Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Faster Development May Have Its Costs

26.01.2011
þWake up and smell the toast:
Scents of death induce faster development in salamanders - but such acceleration has its costs

Fast development is often perceived as an advantage, as it enables better harmony with one's environment and readiness to cope with the challenges that it poses. However, research conducted at the University of Haifa, Israel, and University of California, Santa Cruz, and published in the scientific journal PLoS ONE*, found that the acceleration of developmental rate incurs potentially lethal physiological costs for the developing individual. "Our findings are consistent with research findings on other animals and call for further research on rates of development in humans," said Asaf Sadeh who led the study.

This study, part of Sadeh's PhD research, was conducted on the fire salamander (Salamandra infraimmaculata) in conjunction with Prof. Leon Blaustein and Noa Truskanov from the University of Haifa, and with Prof. Marc Mangel from the University of California. The fire salamander in Israel breeds in temporary pools that fill during the winter rains and usually dry up in the spring. The larvae that are born into these pools must complete their development and metamorphose into terrestrial life before their pools dry. Larvae failing in this developmental race are destined to die from desiccation.

In the first part of the study, the scientists examined whether salamander larvae employ some early warning mechanism that alerts them to step up their rates of development to avoid drying. They reared an experimental group of larvae in water, to which they added a minute quantity of powder of ground larvae that had desiccated in natural temporary ponds. The development of these larvae was compared to a control group that was not exposed to the powder. They found that immediately after their birth into the pond, the larvae detected the presence of the dried remains and developed more quickly than the control group. Sadeh and colleagues propose that the chemical composition of the flesh of the dead larvae changes as they toast in the sun, producing a unique "scent of death". These chemicals are released back into the water during the next rains, when the pond fills up again. This apparently provides information to the newborn larvae on the expected water-holding capacity of their pond, and signals them to set a high developmental rate to avoid a similar fate.

While chemicals from previously desiccated larvae can inform as to possible drying of pools in a relatively short time, reducing water levels can serve as a more reliable predictor of imminent pond drying and risk of desiccation. In the second part of the study, the researchers manipulated the water-levels for both groups, to simulate actual drying or non-drying conditions. They found that, after a while, the larvae will adjust their initial rates of development according to the actual water levels of their ponds.

However, they also found that accelerated development carries costs: larvae that developed more quickly suffered greater rates of mortality. Larvae that falsely perceived the pond environment as long-lasting, and thus started life with a slow developmental rate, but then realized their misperception and compensated with significant acceleration, suffered the greatest rates of mortality. The physiological mechanisms underlying these costs are unknown, but are thought to involve both cellular causes such as oxidative damage from increased metabolic rates, and tissue-level causes such as overexploitation of undifferentiated stem cells or disrupted balance between the differentiation and growth of different tissues in the body. These physiological costs may also lead to increased vulnerability to environmental stresses other than drying, such as heat, disease and parasites, and might result in death.

According to Sadeh, these results are consistent with those of recent studies on the costs of acceleration in growth following starvation in various other organisms, including insects, fish, amphibians and mammals. He suggests that this calls for further research on human development, such as motor, immune, sexual and cognitive development. "These new findings are thought-provoking when considered in relation to widespread perceptions of optimal child development. Boosting a certain aspect of a child's development allows the child to cope better with the corresponding aspect of the environment, but may be traded off with some other aspect of development, potentially rendering the child less competent for other environmental challenges," suggested Sadeh, but emphasized that the study of the costs of development rates is in its infancy, and that more work needs to be carried out before any applicable conclusions can be drawn for human development.

Link: http://newmedia-eng.haifa.ac.il/?p=4418

* Sadeh A, Truskanov N, Mangel M, Blaustein L (2011) Compensatory Development and Costs of Plasticity: Larval Responses to Desiccated Conspecifics. PLoS ONE 6(1): e15602.

Rachel Feldman | Newswise Science News
Further information:
http://www.haifa.ac.il

More articles from Studies and Analyses:

nachricht Do microplastics harbour additional risks by colonization with harmful bacteria?
05.04.2018 | Leibniz-Institut für Ostseeforschung Warnemünde

nachricht Rutgers-led innovation could spur faster, cheaper, nano-based manufacturing
14.02.2018 | Rutgers University

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Magnetic nano-imaging on a table top

20.04.2018 | Physics and Astronomy

Start of work for the world's largest electric truck

20.04.2018 | Interdisciplinary Research

Atoms may hum a tune from grand cosmic symphony

20.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>