Why people and parrots know how to dance

Ed Yong writes:

Before he became an internet sensation, before he made scientists reconsider the nature of dancing, before the children’s book and the Taco Bell commercial, Snowball was just a young parrot, looking for a home.

His owner had realized that he couldn’t care for the sulfur-crested cockatoo any longer. So in August 2007, he dropped Snowball off at the Bird Lovers Only rescue center in Dyer, Indiana—along with a Backstreet Boys CD, and a tip that the bird loved to dance. Sure enough, when the center’s director, Irena Schulz, played “Everybody,” Snowball “immediately broke out into his headbanging, bad-boy dance,” she recalls. She took a grainy video, uploaded it to YouTube, and sent a link to some bird-enthusiast friends. Within a month, Snowball became a celebrity. When a Tonight Show producer called to arrange an interview, Schulz thought it was a prank.

Among the video’s 6.2 million viewers was Aniruddh Patel, and he was was blown away. Patel, a neuroscientist, had recently published a paper asking why dancing—a near-universal trait among human cultures—was seemingly absent in other animals. Some species jump excitedly to music, but not in time. Some can be trained to perform dancelike actions, as in canine freestyle, but don’t do so naturally. Some birds make fancy courtship “dances,” but “they’re not listening to another bird laying down a complex beat,” says Patel, who is now at Tufts University. True dancing is spontaneous rhythmic movement to external music. Our closest companions, dogs and cats, don’t do that. Neither do our closest relatives, monkeys and other primates.

Patel reasoned that dancing requires strong connections between brain regions involved in hearing and movement, and that such mental hardware would only exist in vocal learners—animals that can imitate the sounds they hear. That elite club excludes dogs, cats, and other primates, but includes elephants, dolphins, songbirds, and parrots. “When someone sent me a video of Snowball, I was primed to jump on it,” Patel says. [Continue reading…]

Why did octopuses become so smart?

Ed Yong writes:

A small shark spots its prey—a meaty, seemingly defenseless octopus. The shark ambushes, and then, in one of the most astonishing sequences in the series Blue Planet II, the octopus escapes. First, it shoves one of its arms into the predator’s vulnerable gills. Once released, it moves to protect itself—it grabs discarded seashells and swiftly arranges them into a defensive dome.

Thanks to acts like these, cephalopods—the group that includes octopuses, squid, and cuttlefish—have become renowned for their intelligence. Octopuses, for example, have been seen unscrewing jar lids to get at hidden food, carrying coconut shells to use as armor, barricading their den with stones, and squirting jets of water to deter predators or short out aquarium lights.

But why did they become intelligent in the first place? Why did this one group of mollusks, among an otherwise slow and dim-witted dynasty of snails, slugs, clams, oysters, and mussels, evolve into creatures that are famed for their big brains? These are hard questions to answer, especially because cephalopods aren’t just weirdly intelligent; they’re also very weird for intelligent animals. [Continue reading…]

The dancing species: How moving together in time helped make us human

By Kimerer LaMothe

Dancing is a human universal, but why? It is present in human cultures old and new; central to those with the longest continuous histories; evident in the earliest visual art on rock walls from France to South Africa to the Americas, and enfolded in the DNA of every infant who invents movements in joyful response to rhythm and song, long before she can walk, talk or think of herself as an ‘I’. Dancing remains a vital, generative practice around the globe into the present in urban neighbourhoods, on concert stages, as part of healing rituals and in political revolutions. Despite efforts waged by Christian European and American colonists across six continents over 500 years to eradicate indigenous dance traditions and to marginalise dancing within their own societies, dancing continues wherever humans reside. Any answer to the question of why humans dance must explain its ubiquity and tenacity. In so doing, any answer will challenge Western notions of human being that privilege mind over body as the seat of agency and identity. 

Current explanations for why humans dance tend to follow one of two approaches. The first, seen in psychological and some philosophical circles, begins with a human as an individual person who chooses to dance (or not) for entertainment, exercise, artistic expression or some other personal reason. Such approaches assume that dance is one activity among others offering benefits to an individual that may be desirable, but not necessary, for human well being. Alternatively, a raft of sociological and anthropological explanations focus on community, asserting that dancing is one of the first means by which the earliest humans solidified strong social bonds irrespective of blood lines. In these accounts, dancing is eventually replaced by more rational and effective means of social bonding that the dancing itself makes possible, such as language, morality and religion. While the first type of reasoning struggles to explain why so many humans choose to dance, the second struggles to explain why humans continue to dance. What is missing from these accounts?

What if humans are the primates whose capacity to dance (shared by some birds and mammals) was the signature strategy enabling the evolution of a distinctively large and interconnected brain, empathic heart and ecological adaptability? And what if dancing plays this role for humans not just in prehistoric times, but continuing into the present? What if humans are creatures who evolved to dance as the enabling condition of their own bodily becoming?

[Read more…]

Like humans, ravens mirror the distress they witness in others, study suggests

Katherine J. Wu reports:

Seeing someone else suffer a big disappointment can have a pretty damaging effect on your own morale. That’s definitely the case with people—and it might be true for ravens, too.

New research suggests that, like humans and many other mammals, common ravens (Corvus corax) can read and internalize the emotional states of others. In the study, published today in the journal PNAS, ravens watch their friends grapple with a frustrating task in which they’re denied a tasty treat. Though the onlookers aren’t deprived of anything, they then seem to mirror their partners’ discontent, and start behaving pessimistically themselves.

Unlike people, ravens can’t speak freely about their emotional distress. But these results hint at the tantalizing possibility that humans aren’t alone in their interconnectedness, and could provide early evidence of something akin to empathy in birds.

“This paper is a tremendous step forward in being able to understand the evolutionary roots of empathy,” says Kaeli Swift, an animal behaviorist and corvid expert at the University of Washington who was not involved in the study. “I think it would be too far to say that [this paper shows] ravens are empathetic…but this work could be foundational in eventually arriving at that conclusion.” [Continue reading…]

I’m an evolutionary biologist – here’s why this ancient fungal fossil discovery is so revealing

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Do fungi like this Penicillium mold, which produces the the antibiotic penicillin, trace their origins to an ancestor that lived a billion years ago?
Rattiya Thongdumhyu/Shutterstock.com

By Antonis Rokas, Vanderbilt University

Biologists don’t call them “the hidden kingdom” for nothing. With an estimated 5 million species, only a mere 100,000 fungi are known to scientists. This kingdom, which includes molds, yeasts, rusts and mushrooms, receives far less attention than plants or animals. This is particularly true for fossils of fungi, most of which are discovered while hunting for more charismatic, at least to the eyes of some, plant fossils.

Fungi were key partners of plants during their colonization of land approximately 500 million years ago – an important and well-documented evolutionary transition. Therefore, it is unsurprising that the earliest fungal fossils, found in 450 million-year-old rocks, resemble modern species associated with the roots of plants. But that conflicts with DNA-based estimates, which suggest that fungi originated much earlier – a billion or more years ago. It’s a riddle in the tree of life that evolutionary biologists like me have long been puzzled about.

Fossils versus DNA

For years scientists have tried to reconcile the fungal fossil record with estimates from analyses of fungal DNA. But some of their key morphological characters – that is, the shapes they take – can only be established via microscopic and chemical analyses. That includes the complex networks of microscopic thread-like filaments and cell walls made of chitin, which are also not visible to the naked eye. The effort seemed hopeless, until now.

Corentin Loron, a graduate student at the University of Liege in Belgium and colleagues, discovered microscopic, fossilized specimens of a fungus called Ourasphaira giraldae in shale rock from the Grassy Bay Formation in the Northwest Territories of Canada. Given that Ourasphaira is found on 1,000- to 900-million-year-old rocks, the new fossil pushes back the origin of fungi by half a billion years.

[Read more…]

A jawbone shows Denisovans lived on the Tibetan Plateau long before humans

Science News reports:

Denisovans reached what’s now called “the roof of the world” at least 160,000 years ago.

Found in a Tibetan Plateau cave, a partial lower jawbone represents a Denisovan who is the oldest known hominid to reach the region’s cloud-scraping heights, researchers report online May 1 in Nature.

The fossil suggests that these perplexing, extinct members of the human lineage weathered the plateau’s frigid, thin air long before humans did. Many researchers have assumed that, as far as hominids go, only Homo sapiens settled in that high-altitude, low-oxygen environment, probably no earlier than 40,000 years ago.

“It blows my mind that Denisovans lived on the Tibetan Plateau,” paleoanthropologist and study coauthor Jean-Jacques Hublin of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, said at an April 29 news conference.

Until now, Denisovans were known only from a handful of fossils unearthed in Siberia’s Denisova Cave, and from ancient DNA extracted from one of those bones. Researchers regard Denisovans, who inhabited Denisova Cave from around 300,000 to 50,000 years ago, as close relatives of Neandertals and possibly a distinct Homo species. [Continue reading…]

How culture works with evolution to produce human cognition

Cecilia Heyes writes:

The conventional view, inside and outside academia, is that children are ‘wired’ to imitate. We are ‘Homo imitans’, animals born with a burning desire to copy the actions of others. Imitation is ‘in our genes’. Birds build nests, cats miaow, pigs are greedy, while humans possess an instinct to imitate.

The idea that humans have cognitive instincts is a cornerstone of evolutionary psychology, pioneered by Leda Cosmides, John Tooby and Steven Pinker in the 1990s. ‘[O]ur modern skulls house a Stone Age mind,’ wrote Cosmides and Tooby in 1997. On this view, the cognitive processes or ‘organs of thought’ with which we tackle contemporary life have been shaped by genetic evolution to meet the needs of small, nomadic bands of people – people who devoted most of their energy to digging up plants and hunting animals. It’s unsurprising, then, that today our Stone Age instincts often deliver clumsy or distasteful solutions, but there’s not a whole lot we can do about it. We’re simply in thrall to our thinking genes.

This all seems plausible and intuitive, doesn’t it? The trouble is, the evidence behind it is dubious. In fact, if we look closely, it’s apparent that evolutionary psychology is due for an overhaul. Rather than hard-wired cognitive instincts, our heads are much more likely to be populated by cognitive gadgets, tinkered and toyed with over successive generations. Culture is responsible not just for the grist of the mind – what we do and make – but for fabricating its mills, the very way the mind works. [Continue reading…]

New species of ancient human discovered in the Philippines

 

Science magazine reports:

A strange new species may have joined the human family. Human fossils found in a cave on Luzon, the largest island in the Philippines, include tiny molars suggesting their owners were small; curved finger and toe bones hint that they climbed trees. Homo luzonensis, as the species has been christened, lived some 50,000 to 80,000 years ago, when the world hosted multiple archaic humans, including Neanderthals and Denisovans, and when H. sapiens may have been making its first forays into Southeast Asia.

“This is a truly sensational finding,” says Adam Brumm, an archaeologist at Griffith University in Nathan, Australia. The paper, published this week in Nature, “sent shivers down my spine.”

The discovery echoes that of another unusual ancient hominin—the diminutive H. floresiensis, or “hobbit,” found on the island of Flores in Indonesia. “One is interesting. Two is a pattern,” says Jeremy DeSilva, an expert on Homo foot bones at Dartmouth College. He and others suspect the islands of Southeast Asia may have been a cradle of diversity for ancient humans, and that H. luzonensis, like H. floresiensis, may have evolved small body size in isolation on an island. [Continue reading…]

Dueling dates for Deccan Traps volcanic eruption reignite debate over dinosaurs’ death

Science News reports:

Which came first: the impact or the eruptions? That question is at the heart of two new studies in the Feb. 22 Science seeking to answer one of the most hotly debated questions in Earth’s geologic history: Whether an asteroid impact or massive volcanism that altered the global climate was mostly to blame for the demise of all nonbird dinosaurs 66 million years ago.

The dinosaur die-off is the only known mass extinction that coincides with two cataclysmic events: an asteroid impact linked to the massive Chicxulub crater in Mexico, and a gigantic volcanic eruption, evidenced by kilometers-thick layers of hardened lava at India’s Deccan Traps. The extinction marks the boundary between the Cretaceous and Paleogene periods, or the KPg boundary.

Using two different geochemical dating techniques, two separate teams dated the lava flows. The goal was to try to determine whether the bulk of the lava predates or postdates the KPg boundary. Both estimated that the eruptions lasted in total about 1 million years. But one team, using uranium-lead dating, found that some of the biggest pulses of lava erupted tens of thousands of years before the KPg boundary. The other team, using argon-argon dating, determined that three-fourths of the lava erupted afterward. [Continue reading…]

Plankton that are both plant-like and animal-like are redefining marine ecology

Knowable magazine reports:

Their color gave them away. Ecologist Diane Stoecker was looking at plankton in samples of ocean water from the dock in Woods Hole Harbor in Massachusetts some 40 years ago when she spotted something strange. Under the microscope, she recognized Laboea strobila, shaped like an ice-cream cone — “yellowish green and very beautiful,” she recalls — and the smaller, more spherical Strombidium species — also oddly greenish.

Stoecker knew that these single-celled critters, named ciliates for the hairlike cilia that they bear, got their energy by feeding on other, smaller organisms. So why were the ones she saw so green — a color that generally signifies photosynthesis? Was the pigment leftover food, ingested algae or just the algae’s chloroplasts?

After some groundbreaking experiments, Stoecker was one of the first scientists to describe how these types of plankton not only hunted their prey, but also sequestered the chloroplasts of their food sources and used them to get energy from sunlight. “I was very excited to find that they really were photosynthetic,” she says.

Traditionally, marine microplankton had been divided similarly to species on land. You had plant-like phytoplankton, such as algae, and animal-like zooplankton that ate the phytoplankton. What Stoecker found was that some of these organisms were somewhere in the middle: They could eat like animals when food was present and photosynthesize like plants in the light. “If you think about it, it can be the best of both worlds,” says marine ecologist Dave A. Caron of the University of Southern California. [Continue reading…]