Mar 15, 2018

Axios Science

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Evidence of complex behavior in early humans

Richard Potts surveys assortment of Early Stone Age handaxes discovered in the Olorgesailie Basin, Kenya. Photo: Human Origins Program, Smithsonian

Eileen Drage O'Reilly writes: 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 three 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

The big picture: Potts and his colleagues published three studies — on environmental dynamics, transition chronology, and stone transport and pigment use. He says the studies represent what likely happened in and near Kenya's Olorgesailie basin, where he's studied for 34 years.

Read the full story here.

Yejin Choi: AI needs some common sense

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's 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.

I 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.

"We have a world model in our mind when we do daily operations. AI systems today, despite tremendous advancement in recent years, they are not very good at generalizing out of pure example, so they tend to be very, very task specific, and very domain specific."
"We're taking a similar approach. It may be possible that we can learn to answer these sort of questions, even including those that we've never seen before. That's fundamentally the ability that AI systems needs to have — dealing with unknowns and previously unseen situations."

Read the rest of the interview here.

Axios Science stories
  • Supervolcano: Some researchers think the massive Toba eruption 74,000 years ago killed a large number of ancient people and shrank the human gene pool but at least one group may have "thrived" despite the event, Eileen reports.
  • Coral reefs: In a first-of-its-kind experiment, scientists simulated ocean water acidification due to carbon dioxide emissions on a patch of the southern Great Barrier Reef and found a lower pH decreased the growth of coral by one-third.
  • The AI race: China's approach to AI research is bold, but not to the degree of the U.S. and Canada, Steve LeVine writes. This is evident in its apparent unwillingness to start over or change direction, an inflexibility that may keep the country from ever catching up.
1 cool thing

A microCT scan of a skate (Leucoraja erinacea) embryo. Credit: Katharine Criswell/University of Cambridge

About 500 million years ago, the first animals with a notochord — the foundation of a backbone — emerged on Earth. Today, the string of bone or cartilage that makes a vertebrate a vertebrate takes many shapes.

Researchers like Katharine Criswell, a postdoctoral fellow at the University of Cambridge, look at how different species build this fundamental feature as a window into our deep evolutionary past. She takes CT scans of skate (Leucoraja erinacea) embryos like the one above to study the origin and migration of cells that form the backbone.

What you're looking at: Imagine you're nose to tail with a skate embryo, moving through its body from back to front. The black hole near the top of the image is the notochord, above it the spinal cord and the gray area around both is the developing vertebra. That mesmerizing spiral is the stomach and intestine.

The image is a finalist in the Euro-BioImaging Image Competition.

What we're reading elsewhere
"[I]t’s because Hawking’s discovery that the very building blocks of that world, of everything we see around us, of us, are not ultimately real has forced us to ask, well, what is? The truth is, no one knows. The search for reality continues, but it was Hawking who blazed the trail."
Something wondrous

Giant kelp or Macrocystis pyrifera near San Benito Island, Mexico. Photo: Reinhard Dirscherl/ullstein bild via Getty Images

Along the coasts of California, Maine, Mexico and elsewhere, giant kelp forests stretch from the seafloor to the surface, offering food and refuge to fish, invertebrates, otters and other animals. After marveling at kelp (Macrocystis pyrifera) from the H.M.S. Beagle, Charles Darwin wrote, "The number of living creatures of all Orders, whose existence intimately depends on the kelp, is wonderful."

"We’re not talking about some piddly esoteric species. We’re talking about one of the most important species in the ocean."
— Michael Graham, Moss Landing Marine Laboratories

Understanding exactly how kelp supports biodiversity could inform how it's harvested as well as efforts to restore these ecosystems, which are home to California's spiny lobster fishery — one of the highest grossing in the state.

When a floating kelp canopy breaks down, it rains detritus that feeds inhabitants on the reef below. But in a new study of a kelp forest off the coast of Santa Barbara, researchers suggest kelp's main contribution to the diversity of fauna in the ecosystem isn't nutrients but shade from the seaweed's physical structure.

"Our results go against some of the conventional wisdom on kelp," says study author Robert Miller from the University of California, Santa Barbara. He and his colleagues studied 10 years of data collected in the giant kelp forest there and report that shade from the seaweed keeps algae from flourishing. This then allows sponges, sea squirts and other sessile species that compete with algae to coexist.

Yes, but: Kelp forests are complex and it's difficult to disentangle the species' food contributions from its physical structure, says Graham, who wasn't involved in the work. One way to test it could be to put out fake kelp with the same structure and see if there's a similar result. And, it's unknown whether the results apply to other forests — with different species that feed directly on kelp — and when accounting for the tiniest of kelp particles that feed mussels and barnacles, he says.