When DNA is too damaged to identify a body, perhaps a strand of hair could hold some answers. (Photo: Julie Russell/LLNL, CC BY-SA)
Week 37 | 11 to 17 September
Five things we learned this week! Everything here is published open-access. That means you can read the original scientific research yourself for free with no annoying pay-walls. Enjoy!
1) Climate models explain how vital ocean circulation responded to ice sheets and greenhouse gases. Climate data retrieved from ocean cores suggests that the vital ocean circulation in the Atlantic Ocean was much weaker during the Last Ice Age. But not all climate models agree with this assessment. A new study shows that Ice Age conditions, including low CO2 and widespread ice sheets, do indeed lead to a weakening of the ocean circulation. But there is a snag in these computer simulations. The CO2 needed to simulate these ocean conditions is much lower (145 ppm) than what is known to have actually occurred during the Ice Age (185 ppm). Are the reconstructions wrong or are the models still missing something? Research continues!
2) Ocean acidification is already beyond the bounds of natural variability for most and sometimes all the year. A study in EGU journal Biosciences has discovered that marine life is already exposed to pH conditions that go beyond the thresholds to which they have adapted, before the industrial era. The most vulnerable sites were in open-ocean in the subtropics and subarctic, where shellfish in particular are regularly exposed to conditions that could impact their on growth and survival.
3) The sea ice season across all 19 Arctic polar bear habitats is now seven weeks shorter than in the late 1970s. A study published in the EGU journal Cryosphere has discovered that sea ice is melting earlier and growing back later than at any other time on record. This limits polar bears’ ability to hunt and breed. It is the first time that scientists have quantified sea ice changes in each polar bear habitat. Total number of sea ice days has declined between 7 and 19 days per decade. Spring melt and winter freeze is now occurring 3.5 weeks earlier and later, respectively. At the current pace, polar bears can expect the sea ice season to shrink by another six to seven weeks by the middle of the century.
4) Scientists developed new visualisation tools to track bird migrations at night. A team of ecologists, meteorologists, computer scientists, and graphic designers developed the new tools, which show large-scale flows of animal movement through time. The scientists behind the project expect the tools to be of interest to the military, civil aviation, wind energy industry and conservation agencies.
They are also useful to engage the public in broad discussions about bird migration and impacts of global climate and environmental change.
5) Proteins in your hair can now be used to identify you. Studying hair samples from deceased people who died up to 250 years ago as well as hair from living people, scientists found 185 protein markers that could provide a unique personal signature to identify someone, biologically speaking. It could be accurate enough to identify one person out of a population on one million people. While less precise than DNA-typing, protein markers are more resistant to damage upon death and could provide a good alternative method to identify people after further research to refine the process, concludes the new study published in PLOS ONE.
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Klockmann, M., Mikolajewicz, U., & Marotzke, J. (2016). The effect of greenhouse gas concentrations and ice sheets on the glacial AMOC in a coupled climate model Climate of the Past, 12 (9), 1829-1846 DOI: 10.5194/cp-12-1829-2016
Sutton, A., Sabine, C., Feely, R., Cai, W., Cronin, M., McPhaden, M., Morell, J., Newton, J., Noh, J., Ólafsdóttir, S., Salisbury, J., Send, U., Vandemark, D., & Weller, R. (2016). Using present-day observations to detect when anthropogenic change forces surface ocean carbonate chemistry outside preindustrial bounds Biogeosciences, 13 (17), 5065-5083 DOI: 10.5194/bg-13-5065-2016
Stern, H., & Laidre, K. (2016). Sea-ice indicators of polar bear habitat The Cryosphere, 10 (5), 2027-2041 DOI: 10.5194/tc-10-2027-2016
Shamoun-Baranes, J., Farnsworth, A., Aelterman, B., Alves, J., Azijn, K., Bernstein, G., Branco, S., Desmet, P., Dokter, A., Horton, K., Kelling, S., Kelly, J., Leijnse, H., Rong, J., Sheldon, D., Van den Broeck, W., Van Den Meersche, J., Van Doren, B., & van Gasteren, H. (2016). Innovative Visualizations Shed Light on Avian Nocturnal Migration PLOS ONE, 11 (8) DOI: 10.1371/journal.pone.0160106
Parker, G., Leppert, T., Anex, D., Hilmer, J., Matsunami, N., Baird, L., Stevens, J., Parsawar, K., Durbin-Johnson, B., Rocke, D., Nelson, C., Fairbanks, D., Wilson, A., Rice, R., Woodward, S., Bothner, B., Hart, B., & Leppert, M. (2016). Demonstration of Protein-Based Human Identification Using the Hair Shaft Proteome PLOS ONE, 11 (9) DOI: 10.1371/journal.pone.0160653