Cat evolution

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            The domesticated cat and its closest wild ancestor are both diploid organisms that possess 38 chromosomes and roughly 20,000 genes. About 250 heritable genetic disorders have been identified in cats, many similar to human inborn errors. The high level of similarity among the metabolisms of mammals allows many of these feline diseases to be diagnosed using genetic tests that were originally developed for use in humans, as well as the use of cats as animal models in the study of the human diseases.

"Cat evolution"
       
        The felids are a rapidly evolving family of mammals that share a common ancestor only 10–15 million years ago, and include, in addition to the domestic cat, lions, tigers, cougars, and many others. Within this family, domestic cats (Felis catus) are part of the genus Felis, which is a group of small cats containing approximately seven species (depending upon classification scheme). Members of the genus are found worldwide and include the jungle cat (Felis chaus) of southeast Asia, European wildcat (F. silvestris silvestris), African wildcat (F. s. lybica), the Chinese mountain cat , and the Arabian sand cat (F. margarita), among others.

All the cats in this genus share a common ancestor that probably lived around 6–7 million years ago in Asia. The exact relationships within the Felidae are close but still uncertain,e.g. the Chinese mountain cat is sometimes classified (under the name Felis silvestris bieti) as a subspecies of the wildcat, like the North African variety F. s. lybica. As domestic cats are little altered from wildcats, they can readily interbreed. This hybridization poses a danger to the genetic distinctiveness of wildcat populations, particularly in Scotland and Hungary

Pest-Eating Birds

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hi friends,,,,,,,Sep-11,.

This is the first time scientists have assigned a monetary value to the pest-control benefits rainforest birds can provide to agriculture. Their study could provide the framework for pest management that helps both farmers and biodiversity.

The latest finding from these researchers suggests that the birds are returning the favor to farmers by eating an aggressive coffee bean pest, the borer beetle, thereby improving coffee bean yields by hundreds of dollars per hectare.

The study is the first to put a monetary value on the pest-control benefits rainforest can provide to agriculture, which the researchers hope can inform both farmers and conservationists.

"The benefits that we might get are huge," said Daniel Karp, a graduate student in biology and lead author of the study. "There's lots of unrealized value in these small patches of rainforest. This looks like a sustainable, win-win opportunity for pest management."

The researchers hope that the work will improve conservation efforts in heavily farmed areas by illustrating to farmers the financial benefits of leaving some land in its natural state, while also guiding governments toward the best conservation methods

Pufferfish Meditate Magnesium

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Scientists at Tokyo Institute of Technology collaborate colleagues at Japan's Shimonoseki Academy of Marine Science and Mayo Clinic College of Medicine, Minnasota, USA, to uncovered the molecular mechanisms behind Mg2+ secretion in fresh and seawater Takifugu pufferfish species.
The bodily functions of creatures that live in aquatic environments are affected by the presence of ions of different elements in the water. Bodies naturally absorb and retain ions as essential nutrients, but an excess of any one ion in the body can be damaging.
The magnesium ion Mg2+ is the second most abundant cation in seawater. Both freshwater and seawater fish maintain a certain level of Mg2+ in the plasma in their bodies, and it has long been known that seawater fish secrete Mg2+ into their urine in order to avoid an excess of absorbed Mg2+ from their surroundings. However, certain species of fish are capable of living in both salt and freshwater conditions, and how they alter Mg2+ secretion in their bodies accordingly is not well understood.
Now, Akira Kato and co-workers at Tokyo Institute of Technology, together with researchers from Japan's Shimonoseki Academy of Marine Science and Mayo Clinic College of Medicine, Minnasota, USA, have uncovered the molecular mechanisms behind Mg2+ secretion in fresh and seawater Takifugu pufferfish species.
"For freshwater fish, Mg2+ is an important nutrient which should be retained if excess Mg2+ is not absorbed from food," explains Kato. "Seawater contains around 30 times more Mg2+ than the blood of seawater fish. If seawater fish cannot excrete excess Mg2+, they face hypermagnesemia which causes failure of normal tissue functions in the nerves, muscles, and heart."

Safe' Levels of Environmental Pollution May Have Long-Term Health Consequences

This study adds evidences for rethinking the way of addressing risk assessment especially when considering that the human population is widely exposed to low levels of thousands of chemicals, and that the health impact of realistic mixtures of pollutants will have to be tested as well," said Brigitte Le Magueresse-Battistoni, a researcher involved in the work from the French National Institute of Health and Medical Research (INSERM). "Indeed, one pollutant could have a different effect when in mixture with other pollutants. Thus, our study may have strong implications in terms of recommendations for food security. Our data also bring new light to the understanding of the impact of environmental food contaminants in the development of metabolic diseases."

To make this discovery, scientists used two groups of obese mice. Both were fed a high-fat, high-sucrose enriched diet, with one group receiving a cocktail of pollutants added to its diet at a very low dosage. These pollutants were given to the mice throughout -- from pre-conception to adulthood. Although the researchers did not observe toxicity or excess of weight gain in the group having received the cocktail of pollutants, they did see a deterioration of glucose tolerance in females, suggesting a defect in insulin signaling. Study results suggest that the mixture of pollutants reduced estrogen activity in the liver through enhancing an enzyme in charge of estrogen elimination. In contrast to females, glucose tolerance was not impacted in males exposed to the cocktail of pollutants. However, males did show some changes in liver related to cholesterol synthesis and transport. This study fuels the concept that pollutants may contribute to the current prevalence of chronic diseases including metabolic diseases and diabetes.