Category Archives: Science

Midges Versus Pollen for Understanding Past Climate – 365papers – 2017 – 79

#365papers for March 20, 2017

Samartin, Heiri, Joos, Renssen, Franke, Bronnimann, and Tinner, 2017, Warm Mediterranean mid-H0locene summers inferred from fossil midge assemblages: Nature Geoscience, v. 10, p. 207-212.

What’s it about?

Many global climate records show an episode of warming between 9000 and 5000 years ago. However, in the eastern Mediterranean region, the usual tools used to estimate temperature (in this case pollen) suggested that this was a cooler interval. The authors use fossilized larval chironomids (non-biting midges) found in lake deposits as another means to estimate summertime temperatures. The midges do show the expected warmth.Continue reading “Midges Versus Pollen for Understanding Past Climate – 365papers – 2017 – 79”

Hypercarnivory, Tooth Development, and Evolutionary Dead Ends – #365papers – 2017 – 78

#365papers for March 19, 2017

Sole and Ladeveze, 2017, Evolution of the hypercarnivorous dentition in mammals (Metatheria, Eutheria) and its bearing on the development of tribosphenic molars: Evolution & Development, v. 19, p. 56-68.

What’s it about?

This paper discusses the teeth of carnivorous mammals, in particular the carnassials, or cutting teeth, characteristic of a meat-eating diet. These are the long, bladelike teeth toward the back of a dog or cat’s jaw, that come together with a scissor-like action to snip off bits of meat. Mammals from many different groups (including marsupials) have developed carnassial teeth.

The degree to which these teeth are blade like or still possess some of the crushing and puncturing features of ancestral mammals is an indication of how dependent on meat the mammal is. Cats, for example, lack the crushing and puncturing structures and are thus ‘hypercarnivores.’ Dogs in contrast, still have these ancient structures and are known to have a broader, more flexible diet.Continue reading “Hypercarnivory, Tooth Development, and Evolutionary Dead Ends – #365papers – 2017 – 78”

Putting All the Data Together Makes a More Complete History – #365papers – 2017 – 77

#365papers for March 18, 2017

Feakins, Levin, Liddy, Sieracki, Eglinton, and Bonnefille, 2017, Northeast African vegetation change over 12 m.y.: Geology, v. 41, p. 295-298.

What’s it about?

The authors combine pollen and isotopic data from fossil leaf waxes from an ocean core with soil carbonate data from northeast Africa to better understand the origin and composition of grasslands in northeast Africa over the last 12 million years.Continue reading “Putting All the Data Together Makes a More Complete History – #365papers – 2017 – 77”

Global Warming; Shrinking Mammals – #365papers – 2017 – 76

#365papers for March 17, 2017

D’Ambrosia, Clyde, Fricke, Gringerich, Abels, 2017, Repetitive mammalian dwarfing during ancient greenhouse warming events: Science Advances, v. 3, e1601430.

What’s it about?

Rapid global warming in Earth’s past had occurred more than once. The most commonly studied episode occurred 55 million years ago, at the boundary between the Paleocene and Eocene epochs (Paleocene Eocene Thermal Maximum, PETM). Several other episodes have happened, including the ETM2 and H2 episodes which are discussed in this paper.

Dwarfing of mammalian species has been documented at the PETM. This paper shows dwarfing of mammals also occurred at the ETM2.Continue reading “Global Warming; Shrinking Mammals – #365papers – 2017 – 76”

How Soil Carbonate Can Tell Us About Climate – #365papers – 2017 – 75

#365papers for March 16, 2017

Cerling, T.E., 1984, The stable isotopic composition of modern soil carbonate and its relationship to climate: Earth and Planetary Science Letters, v. 71, p. 229-240.

What’s it about?

This paper discusses in detail how isotopes of carbon and oxygen in carbonate minerals that form in soils are related to that of plant biomass (carbon) or local precipitation (oxygen).Continue reading “How Soil Carbonate Can Tell Us About Climate – #365papers – 2017 – 75”

Rocks and Fossils in the Uinta Basin, Getting it in Order – #365papers – 2017 – 74

#365papers for March 15, 2017

Townsend, Friscia, and Rasmussen, 2006, Stratigraphic distribution of upper middle Eocene fossil vertebrate localities in the eastern Uinta Basin, Utah, with comments on Uintan biostratigraphy: The Mountain Geologist, v. 43, p. 115-134.

What’s it about?

This paper is a synthesis of over 100 years worth of research in the Uinta Basin, making a huge effort to sort out how the rocks and fossils correlate and to get everything in the correct chronologic order. Continue reading “Rocks and Fossils in the Uinta Basin, Getting it in Order – #365papers – 2017 – 74”

The Relative Amounts of Essential Oils in Hops Gives Them Unique Flavor and Aroma – #365papers – 2017 – 73

#365papers for March 14, 2017

Auerbach, Dost, and Davidson, 2000, Characterization of verietal differences in essential oil components of hops (Humulus lupulus) by SFC-FTIR spectroscopy: Journal of AOAC International, v. 83, p. 621-626.

What’s it about?

This paper discusses a spectroscopy method to explore what makes the flavors and aromas of different hop varieties distinct. They focus on the three most common components of hop essential oils: humulene, caryophyllene, and myrcene.Continue reading “The Relative Amounts of Essential Oils in Hops Gives Them Unique Flavor and Aroma – #365papers – 2017 – 73”

Appearance and Spread of Modern Forests in Asia and North America – #365papers – 2017 – 72

#365papers for March 13, 2017

Baskin and Baskin, 2016. Origins and relationships of the mixed mesophytic forest of Oregon-Idaho, China, and Kentucky: Review and synthesis: Annals of the Missouri Botanical Gardens, v. 101, p. 525-552.

What’s it about?

Modern forests of North America and Asia are remarkably similar in the species of trees present, but there is no obvious connection between the two. This paper discusses the lead hypotheses to explain the similaritiesContinue reading “Appearance and Spread of Modern Forests in Asia and North America – #365papers – 2017 – 72”

Conservation in Beer: Barley, Hops, and Finished Beer – #365papers – 2017 – 71

#365papers for March 12, 2017

Jerumanis, 1985, Quantitative analysis of flavanoids in barley, hops, and beer by high-performance liquid chromatography (HPLC): Journal of the Institute of Brewing, v. 91, p. 250-252.

What’s it about?

This paper takes a liquid chromatographic approach to determining where compounds important to the success of beer come from. Polyphenols (including flavanoids) can contribute to haze, coloration, and taste in beer. The authors describe methods to extract the polyphenols and analyze them.

This is just a methods paper, so they really don’t draw conclusions from the analyses that they did. Should such a paper be published today, there would have to be an important research question associated with it. Science has changed in the last 30 years…Continue reading “Conservation in Beer: Barley, Hops, and Finished Beer – #365papers – 2017 – 71”

What Makes Aroma Hops So Fragrant? – #365papers – 2017 – 70

#365papers for March 11, 2017

Nance and Setzer, 2011, Volatile components of aroma hops (Humulus lupulus L.) commonly used in beer brewing: Journal of Brewing and Distilling, v. 2, p. 16-22.

What’s it about?

The authors use gas chromatography – mass spectrometry (GCMS) to determine what makes the aromatic nature of different varieties of hops so distinct. They use the similarities and differences to show which hop varieties are more closely related to each other.Continue reading “What Makes Aroma Hops So Fragrant? – #365papers – 2017 – 70”