Mollusc

An anatomical diagram of a hypothetical ancestral mollusc. Whether or not such a creature ever existed is a subject of debate among evolutionary biologists, but the construct or bauplan depicted here includes most of the physical attributes likely present in some form of shared molluscan ancestor, including a nervous system which ishypoathroid, an unsegmented, bilaterally symmetrical body, a single domed shell, and with organs occurring either singly or in pairs (i.e., with no metamerism).

Biologists began drawing bauplans of molluscs in the late 19th century in an attempt to summarize the common features of the molluscan phylum. As pictures, however, these illustrations sometimes may actually serve to constrain theoretical understanding rather than aid it, especially given the absence of any specific fossil evidence of such a creature having existed. Nevertheless, depictions continue to be made and revised: organs become rearranged, emphases shift and settle, and the pictures themselves become a subject of analysis (or meta-analysis) quite apart from their completeness or accuracy as scientific works.

White-necked petrel

The white-necked petrel(Pterodroma cervicalis) is aseabird in the familyProcellariidae; adults measure some 43 centimetres (17 in) in length, with a wingspan of 95–105 centimetres (37–41 in). Although the species is found in much of the South Pacific, it breeds on only three islands and is thus considered vulnerable by theIUCN.

Inupiat

A family portrait of an Inupiat mother, father, and son, photographed in Noatak, Alaska, by Edward S. Curtis circa 1929. The Inupiat are an Alaska Native people whose traditional territory spans from the Norton Sound on the Bering Sea to the Canadian border. At the time this picture was taken, most were living in coastal areas, having migrated there during a period of starvation and an influenza epidemic.

CCockroach

The bush cockroach (Ellipsidion australe) is a cockroach of the order Blattodea, of which about 30 species out of 4,600 total are associated with human habitats. Living in a wide range of environments around the world, cockroaches are among the hardiest insects, capable of remaining active for a month without food and able to survive on limited resources.

Gassed

Gassed is a 231 × 611 cm (7.6 × 20 ft) oil painting completed in March 1919 by John Singer Sargent. Painted after Sargent visited the Western Front on a commission by the British War Memorials Committee, it depicts the aftermath of a mustard gas attack during the First World War, with a line of wounded soldiers walking towards a dressing station. The painting, voted picture of the year by the Royal Academy of Arts in 1919, is now held by the Imperial War Museum.

Carina Nebula

The Carina Nebula is a large bright nebula that has within its boundaries several relatedopen clusters of stars. Discovered by Nicolas Louis de Lacaille in 1751–52, it is only visible from the Southern Hemisphere. Located an estimated 6,500 to 10,000 light yearsfrom Earth, it is one of the largest diffuse nebulae in the planet's skies and home to such stars as Eta Carinae and HD 93129A.

Slender Mongoose

The slender mongoose (Galerella sanguinea) is a common species ofmongoose found throughout much of sub-Saharan Africa. Dozens of subspecies are known, and the fur color varies between subspecies. The slender mongoose tends to live alone or in pairs, and, although it is an opportunistic omnivore, it feeds primarily on insects.

This specimen was photographed at thePrague Zoo in the Czech Republic.

Point Pinos Lighthouse

Point Pinos Lighthouse is a lighthouse located in Pacific Grove, California. Lit in 1855, it is the oldest continuously operating lighthouse on the West Coast of the United States, and was added to the National Register of Historic Places in 1977.

Neutral density filter

A neutral density filter is a filter that reduces or modifies the intensity of all wavelengths or colors of light equally, giving no changes in hue of color rendition. The filter reduces the amount of light entering the lens, allowing the photographer to select combinations of aperture, exposure time and sensor sensitivity to avoid overexposed pictures. It would normally be attached to the lens, but is hand-held here to illustrate the effect.

Mount John Laurie

Mount John Laurie is a mountain found in Alberta, Canada. Part of the Canadian Rockies, it is a popular rock climbing destination.