Emma Morano is an Italian supercentenarian who is, at the age of 116 years, 169 days, the world's oldest living person, and the last verified living person to have been born in the 1800s. Born on Nov. 29, 1899, Morano is believed to be the last person living born in the 19th century.
Depending on their size, barrier reefs and atolls can take from 100,000 to 30,000,000 years to fully form. As coral reefs grow, they establish characteristic biogeographic patterns. Click the image for a larger view. All three reef typesfringing, barrier and atollshare similarities in their biogeographic profiles.s the corals grow and expand, reefs take on one of three major characteristic structures fringing, barrier or atoll. Fringing reefs, which are the most common, project seaward directly from the shore, forming borders along the shoreline and surrounding islands.
Reef-building corals are restricted in their geographic distribution by their physiology. For instance, reef-building corals cannot tolerate water temperatures below 18 0 Celsius (C). Many grow optimally in water temperatures between 23 0 and 29 0 C, but some can tolerate temperatures as high as 40 0 C for short periods.