Tag Archives: Evolution
Crabs have evolved five separate times—why do the same forms keep appearing in nature?
Charles Darwin believed evolution created “endless forms most beautiful.” It’s a nice sentiment but it doesn’t explain why evolution keeps making crabs. Crabs belong to a group of crustaceans called decapods, literally “ten footed”, since they have five pairs of walking legs. Some decapods, like lobsters and shrimp, have a thick, muscular abdomen, which is the bulk of the animal that we eat. With a quick flick of their abdomen lobsters can shoot off backwards and escape predators. Crabs, by contrast, have a compressed abdomen, tucked away under a flattened but widened thorax and shell. This allows them to scuttle into rock crevices for protection. Evolution repeatedly hit upon this solution because it works well under similar sets of circumstances. Five groups of “crabs”,,, >click to read< 14:10
Land & Sea: Wooden vs. Steel Longliners – Take a trip back in time with an archival episode from 1980
This 1980 episode of Land & Sea opens with the scene of a champagne bottle exploding on the bow of a new longliner. The show explores the tension surrounding wooden and steel-hulled longliners at a time when boatbuilding design was evolving to match new fishing technology. Owner Charles Hussey of Port de Grave isn’t bothered by the $500,000 price tag for his new, wooden, 17-metre vessel, the Eastern Harvester, built in Arthur Petten’s boat yard in South River.,,, The Land & Sea crew went south in this episode to Bayou la Batre, the headquarters for steel-hulled boat building. Video, click here to read the story 20:31
An Evolutionary Family Drama
Alewives are anadromous fish: Born in freshwater, they spend their lives in the ocean, returning annually to their birthplaces to spawn. Until colonial-era dams cut off their migration,,, Read more here NYT 08:05
