philosophical transactions of the royal society b

Ocean acidification and the development of calcifying organisms

What is ocean acidification?
Increased CO2 results in a lowering of pH in the ocean, making it more acidic.
Since cold water absorbs CO2 more easily than warm water, polar regions are more at risk.

How does it impact calcifying organisms?
It decreases the saturation state of CaCO3 (calcium carbonate), meaning that animals which produce calcium carbonate shells or skeletons (such as molluscs, echinoderms, and corals) will be severely impacted. Their skeletons and shells may become stunted, deformed, and more porous (see below).

Pictured Above:
Echinoderm larvae from tropical, temperate and polar sea urchins under different pH levels (note: the lower the pH, the more acidic). This figure shows that increasing acidity significantly inhibits their development (Byrne et al., 2013). Scale bars = 200 µm. 

Whats going to happen?
- Species extinctions
- A decrease in biodiversity, species richness, and biomass of coral reefs
- Food webs will be simplified
- Habitat complexity will be reduced
- A shift from coral reefs to seagrass/algae based ecosystems in some areas

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sherifsaadg  asked:

in a documentary called the leapord queen hyenas pack fight vigorously about food even they would hurt each other , I read a post about dominace theory that animals dont fight each other and every animal know well about their hierarchy your opinion?

The important thing to remember about any animal documentaries you see on tv is that the editors know that footage of animals squabbling and fighting over food is going to merit more public interest than footage of animals calmly feeding together.

The other important thing to remember is that hyena pack structure is very, VERY different from any canid pack structure. While canid pack structure is age-graded and reliant on submissive appeasement behaviors, hyena pack structure is actually much more similar to the group structure of many old-world primates.

Hyenas practice many more overtly “aggressive” behaviors with one another than canids do, but on the whole they are still largely symbolic, with few serious injuries occurring (so long as the fighters are members of the same clan). This increased aggression compared to canids probably has much to do with the much greater complexity of hyena social behavior. Rather than a single breeding pair, any female in the clan is allowed to breed, and cubs inherit their mother’s rank. Furthermore, coalitions form, so that more submissive members may rise in rank in the presence of ‘friends,’ and behavior can change drastically depending on who is in the area and who isn’t. Hyenas even go so far as to have fission-fusion societies, where splinter groups can detach and later rejoin with the main.

Retaining all this social ranking information takes significantly more social intelligence and significantly more social signals, and so aggression is employed along with submission. What most of those documentaries won’t show you is how hyenas may reconcile after a fight, with one approaching the other with appeasement signals. Usually, a grooming session follows.

Further Reading

Holekamp, K. E., Sakai, S. T., & Lundrigan, B. L. (2007). Social intelligence in the spotted hyena (Crocuta crocuta). Philosophical Transactions of the Royal Society B: Biological Sciences, 362(1480), 523-538.

Smith, J. E., Memenis, S. K., & Holekamp, K. E. (2007). Rank-related partner choice in the fission–fusion society of the spotted hyena (Crocuta crocuta). Behavioral Ecology and Sociobiology, 61(5), 753-765.

Wahaj, S. A., Guse, K. R., & Holekamp, K. E. (2001). Reconciliation in the spotted hyena (Crocuta crocuta). Ethology, 107(12), 1057-1074.

Turning Out the Lights on Disease-Carrying Insects

Night falls, and the lights on streets and in homes go on. For more than 130 years, artificial light has been a key contributor to human development, allowing people to extend their work hours beyond when the sun goes down, school children to study their lessons, and communities to feel more secure on roads and in shared public spaces. 

In many parts of the world, though, the simple act of turning on a light after dark comes with dangerous risks. Lightbulbs attract insects. Some of these bugs are infected with microbes, which get transferred to people and cause chronic or deadly diseases. Certain mosquitoes bring malaria, Dengue fever or rash- and fever-inducing Chikungunya virus. Sandfly bites can pass on the ulcer-causing Leishmaniasis parasite. A kissing bug kiss can impart Chagas disease.

The impact is substantial, with insect-borne illnesses representing 17 percent of all infectious diseases and 1 million deaths annually around the world. But now researchers say there is a new disease prevention tool that could help lower infections by insects that find their way indoors using light as their guide. Scientists have found that LED bulbs tuned to emit certain wavelengths of light attract significantly fewer insects.

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