Tech & Science
Technology and Science news from Boulder, Colorado
CU Boulder study: fossils show evolution of bug hearing
Jan 3rd
FROM COLORADO HINT AT ORIGIN OF INSECT HEARING
How did insects get their hearing? A new study of 50-million-year-old cricket and katydid fossils sporting some of the best preserved fossil insect ears described to date are helping to trace the evolution of the insect ear, says a new study involving the University of Colorado Boulder and the University of Illinois at Chicago.
According to University of Colorado Museum of Natural History paleontologist Dena Smith and University of Illinois Professor Roy Plotnick, who collaborated on the new study at the National Evolutionary Synthesis Center, or NESCent, in Durham, N.C., insects hear with help from some very unusual ears.
Grasshoppers have ears on their abdomens. Lacewings have ears on their wings. The ears of the tachinid fly are tucked under the chin. “Insects have ears on pretty much every part of their body except on their head proper,” Plotnick said.
Insects have evolved ears at least 17 times in different lineages, said Smith, also an assistant professor in CU-Boulder’s geological sciences department. Smith and Plotnick are trying to figure out when different insects got their ears, and whether predators may have played a role.
Modern insects use their ears to tune in to each other’s chirps, trills and peeps. Think of the chorus of crickets, or the love songs of cicadas. But many species can also pick up sounds beyond the range of human hearing, such as the high-pitched sonar of night-hunting bats, according to Smith and Plotnick.
Crickets, moths and other flying insects have ultrasound-sensitive hearing and can hear bats coming, diving or swerving in midflight to avoid being eaten. Insects that evolved such supersensitive hearing would have had a crucial survival advantage, the researchers said.
“The big evolutionary trigger for the appearance of hearing in many insects is thought to be the appearance of bats,” Plotnick said. “Prior to the evolution of bats we would expect to find ears in relatively few insects, but after that we should see ears in more insect groups,” he explained.
Did insect ears get an upgrade when bats came to be? Before this study the fossil evidence for insect hearing was too poorly preserved or scantily described to know for sure, according to the researchers.
To find out, Plotnick and Smith turned to remarkably well-preserved fossils from a series of lake deposits in Wyoming, Utah and Colorado known as the Green River Formation, where some of the earliest bats are found.
Roughly 50 million years ago, fine-grained sediment covered and buried the animals that lived there and managed to preserve them in exquisite detail. “You can see every tiny feature down to the veins in their wings and the hairs on their legs,” said Smith, who has been studying Green River fossils for more than 15 years.
For this study, the researchers examined fossils from a Green River site in Colorado, focusing on crickets and katydids, which have ears on their front legs, just below their knees.
The team scoured more than 500 museum drawers of Green River fossils for crickets and katydids with intact front legs, looking for evidence of ears. “You can just make them out with the naked eye,” Plotnick said. “They look like the eye of a needle.”
In crickets and katydids living today, the ear is a tiny oval cavity with a thin membrane stretched over it that vibrates in response to sound, much like our own eardrum.
The fossil ears measured half a millimeter in length, and were virtually identical in size, shape and position to their modern counterparts. The findings suggest that this group of insects evolved their supersensitive ultrasonic hearing long before bat predators came to be, the researchers say. “Their bat-detecting abilities may have simply become apparent later,” Smith said. “The next step is to look for ears in other insect groups.”
The study appears in this month’s issue of the Journal of Paleontology. NESCent is a nonprofit science center dedicated to cross-disciplinary research in evolution and is jointly operated by Duke University, the University of North Carolina at Chapel Hill and North Carolina State University, with funding from the National Science Foundation.
-CU-
No consensus for GMOs, pesticides, “experimental farming” in #Boulder County’s cropland policy
Dec 13th
Commissioners to consider Cropland Policy at Dec. 20 public meeting
Boulder County, Colo. – The Boulder County Commissioners will deliberate on public testimony and comments received concerning the Cropland Policy Advisory Group’s (CPAG) policy recommendations for Boulder County Open Space croplands on Dec. 20 from 1-3 p.m.
What: Public meeting for the Board of County Commissioners to consider the proposed Cropland Policy for Boulder County Open Space agricultural lands
When: Tuesday, Dec. 20 at 1 p.m.
Where: Commissioners’ Hearing Room, Boulder County Courthouse, third floor, 1325 Pearl St.
Alternative viewing: Watch the meeting live online the day of the deliberations
The meeting on Dec. 20 is open to the public, but no further public testimony will be taken. All comments submitted to the commissioners via regular mail, electronic mail, phone calls and in-person testimony leading up to the Dec. 20 meeting date will be taken into consideration.
The meeting will be Web streamed live on Dec. 20. Members of the public can view the meeting online at:www.bouldercounty.org/government/pages/hearings.aspx. A taped version of the meeting will also be posted on the website as part of the commissioners’ video archive.
Background
The CPAG, consisting of nine members appointed by the commissioners, held meetings over a nine-month period to create a comprehensive Cropland Policy for Boulder County Open Space agricultural lands. The policy recommendations address soil health, economic sustainability, pest management, program administration, water, livestock, recreation and natural resource protection on agricultural lands. Through a consensus process, CPAG developed more than 80 policy recommendations. Three areas failed to achieve consensus: genetically engineered crops, use of certain pesticides, and experimental farming practices.
On Dec. 8, the county commissioners held a public hearing attended by more than 500 people, many of whom signed up to speak. At the hearing, the commissioners and attendees received a staff presentation on the county’s existing practices and programs, an overview of CPAG’s recommendations and a summary of input from the Food and Agriculture Policy Council (FAPC), the Parks and Open Space Advisory Committee (POSAC), and Parks and Open Space staff. The presentation was followed by 8 ½ hours of open public comment.
Members of the public have been providing input over the nine-month period, and all comments have been recorded as part of the public record. In addition to the many open meetings and hearings held by CPAG as they formed their recommendations for the cropland policy, several subsequent public meetings have been held to consider the draft policy: a staff presentation and joint public hearing on Nov. 15 to FAPC and POSAC, FAPC deliberations on Nov. 16, POSAC deliberations on Nov. 17, and the public open comment hearing with the Board of County Commissioners on Dec. 8.
For a copy of the Cropland Policy provided to the commissioners and information about the policy, please visit the Cropland Policy website or contact Resource Planner Jesse Rounds at 303-678-6271 or croplandpolicy@bouldercounty.org.
CU’s VOYAGERS 1, 2, 3 are boldly going, and going and going
Dec 13th
AS VOYAGER 1 NEARS EDGE OF SOLAR
SYSTEM, CU SCIENTISTS LOOK BACK
In 1977, Jimmy Carter was sworn in as president, Elvis died, Virginia park ranger Roy Sullivan was hit by lightning a record seventh time and two NASA space probes destined to turn planetary science on its head launched from Cape Canaveral, Fla.
The identical spacecraft, Voyager 1 and Voyager 2, were launched in the summer and programmed to pass by Jupiter and Saturn on different paths. Voyager 2 went on to visit Uranus and Neptune, completing the “Grand Tour of the Solar System,” perhaps the most exciting interplanetary mission ever flown. University of Colorado Boulder scientists, who designed and built identical instruments for Voyager 1 and Voyager 2, were as stunned as anyone when the spacecraft began sending back data to Earth.
The discoveries by Voyager started piling up: Twenty-three new planetary moons at Jupiter, Saturn, Uranus and Neptune; active volcanoes on Jupiter’s moon, Io; Jupiter’s ring system; organic smog shrouding Saturn’s moon, Titan; the braided, intertwined structure of Saturn’s rings; the solar system’s fastest winds (on Neptune, about 1,200 miles per hour); and nitrogen geysers spewing from Neptune’s moon, Triton.
Amazingly, both spacecraft have kept on chugging (if one can call 35,000 miles per hour chugging). NASA announced last week that Voyager 1 — about 11 billion miles from Earth — has now sailed to the edge of the solar system and is expected to punch its way into interstellar space in a time span ranging from a few months to a few years. Voyager 2 is not far behind, but on a different trajectory. –
Charlie Hord, a former planetary scientist at CU-Boulder’s Laboratory for Atmospheric and Space Physics, remembers the salad days of the Voyager program, which was managed by NASA’s Jet Propulsion Laboratory in Pasadena. Hord, the principal investigator for a time on the LASP instrument known as a photopolarimeter built for Voyager, still shakes his head in wonder as he recalls some of the discoveries.
“All of the scientists were dazzled by the pictures of the moons of Jupiter and Saturn coming back,” recalled Hord, 74, who still lives in Boulder. “To finally look at them up close was the most remarkable thing I’ve ever seen in my life.” Since the early Voyager days were pre-Internet, “We used to send people over to the JPL newsroom to steal press kits so we could look at the pictures taken by the imaging team,” he laughs.
The LASP photopolarimeter, a small telescope that measured the intensity and polarization of light at different wavelengths, was used for a variety of observations during the mission. The instrument helped scientists distinguish between rock, dust, frost, ice and meteor material. And it helped scientists determine the structure of Jupiter’s Great Red Spot, which Hord called “a giant hurricane that has blown for 200 years,” as well as the properties of the clouds and atmospheres of Jupiter, Saturn Uranus and Neptune, and Saturn’s largest moon, Titan.
The CU-Boulder instrument also was used to learn more about the makeup of the Io torus, a doughnut-shaped ring around Jupiter formed by volcanic eruptions from its moon, Io, as well as determining the distribution of ring material orbiting Saturn, Uranus and Neptune and the surface compositions of the outer planet moons.
One of the finest mission moments for Hord was analyzing the data returned from the photopolarimeter when it was locked on the star Delta Scorpii as it emerged from behind Saturn and passed behind the elegant rings in a “stellar occultation” when the light from a star is blocked by an intervening object. The processed photopolarimeter data showed each ring was made up of numerous smaller ringlets. “They were beautiful — they looked just like the grooves on a phonograph record,” he said.
On the off chance either spacecraft is encountered by an alien civilization, each are carrying what are known as “Golden Records” — gold-plated copper, audiovisual phonograph records with greetings in 54 languages, photos of people and places on Earth, the sounds of surf, wind, thunder, birds and whales, diagrams of DNA and snippets of music ranging from Bach and Beethoven to guitarist Chuck Berry’s classic rock-and-roll song, Johnny B. Goode. The spacecraft even carries a stylus set up in the correct position so that aliens could immediately play the record, named “Murmurs from Earth” by Carl Sagan, who conceived the Golden Record effort.
“I thought adding the Golden Record to the mission was a neat thing to do,” said Hord. A guitar player himself who performs jazz and Big Band music with a trio that visits Boulder retirement homes, Hord recalled that JPL threw the Voyager team a party to celebrate the end of Voyager 2’s Grand Tour as it passed by Neptune in 1989 (Pluto was in a distant part of its orbit at the time). “We even had Chuck Berry playing his guitar on the steps of the Jet Propulsion Laboratory,” he said. “It was really something.”
In 1990, Voyager 1 turned around one last time and took a portrait of the solar system — a sequence of photos that revealed six of the nine planets in an orbital dance. From nearly 4 billion miles away, Earth took up only a single pixel.
“To me, Voyager was the most fun and interesting planetary mission ever,” said Hord, who enlisted the help of then-graduate students Carol Stoker (now a NASA planetary scientist) and Wayne Pryor (now a professor at Central Arizona University) to analyze data from the mission. Over its lifetime, the CU-Boulder photopolarimeter science team also included LASP Professor Larry Esposito, Senior Research Associate Ian Stewart, retired faculty members Karen Simmons, Charles Barth and Robert West, as well as tireless work by many undergraduate and graduate students.
Esposito, who is still at LASP and is the principal investigator on a $12 million CU-Boulder instrument package aboard NASA’s Cassini Mission to Saturn, said his biggest thrill of the Voyager mission was the Neptune fly-by in 1989 when the gas giant “went from being a small blurry dot to a planet with bright clouds and numerous moons and rings. “Triton erupted before our eyes, and Neptune’s partial rings were punctuated and variable like a type of sausage that the French make.”
Then-CU President Gordon Gee was so impressed with the blue image the LASP team made of Neptune’s ring system that he used it on his Christmas cards, said Esposito, a professor in the astrophysical and planetary sciences department.
Esposito believes the biggest discovery by CU-Boulder’s Voyager photopolarimeter team was the intricate structure of Saturn’s F ring — a ring he discovered in 1979 using data from NASA’s Pioneer 11 mission. The CU-Boulder team determined the faint F ring was made up of three separate ringlets that appeared to be braided together, and that the inner and outer limits of the ring were controlled by two small “shepherd satellites.”
In addition, Esposito said that density waves — ripple-like features in the rings caused by the influence of Saturn’s moons — allowed the team to estimate the weight and age of Saturn’s rings.
As for Hord, the Casper, Wyo., native went on to be the principal investigator for two spectrometers designed for NASA’s Galileo Mission to Jupiter that launched in 1989 to tour the Jovian system, including its bizarre moons. Hord officially retired in 1997, but returns to campus for occasional visits with his colleagues.
In 40,000 years, Voyager 1 will float within 9.3 trillion miles of the star AC+793888 in the constellation Camelopardalis. In 296,000 years, Voyager 2 will pass within 25 trillion miles of Sirius, the brightest star in the sky. Perhaps on the way, the spacecraft will encounter some musically inclined aliens up for a little Bach, Beethoven or Berry.
-CU