Human evolution hasn't stopped: traits that help people survive and reproduce spread through populations over generations. Most adults once could not digest milk, but after people began herding cattle and goats, a gene allowing milk digestion spread until most adults could drink it. Skin pigment is shaped by sunlight, with darker skin protecting against strong ultraviolet rays in sunny regions, while lighter skin helps make vitamin D in cloudy places. After the 14th-century bubonic plague, which killed about a third of Europe's population, survivors with a resistance gene had better odds in later epidemics. Other examples include the Turkana people's ability to go long periods with little water.

Israeli reports also say the cabinet directed the military to prepare for a possible new attack on Iran.

Angkor, near Siem Reap in northern Cambodia, was the capital of the Khmer Empire, which ruled much of mainland Southeast Asia between roughly the 9th and 15th centuries. At its height the city spread across about 3,000 square kilometres, making it the largest pre-industrial city on Earth by area. Its growth depended on water: huge reservoirs called barays, along with canals and embankments, stored monsoon rain and carried it to rice fields. That system let farmers harvest more than once a year and fed a very large population through the dry season. The temple complex of Angkor Wat, built in the early 12th century, is the best-known monument and still stands at the heart of the park.