When Two Species Merge into One – #365papers – 2018 – 60

Kearns, Restani, Szabo, Schoder-Nielsen, Kim, Richardson, Marzluff, Fleisher, Johnsen, and Omland, 2018, Genomic evidence of speciation reversals in ravens: Nature Communications, v. 9, 906

What’s it about?

The authors describe how what were once two distinct lineages of ravens (the Californian and the holarctic) have merged into what we now refer to as the common raven in the western United States. Using evidence from mitochondrial DNA, the authors show that not only is the common raven the result of the fusion of two lineages, but that the Chihuahuan raven, that lives alongside the common raven, is a descendant of the Californian raven. Continue reading

Clay Keeps Records of Ancient Water – #365papers – 2018 – 56

Mix and Chamberlain, 2014, Stable isotope records of hydrologic change and paleotemperature from smectite in Cenozoic western North America: Geochimica et Cosmochimica Acta, v. 141, p. 532-546

What’s it about?

Smectite is a specific kind of clay mineral, common in volcanic ash. This kind of clay incorporates water during its formation, which, as the authors show, can provide a record of what surface water was like when the clay formed. Continue reading

Where, Oh Where Do the Ganglia Go (in Lampreys) – #365papers – 2018 – 50

Modrell, Hockman, Uy, Buckley, Sauka-Spengler, Bronner, and Baker, 2014, A fate-map for cranial sensory ganglia in the sea lamprey: Developmental Biology, v. 385, p. 405-416

What’s it about?

Fate-maps show where tissues in an embryo wind up in the adult. It is truly remarkable how cells move around in embryos. I mean, seriously.

In this case, the authors are tracing sensory ganglia, in particular, to branches of the trigeminal nerve: the ophthalmic (or profundal) and the maxillomandibular, which provide sensory functions to parts of the lips and mouth. Continue reading

Squids, and Octopodes, and Nautiluses, Oh My! – #365papers – 2018 – 49

Sanchez, Setiamarga, Tuanapaya, Tongtherm, Winkelmann, Schmidbaur, Umino, Albertin, Allcock, Perales-Raya, Gleadall, Strugnell, Smiakov, and Nabhitabhata, 2018, Genus-level phylogeny of cephalopods using molecular markers: current status and problematic areas: PeerJ v. 6, e4331

What’s it about?

Using DNA sequences, the authors sort out the evolutionary relationships among squids, octopuses, nautiluses, and cuttlefish. Continue reading

We Know Sea Level Rise is Getting Faster – #365papers – 2018 – 48

Nerem, Beckley, Fasullo, Hamlington, Masters, and Mitchum, 2018, Climate-change-driven accelerated sea-level rise detected in the altimeter era: Proceedings of the National Academy of Sciences

What’s it about?

Sea level is rising. In fact, it’s rising faster and faster. Using satellite data, the authors show that this is the case, even when variations from volcanic events and ‘ordinary’ ocean shifts (like El Nino) are taken into account. Continue reading

Waves of Extinction Add Up – #365papers – 2018 – 47

Wang and Zhong, 2018, Estimating the number of pulses in a mass extinction: Paleobiology, 1-20

What’s it about?

The problem with the rock record is that it is incomplete. This means that what was really a gradual extinction could look abrupt, or that a large-scale mass extinction can look like it was spread out. The authors of this paper present a method by which it is possible to determine how many pulses or waves of extinction added up to what we consider a mass extinction. Continue reading

Did the Chixulub Impact Make the Oceans Erupt More? – #365papers – 2018 – 43

Byrnes and Karlstrom, 2018, Anomalous K-Pg-aged seafloor attributed to impact-induced mid-ocean ridge magmatism: Science Advances, v. 4: eaao2994

What’s it about?

The Chixulub Impact is the event linked to the extinction of the dinosaurs. The authors here show that at the same time as the impact, ocean floor spreading increased for just a little while. They hypothesize that the seismic waves caused by the impact resulted in the mobilization of molten rock, leading to this increase in volcanic activity. Continue reading

What Happens When a Cat Jumps on Your Keyboard While You’re Composing a Blog Post? – #UREES270 – #365papers- 2018

Leslie, 2014, Impacts of phylogenetic nomenclature on the efficacy of the U.S. Endangered Species Act: Conservation Biology, v. 29, p. 69-77

What’s it about?

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I read this paper last year!

 

Defining and Distinguishing Species of Organisms – #365papers – 2018 – 40

de Queiroz, 2007, Species concepts and species delimitations: Systematic Biology, v. 56, 879-886.

What’s it about?

Species is a difficult concept in biology, even if it seems straightforward. The author of this paper shows that it really is as simple as it seems, but the means of distinguishing one species from another. The problem isn’t in the definition of species but in the distinction among species. Continue reading