Using the power of artificial intelligence (AI), scientists have revealed new insights into the creation and destruction of mass extinction. Contrary to conventional knowledge, their study suggests that larger extinctions are not always a form of “creative destruction” that allows new organisms (生物体) to radiate and evolve. Instead, it suggests that mass extinction is rarely associated with new species of radiation.

Dr. Hoyal Cuthill, the lead study author from the University of Essex in the UK and the Tokyo Institute of Technology, said in a statement, “Some of the most challenging things to understand the history of life are the vast timelines involved and the number of species. New machine learning applications can help us understand this information in human-readable form. This means that we can, so to speak, hold the evolution of half a billion years in the palm of our hand and gain new insights from what we see.”

They concluded that mass extinction and later radiation were not connected as previously thought. Within 5 percent of the most significant periods of disruption (中断), AI detected “big five” mass extinctions, seven more mass extinctions, two mass extinction-radiation events, and 15 mass radiations. Most importantly, it discovers that massive radiation and extinction rarely occurred with each other, changing the view that greater extinction leads to a kind of deep cycle-like species radiation of nature. It appears that larger extinctions are certainly not the engine of evolutionary radiation. Take the Cambrian eruption for example and it was about 41 million years ago when a large group of animals first appeared on the record of the first fossil record and the dawn of a high mobile animal equipped with modern physical features.

This new study found that a handful of other notable explosions of biodiversity, including the Cambrian eruption, usually occurred at a time when they were largely isolated (隔离) from extinction. Dr. Nicholas Guttenberg, a study co-author from the Tokyo Institute of Technology explained, “Ecosystems are dynamic and you don’t need anything to exist to allow something new to appear.”

Teotihuacan was once one of the world's most important cities, but many things about it are still unknown today. How did the people live , and why did they abandon（放弃）their city? For years, answers to some of those questions have been buried in the Pyramid of the Moon. Now, findings in this ancient structure are helping archeologists learn more about Teotiuacan's people and their culture.

Until recently many experts thought Teotihuacan was a peaceful society mostly ruled by gentle and wise leaders. But recent findings in the Pyramid of the Moon show something else. Archeologists discovered a number of headless bodies. Most were foreigners, and other objects of power. Clearly the people and objects found inside the pyramid were offerings.

However, the findings in the pyramid are difficult to interpret. "These findings are like sentences." says archeologist Leonardo Lopez Lujan," but we don't have all the words… so they're hard to read." Despite these problems, several archeologists have concluded this; Teotihuacan was not a society governed by peaceful rulers. " In reality, officials used human sacrifice（祭品）says archeologist Saburo Sugiyama," to control the people. "The city probably also had a powerful army.

Who were the city leaders? Scientists don't know. They have not found a king buried in the pyramid or any status of Teotihuacan's rulers. But archeologists continue to search for them. They hope to learn more about the pyramid's creators and one of the world's most powerful ancient cities.

Have a hard time waking up when it’s cold out? Scientists say your brain is to blame. A study conducted by scientists from Northwestern University made it possible to offer some explanations for this phenomenon.

Their study on fruit flies shows how seasonally cold and dark conditions can prohibit neurons within the fly brain that promote activity and wakefulness from sending out signals, particularly in the morning. It helps explains why, for both flies and humans, it is so hard to wake up in the morning in winter.

“By studying behaviors in a fruit fly, we can better understand how and why temperature is so vital to regulate sleep,” said Marco Gallio, associate professor of neurobiology in the Weinberg College of Arts and Sciences.

The study describes for the first time “absolute cold” receptors in the fly antenna, which respond to temperature only below the fly’s “comfort zone” of about 25°C. Having recognized those neurons, the researchers followed them all the way to their targets within the brain. They found their targets are a small group of brain neurons that are part of a larger network that controls rhythms of activity and sleep. When the neurons they discovered are active, the target cells, which normally are made active by morning light, are shut down.

“Temperature sensing is one of the most fundamental abilities,” said Gallio, whose group is one of only a few in the world that are systematically studying temperature sensing in fruit flies. “The principles we are finding in the fly brain, the logic and organization, may be the same all the way to humans. And future studies on human brain will surely find some reference information in this study.”