scholarly journals The evolution of targeted cannibalism and cannibal-induced defenses in invasive populations of cane toads

2021 ◽  
Vol 118 (35) ◽  
pp. e2100765118 ◽  
Author(s):  
Jayna L. DeVore ◽  
Michael R. Crossland ◽  
Richard Shine ◽  
Simon Ducatez
Keyword(s):  
Selective Pressure ◽  
Life Stage ◽  
Rapid Evolution ◽  
Inducible Defenses ◽  
Native Range ◽  
Selective Force ◽  
Arms Races ◽  
Constitutive Defenses ◽  
Native Populations ◽  
Plastic Responses

Biotic conflict can create evolutionary arms races, in which innovation in one group increases selective pressure on another, such that organisms must constantly adapt to maintain the same level of fitness. In some cases, this process is driven by conflict among members of the same species. Intraspecific conflict can be an especially important selective force in high-density invasive populations, which may favor the evolution of strategies for outcompeting or eliminating conspecifics. Cannibalism is one such strategy; by killing and consuming their intraspecific competitors, cannibals enhance their own performance. Cannibalistic behaviors may therefore be favored in invasive populations. Here, we show that cane toad tadpoles (Rhinella marina) from invasive Australian populations have evolved an increased propensity to cannibalize younger conspecifics as well as a unique adaptation to cannibalism—a strong attraction to vulnerable hatchlings—that is absent in the native range. In response, vulnerable conspecifics from invasive populations have evolved both stronger constitutive defenses and greater cannibal-induced plastic responses than their native range counterparts (i.e., rapid prefeeding development and inducible developmental acceleration). These inducible defenses are costly, incurring performance reductions during the subsequent life stage, explaining why plasticity is limited in native populations where hatchlings are not targeted by cannibalistic tadpoles. These results demonstrate the importance of intraspecific conflict in driving rapid evolution, highlight how plasticity can facilitate adaptation following shifts in selective pressure, and show that evolutionary processes can produce mechanisms that regulate invasive populations.

Rapid evolution of constitutive and inducible defenses against an invasive predator

Ecology ◽  
2014 ◽  
Vol 95 (6) ◽  
pp. 1520-1530 ◽  
Author(s):  
Ana L. Nunes ◽  
Germán Orizaola ◽  
Anssi Laurila ◽  
Rui Rebelo
Keyword(s):  
Rapid Evolution ◽  
Inducible Defenses ◽  
Invasive Predator

scholarly journals Genomic evidence of adaptive evolution in the reptilian SOCS gene family

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11677
Author(s):  
Tian Xia ◽  
Lei Zhang ◽  
Guolei Sun ◽  
Xiufeng Yang ◽  
Honghai Zhang
Keyword(s):  
Negative Selection ◽  
Molecular Mechanisms ◽  
Evolutionary Dynamics ◽  
Theoretical Foundation ◽  
Selective Pressure ◽  
Rapid Evolution ◽  
Cytokine Signaling ◽  
Signal Pathways ◽  
Branch Model ◽  
Comprehensive Study

The suppressor of the cytokine signaling (SOCS) family of proteins play an essential role in inhibiting cytokine receptor signaling by regulating immune signal pathways. Although SOCS gene functions have been examined extensively, no comprehensive study has been performed on this gene family’s molecular evolution in reptiles. In this study, we identified eight canonical SOCS genes using recently-published reptilian genomes. We used phylogenetic analysis to determine that the SOCS genes had highly conserved evolutionary dynamics that we classified into two types. We identified positive SOCS4 selection signals in whole reptile lineages and SOCS2 selection signals in the crocodilian lineage. Selective pressure analyses using the branch model and Z-test revealed that these genes were under different negative selection pressures compared to reptile lineages. We also concluded that the nature of selection pressure varies across different reptile lineages on SOCS3, and the crocodilian lineage has experienced rapid evolution. Our results may provide a theoretical foundation for further analyses of reptilian SOCS genes’ functional and molecular mechanisms, as well as their roles in reptile growth and development.

Isozyme Variation in Australian and South-African Populations of Emex australis Steinh

1990 ◽  
Vol 38 (2) ◽  
pp. 161 ◽  
Author(s):  
FD Panetta
Keyword(s):  
South African ◽  
Isozyme Variation ◽  
Native Range ◽  
Low Level ◽  
Emex Australis ◽  
African Populations ◽  
Native Populations ◽  
Australian Colonial ◽  
South African Populations

Isozyme variation was surveyed at 25 loci in 65 Australian (colonial) and 21 South African (native) populations of Emex australis. Only one polymorphism, restricted in distribution to the eastern States, was observed in Australia. Three additional polymorphisms were detected in South African populations, but most (16) South African populations were indistinguishable from the Australian ones. Thus, the relative uniformity of colonial populations of E. australis reflects the low level of isozyme variation in many populations within its native range.

scholarly journals IntroducedBrassica nigrapopulations exhibit greater growth and herbivore resistance but less tolerance than native populations in the native range

2011 ◽  
Vol 191 (2) ◽  
pp. 536-544 ◽  
Author(s):  
Ayub M.O. Oduor ◽  
Richard A. Lankau ◽  
Sharon Y. Strauss ◽  
José M. Gómez
Keyword(s):  
Native Range ◽  
Herbivore Resistance ◽  
Native Populations

scholarly journals Retrocopying expands the functional repertoire of APOBEC3 antiviral proteins in primates

2020 ◽  
Author(s):  
Lei Yang ◽  
Michael Emerman ◽  
Harmit S. Malik ◽  
Richard N. McLaughlin
Keyword(s):  
Rapid Evolution ◽  
Endogenous Retroviruses ◽  
New World Monkeys ◽  
Restriction Factors ◽  
New Host ◽  
Arms Races ◽  
Cytidine Deaminases ◽  
Host Restriction ◽  
Host Restriction Factors ◽  
Evolution Of Viruses

AbstractHost-virus arms races are inherently asymmetric; viruses evolve much more rapidly than host genomes. Thus, there is high interest in discovering mechanisms by which host genomes keep pace with rapidly evolving viruses. One family of restriction factors, the APOBEC3 (A3) cytidine deaminases, has undergone positive selection and expansion via segmental gene duplication and recombination. Here, we show that new copies of A3 genes have also been created in primates by reverse transcriptase-encoding elements like LINE-1 or endogenous retroviruses via a process termed retrocopying. First, we discovered that all simian primate genomes retain the remnants of an ancient A3 retrocopy: A3I. Furthermore, we found that some New World monkeys encode up to ten additional APOBEC3G (A3G) retrocopies. Some of these A3G retrocopies are transcribed in a variety of tissues and able to restrict retroviruses. Our findings suggest that host genomes co-opt retroelement activity in the germline to create new host restriction factors as another means to keep pace with the rapid evolution of viruses. (163)

scholarly journals Rapid Evolution of HERC6 and Duplication of a Chimeric HERC5/6 Gene in Rodents and Bats Suggest an Overlooked Role of HERCs in Mammalian Immunity

2020 ◽  
Vol 11 ◽  
Author(s):  
Stéphanie Jacquet ◽  
Dominique Pontier ◽  
Lucie Etienne
Keyword(s):  
Rapid Evolution ◽  
Chimeric Gene ◽  
Viral Pathogens ◽  
Arms Races ◽  
Evolutionary Diversification ◽  
Independent Duplication ◽  
New Research ◽  
Herc Proteins ◽  
Antiviral Innate Immunity

Studying the evolutionary diversification of mammalian antiviral defenses is of main importance to better understand our innate immune repertoire. The small HERC proteins are part of a multigene family, including HERC5 and HERC6, which have probably diversified through complex evolutionary history in mammals. Here, we performed mammalian-wide phylogenetic and genomic analyses of HERC5 and HERC6, using 83 orthologous sequences from bats, rodents, primates, artiodactyls, and carnivores—the top five representative groups of mammalian evolution. We found that HERC5 has been under weak and differential positive selection in mammals, with only primate HERC5 showing evidences of pathogen-driven selection. In contrast, HERC6 has been under strong and recurrent adaptive evolution in mammals, suggesting past and widespread genetic arms-races with viral pathogens. Importantly, the rapid evolution of mammalian HERC6 spacer domain suggests that it might be a host-pathogen interface, targeting viral proteins and/or being the target of virus antagonists. Finally, we identified a HERC5/6 chimeric gene that arose from independent duplication in rodent and bat lineages and encodes for a conserved HERC5 N-terminal domain and divergent HERC6 spacer and HECT domains. This duplicated chimeric gene highlights adaptations that potentially contribute to rodent and bat immunity. Our findings open new research avenues on the functions of HERC6 and HERC5/6 in mammals, and on their implication in antiviral innate immunity.

Biogeographic origins and reproductive mode of naturalised populations of Acacia saligna

2012 ◽  
Vol 60 (5) ◽  
pp. 383 ◽  
Author(s):  
M. A. Millar ◽  
M. Byrne
Keyword(s):  
Seedling Recruitment ◽  
South Australia ◽  
Reproductive Mode ◽  
Acacia Saligna ◽  
Native Range ◽  
Single Population ◽  
Population Genetic Analysis ◽  
Native Populations ◽  
History Of ◽  
Root Suckering

Acacia saligna (Labill.) H.L.Wendl. is a species complex with an extensive history of anthropogenic utilisation and distribution. The taxon is naturalised and invasive in many countries. Extensive morphological variation makes accurate taxonomic identification of populations difficult. We used population genetic analysis to determine the biogeographic origins of 12 naturalised populations sampled from throughout south-eastern South Australia and assess the mode of reproduction (seedling or root suckering) at sites with active recruitment. Ten naturalised populations were assigned to Eastern ‘saligna’, although some also showed a lesser degree of affinity with other entities. A single population was assigned to Western ‘saligna’, but showed some affinity with Eastern ‘saligna’, and one population assigned to subsp. ‘lindleyi’ showed some affinity with Northern ‘lindleyi’. These assignments suggest that although several genetic entities of A. saligna are represented in South Australia, the majority of germplasm has originated from native populations of Eastern ‘saligna’ located around Esperance on Western Australia’s southern coast. Genetic diversity is limited in naturalised A. saligna compared with that present in the native range, suggesting a restricted number of historical introductions. Reproduction is predominantly by seedling recruitment, as opposed to clonal reproduction.

Functional shifts in leaves of woody invaders of deciduous forests between their home and away ranges

2019 ◽  
Vol 39 (9) ◽  
pp. 1551-1560 ◽  
Author(s):  
Kelsey A Martinez ◽  
Jason D Fridley ◽  
Riichi Oguchi ◽  
Masahiro Aiba ◽  
Kouki Hikosaka
Keyword(s):  
Rapid Evolution ◽  
Light Availability ◽  
Leaf Traits ◽  
Enemy Release ◽  
Carbon Gain ◽  
Native Range ◽  
Low Light ◽  
Trait Variation ◽  
Unit Leaf ◽  
Leaf Chlorophyll

Abstract Temperate forests are widely invaded by shade-tolerant shrubs and trees, including those of Eastern North America (ENA). However, it remains unknown whether these invaders are ‘preadapted’ for success in their new ranges due to unique aspects of their evolutionary history or whether selection due to enemy release or other postintroduction processes have driven rapid evolution in the invaded range. We sampled leaf traits of populations of woody understory invaders across light gradients in their native range in Japan and in their invaded ENA range to examine potential phenotypic shifts related to carbon gain and nitrogen use between ranges. We also measured leaf traits in three co-occurring ENA native shrub species. In their invaded range, invaders invested significantly less in leaf chlorophyll content (both per unit leaf mass and area) compared with native range populations of the same species, yet maintained similar rates of photosynthesis in low light. In addition, compared with ENA natives, ENA invaders displayed greater trait variation in response to increasing light availability (forest edges, gaps), giving them a potential advantage over ENA natives in a variety of light conditions. We conclude that, for this group of species, newly evolved phenotypes in the invaded range are more important than preadaptation for their success as shade-tolerant forest invaders.

scholarly journals Team swimming in ant spermatozoa

2014 ◽  
Vol 10 (6) ◽  
pp. 20140308 ◽  
Author(s):  
Morgan Pearcy ◽  
Noémie Delescaille ◽  
Pascale Lybaert ◽  
Serge Aron
Keyword(s):  
Selective Pressure ◽  
Multiple Mating ◽  
Reproductive Traits ◽  
Sperm Cells ◽  
Sperm Length ◽  
Sperm Number ◽  
Storage Organ ◽  
Selective Force ◽  
Remarkable Case ◽  
Desert Ant

In species where females mate promiscuously, competition between ejaculates from different males to fertilize the ova is an important selective force shaping many aspects of male reproductive traits, such as sperm number, sperm length and sperm–sperm interactions. In eusocial Hymenoptera (bees, wasps and ants), males die shortly after mating and their reproductive success is ultimately limited by the amount of sperm stored in the queen's spermatheca. Multiple mating by queens is expected to impose intense selective pressure on males to optimize the transfer of sperm to the storage organ. Here, we report a remarkable case of cooperation between spermatozoa in the desert ant Cataglyphis savignyi . Males ejaculate bundles of 50–100 spermatozoa. Sperm bundles swim on average 51% faster than solitary sperm cells. Team swimming is expected to increase the amount of sperm stored in the queen spermatheca and, ultimately, enhance male posthumous fitness.

Enhanced Growth and Seed Properties in Introduced vs. Native Populations of Yellow Starthistle (Centaurea solstitialis)

Weed Science ◽  
2007 ◽  
Vol 55 (5) ◽  
pp. 465-473 ◽  
Author(s):  
Timothy L. Widmer ◽  
Fatiha Guermache ◽  
Margarita Yu Dolgovskaia ◽  
Sergey Ya. Reznik
Keyword(s):  
Seedling Growth ◽  
Starch Content ◽  
Field Studies ◽  
The United States ◽  
Native Range ◽  
Yellow Starthistle ◽  
Invasive Range ◽  
Native Populations ◽  
Chamber Studies ◽  
Growth Chamber Studies

There is much discussion as to why a plant becomes invasive in a new location but is not problematic in its native range. One example is yellow starthistle, which originates in Eurasia and is considered a noxious weed in the United States. We grew yellow starthistle originating from native and introduced regions in a common environment to test whether differences in growth would be observed. In growth chamber studies, seedlings originating from the invasive range were larger than seedlings from the native range after 2 wk. Seed starch content is an important component of initial seedling growth. The starch content of seeds from introduced populations was higher than that of seeds from native populations. Regression analysis showed a relationship between the amount of starch in the seeds and the weight of yellow starthistle seedlings after 2 wk growth. There was no difference in chromosome number, except in accessions originating from Sicily and Sardinia. Field studies conducted in France and Russia revealed that rosettes and mature plants grown under natural conditions were larger when grown from seeds originating from the invasive range than from seeds originating from the native range. The number of capitula per plant and stem diameters were not significant among all populations, but differences were noted. The F1 progeny of plants originating from U.S. seed, but grown and pollinated in France, showed no differences in seedling growth, mature plant characteristics, and seed starch content from the plants grown from field-collected U.S. seed. The changes in seed starch resource allocation and its relation to plant growth is useful in understanding factors that contribute to yellow starthistle's invasibility.

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