Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The Bear Necessities of Aging

12.12.2007
According to George Bernard Shaw: “We don’t stop playing because we grow old; we grow old because we stop playing,” but how fast does that aging occur once started? In the case of populations of salmon in Alaska studied by Stephanie Carlson and colleagues at the University of Washington and McGill University and reported on in this week’s PLoS ONE, it all depends on how choosy are the bears which feed on them.

Pacific salmon are noted for not feeding during their breeding period, relying instead on stored energy reserves and for their rapid senescence – the physiological deterioration associated with aging – once breeding is over. It is, thus, more beneficial for bears to consume fish with fewer signs of senescence because these fish have more energy reserves. However, these “fresh” fish are also more vigorous and harder to catch and so are more effectively caught in smaller, shallower streams.

Carlson and colleagues studied populations of salmon and brown bears in six creeks in southwest Alaska to determine whether the rate of senescence in salmon was driven primarily by the rate of predation by bears or by the tendency of the bears to prey on salmon with less evidence of senescence. They measured the reproductive lifespan of each fish as the number of days between stream entry and death and recorded the mode of death for each fish. They found that the selectivity of the bears for salmon of various senescent conditions was the prime factor determining the rate of senescence in the salmon.

In populations where bears killed old, decrepit salmon, the salmon senesced more slowly relative to populations where bears killed young, “fresh” salmon. This result contrasts with the established expectation that senescence evolves because of the number of individuals killed by predators, rather than their physical characteristics.

... more about:
»Carlson »Rate »bears »senescence

“The work offers new insight into the relationship between an individual’s senescent condition and it’s susceptibility to predation and the long-term consequences of this relationship” says Carlson, corresponding author on the publication.

Citation: Carlson SM, Hilborn R, Hendry AP, Quinn TP (2007) Predation by Bears Drives Senescence in Natural Populations of Salmon. PLoS ONE 2(12): e1286. doi:10.1371/journal.pone.0001286

Rebecca Walton | alfa
Further information:
http://www.plosone.org/doi/pone.0001286
http://www.plos.org

Further reports about: Carlson Rate bears senescence

More articles from Life Sciences:

nachricht Zap! Graphene is bad news for bacteria
23.05.2017 | Rice University

nachricht Discovery of an alga's 'dictionary of genes' could lead to advances in biofuels, medicine
23.05.2017 | University of California - Los Angeles

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

 
Latest News

Scientists propose synestia, a new type of planetary object

23.05.2017 | Physics and Astronomy

Zap! Graphene is bad news for bacteria

23.05.2017 | Life Sciences

Medical gamma-ray camera is now palm-sized

23.05.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>