Spiders hear better than expected, new research

This video says about itself:

13 October 2016

In a test of hearing airborne noises, a small dark jumping spider stops moving abruptly (red pointer appears) when researchers broadcast a tone similar to the scary droning of the wings of a predatory wasp.

Video: G. Menda, Hoy Lab at Cornell

From Science News:

Be careful what you say around jumping spiders

Arachnids hear airborne sounds over greater distances than thought

By Susan Milius

8:00am, October 15, 2016

Accidental chair squeaks in a lab have tipped off researchers to a new world of eavesdroppers.

Spiders don’t have eardrums, though their exquisitely sensitive leg hairs pick up vibrations humming through solids like web silk and leaves. Biologists thought that any airborne sounds more than a few centimeters away would be inaudible. But the first recordings of auditory nerve cells firing inside a spider brain suggest that the tiny Phidippus audax jumping spider can pick up airborne sounds from at least three meters away, says Ronald Hoy of Cornell University.

During early sessions of brain recordings, Hoy’s colleagues saw bursts of nerve cell, or neuron, activity when a chair moved. Systematic experiments then showed that from several meters away, spiders were able to detect relatively quiet tones at levels comparable to human conversation. In a hearing test based on behavior, the spiders also clearly noticed when researchers broadcast a low droning like the wing sound of an approaching predatory wasp. In an instant, the spiders hunkered down motionless, the researchers report online October 13 in Current Biology.

Jumping spiders have brains about the size of a poppy seed, and Hoy credits the success of probing even tinier spots inside these (anesthetized) brains to Cornell coauthor Gil Menda and his rock-steady hands. “I close my eyes,” Menda says. He listens his way along, one slight nudge of the probe at a time toward the auditory regions, as the probe monitor’s faint popping sounds grow louder.

When Menda first realized the spider brain reacted to a chair squeak, he and Paul Shamble, a study coauthor now at Harvard University, started clapping hands, backing away from the spider and clapping again. The claps didn’t seem earthshaking, but the spider’s brain registered clapping even when they had backed out into the hallway, laughing with surprise.

Clapping or other test sounds in theory might confound the experiment by sending vibrations not just through the air but through equipment holding the spider. So the researchers did their Cornell neuron observations on a table protected from vibrations. They even took the setup for the scary wasp trials on a trip to the lab of coauthor Ronald Miles at State University of New York at Binghamton. There, they could conduct vibration testing in a highly controlled, echo-dampened chamber. Soundwise, Hoy says, “it’s really eerie.”

Neuron tests in the hushed chamber and at Cornell revealed a relatively narrow, low-pitched range of sensitivity for these spiders, Hoy says. That lets the spiders pick up rumbly tones pitched around 70 to 200 hertz; in comparison, he says, people hear best between 500 and 1,000 Hz and can detect tones from 50 Hz to 15 kilohertz.

Spiders may hear low rumbles much as they do web vibes: with specialized leg hairs, Hoy and his colleagues propose. They found that making a hair twitch could cause a sound-responsive neuron to fire.

“There seems to be no physical reason why a hair could not listen,” says Jérôme Casas of the University of Tours in France. When monitoring nerve response from hairs on cricket legs, he’s tracked airplanes flying overhead. Hoy’s team calculates that an 80 Hz tone the spiders responded to would cause air velocities of only 0.13 millimeters a second if broadcast at 65 decibels three meters away. That’s hardly a sigh of a breeze. Yet it’s above the threshold for leg hair response, says Friedrich Barth of the University of Vienna, who studies spider senses.

An evolutionary pressure favoring such sensitivity might have been eons of attacks from wasps, such as those that carry off jumping spiders and immobilize them with venom, Hoy says. A mother wasp then tucks an inert, still-alive spider into each cell of her nest where a wasp egg will eventually hatch to feed on fresh spider flesh. Wasps are major predators of many kinds of spiders, says Ximena Nelson of the University of Canterbury in Christchurch, New Zealand. If detecting their wing drone turns out to have been important in the evolution of hearing, other spiders might do long-distance eavesdropping, too.

Noisy dinosaur age bird discovered in Antarctic

This video says about itself:

Discovery of fossil “voice box” of Antarctic bird suggests dinosaurs couldn’t sing

2 October 2016

Researchers have found the oldest known fossil vocal organ of a bird … in Antarctica. The voice box is from a species related to ducks and geese that lived during the age of dinosaurs more than 66 million years ago. A National Science Foundation funded team led by the University of Texas at Austin discovered the ancient vocal organ called a syrinx–and its apparent absence from non-bird dinosaur fossils of the same age. Researchers believe the organ may have originated late in the evolution of birds after the origin of flight. Drawing on their research, team leader Julia Clarke said that other dinosaurs may not have been able to make noises similar to modern bird calls, but most likely made closed-mouth sounds similar to ostrich booms that don’t require a syrinx.

The organ was found in a fossil species called Vegavis iaai. The fossil was discovered in 1992 on Vega Island in the Antarctic Peninsula by a team from the Argentine Antarctic Institute. It was named in 2005 by Clarke and Argentine colleagues. But, it wasn’t until 2013 Clarke discovered the fossil syrinx in the new specimen and began analysis. The international team may figure out what dinosaurs sounded like, gaining insight into the origins of bird song. The findings appear in the October 12 issue of “Nature”.

See also here.

From Science News:

Birds’ honks filled Late Cretaceous air

Sounds inferred from oldest preserved avian voice box

By Meghan Rosen

3:53pm, October 12, 2016

ANCIENT VOICE BOX: A ducklike bird that lived some 68 million to 66 million years ago left behind fossilized remains of a voice box, or syrinx, on an island off the coast of Antarctica.

Some ancient birds may have sounded like honking ducks.

For the first time, scientists have discovered the fossilized remains of a voice box from the age of the dinosaurs. The sound-making structure, called a syrinx, belonged to Vegavis iaai, a bird that lived 68 million to 66 million years ago, researchers report October 12 in Nature.

“It may be a once-in-a-lifetime discovery,” says evolutionary biologist Patrick O’Connor of Ohio University in Athens, who wrote a commentary in Nature about the fossil. Now, he says, the hunt will be on to find voice boxes in other fossils.

The new work helps fill in the soundscape of the Late Cretaceous Epoch. It could also offer hints about sounds made by all sorts of dinosaurs, says study coauthor Julia Clarke of the University of Texas at Austin.

Unlike in humans, where the larynx lies below the throat, birds’ voice boxes rest inside the chest at the base of the windpipe. Stacked rings of cartilage anchor vibrating membranes that make sound when air whooshes through.

This delicate structure doesn’t typically fossilize. In fact, scientists have previously spotted just a few syrinxes in the fossil record. The oldest known, from a wading bird, was about 50 million years old. Clarke’s team examined that syrinx, which hadn’t been studied before, and the one from V. iaai.

The V. iaai fossil, a partial skeleton discovered on an island off the coast of Antarctica, was removed from a rock about the size of a cantaloupe, Clarke says. Just one small area remained encased in rocky material. Everyone thought that bit was trivial, she says. But “it was within that tiny little section that I saw the syrinx.” Three-dimensional CT scans let her peer within the rock and see the telltale rings of a voice box, a structure roughly half the size of a multivitamin pill. “It was one of the biggest, happiest days of my career,” Clarke says.

Biologist Philip Senter of Fayetteville State University in North Carolina, who was not involved in the study, echoes Clarke’s enthusiasm. “It’s quite exciting to find such a rarely preserved structure,” he says. Seeing it in 3-D will make paleontologists “chortle joyously.”

Comparing the fossil with living birds helped Clarke and her team figure out what sounds the ancient bird might have made. Both the bird’s skeleton and its syrinx suggest it squawked like today’s ducks and geese.

The find also proves that voice boxes from dinosaurs’ time can indeed fossilize. No one has found the structures in nonavian dinosaurs, Clarke says. “That suggests that most dinosaurs may not have had a syrinx.”

Instead, she proposes, dinosaurs like Tyrannosaurus rex and Stegosaurus might have made noises like crocodiles: deep “booming” sounds generated in the back of the mouth.

Naked mole-rats and pain, new research

This video says about itself:

18 June 2015

Naked mole-rats are some of the most fascinating members of the animal kingdom – but just how unique are they? Turns out, they diverged from their nearest relative more than 31 MILLION years ago! Field Museum curator Dr. Bruce Patterson, and Yale postdoctoral researcher Nate Upham have determined they ought to be in their own scientific family. Now, can someone please update their Wikipedia page?

Read more about this discovery on The Field Museum’s website.

Here‘s the abstract for the paper:

Patterson, B. and Upham, N. “A newly recognized family from the Horn of Africa, the Heterocephalidae (Rodentia: Ctenohystrica).” (abstract)

Shout-out to Jillian at Chicago’s Lincoln Park Zoo for allowing us to get footage of their colony!

HUGE thank-you to Bruce and Nate for their help with this episode! And, congratulations to Bruce for being the 2015 recipient of the prestigious C. Hart Merriam Award from the American Society of Mammalogists!

From Science News:

Hot and spicy pain signals get blocked in naked mole-rats

by Laura Sanders

5:23pm, October 12, 2016

Like Marvel’s surly superhero Luke Cage, naked mole-rats are seemingly indestructible, hairless creatures that are impervious to certain kinds of pain. This last power has puzzled researchers, because like other mammals, mole-rats have functional versions of a protein called TRPV1, which responds to painfully hot stimuli.

It turns out that a different protein, TrkA, is the key to the missing pain signals, Gary Lewin of the Max Delbrück Center for Molecular Medicine in Berlin and colleagues report in the Oct. 11 Cell Reports. Usually, TrkA detects inflammation and kicks off a molecular reaction that produces pain sensation by activating TRPV1. But naked mole-rats produce a version of TrkA that doesn’t trigger this pain cascade.

That means that certain nerve cells don’t become more sensitive after encountering something hot, such as capsaicin, a molecule that puts the burn in spicy peppers. Because naked mole-rats spend their time in hot African climates, the rodents might have evolved to not need the pain signals that come from heat, the authors speculate.

Little dinosaur, belemnites, dukes in Pomeranian State Museum

This March 2016 video is about the Pommersches Landesmuseum, the Pomeranian State Museum in Greifswald town in Germany.

This 2015 video is about the Pommersches Landesmuseum as well.

As this blog has mentioned, we arrived there on 1 October 2016.

Not far from the museum entrance was the paleontology room.

There, the fossil, discovered in 1963, of Emausaurus ernstii. An ornithischian young dinosaur … well, by now about 190 million years old, so from the early Jurassic. The name refers to the Ernst Moritz Arndt University. This ornithischian, herbivorous dinosaur was about one meter in size.

Later in the Jurassic, the land of what is now Pomerania became sea; and remained so during the Cretaceous.

In the museum were fossils of Cretaceous cephalopods, belemnites, of the Belemnella genus.

Belemnella lanceolata

This picture shows a Belemnella lanceolata.

A bit further in the museum, amber, about forty million years old.

Still further, humans in the prehistory and history of Pomerania.

In the early Middle Ages, its inhabitants were Slavic tribes, practicing a polytheist religion. However, the Christian German empire attacked them. In the twelfth century, the Slavic dukes of Pomerania could only keep their dukedom by converting to Christianity, recognizing the German emperors as their overlords, and destroying the pagan temples.

In the sixteenth century, another conversion for the dukes and people of Pomerania: from Roman Catholicism to Protestantism. This is documented by an important item in the museum: the Croy Tapestry from 1544.

Croy Tapestry

In the seventeenth century, the ducal dynasty became extinct, and the kings of Sweden became the rulers. The harsh serfdom for the peasants in Pomerania became a model for the oppression of the peasantry in Sweden proper.

Stay tuned! As soon as the photos will be sorted out, there will be more blog posts here on the German Baltic Sea region, especially its birdlife.

Intelligent bumblebees can learn to pull strings

This video says about itself:

Social learning and cultural transmission in bees

Footage shows a pair of bees (the seeded demonstrator and an observer) tested with the string pulling task in Colony 8. The red dot indicates the seeded demonstrator. The observer has not learned string pulling yet but has already been tested three times in paired foraging bouts. The demonstrator lands at the edge of the table, repositions herself in front of the string, and starts pulling immediately.

The observer is first attracted to the blue flower and lands on top of the table. The observer subsequently flies to the demonstrator, lands at her side, and walks to the nearby flower and string. She walks along the protruding string, reaches the table edge, and moves sideways. She notices the demonstrator and walks to her side, moving around her whilst the demonstrator is pulling, always in close contact.

The observer touches the string a few times but does not grasp it. The demonstrator eventually extracts the blue disk and steps onto it. The observer copies the demonstrator. They both slide the flower from under the table and obtain the reward.

Once the first pulled flower is depleted, the demonstrator moves to the nearest flower and pulls the string. The observer stays on the extracted flower for a short period, circling, probing the emptied inverted cap before noticing the demonstrator drinking from a second flower and joining her. In a similar way, once the second pulled flower is emptied, the demonstrator moves and pulls a third flower and the observer joins her. Her crop filled up, the demonstrator flies back to the colony.

From PLOS Biology:

Associative Mechanisms Allow for Social Learning and Cultural Transmission of String Pulling in an Insect

October 4, 2016


Social insects make elaborate use of simple mechanisms to achieve seemingly complex behavior and may thus provide a unique resource to discover the basic cognitive elements required for culture, i.e., group-specific behaviors that spread from “innovators” to others in the group via social learning. We first explored whether bumblebees can learn a nonnatural object manipulation task by using string pulling to access a reward that was presented out of reach. Only a small minority “innovated” and solved the task spontaneously, but most bees were able to learn to pull a string when trained in a stepwise manner.

In addition, naïve bees learnt the task by observing a trained demonstrator from a distance. Learning the behavior relied on a combination of simple associative mechanisms and trial-and-error learning and did not require “insight”: naïve bees failed a “coiled-string experiment,” in which they did not receive instant visual feedback of the target moving closer when tugging on the string.

In cultural diffusion experiments, the skill spread rapidly from a single knowledgeable individual to the majority of a colony’s foragers. We observed that there were several sequential sets (“generations”) of learners, so that previously naïve observers could first acquire the technique by interacting with skilled individuals and, subsequently, themselves become demonstrators for the next “generation” of learners, so that the longevity of the skill in the population could outlast the lives of informed foragers. This suggests that, so long as animals have a basic toolkit of associative and motor learning processes, the key ingredients for the cultural spread of unusual skills are already in place and do not require sophisticated cognition.

Author Summary

Social insects make use of simple mechanisms to achieve many seemingly complex behaviors and thus may be able to provide a unique resource for uncovering the basic cognitive elements required for culture. Here, we first show that bumblebees can be trained to pull a string to access a reward, but most could not learn on their own. Naïve bees learned how to pull strings by observing trained demonstrators from a distance.

Learning the behavior through observation relied on bees paying attention to both the string and the position of the trained demonstrator bee while pulling the string. We then tested whether bees could pass this information to others during a semi-natural situation involving several colonies. We found that once one bee knew how to string pull, over time, most of the foraging bees learned from the initially trained bee or from bees who had learned from the trained bee, even after the initial demonstrator was no longer available. These results suggest that learning a nonnatural task in bumblebees can spread culturally through populations.

These bumblebees were Bombus terrestris, large earth bumblebees.

Primitive signs of emotions spotted in sugar-buzzed bumblebees. After a treat, insects appeared to have rosier outlooks. By Emily Underwood, 2:00pm, September 29, 2016: here.

‘Mass extinctions killed less wildlife than thought’

This video from Britain says about itself:

Catastrophe – The Permian Extinction

The Permian-Triassic extinction event, informally known as the Great Dying, was an extinction event that occurred 252 million years ago, forming the boundary between the Permian and Triassic geologic periods, as well as the Paleozoic and Mesozoic eras. It is the Earth’s most severe known extinction event, with up to 96% of all marine species and 70% of terrestrial vertebrate species becoming extinct. It is the only known mass extinction of insects. Some 57% of all families and 83% of all genera became extinct. Because so much biodiversity was lost, the recovery of life on Earth took significantly longer than after any other extinction event, possibly up to 10 million years.

Presented by Tony Robinson.

Originally published in 2008 by Channel 4

That was the prevalent view in 2008. And now …

From the Proceedings of the National Academy of Sciences of the United States of America:

Estimates of the magnitudes of major marine mass extinctions in earth history

Steven M. Stanley

October 3, 2016


This paper shows that background extinction definitely preceded mass extinctions; introduces a mathematical method for estimating the amount of this background extinction and, by subtracting it from total extinction, correcting estimates of losses in mass extinctions; presents a method for estimating the amount of erroneous backward smearing of extinctions from mass extinction intervals; and introduces a method for calculating species losses in a mass extinction that takes into account clustering of losses. It concludes that the great terminal Permian crisis eliminated only about 81% of marine species, not the frequently quoted 90–96%. Life did not almost disappear at the end of the Permian, as has often been asserted.


Procedures introduced here make it possible, first, to show that background (piecemeal) extinction is recorded throughout geologic stages and substages (not all extinction has occurred suddenly at the ends of such intervals); second, to separate out background extinction from mass extinction for a major crisis in earth history; and third, to correct for clustering of extinctions when using the rarefaction method to estimate the percentage of species lost in a mass extinction. Also presented here is a method for estimating the magnitude of the Signor–Lipps effect, which is the incorrect assignment of extinctions that occurred during a crisis to an interval preceding the crisis because of the incompleteness of the fossil record.

Estimates for the magnitudes of mass extinctions presented here are in most cases lower than those previously published. They indicate that only ∼81% of marine species died out in the great terminal Permian crisis, whereas levels of 90–96% have frequently been quoted in the literature. Calculations of the latter numbers were incorrectly based on combined data for the Middle and Late Permian mass extinctions. About 90 orders and more than 220 families of marine animals survived the terminal Permian crisis, and they embodied an enormous amount of morphological, physiological, and ecological diversity. Life did not nearly disappear at the end of the Permian, as has often been claimed.

Origin of the universe, evolution of life, new film

This video from the USA says about itself:

Voyage of Time IMAX® Trailer

30 June 2016

Voyage of Time: The IMAX Experience, a 40-minute, giant-screen adventure narrated by Brad Pitt, which immerses audiences directly into the story of the universe and life itself, will be shown exclusively in IMAX® theatres. For more info, visit here.

From Science News:

‘Voyage of Time’ is Terrence Malick’s ode to life

Film offers an artistic take on science

By Erin Wayman

4:38pm, October 7, 2016

Condensing billions and billions and billions of years into a 45-minute film is a tall order. But director Terrence Malick took on the challenge with Voyage of Time. The film, now playing in IMAX theaters, surveys the 13.8-billion-year history of the universe and even looks eons into the future when we — life on Earth, the planet and the entire solar system — are gone.

Starting with the Big Bang, Voyage of Time progresses through highlights of the past, with a central focus on the evolution of life. Malick, best known for directing visually rich dramas such as The Thin Red Line and The Tree of Life, presents breathtaking cinematography, using locales such as Hawaii’s lava-oozing Kilauea volcano as stand-ins for the past. Stunning visualizations and special effects bring to life the formation of the planets, the origin of the first cells, the demise of the sun and other events that scientists can only imagine.

The film marks Malick’s first attempt at documentary filmmaking. If you can call it that. Viewers hoping for a David Attenborough–style treatment of the subject matter will be disappointed. The film is more evocative, with moody scenes that provide little explication. And what narration (by Brad Pitt) there is tends to be philosophical rather than informative.

Serious science enthusiasts may find some reasons to quibble with the movie. For one, it’s hard to grasp the true immenseness and scale of cosmic time. With so much screen time devoted to the evolution of life, many viewers may not realize just how relatively recent a phenomenon it is. After the Big Bang, more than 9 billion years passed before Earth began to form. It took many hundred thousand more years before the first microbes emerged.

Malick’s treatment of evolution may also rankle some viewers. At times, the narration seems to imply life was destined to happen, with the young, barren Earth just waiting around for the first seeds of life to take root. At other times, the narration imbues evolution with purpose. Pitt notes, for instance, that perfecting a leaf took eons. Yet perfection is something evolution neither achieves nor strives for — it’s a process that lacks intentionality.

These critiques aside, Malick sought to tell an accurate story, enlisting an accomplished group of scientists as advisers, including Lee Smolin of the Perimeter Institute for Theoretical Physics in Waterloo, Canada. Smolin says he was impressed with the end result. “It’s a very unusual film,” he says, likening it to a visual poem or piece of art.

And that’s probably the best mindset to watch Voyage of Time: Just sit back, soak in the dazzling visuals and contemplate the wonders of nature.