“Ebbett's Pass” or “Ebbetts Pass?”

The Ebbett's Pass Trailhead is a gateway for hikers and horseback riders to the Pacific Crest Trail, connecting with scenic lakes as well as ancient volcanic peaks and rock formations on both sides of the Pacific Crest, including the Carson Iceberg Wilderness. The well-posted sign along California State Highway 4 in Alpine County, California, directs visitors to this trailhead and clearly says “Ebbett's Pass” (see picture). A historical landmark board uses the same writing and explains that this pass is named after Major John Ebbett, who, in 1853, suggested this location to surveyor George H. Goddard as a promising route for the Transcontinental Railroad [1].

Referring to the family name Ebbett, “Ebbett's Pass” is a correctly written possessive phrase. But why do we find the form “Ebbetts Pass” in so many documents?

Apparently, authors didn't simply got tired of including the possessive-indicating apostrophe. Instead, they refer to “Captain” John Ebbetts [2]:

It wasn't until 1850 when John Ebbetts—Captain of the Knickerbocker Exploring Party of New York—crossed this pass with a large train of mules, guiding a party of miners into the then gold-frenzied California.

A few years later, John Ebbett, let's call him John Ebbetts from now on, led a survey party for the Atlantic and Pacific Railroad Company to this high mountain pass in search of a possible route for the Transcontinental Railroad. His friend and lead surveyor George H. Goddard eventually named the pass Ebbetts Pass in honor of the “Knickerbocker pioneer” [2,3].

Referring to the surname Ebbetts, the genitive case seems to be dismissed: I haven't seen the writing “Ebbetts' Pass” or, worse, “Ebbetts's Pass.”

Keywords: grammar, spelling, writing, name places, history.

References and more to explore
[1] Wikipedia: Historical Landmark: Ebbett's Pass.JPG [http://en.wikipedia.org/wiki/File:R39287918565_Sign_-_Historical_Landmark%EF%BC%9A_Ebbett%27s_Pass.JPG].
[2] Sierra Nevada Geotourism MapGuide: Ebbetts Pass National Byway [www.sierranevadageotourism.org/content_detail.php?uid=sie6DA429BAE628F80E3].
[3] Judith Marvin: Ebbetts Pass History [www.calaverashistory.org/overview/ebbetts-pass-history].

A term in biology: constructive neutral evolution

The rise and evolution of novel, complex structures and operations in biological organisms is typically explained by processes involving random mutations followed by natural selection: complexity is emerging from environmentally driven, essentially non-random processes discovered by Charles Darwin and illustrated, for example, by Richard Dawkins in his book The Blind Watchmaker [1].

But is evolution completely directed by natural selection or do non-Darwinian factors (non-selective factors: chance, neutral changes, bio-molecular side effects) play a significant role? Currently, the possibility of constructive neutral evolution (CNE) is discussed [2-5]. The CNE idea opens additional routes in biological inquiry that allow the development of neutral models, which can anchor molecular-evolution studies—designed to explain complexity as well as biodiversity—on grounds free of a priori adaptionist explanations. The scheme of CNE will supplement or may revolutionize our understanding of the origin, direction and meaning of life. 

Carl Zimmer instructively put the origin of the term “constructive neutral evolution” into context [4]:

In the 1990s a group of Canadian biologists started to ponder the fact that mutations often have no effect on an organism at all. These mutations are, in the jargon of evolutionary biology, neutral. The scientists, including Michael Gray of Dalhousie University in Halifax, proposed that the mutations could give rise to complex structures without going through a series of intermediates that are each selected for their help in adapting an organism to its environment. They dubbed this process “constructive neutral evolution.”

Keywords: life science, evolutionary theory, neutral theory, neo-Darwinian thinking, evolutionary genetics, bio-molecular complexity.

References and more to explore
[1] R. Dawkins: The Blind Watchmaker. Penguin Books, London, England, reprinted (from the 1986 Longman publication) with an appendix 1991.
[2] A. Stoltzfus: On the possibility of constructive neutral evolution. J. Mol. Evol. August 1999, 49 (2), pp. 169-181 [www.ncbi.nlm.nih.gov/pubmed/10441669].
[3] A. Stoltzfus: Constructive neutral evolutionary theory: exploring evolutionary theory's curious disconnect. Biology Direct 2012, 7:35. doi: 10.1186/1745-6150-7-35. 
[4] C. Zimmer: The surprising origins of life's complexity. Sci. Am. August 2013, 309 (2), pp. 84-89 [www.scientificamerican.com/article.cfm?id=the-surprising-origins-of-evolutionary-complexity].
[5] Entropic Existence: Selection, Neutrality, and the Appearance of Design. April 23, 2010 [entropicexistence.blogspot.com/2010/04/selection-neutrality-and-appearance-of.html].

Talus, meaning “rock debris” or “slope of rock debris”

The word talus refers to rock debris at the base of a cliff, crag or valley shoulder. This word may also specify a slope covered with such rock debris [1,2]. In the latter case, one often speaks of a talus slope. A good example are the talus slopes below the south-facing cliffs of Castle Peak in the Sierra Nevada northwest of Truckee, California. The picture above shows Castle Peak seen from nearby Andesite Peak: concave talus slopes are skirting the cliffs keeping vegetation away from the upper mountain belt. The lower, less steep areas have some single conifers (survivors of rock slides). The forest begins where the slopes turn into a saddle and plateau topography, on the surface of which the impact of rolling rocks is becoming less powerful.   

Talus is created by weathering and fracturing of granite and other types of rock. Talus accumulates through periodic rockfall. F. J. Smiley, in 1915, briefly described the degrading process of Sierran mountain walls—while studying the Lake Tahoe region—and pointed out “the immense heaps of angular talus, which skirts the bases of Mt. Tallac, Maggie's Peaks and Castle Peak” [3]. 

A talus slope is always ready for a slide—triggered by an earthquake, an animal or a reckless mountaineer. Needless to say that a talus slope is dangerous terrain to walk across or to climb up or down on.

In addition to its meaning in topography and geology, the word talus means ankle or ankle bone in anatomy [1,2]. How the word and its meanings derived, is not completely clear. Old French, Latin or Celtic origins are typically mentioned. The plural form of talus is tali. Another word for talus is scree, probably from Old Norse skridha, meaning landslide [4].

Keywords: geology, etymology, synonyms.

References
[1] Merriam-Webster: talus [www.merriam-webster.com/dictionary/talus].
[2] The Free Dictionary: talus [www.thefreedictionary.com/talus]. 
[3] F. J. Smiley: The Alpine and Subalpine Vegetation of the Lake Tahoe Region. Botanical Gazette April 1915, 59 (4), pp. 265-286 [www.jstor.org/stable/2468057].
[4] The Free Dictionary: scree [www.thefreedictionary.com/scree].

Acronym in scent detection and civil security: EDC for explosive detection canine

Explosive-sniffing dogs are trained and employed to detect hidden reactive substances with a destructive potential. Such dogs are called bomb dogs,  or—more formal—explosive detection canines (EDCs) [1,2]. They are becoming best friends of security officials and safety personal who are in charge of protecting public places and controlling conflict zones.

EDCs do not smell bombs. But they can be trained to be highly alert to the ingredients of explosive materials. At the MSA Security Training Academy, for example, odors of chemical vapors are imprinted on the olfactory cortex of the dog's brains—Pavlov-style by task repetition and reward [2]:

MSA's dogs begin building their vocabulary of suspicious odors working with rows of more than 100 identical cans laid out in a grid. Ingredients from the basic chemical families of explosives—such as powders, commercial dynamite, TNT, water gel and RDX, a component of the plastic explosives C4 and Semtex—are placed in random cans. In addition, urea nitrate and hydrogen peroxide—primary components of improvised explosive devices—have joined the training regime.

EDCs learn not to scratch a potentially threatening material or device (avoiding a possible blow-up), but to respond by just sitting down when they sense one. Today, EDCs at airports, train stations, stadiums, fairs and banks are not even noticed by travelers and visitors; and if, they are greated with a friendly look or smile. The simple presents of EDCs hopefully keeps people safe and threats away. 

Keywords: threat protection, chemistry, sensory system, dog's nose, Canis lupus.

References and more to explore
[1] MSA Security: Bomb Dogs [www.msasecurity.net/bomb-dogs/].
[2] Joshua Levine: The education of a bomb dog. Smithsonian July-August 2013, 44 (4), pp. 72-78 [http://www.smithsonianmag.com/ideas-innovations/The-Education-of-a-Bomb-Dog-213881241.html#Bomb-Dogs-explosive-detection-canine-training-1.jpg].