Animal Kids Listen to Their Parents Even before Birth

Human children: please take note of the behavior of prebirth zebra finches

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#evolution, #the-sciences

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Human Evolution Led to an Extreme Thirst for Water

We are more dependent on water than many other mammals and have developed a host of clever strategies for obtaining it

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Puppies Understand You Even at a Young Age, Most Adorable Study of the Year Confirms

Researchers in the happiest lab in the world tested 375 pups and found they connected with people by eight weeks

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#evolution, #the-sciences

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At the Bottom of Lake Huron, an Ancient Mystery Materializes

The air was likely frigid as the hunter lit a small fire. The caribou would come in the morning—forced through the narrow strip of marshland where he camped. There was nowhere else to go. The…

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#evolution, #the-sciences

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Bats on Helium Reveal an Innate Sense of the Speed of Sound

A new experiment shows that bats are born with a fixed reference for the speed of sound—and living in lighter air can throw it off.

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New Process Helps Unscramble Dinosaur Boneyard Chaos

Piecing together a paleontological puzzle

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Evolution’s Favorite Fish Diversify through ‘Noncoding’ Genes

Proliferating cichlids may specialize using regulatory DNA

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Who Laps Whom on the Walking Track–Tyrannosaurus rex or You? Science Has a New Answer

An analysis of the animal’s walking speed suggests that T. rex’s walking pace was close to that of a human. It’s too bad the king of the dinosaurs didn’t just walk…

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Genes Linked to Self-Awareness in Modern Humans Were Less Common in Neandertals

Brain networks for memory and planning may have set us apart from Neandertals—and chimps

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How 3-D Scanning is Reinventing Paleoanthropology

It lets us excavate ancient fossils while preserving information about the sediments that hold them—crucial to understanding their age, among other things

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#evolution, #tech

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Genomes Reveal Humanity’s Journey into the Americas

DNA has upended neat and tidy accounts of the peopling of the American continents

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Arkansas House passes unconstitutional bill putting creationism in schools

Image of a large, neoclassical building.

Enlarge / The Arkansas state capitol. (credit: Daniel Schwen)

Last week, the Arkansas state House of Representatives passed a bill that would amend state education law to allow teachers in public schools to teach creationism as “a theory of how the earth came to exist.” As it stands, the act promotes blatantly unconstitutional behavior as made clear by a precedent set in a 1982 case involving the Arkansas Board of Education. Despite that, the bill passed 72-21, and it already has a sponsor in the state Senate.

The body of the bill is mercifully short, consisting of two sentence-long amendments to the existing Arkansas code:

A teacher of a kindergarten through grade twelve (K-12) science class at a public school or open-enrollment public charter school may teach creationism as a theory of how the earth came to exist.

This section is permissive and does not require a teacher to teach creationism as a theory of the earth came to exist.

But those two sentences are enough to land teachers and their local school system in a world of trouble, in that the permission given runs afoul of a lot of legal precedent. In a key case that involved Arkansas itself, McLean V. Arkansas Board of Education, a group of plaintiffs banded together to challenge a state law that mandated the teaching of “creation science” in public schools. The judge in that case correctly recognized that creation science was actually religious in nature, and it therefore violated the constitution’s prohibition against the establishment of state religion.

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#creationism, #evolution, #government, #law, #policy, #science, #science-education

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Our ancestors left Africa both with and without modern brains

Image of a skull partially buried in sediments.

Enlarge / One of the remarkably intact Dmanisi skulls at the time of its discovery. (credit: Guy Bar-Oz)

We have an extensive collection of fossils from the lineages that produced us humans. A large number of Australopithecus and early Homo skeletons track the transition to bipedal walking and the appearance of features that mark our present anatomy. But it’s much harder to figure out what led to the mental capabilities—complex language, the near-constant use of tools, and so on—that help set humans apart.

Much harder—but not entirely impossible. Remains of skulls can help us figure out the likely cranial capacity of extinct species. And the brain actually leaves its mark on the interior of skulls, allowing some aspects of the brain’s anatomy to be pieced together. Now, an international team has done this sort of analysis on a set of Homo erectus from a critical point in our species’ past. They have found that some earlier brain species persisted well into the history of our genus Homo, but that didn’t stop those ancestors from migrating out of Africa.

Reconstructing brains

How do you figure out what a brain once looked like? You need a reasonably intact skull, which is relatively rare, given the fragility of the bones. Once the skull is reconstructed, it’s possible to make what’s called an “endocast” of the interior of the skull, capturing the details of its features, including where it conformed to the underlying brain. In some cases, endocasts form naturally during the deposition of material around a fossil. They could also be made after discovery and now can be done virtually thanks to our ability to scan and reconstruct 3D volumes.

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#biology, #brains, #evolution, #human-evolution, #science

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How to Make a Hippogriff Fly and Other Flights of Fancy

A paleontologist and an illustrator team up to make mythical creatures follow biomechanical rules

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#artsculture, #evolution, #features, #the-sciences

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Boston’s Pigeons Coo ‘Wicked,’ New York’s ‘Fuhgeddaboudit’

The two city’s rock doves are genetically distinct, research shows.

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#evolution, #the-sciences

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Boston’s Pigeons Coo, ‘Wicked’; New York’s Birds Coo, ‘Fuhgeddaboudit’

The two cities’ rock doves are genetically distinct, research shows.

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The Asteroid That Killed the Dinosaurs Created the Amazon Rain Forest

Fossilized pollen and leaves reveal that the meteorite that caused the extinction of nonavian dinosaurs also reshaped South America’s plant communities to yield the planet’s largest rain…

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A Tsunami Likely Hurled Huge Rocks onto a Tiny Island

A Caribbean island’s giant rocks were thought to be deposited by enormous waves

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Strange microbe “breathes” nitrates, has a mitochondria-like symbiont

Image of a spiky oval with yellow and blue shapes inside.

Enlarge / The bacteria (yellow) live inside a larger eukaryotic cell. (credit: MAX PLANCK INSTITUTE FOR MARINE MICROBIOLOGY)

Deep in Switzerland’s Lake Zug swims a microorganism that has evolved a strange way to “breathe.” A team of researchers discovered a novel partnership between a single-celled eukaryote—an organism with a clearly defined nucleus holding its genome—and a bacteria that generates energy for its host. But instead of using oxygen to do so, it uses nitrate.

“This is a very weird, [newly discovered] organism,” said Jana Milucka, a biologist at the Max Planck Genome Center in Cologne and senior author on the resulting paper, published in Nature in early March.

The team named the bacteria Candidatus Azoamicus ciliaticola, meaning “nitrogen-friend that lives inside a ciliate.” Its partner, the ciliate, is a microorganism that moves around using cilia, tiny hair-like protrusions outside their cell walls. The host organism is part of a group of ciliates called Plagiopylea.

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#biology, #evolution, #metabolism, #science

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Chimpanzees Show Altruism While Gathering Around the Juice Fountain

New research tries to tease out whether our closest animal relatives can be selfless

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#evolution, #the-sciences

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That Mouse in Your House—It’s Smarter, Thanks to You

Scientists studied three varieties of house mice, and found those that had lived alongside humans the longest were also the craftiest at solving food puzzles. Christopher Intagliata reports.

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#biology, #evolution, #the-sciences

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Prehistoric Plankton Became Predators to Survive a Mass Extinction

When the sun disappeared, tiny coccoliths turned to hunting

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Neandertals Probably Perceived Speech Quite Well

Could they speak, too? Did they proposition modern humans in an interspecies creole language?

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#evolution, #the-sciences

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An Ancient Proto-City Reveals the Origin of Home

The 9,000-year-old settlement of Çatalhöyük in Turkey shows how humans began putting down roots

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Million-year-old mammoth DNA rewrites animal’s evolutionary tree

Image of a fractured, white post partially embedded in the soil.

Enlarge / A mammoth tusk thaws out of the ground in Siberia.

Ancient DNA has revolutionized how we understand human evolution, revealing how populations moved and interacted and introducing us to relatives like the Denisovans, a “ghost lineage” that we wouldn’t realize existed if it weren’t for discovering their DNA. But humans aren’t the only ones who have left DNA behind in their bones, and the same analyses that worked for humans can work for any other group of species.

Today, the mammoths take their turn in the spotlight, helped by what appears to be the oldest DNA ever sequenced. DNA from three ancient molars, one likely to be over a million years old, has revealed that there is a ghost lineage of mammoths that interbred with distant relatives to produce the North American mammoth population.

Dating and the mammoth family tree

Mammoths share something with humans: like us, they started as an African population but spread across much of the planet. Having spread out much earlier, mammoth populations spent enough time separated from each other to form different species. After branching off from elephants, the mammoths first split into what are called southern and steppe species. Later still, adaptations to ice age climates produced the woolly mammoth and its close relative, the North American mammoth, called the Columbian mammoth. All of those species, however, are extinct, and the only living relatives are the elephants.

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#ancient-dna, #biology, #evolution, #genomics, #mammoths, #science

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Mammoth Genomes Shatter Record for Oldest DNA Sequences

Researchers extracted DNA from fossils that are more than a million years old, illuminating the origins of the woolly mammoth and the Columbian mammoth

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Dinosaur Discoveries Are Booming

Fossils are being found worldwide, and there are plenty more to come

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#evolution, #graphic-science, #the-sciences

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Evolution Could Explain Why Psychotherapy May Work for Depression

Persistent rumination may be an attribute that lets us think our way out of despair—a process enhanced through talk therapy

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#evolution, #mental-health, #mind

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What happens when you replace a human gene with its Neanderthal version?

Image of two skulls.

Enlarge / The difference between modern human (left) and Neanderthal skulls means there must be some differences in how their brains develop. (credit: Wikimedia Commons)

What are the key differences between modern humans and our closest relatives, the Neanderthals and Denisovans? For the Neanderthals, there doesn’t look to be any sort of obvious difference. They used sophisticated tools, made art, and established themselves in some very harsh environments. But, as far as we can tell, their overall population was never particularly high. When modern humans arrived on the scene in Eurasia, our numbers grew larger, we spread even further, and the Neanderthals and Denisovans ended up displaced and eventually extinct.

With our ability to obtain ancient DNA, we’ve now gotten a look at the genomes of both Neanderthals and Denisovans, which allows us to ask a more specific question: could some of our differences be due to genetics?

The three species are close relatives, so the number of differences in our proteins are relatively small. But a large, international research team has identified one and engineered it back into stem cells obtained from modern humans. And the researchers found that neural tissue made of these cells has notable differences from the same tissue grown with the modern human version of this gene.

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#biology, #brains, #evolution, #human-evolution, #neanderthal, #neuroscience, #science, #stem-cells

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Neandertalized ‘Mini Brains’ Yield Clues to Modern Human Uniqueness

Experiments on clusters of cultured cells hint that a gene variant found only in Homo sapiens profoundly changed brain development in our species compared to our extinct relatives

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How Evolution Helps Us Understand Cancer and Control It

Cells need to cooperate to coexist in people, and when some break the rules, cancer results

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Ancient Dogs Had Complex Genetic Histories

Some dog population genetics show similarities to ours, such as in the ability to digest grains, but other lineages differ.  

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The Evolutionary Origins of Friendship

The emergence of this crucial kind of relationship relied on the ability to recognize the unique benefits others have to offer

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The World’s Oldest Animal Paintings Are on This Cave Wall

Depictions of pigs found in Indonesia date back at least 45,500 years

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Dire wolves aren’t wolves at all—they form a distinct lineage with jackals

Two canid skeletons facing each other.

Enlarge (credit: Wikimedia commons)

Dire wolves had a burst of newfound fame with their appearance in Game of Thrones, where they were portrayed as a far larger version of more mundane wolves. Here in the real world, only the largest populations of present-day wolves get as large as the dire wolf, which weighed nearly 70 kilograms. These animals once shared North America—and likely prey—with predators like the smilodon, a saber-toothed cat. Prior to the arrival of humans, dire wolves were far more common than regular wolves, as indicated by the remains found in the La Brea tar seeps, where they outnumber gray wolves by a factor of about 100.

Like the smilodon and many other large North American mammals, the dire wolf vanished during a period of climate change and the arrival of humans to the continent, even as gray wolves and coyotes survived. And with their departure, they left behind a bit of a mystery: what were they?

A new study uses ancient DNA from dire wolf skeletons to determine that they weren’t actually wolves and had been genetically isolated from them for millions of years.

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#dire-wolves, #dogs, #evolution, #genetics, #genomics, #paleontology, #science, #wolves

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Dire Wolves Were Not Really Wolves, New Genetic Clues Reveal

The extinct giant canids were a remarkable example of convergent evolution

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Humans May Have Befriended Wolves with Meat

Unlike humans, wolves can subsist on protein alone for months — so scientists say we may have lobbed leaner leftovers their way. Christopher Intagliata reports.

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#evolution, #the-sciences

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Dog Domestication May Have Begun because Paleo Humans Couldn’t Stomach the Original Paleo Diet

Unable to digest large amounts of protein, hunters likely left scraps that could have led to the taming of wolves

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Ancient Peruvian Farmers Harnessed El Niño Floodwaters

Structures diverted the weather pattern’s floods to new farmlands 2,000 years ago

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A Breakdown of Beavers

Environmental journalist Ben Goldfarb talks about his book Eager: The Surprising, Secret Life of Beavers and Why They Matter.

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#biology, #conservation, #earth, #environment, #evolution, #policyethics, #sustainability, #the-sciences

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Ravens Measure Up to Great Apes on Intelligence

Juvenile ravens performed just as well as chimps and orangutans on a battery of intelligence tests—except for spatial skills. Christopher Intagliata reports.

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#biology, #cognition, #evolution, #mind, #the-sciences

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The Real Dilophosaurus Would Have Eaten the Jurassic Park Version for Breakfast

The most comprehensive study of the iconic dinosaur reveals a very different animal from the one portrayed on film

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#evolution, #features, #the-sciences

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Pterosaur Origins Flap into Focus

Fossils of small, delicate animals may reveal the early history of gigantic flying reptiles

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#evolution, #the-sciences

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Unprecedented 3-D view inside Animal Mummies

X-ray scans of ancient Egyptian cat, bird and snake mummies show details never seen before

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#biology, #evolution, #the-sciences

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When Same-Sex Mating Makes Reproductive Sense

Under the right circumstances, indiscriminate mating with both males and females can enhance animals’ evolutionary success

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#evolution, #mind, #the-sciences

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The Denisovans Expand Their Range Into China

Evidence of the ancient humans was limited to a cave in Siberia—but now, scientists have found genetic remains of the Denisovans in China. Christopher Intagliata reports. 

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#evolution, #the-sciences

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Cretaceous birds were thought to have small bills—except this one

Precise anatomical profile of a prehistoric bird.

Enlarge / Artist’s depiction of Falcatakely forsterae. (credit: Mark Witton)

Given the unusual attention granted to turkeys this week, let’s talk dinosaurs. Today’s birds are, of course, descendants of the only branch of the dino tree that made it through the end-Cretaceous mass extinction. In the dinosaurs’ halcyon days, the early birds were a bit different, still retaining teeth and foreclaws among some subtler anatomical differences with their modern descendant. A new fossil find reveals an unexpected bird from that time—one with a whopping-great, toucan-like beak.

The fossil, named Falcatakely forsterae, comes from late Cretaceous rocks in Madagascar. Many of the early bird fossils we’ve discovered so far come from older, early-Cretaceous rocks in China, with the timeframe between then and the end-Cretaceous extinction more of a question mark. The new fossil is a nicely preserved head of a crow-sized bird with a strikingly long, tall, and narrow beak.

The early Chinese bird fossils don’t show much diversity in beak shape. That’s a big contrast with modern birds, which have a wild variety of beak shapes befitting their many different ecological niches. Pelicans, woodpeckers, and parrots have very different diets that require a beak adapted to the job. It had been thought that enlarged beaks may not have been possible until some anatomical shifting in the parts of the skull took place, meaning that the early birds were simply limited. But the new find shows that wasn’t entirely true. This species could have inhabited an ecological niche that was empty after the extinction—until a more modern bird drifted back into it much later.

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#birds, #evolution, #fossils, #science

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Clues to Puebloan History Drip Away in Melting Ice Caves

Charcoal dating back nearly 2,000 years show the ancestral Puebloans used the ice for drinking water during droughts

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#climate, #evolution, #sustainability

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Early Mammals Had Social Lives, Too

Chipmunk-like animals that lived among the dinos appear to have been social creatures, which suggests that sociality arose in mammals earlier than scientists thought. Christopher Intagliata…

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#biology, #evolution, #the-sciences

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Dramatic Scope of the Anthropocene Can Be Seen from Above

Aerial photography highlights the effect humankind is having on the earth

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#evolution, #the-sciences

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