Sea turtle migration Studies of loggerhead and leatherback hatchlings have shown that moonlight reflected from the sea is an important visual cue in guiding movement from the beach to the sea. This navigational mechanism becomes a handicap if nesting sites are affected by artificial lighting since this can mean that hatchlings head towards the artificial lights rather than offshore towards the moonlit sea. Hence, the use of moonlight by turtle hatchings as a navigational cue can be considered an 'evolutionary trap'. Loggerhead and green turtles can detect the orbital movement of waves and use this information to swim perpendicular to the waves crests.
Varieties of Chinese their own standard languages. In China, however, Literary Chinese maintained its monopoly on formal writing until the start of the 20th century. The logographic writing, read with varying local pronunciations, continued to serve as a source of vocabulary and idioms for the local varieties. The new national standard, Vernacular Chinese, the written counterpart of spoken Standard Chinese, is also used as a literary form by speakers of all varieties. Dialectologist Jerry Norman estimated that there are hundreds of mutually unintelligible varieties of Chinese. These varieties form a dialect continuum, in which differences in speech generally become more pronounced as distances