Darwin Tunes: Scientists Examine How Consumer Choice Can Drive the Evolution of Music from Noise

Image Courtesy: Flickr User all that improbable blue (CC)

Here's an application of evolutionary theory you don't see everyday: the evolution of music by natural, make that public selection.

Researchers from the Department of Life Sciences at the Imperial College of London and the Media Interaction Group at the National Institute of Advanced Industrial Science and Technology in Tsukuba, Japan joined forces to investigate how consumer preferences--as opposed to directed artistic efforts--can affect the evolution of music.  They set out to answer some very interesting questions, including:  Is it possible to make music without a composer? If so, what kind of music is made? What limits the evolution of music?

Inspired by research on evolution in microbes and studies on how art and music develop and change in response to cultural forces, the team created "Darwin Tunes," a computer-based system for simulating natural selection within a "population" of audio clips. Darwin Tunes is powered by an algorithm that creates "digital genomes"--computer programs, which, when executed, create short loops of sound. Like a biological genome that serves as a blueprint for an organism, each digital genome specifies certain parameters--in this case things like instrumentation and note placement. The algorithm does not receive any melodies, rhythms, or other human-created sounds as inputs, so the music created by Darwin Tunes is truly computer-generated.

Running the algorithm once produces a population of 100 audio loops that go through a number of "life cycles" during the course of the experiment. Which loops get to "reproduce" and which "die off" is determined by the ratings given by a group of nearly 7,000 human listeners who use a five-point scale ranging from "I can't stand it" to "I love it." Those clips that are deemed most pleasing reproduce and those that are hard-on-the-ears go extinct. In evolutionary terms, listener ratings are the "selective pressure" acting on the population.

As with living organisms, the offspring of the audio loops differ from their parents for reasons that also mirror biological evolution.  Each audio loop in the second generation is produced by combining the genomes of two first-generation loops (akin to sexual reproduction in nature). The genomes of the second generation are also modified with new, random musical "genetic material" akin to DNA mutations in nature. Each new generation is again rated by listeners.

By repeating this process a few thousand times, the research team found that clips changed over time--moving from sound that would most aptly be called "noise" to sound that qualified as "music." The difference is easy to hear in the clips below, which contain loops produced initially by Darwin Tunes (generation zero), loops from generation 1,500, and loops from generation 3,000.


Generation Zero

Generation 1500

Generation 3000

As any musician or music lover can tell you, the qualities that make a piece of music appealing are complex. To better understand which traits were being "selected for" in the Darwin Tunes populations, the researchers looked to the emerging field of music information retrieval (MIR) technology. MIR is what allows services like Pandora and iTunes to suggest new music based on the songs already on a user's playlist. Using two MIR algorithms to analyze the various generations of clips (both those that evolved with listener input and controls that were randomly assigned ratings), the researchers identified two specific traits that were changing over time: the presence of chords commonly used in popular music and the complexity of rhythmic patterns in the music.

While these two features are clearly important, the researchers conclude that there are many other musical factors in the evolution of these clips and that additional experiments using a wider variety of MRI algorithms would be interesting. The results of the study appear in today's early online edition of the Proceedings of the National Academy of Sciences. You can listen to and rate clips by visiting the Darwin Tunes website.

For more about evolution and natural selection, browse our modules on Adaptation and Charles Darwin (and don't miss Part 2 or Part 3!).


Want to read more about the science of music? Check out the research conducted by the Pattern Analysis and Intelligent Systems Research Group at the University of Bristol. Their work to develop a mathematical equation that can predict hit songs was presented in December 2011 at the 4th International Workshop on Machine Learning and Music. Visit their Score a Hit website or download the short paper that appeared in the conference proceedings.

Image of the Week: Deep Sea Life Under Pressure

Image Courtesy: NOAA Ocean Explorer and Kevin Raskoff, California State University, Monterey Bay. (CC)

This stunning red deep sea jellyfish from the genus Crossota was photographed during the "Hidden Ocean Expedition" in 2005. That summer, a team of scientists from the United States, Canada, China and Russia embarked on a journey to explore the frigid depths of the Canada Basin, one of the deepest parts of the Arctic Ocean. This jelly, our image of the week, is just one of the many beautiful, bizarre, and mysterious creatures that inhabit the deep sea.

To many scientists, the deep sea (generally defined as below 200 meters) is the Earth's last frontier, and it remains one of the least explored places on our planet. In human history, 12 people have walked on the moon but only three have ever been to the deepest part of the ocean--an area called Challenger Deep in the Mariana Trench. And we know relatively little about the lifeforms that call the deep sea home. Which species live there? How do their ecosystems function? Physiologically, how do they withstand the extreme high pressure?

This week's issue of Science News features several scientists who are coming up with inventive ways to answer these questions, including a contraption called the Abyss Box. Check out Susan Gaidos' feature story Defying Depth to learn more.

For more images of incredible deep sea creatures, browse NOAA's Aliens from the Deep gallery.

Beach Reads of the Science Variety

Looking for some titles to add to your summer reading list?
Check out some of the Visionlearning team's favorite books.  
Photo courtesy: Flickr User cmcgough. (CC)

Temperatures are on their way up and the swimming suits are coming out of hiding, which can only mean one thing: summer break. Before you buy the latest "beach lit" paperback to while away those sunny hours or download the entire Twilight saga to your e-reader, consider this humble suggestion: this summer, try a page-turner of the science variety.

Think we're joking? Not hardly.  The stories of science are full of complex and intriguing characters who experience, and are shaped by, all the same things as their fictional counterparts--conflict, mistakes, rivalry, passion, doubt, discovery, and luck, to name a few.  But these stories are even more compelling because they are true.

To get you started, we took a quick survey of the Visionlearning team's favorite (nonfiction) science books. They are a combination of recent releases and trusty classics, spanning the range of disciplines. This is by no means a comprehensive list, and we hope you will help improve it by critiquing our suggestions and offering up favorite titles in the comments section below. Happy reading!

ASTRONOMY
Death by Black Hole and Other Cosmic Quandaries by Neil deGrasse Tyson
This collection of witty essays from well-known astrophysicist and science communicator Neil deGrasse Tyson runs the gamut, exploring what would happen if you actually fell into a black hole, the most egregious astronomy errors on the big screen, and everything in between.

The Day We Found the Universe by Marcia Bartusiak
In a book that is part scientific thriller, part character-driven drama, Marcia Bartusiak describes the exciting early days of modern astronomy in the United States. The characters, some of whom are rarely mentioned in pages of textbooks, show how breakthroughs are often not single moments of brilliance, but a collection of hard work, imagination, rivalry, and luck.


BIOLOGY
The Immortal Life of Henrietta Lacks by Rebecca Skloot
One of science's unsung heroes, Henrietta Lacks was a poor tobacco farmer from Virginia whose cells (taken without her consent) were grown in culture and used throughout decades of medical research on polio, cancer, the effects of radiation exposure, and much more. Yet Lacks died virtually unknown, and her family never received compensation from the multi-billion dollar industry that her cells made possible. Science writer Rebecca Skloot offers a riveting look at Lacks' story and her legacy, weaving together biology, business, ethics, and the ties that bind families together.

Stiff: The Curious Lives of Human Cadavers by Mary Roach
Science writer Mary Roach blends humor, science, and old-fashioned grossology as she explores the fascinating exploits and scientific contributions of human bodies--after they're dead.

The Reluctant Mr. Darwin by David Quammen
As a winner of the John Burroughs Medal, David Quammen is known for his nature writing, but his ability to write about human nature and all our quirks and foibles is equally impressive. This book takes readers back to the 19th century to trace the journey of Charles Darwin--not so much his fabled voyage aboard the HMS Beagle,  but his intellectual and emotional struggle to understand the evidence for natural selection piling up before him.

Evolution's Rainbow by Joan Roughgarden
Evolutionary biologist Joan Roughgarden takes readers on a fascinating tour of sexual diversity among fish, reptiles, amphibians, birds, and mammals, challenging traditional notions of gender and sexuality in the animal kingdom and human society.

The Journey of Man by Spencer Wells
Using DNA as a guide, population geneticist Spencer Wells maps all of human history, from our earliest common ancestor to the global diversity we see today, and illuminates the surprising links that connect all of humankind.


CHEMISTRY
The Invention of Air by Steven Johnson
Prolific author Steven Johnson tells the quirky, dramatic story of Joseph Priestley--an 18th century scientist, minister, and associate of Benjamin Franklin and Thomas Jefferson, whose intellectual contributions spanned chemistry, theology, and politics.

The Periodic Table by Primo Levi
Writer, chemist, and Holocaust survivor Primo Levi blends memoir and science writing to tell the beautiful, poignant stories of his life and community--using one element from the periodic table to anchor each chapter.


EARTH SCIENCE
The Two-Mile Time Machine by Richard Alley
Climatologist  Richard Alley offers a glimpse into the world of a climate sleuth and a history of Earth's climate as written in the rings of Greenland's ice cores.

Basin and Range by John McPhee
A classic from Pulitzer Prize-winner John McPhee, Basin and Range is a poetic exploration of the rugged terrain along Interstate-80 through Utah, Nevada, and California--and the geologic processes that created it. A great book for anyone who has ever looked at a landscape and wondered how it came to be.

The Map that Changed the World by Simon Winchester
Prolific journalist and author Simon Winchester chronicles the story of William Smith--a British coal miner whose on-the-job observations of patterns in rock layers and fossils beds led him to develop the first geologic map of the strata beneath the Earth's surface. The map was not greeted with the acclaim one might expect, but Smith and the power of his idea ultimately triumphed.


ENVIRONMENTAL SCIENCE & NATURE WRITING
Last Child in the Woods by Richard Louv
Journalist Richard Louv examines the body of research showing how healthy childhood development is linked with direct exposure to the natural world and makes a compelling case that the current "wired generation" is seriously threatened by "nature deficit disorder."

The Omnivore's Dilemma by Michael Pollan
From the dizzying overabundance of a modern supermarket to the quiet intensity of wild mushroom gathering, Michael Pollan tackles the seemingly simple but ultimately profound question: what should we have for dinner?

The Sea Around Us by Rachel Carson
Today, marine biologist Rachel Carson is probably best remembered for her book Silent Spring and its role in chronicling the effects of pesticides and jumpstarting the American environmental movement. But a decade earlier, in 1951, Carson penned this beautiful, best-selling treatise on the science and poetry of the sea.

The Whale and the Supercomputer by Charles Wohlforth
Journalist and lifelong Alaskan Charles Wohlforth takes readers on a journey to the far North, where climate change is very tangible--to both the scientists studying it and the native people struggling to cope with it.


PHYSICS
How to Teach Physics to Your Dog by Chad Orzel
Physicist Chad Orzel, and his curious dog, Emmy, offer a fun, engaging, and truly unique way to explore quantum mechanics. By considering such practical questions as how to catch a squirrel or locate a bone, Orzel and Emmy dig into the history and technical details of weighty topics like particle-wave duality, the Heisenberg Uncertainty Principle, and quantum entanglement.

Einstein: His Life and the Universe by Walter Isaacson
Acclaimed biographer Walter Isaacson examines the life and world-changing ideas of Albert Einstein. Like many icons of history and science, Einstein is surrounded by legends, and Isaacson offers an interesting new take on what is fact and what is folklore.


TECHNOLOGY & ENGINEERING
The Code Book by Simon Singh
Physicist-turned-award-winning-journalist Simon Singh explores the history and science underlying the secret world of codes and cryptography from Egyptian hieroglyphics to Internet security.

The Human Factor by Kim Vincente
If you've ever felt confused, frustrated, or even endangered by the very technology that is supposed to make life easier and safer, you are not alone. Scientist and engineer Kim Vincente offers a compelling look at how technology has failed us and how we can make dramatic improvements in our satisfaction and safety by factoring the realities of human needs, limits, and habits into technology design.

Biomimicry: Innovation Inspired by Nature by Janine Benyus
Writer, educator, and sustainability consultant Janine Benyus presents a simple but powerful strategy for good design: ask nature. She argues, using compelling examples, that we can learn to design cleaner, more efficient products and technologies by studying nature's 3.8 billion-year record of innovation.


INTERDISCIPLINARY READS
A Short History of Nearly Everything by Bill Bryson
Renowned travel and nature writer Bill Bryson offers a quick and cheeky tour of, well…everything, from the beginning of the universe to the rise of modern human society. Not content to simply rehash what we know, Bryson takes readers on a thoroughly entertaining and enlightening quest to understand how we know what we know.

Merchants of Doubt by Naomi Oreskes and Eric Conway
Science historians Naomi Oreskes and Eric Conway shine the light on a group of high-level scientists who have repeatedly been the voices of dissent on topics like acid rain, climate change, DDT, and secondhand smoke and examine what can happen when scientific research is at odds with political motives.

Finally, we would be remiss not to mention Visionlearning's own book: The Process of Science by Anthony Carpi and Anne Egger
Using examples drawn from everyday life as well as historical case studies from nearly every branch of science, Carpi and Egger offer a clear and concise explanation of how science really works. While that may not sound like the first thing you'd normally toss in your beach bag, The Process of Science is an easy read and great way to reinvigorate (or start) a thirst for scientific thinking. If you're a student considering a career in science or a teacher looking for resources to help students engage in science, this is a must-read.

Video of the Week: Science (and Math) on Ice

Tonight the Los Angeles Kings and the New Jersey Devils will suit up and hit the ice for the first game of the National Hockey League (NHL) Stanley Cup Finals. The players probably won't be thinking about Newton's Laws of Motion while being checked against the glass or how they make use of kinetic and potential energy to launch that 160 kilometer per hour slapshot, but a hockey game is a fast and furious demonstration of many of the key concepts of physics.

In fact, a careful observer can see physics, statistics, geometry, and biology all at work in the rink. Even if you're not a hockey fan, the speed, power, and reaction time of NHL players is undeniably impressive, and the Science of NHL Hockey video series from the National Science Foundation and NBC Learn offers a view you can't get from the nosebleed seats. We're crowning the segment entitled "Work, Energy, and Power" our video of the week, but they are all worth a watch.



For more videos from the Science of NHL Hockey series, visit the NSF's Science360 Network.

For ideas from the National Science Teachers Association about how to incorporate these videos into lesson plans for high school and junior high students, visit NBC Learn. (Scroll down, select a lesson plan, and then click on full-screen mode to read the document.)

Image of the Week: Solar Eclipse Dazzles

This past Sunday, observers in and parts of Southeast Asia and North America witnessed an annular solar eclipse--an arrangement in which the moon shades out most but not all of the sun, leaving a bright ring around the dark lunar form. Although Earth-bound viewers couldn't look at the eclipse directly with naked eyes, the Hinode spacecraft snapped some dazzling shots, including the one below. Hinode, a joint venture between NASA and the Japan Aerospace Exploration Agency (JAXA), is cruising in low-Earth orbit to help scientists study the sun's magnetic field and energy releases.

A picture of the annular solar eclipse on May 20, 2012, captured by the Hinode spacecraft.
Image Courtesy: NASA Goddard Space Flight Center

To see more images of the eclipse and the wild shadows it created, visit the 2012 Annular Solar Eclipse Group on Flickr.

Then tell us: did you witness the eclipse? Where were you, and how did you view it?

Video: Virtual Tour of Vesta Asteroid with Data from NASA's Dawn Spacecraft

Call it a giant asteroid. Call is a planetoid. Scientists call it Vesta--a 300 mile wide celestial body in the asteroid belt between Mars and Jupiter that, in some ways, bares a striking resemblance to a rocky planet like Earth. NASA's Dawn spacecraft has been orbiting Vesta since July 2011 collecting data and taking photographs.

Last week, scientists released a bevy of images and information about Vesta, including data confirming that Vesta is indeed structured like a planet with an iron core and that it separated into layers (crust, mantle, etc.) as it formed. (For more information about the structure of our own planet, see our module on Earth's Structure.) Vesta's topography is also quite varied, exhibiting landslides, craters, and a mountain twice the height of Mt. Everest. Using data from Dawn, NASA's Jet Propulsion Laboratory created this ethereal virtual tour of Vesta's surface.

Video Courtesy: NASA Jet Propulsion Laboratory California Institute of Technology

For more information, check out NASA's Dawn news page or some of the widespread media coverage from the New York Times, Nature, and the LA Times, among others.

Next Generation Science Standards Open for Public Comment through June 1

Among other things, the Next Generation Science
Standards aim to emphasize the process and practice of
science.   Photo Courtesy: Argonne National Laboratory (CC)

Today, a draft of the Next Generation Science Standards was released for a three-week public comment period. The new Standards are based on the National Research Council’s (NRC) Framework for K–12 Science Education and are the first update since the original National Science Education Standards were released in 1996.

Among other things, the new Standards are intended to place a broader emphasis on the process and practice of the scientific enterprise. This is highlighted by the fact that the very first Dimension of the Framework on which the Standards are based is entitled Practices, and is meant to describe how scientists work. This is an ambitious and long-overdue goal, and we are excited to see more emphasis placed on it.

Over the past decades, science education has migrated away from teaching about science and has migrated towards conveying facts and figures. As Bruce Alberts, editor of the journal Science has said, “Rather than learning how to think scientifically, students are generally being told about science and asked to remember facts.”

There are many reasons proposed to explain this migration—an emphasis on standardized test performance, lack of specialized teacher preparation, etc. But probably the most reasonable of these explanations is the fact that science textbooks fail to describe the scientific process and instead present science as a series of facts and predetermined endpoints.

In his landmark book, The Structure of Scientific Revolutions, published almost 50 years ago today, Thomas Kuhn wrote:

Textbooks thus begin by truncating the scientist’s sense of his discipline’s history and then proceed to supply a substitute for what they have eliminated. …Yet the textbook-driven tradition in which scientists come to sense their participation is one that, in fact, never existed.

To educate students about science, we need to present the discipline as it is practiced, not as a series of inevitable facts discovered by fate.

In 2006, we began an initiative to develop a series of modules that expressly describe the Process of Science. This initiative—possibly better described as an ongoing journey—has been both incredibly rewarding and at times slightly maddening. As the core authors of the Process content, Anne Egger and I have invested thousands of hours into researching these ideas, writing about them, editing, rewriting, and eventually launching these to the public.

Writing some of these modules was relatively straightforward. For example, there is an extensive literature underscoring the concept of Scientific Ethics, and there are well defined ideas about how a scientific Experiment differs from a Comparative study. However, there is less written about many other core ideas underscoring scientific practice such as how and why individual scientists collaborate, how subjectivity affects data interpretation, and how error and uncertainty in data are quantified and expressed. Still other concepts that need explaining, such as “What is the Scientific Method?” or “How does scientific knowledge differ from other types of knowledge?” are sometimes defined by scientists in the same way Supreme Court Justice Potter Stewart defined pornography in 1964: “I know it when I see it.”

In fact, Nobel laureate Sir Peter Medawar once said, “Ask a scientist what he conceives the scientific method to be and he adopts an expression that is at once solemn and shifty-eyed: solemn, because he feels he ought to declare an opinion; shifty-eyed because he is wondering how to conceal the fact that he has no opinion to declare.”

We hope that the Next Generation Science Standards will help catalyze a shift back towards teaching about science as it is practiced. In the meantime, please join us in reviewing the new Standards and submitting comments to make sure they emphasize the practices used by scientists.  Comments are due by June 1.

Need help getting started?  The National Science Teachers Association has created a “study guide” for organizing a group discussion, including questions to consider for each section of the new standards (see page 11).