Erin Ross Nov 28
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Indus Valley civilization may have arisen without a river

Kalibangan is sited on the topographically higher margins of the palaeochannel. Credit: S. Gupta (Imperial College London)

History texts teach that the Indus Valley society, one of the earliest known human civilizations, arose along the banks of the Sutlej River. But a new study published in Nature Communications suggests the river may have shifted away from the area 3,000 years before humans built their cities, writes Jonathan Amos at the BBC.

What's different: Other ancient civilizations, like Egypt and Mesopotamia, were built and flourished along rivers with consistent water. The authors of this study believe that in contrast, the Indus Valley civilizations depended on seasonal floods from monsoon rains.

What's there: The Indus Valley archaeological sites include Mohenjo-daro and Harappa. Although the sites were discovered later, the civilization appears to have been larger and more widespread than contemporary societies in Mesopotamia and Egypt scattered along and throughout what appears to be a massive, ancient riverbed.

What they did: The researchers used satellite imagery to map the course of the Sutlej River through time, and determined that the Sutlej indeed formed the riverbed the civilization flourished along. However, when they dated the sediments in the channel left by the river, they found it hadn't run through that region for over 8,000 years.

A benefit? It's possible the absence of the river helped the fledgling civilization. "Some of their sites were actually built in the palaeo-channel itself and that makes no sense if there was a big raging Himalayan river there at the time because these people would have been wiped out" by devastating, seasonal floods, study author Rajiv Sinha told the BBC.

Not so fast: Rita Wright, an anthropologist who was not involved in the study, tells the BBC that it's important to keep in mind that the Indus civilization was large and sprawling, and this only examines one region of it.

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Early humans innovated tools earlier than thought

Archaeologist Rick Potts squats in the Olorgesailie Basin in Kenya with various surprisingly sophisticated tools found from 320,000 years ago.
Richard Potts surveys assortment of Early Stone Age handaxes discovered in the Olorgesailie Basin, Kenya. Photo: Human Origins Program, Smithsonian

Unpredictable climate and natural disasters like earthquakes may have spurred early humans to create innovative tools and ways to communicate earlier than previously thought, according to 3 studies published Thursday in Science.

What they found: Evidence that around 320,000 years ago — near the start of the Middle Stone Age (MSA) and tens of thousands of years earlier than previous evidence has shown — early humans in East Africa may have created projectile hunting tools, developed ways to communicate using colors for mapping or identification purposes, and traveled longer distances to trade, hunt or obtain valuable materials.

"It's not just humans changing but really the entire ecosystem. It's a picture that's bigger than just the human ancestors themselves."
— Smithsonian's Richard Potts, who spearheaded the studies
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Yejin Choi: Trying to give AI some common sense

A photo of Yejin Choi from the University of Washington and the Allen Institute for Artificial Intelligence.
Photo illustration: Axios Visuals

Artificial intelligence researchers have tried unsuccessfully for decades to give machines the common sense needed to converse with humans and seamlessly navigate our always-changing world. Last month, Paul Allen announced he is investing another $125 million into his Allen Institute for Artificial Intelligence (AI2) in a renewed effort to solve one of the field's grand challenges.

Axios spoke with Yejin Choi, an AI researcher from the University of Washington and AI2 who studies how machines process and generate language. She talked about how they're defining common sense, their approach to the problem and how it's connected to bias.