scholarly journals An analytical model assessing the potential threat to natural habitats from insect resistance transgenes: continuous transgene input

2006 ◽  
Vol 2 (2) ◽  
pp. 293-297 ◽  
Author(s):  
Colleen K Kelly ◽  
Michael Bowler ◽  
Felix Breden

The potential effects of ‘escape’ of genetically modified material (transgenes) into natural communities is a major concern in their use. These effects may be limited in the first instance by limiting the proportion of transgene-carrying plants in the natural community. We previously presented an analytical model of the ecological processes governing the relative abundance and persistence of insect resistance (IR) transgenes in a natural community. In that paper, we illustrated the case in which the transgene is input into the community in a single season using data from oilseed rape (OSR) and its known herbivore, Plutella macropennis . We found that the transgene is unlikely to have a great impact on the natural community. Here, we extend the model for repeated input of crop pollen carrying the transgene. We show the model output, again using OSR, for continuous input of the transgene over 10 years, the projected commercial lifetime of a transgene without associated undesirable agronomic effects. Our results do not change our original conclusion that the IR transgene need not have a large impact on the natural community and our suggestions for assessing and mitigating any threat still stand.

2005 ◽  
Vol 272 (1574) ◽  
pp. 1759-1767 ◽  
Author(s):  
Colleen K Kelly ◽  
Michael G Bowler ◽  
Felix Breden ◽  
Michael Fenner ◽  
Guy M Poppy

We examine the role of ecological interactions on effective gene flow from genetically manipulated plants to their wild relatives. We do so by constructing and applying to oilseed rape (OSR) an analytical model for interaction between plants with and without an insect resistance (IR) allele in natural communities, incorporating documented levels of herbivore variability. We find that with reasonable values of advantage to the IR allele, little concomitant disadvantage (physiological costs of the allele) restricts it to low proportions of the natural population for large numbers of generations. We conclude that OSR IR transgenes are unlikely to pose an immediate threat to natural communities. Our model identifies those factors best able to regulate particular transgenes at the population level, the most effective being impaired viability of seeds in the period between production and the following growing season, although other possibilities exist. Because solutions rely on ratios, limiting values of regulating factors are testable under controlled conditions, minimizing risk of release into the environment and offering significant advancement on existing testing programmes. Our model addresses folivory but is easily modified for herbivory damaging the seed or directly affecting seed production by infested plants, or for pathogens altering seed survival in the seedbank.


2003 ◽  
Vol 13 (1) ◽  
pp. 45-58 ◽  
Author(s):  
Johel Chaves-Campos ◽  
J. Edgardo Arévalo ◽  
Mariamalia Araya

Bare-necked Umbrellabird Cephalopterus glabricollis is endemic to Costa Rica and western Panama. It eats fruit, breeding at high elevations (≥ 800 m) and migrating to lower elevations during the non-breeding season. Using data from transect counts and radio-telemetry, we monitored bird movements in a protected area (Monteverde–Arenal–San Ramón reserves) in the Tilarán Mountains, Costa Rica. We also monitored fruit abundance along an altitudinal gradient to explore the potential relationship between bird movements and the abundance of the fruits this species consumed. The presence and abundance of umbrellabirds at high elevations (1,400 m) during the breeding season (March–June) coincided with the highest peak of fruit abundance. The presence of umbrellabirds in the lowlands (400 m) during the non-breeding season overlapped with the period of highest fruit abundance at these elevations. At middle elevations, bird presence and abundance did not correlate with fruit abundance. Radio-tagged birds left the protected area during the non-breeding season and there were no umbrellabirds inside the protected area during this period. Habitats where this species bred were well represented in the protected area but the habitat where they spent the non-breeding season was poorly represented, and was not adequately protected. This represents a potential threat to this species in the Tilarán Mountains.


Ecology ◽  
2008 ◽  
Vol 89 (4) ◽  
pp. 962-970 ◽  
Author(s):  
Colleen K. Kelly ◽  
Michael G. Bowler ◽  
Oliver Pybus ◽  
Paul H. Harvey

Author(s):  
Alexandre Gannier

Small boat surveys were organized to study cetaceans of the Marquesas (9°S and 140°W) and the Society Islands (17°S and 150°W) in French Polynesia. Prospecting took place from 12–15 m sailboats, between 1996 and 2001 with systematic visual searching. Boats moved according to sea conditions, at a mean speed of 10 km/h. Effective effort of 4856 km in the Marquesas and 10,127 km in the Societies were logged. Relative abundance indices were processed for odontocetes using data obtained with Beaufort 4 or less. In the Marquesas, 153 on-effort sightings were obtained on 10 delphinids species including the spotted dolphin, spinner dolphin, bottlenose dolphin, melon-headed whale and rough-toothed dolphin. In the Societies, 153 sightings of 12 odontocetes included delphinids (spinner, rough-toothed and bottlenose dolphins, short-finned pilot and melon-headed whales, Fraser's dolphin, Risso's dolphin and pygmy killer whale) and two species of beaked whales, the sperm whale and dwarf sperm whale. Relative abundance indices were higher in the Marquesas than in the Societies both inshore (0.93 ind/km2 against 0.36 ind/km2) and offshore (0.28 ind/km2 against 0.14 ind/km2). Differences in remote-sensed primary production were equally important, the Marquesas waters featuring an annual average of 409 mgC.m−2 · day−1 and the Societies of only 171 mgC · m−2 · day−1. The presence of a narrow shelf around the Marquesas also accounted for differences in odontocete populations, in particular the delphinids.


2012 ◽  
Vol 51 (4) ◽  
pp. 763-779 ◽  
Author(s):  
Terry J. Schuur ◽  
Hyang-Suk Park ◽  
Alexander V. Ryzhkov ◽  
Heather D. Reeves

AbstractA new hydrometeor classification algorithm that combines thermodynamic output from the Rapid Update Cycle (RUC) model with polarimetric radar observations is introduced. The algorithm improves upon existing classification techniques that rely solely on polarimetric radar observations by using thermodynamic information to help to diagnose microphysical processes (such as melting or refreezing) that might occur aloft. This added information is especially important for transitional weather events for which past studies have shown radar-only techniques to be deficient. The algorithm first uses vertical profiles of wet-bulb temperature derived from the RUC model output to provide a background precipitation classification type. According to a set of empirical rules, polarimetric radar data are then used to refine precipitation-type categories when the observations are found to be inconsistent with the background classification. Using data from the polarimetric KOUN Weather Surveillance Radar-1988 Doppler (WSR-88D) located in Norman, Oklahoma, the algorithm is tested on a transitional winter-storm event that produced a combination of rain, freezing rain, ice pellets, and snow as it passed over central Oklahoma on 30 November 2006. Examples are presented in which the presence of a radar bright band (suggesting an elevated warm layer) is observed immediately above a background classification of dry snow (suggesting the absence of an elevated warm layer in the model output). Overall, the results demonstrate the potential benefits of combining polarimetric radar data with thermodynamic information from numerical models, with model output providing widespread coverage and polarimetric radar data providing an observation-based modification of the derived precipitation type at closer ranges.


2019 ◽  
Vol 62 (2) ◽  
pp. 158-168
Author(s):  
Arindam Ganguly ◽  
Amrita Banerjee ◽  
Asish Mandal ◽  
Pradeep K. Das Mohapatra

Clarias batrachus (Linn.) is widely recognized in Indian sub-continent for its nutritional and economic significance. At present, it remains at a merely vulnerable state. Pathogenic infections, diminution of natural habitats and introduction of allied exotic fishes are the causes of productivity constraint, particularly in Southern Asia. Conversely, African cat fish Clarias gariepinus has been significantly identified as a potential threat to biodiversity, despite being its large scale cultivation across the world. Thus emphasis on indigenous C. batrachus farming is becoming inevitable. Currently, screening of autochthonous probiotic organisms for the cultivation of C. batrachus in semi-intensive manner is getting importance. At the same time, molecular omics-based technologies are also gaining considerable attention to identify potential probiotic markers. This review provides an overall concept of probiotics, its application and future perspectives in relation to the cultivation of C. batrachus.


2017 ◽  
Author(s):  
H. De Kort ◽  
M. Baguette ◽  
J.G Prunier ◽  
M. Tessier ◽  
J. Monsimet ◽  
...  

AbstractHabitat fragmentation increasingly threatens the services provided by natural communities and ecosystem worldwide. An understanding of the underlying eco-evolutionary processes in natural settings is lacking, yet critical to realistic and sustainable conservation. Through integrating the multivariate genetic, biotic and abiotic facets of a natural community network experiencing various degrees of habitat fragmentation, we provide unique insights into the processes underlying community functioning in real, natural conditions. The focal community network comprises a parasitic butterfly of conservation concern, and its two obligatory host species, a plant and an ant. We show that fragmentation of butterfly habitat has the potential to impair the balance between dispersal and coevolution. This process can cause coevolutionary burning spots of decreased genetic diversity and therefore of increased extinction risk. We stress that ignoring such eco-evolutionary feed-backs inherent to the very functioning of natural communities can strongly impact their persistence.One Sentence Summary:Communities under threat of habitat fragmentation suffer increased extinction risk through coevolutionary overheating.


2020 ◽  
Author(s):  
Richmond Sam-Quarm ◽  
Mohamed Osman Elamin Busharads

Currently, the world has entered into the 5th generation war, and this war in the 5th generation can be said to be an invisible war. This war can be interpreted as an information war, an economic war, including cyber warfare. The rapid progress of the development of science and technology today has a very broad impact on various aspects of human life. The threat of cyber attacks that can cripple the stability of national security needs to be watched out for. For this reason, the Indonesian nation must have strategic steps to anticipate all possibilities from the threat of cyber attacks. The research objective in this paper is to identify the potential threat of 5th generation war, analyze cyber threats and cyber attacks in Indonesia and how the Universal War Strategy in dealing with the threat of cyber attacks. This research method uses a qualitative descriptive phenomenology research method, using data sources from some literature and mass media. The research results from the researcher's analysis provide significant results with the conclusion that Indonesia is vulnerable to cyber threats so that it is necessary to equalize perceptions in drafting the concept of defense and security from the threat of cyber attacks.


2020 ◽  
Vol 117 (40) ◽  
pp. 24893-24899
Author(s):  
Thomas Kiørboe ◽  
Mridul K. Thomas

Gleaners and exploiters (opportunists) are organisms adapted to feeding in nutritionally poor and rich environments, respectively. A trade-off between these two strategies—a negative relationship between the rate at which organisms can acquire food and ingest it—is a critical assumption in many ecological models. Here, we evaluate evidence for this trade-off across a wide range of heterotrophic eukaryotes from unicellular nanoflagellates to large mammals belonging to both aquatic and terrestrial realms. Using data on the resource acquisition and ingestion rates in >500 species, we find no evidence of a trade-off across species. Instead, there is a positive relationship between maximum clearance rate and maximum ingestion rate. The positive relationship is not a result of lumping together diverse taxa; it holds within all subgroups of organisms we examined as well. Correcting for differences in body mass weakens but does not reverse the positive relationship, so this is not an artifact of size scaling either. Instead, this positive relationship represents a slow–fast gradient in the “pace of life” that overrides the expected gleaner–exploiter trade-off. Other trade-offs must therefore shape ecological processes, and investigating them may provide deeper insights into coexistence, competitive dynamics, and biodiversity patterns in nature. A plausible target for study is the well-documented trade-off between growth rate and predation avoidance, which can also drive the slow–fast gradient we observe here.


Sign in / Sign up

Export Citation Format

Share Document