

Nematology ◽

10.1163/156854112x645598 ◽

2013 ◽

Vol 15 (1) ◽

pp. 57-100 ◽

Cited By ~ 10

Author(s):

Wilfrida Decraemer ◽

Juan E. Palomares-Rius ◽

Carolina Cantalapiedra-Navarrete ◽

Blanca B. Landa ◽

Isabel Duarte ◽

...

Keyword(s):

New Species ◽

Iberian Peninsula ◽

Body Length ◽

Excretory Pore ◽

Species Group ◽

Southern Spain ◽

Natural Environments ◽

Type Specimens ◽

Speciation Event ◽

Recent Speciation Event

During a survey for Trichodoridae in cultivated and natural environments, mainly from southern Spain, 7 new Trichodorus species were found. Four of them, T. andalusicus n. sp., T. asturanus n. sp., T. silvestris n. sp. and T. parasilvestris n. sp., belong to the T. lusitanicus morpho-species group characterised in the male by the slightly ventrally curved spicules with a mid-blade constriction with bristles, and in the female by well developed, rounded triangular to quadrangular, vaginal sclerotised pieces. They were mainly differentiated based upon differences in body length, onchiostyle length, spicule shape and number of ventromedian cervical papillae in the male, and size and shape of the vaginal sclerotised pieces in the female. The presence of the T. lusitanicus morpho-species group with 8 species, apparently endemic to the Iberian Peninsula, could point to a recent speciation event. Additionally, 3 new species, T. onubensis n. sp., T. iliplaensis n. sp. and T. paragiennensis n. sp., more closely resembling the morpho-species group of T. sparsus, to which the Spanish species T. giennensis also belongs, were identified. They were differentiated based on body length, length of onchiostyle and position of the secretory-excretory pore and, in the male, by length and shape of the spicules and number of ventromedian cervical papillae and in the female by the vaginal sclerotised pieces. Molecular support to differentiate the new species using the D2-D3 expansion segments of 28S rDNA is also provided. In addition, a new population of T. variabilis from Greece was studied as well as T. lusitanicus type specimens, and a population of T. giennensis and T. lusitanicus were also sequenced.

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Speciation genes are more likely to have discordant gene trees

10.1101/244822 ◽

2018 ◽

Cited By ~ 1

Author(s):

Richard J. Wang ◽

Matthew W. Hahn

Keyword(s):

Gene Flow ◽

Reproductive Isolation ◽

Incomplete Lineage Sorting ◽

Gene Trees ◽

Species Trees ◽

Species Relationships ◽

Lineage Sorting ◽

Epistatic Interactions ◽

Speciation Event ◽

History Of

AbstractSpeciation genes are responsible for reproductive isolation between species. By directly participating in the process of speciation, the genealogies of isolating loci have been thought to more faithfully represent species trees. The unique properties of speciation genes may provide valuable evolutionary insights and help determine the true history of species divergence. Here, we formally analyze whether genealogies from loci participating in Dobzhansky-Muller (DM) incompatibilities are more likely to be concordant with the species tree under incomplete lineage sorting (ILS). Individual loci differ stochastically from the true history of divergence with a predictable frequency due to ILS, and these expectations—combined with the DM model of intrinsic reproductive isolation from epistatic interactions—can be used to examine the probability of concordance at isolating loci. Contrary to existing verbal models, we find that reproductively isolating loci that follow the DM model are often more likely to have discordant gene trees. These results are dependent on the pattern of isolation observed between three species, the time between speciation events, and the time since the last speciation event. Results supporting a higher probability of discordance are found for both derived-derived and derived-ancestral DM pairs, and regardless of whether incompatibilities are allowed or prohibited from segregating in the same population. Our overall results suggest that DM loci are unlikely to be especially useful for reconstructing species relationships, even in the presence of gene flow between incipient species, and may in fact be positively misleading.

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MÖSSBAUER AND CHEMICAL ANALYSES OF SOME SEDIMENTS FROM THE ROMANIAN SHORE OF THE BLACK SEA

Le Journal de Physique Colloques ◽

10.1051/jphyscol:19792155 ◽

1979 ◽

Vol 40 (C2) ◽

pp. C2-445-C2-448

Author(s):

D. Barb ◽

L. Diamandescu ◽

M. Morariu ◽

I. I. Georgescu

Keyword(s):

Black Sea ◽

The Black Sea ◽

Chemical Analyses

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A STUDY ON ICHTHYO-DIVERSITY OF MUNTJIBPUR POND OF ALLAHABAD (U.P.) INDIA

FLORA AND FAUNA ◽

10.33451/florafauna.v23i1pp220-224 ◽

2017 ◽

Vol 23 (1) ◽

Author(s):

ASHOK KUMAR VERMA

Keyword(s):

Single Species ◽

Single Genus ◽

One Year

An attempt was made to find the ichthyo-diversity of Muntjibpur pond of Allahabad. Systematic surveys were conducted during a period of one year. A total of 13 species of fishes belonging to 12 genera, 8 families and 5 orders were identified. Siluriformes order is represented by 5 genera and 5 species while Cypriniformes order by 4 genera and 5 species. Each of the orders Clupeiformes, Osteoglossiformes and Ophiocephaliformes is represented by single genus and single species.

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Role efficacy: A comprehensive study

Indian Journal of Positive Psychology ◽

10.15614/ijpp.v9i01.11764 ◽

2018 ◽

Vol 9 (01) ◽

Author(s):

Gopa Bhardwaj ◽

Swati Sharma ◽

Neeti B. Karnick

Keyword(s):

Personal Growth ◽

Role Models ◽

Qualitative Approach ◽

Potential Effectiveness ◽

Role Integration ◽

Helping Relationship ◽

Role Efficacy ◽

Comprehensive Study

A case study in manufacturing giant attempts to capture how potential effectiveness of a role is psychologically tuned along ten dimensions on which efficacy of an employee is defined. Further, how position, age and tenure of employment interact with role efficacy. A combination of quantitative and qualitative approach is followed, where n=28. Managers are seen as leaders and act like role models for the subordinates. Further, managers are high on helping relationship. Both see an opportunity for personal growth in their role. Self- role integration is lesser in managers than subordinates. Subordinates are found to be more reactive. Confrontation is greater for subordinates than managers. Elders are strong on dimensions common to achievers and youngest seems to have politics. Longer tenures exhibits more helping attitude and more confrontation than with smaller tenures. Thus, the dynamism between position, age and tenure seems to have an effect on role-efficacy.

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