Fish species failing to adapt to warming oceans

Biotest study species European perchA research project associated with Sweden’s University of Gothenberg has found the impact from steadily rising ocean temperatures could prove fatal for some fish species. As well as the loss of biodiversity in the world’s oceans, the impact from warming seas on both marine mammals, and human populations that rely heavily on fish as a food source, would also be dramatic.
University of Tasmania senior research fellow Timothy Clark was a member of the Swedish team that conducted tests during 2012 and 2013 on European perch (Perca fluviatilis) from the ‘Biotest’ lake enclosure in the Baltic Sea. For over 30 years, these fish have been subjected to the lake’s ‘elevated’ water temperatures that are heated by the nearby Forsmark nuclear power plant.
The tests were also conducted on ‘reference’ fish populations from outside the enclosure, and results showed that while the fish are able to adapt their resting physiological functions to slowly rising temperatures, their maximum physiological functions are far less flexible.
“The fish can increase their lethal temperature by a certain amount, but they can’t keep up with the current rate of global water temperature increases,” Clark said. Continue reading Fish species failing to adapt to warming oceans

Did domestication start with the stomach?

Howlsnow WIKI wolfRecent research has suggested the stomach may also have been the pathway that led to man and dog becoming best friends.

A study led by evolutionary geneticist Erik Axelsson from the Department of Medical Biochemistry and Microbiology at Sweden’s Uppsala University, has found evidence of genetic differences between domestic dogs and wolves that could explain why dogs evolved to eat a more varied diet than their wolf ancestors.

Axelsson and a team that included researchers from Sweden, Norway and the US, sequenced genetic codes of 12 wolves from around the world, and of 60 domestic dogs from 14 different breeds. The dogs’ results were merged to eliminate individual breed traits before they were compared with those of wolves.

Their analysis led the scientists to focus on 36 different regions, and 122 genes likely to have contributed to canine evolution. Genes crucial for brain function were found in 19 regions, including eight important for the development of the nervous system, while 10 regions were found to hold genes specifically related to the breakdown of starches in diet.

“Our findings show that the digestive system of dogs has adapted to be able to live on a diet similar to ours. It’s cool that we’ve shared an environment for such a long time and we’ve eaten the same kind of food for such a long time that we’ve started to become more similar in that way,” Axelsson said.

The study also found that dogs have four to 30 copies of AMY2B, the gene crucial for amylase production, compared to the two copies found in wolves – one on each chromosome. This gene is 28 times more active in the dog pancreas than it in wolves, and results in more protein. Comparative variations are also found in human societies where either high or low carbohydrate diets have traditionally been eaten. Continue reading Did domestication start with the stomach?