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Which came first: the chicken or the egg?
The age-old question, finally answered. Kind of.
- It's one of the oldest—and easiest to picture—philosophical conundrums of our time.
- It can be best answered by combining two of the most popular takes on it.
- Even so — there's a reason the question has been asked for at least 2,000 years.
Which came first, the chicken or the egg? It's the kind of question children ask each other on the playground in a bid to blow minds. Others include "Could your color red be my color blue?" and "How do I know the world exists outside my mind?" and "What is the meaning of life and all that stuff?"
Turns out, children are natural philosophers, comfortably tackling the problems doctorate-brandishing philosophers have been debating for centuries — albeit without the highfalutin language. Can we describe qualia to others? Can we epistemologically attest for consciousness outside our own minds? Is there a telos the universe?
Each of these questions deserves exploration, but as the headline suggests, today we'll be exploring the enduring predicament of chickens and eggs. Here's your guide to finally understanding the chicken-and-egg problem.
The problem in an eggshell
Flickr, Creative Commons
All chickens hatch from eggs, and all eggs are laid by chickens. This fact is nothing special; everything depends on a preexisting something for its existence. Schoolyard bewilderment sets in when our imaginations trace this line of thought back as far as possible.
Where did the first chicken come from? It came from an egg. Okay, where did that egg come from? It came from a chicken. Fair enough, but where did that chicken come from? An egg. And that egg? A chicken. And on and on, until we get bored and decide to swing on the monkey bars.
This is called infinite regression: the initial link in the causal chain (chickens come from eggs) is supported by the truth of a second link (eggs come from chickens), but that proposition can only be true if the first one is beforehand. It's the logical equivalent of standing between two mirrors so that infinite yous extend on forever.
Infinite regression inevitably leads to a dilemma. Everyday experience tells us that no effect can occur without an initial cause. But the chicken-and-egg problem makes it impossible to tell cause from effect. Each relies on the other, but it is logically unsatisfactory to say history is an endless cycle of chickens and eggs.
So which one was first?
The philosopher’s chicken
Creative commons: John Towner.
Plutarch was the first person to describe the chicken-and-egg problem, writing in his Symposiacs: "Soon after [Alexander] proposed that perplexed question, that plague of the inquisitive, Which was first, the bird or the egg?" The gathered symposiasts then debate the matter, but the discussion quickly moves beyond metaphorical chickens and eggs to tackle the "great and weighty problem" of "whether the world had a beginning."1
While Plutarch gave the problem its favored form, the tradition of questioning first causes goes back to at least the Ancient Greeks. The Greeks realized that the world, the universe, and everything must have had a beginning, but what caused it to come into being? And even if you solve that, what caused that cause to come into being?
Aristotle answered this causal quandary with the "unmoved mover" — an eternal, motionless substance or energy that can neither come into nor go out of existence yet started the causal chain that led to the universe.
Framing Aristotle's concept in the language of the chicken-and-egg problem, let's call this unmoved hen Chicken Prime. Far more than Optimus's cowardly sibling, Chicken Prime is the initial chicken that began the causal chain of all chickens and eggs to come. But unlike other chickens, Chicken Prime requires no cause to explain her existence. She did not come into being, but has always existed out of rational necessity.
As you can see, this unmoved mover is a short hop away from the Judeo-Christian-Islamic concept of God, and for this reason, Aristotle was favored by many influential medieval philosophers. Thomas Aquinas drew from Aristotle to develop his five arguments for the existence of God, called the Five Ways.
As summarized in the Oxford Dictionary of Philosophy, the first two of these five arguments go like this: "Motion is only explicable if there exists an unmoved, first mover" and "[t]he chain of efficient causes demands a first cause."2 The first argument is cribbed directly from Aristotle. The second solves the chicken-and-egg problem if you accept its premise.
An infinite chain of causes demands a foundational cause, and for Aquinas, that foundation is God. According to Genesis, God created animals first, so the chicken came first. More importantly, God stands as the initial cause for all things. This is called the first-cause argument.
Of course, the first-cause argument is not without its detractors. Bertrand Russell argued that the very argument contradicts itself. If every event must have a preceding cause, he argued, then the very idea of a first cause would be contradictory.2 It is logical sleight of hand.
The scientist’s egg
The philosopher's chicken is metaphorical, so let's restate the question from a technical perspective. Which came first, actual chickens or actual eggs? At this juncture, scientific evidence allows us to solve the problem. The answer, it turns out, is the egg.
Modern birds evolved from small, carnivorous dinosaurs. The first intermediate species between birds and therapods, such as Archaeopteryx, lived during the late Jurassic, and the true ancestor of birds probably arrived during the late Cretaceous.3 This lineage tells us that birds evolved much later than dinosaurs or ancient reptiles, both of which laid eggs. As such, the egg must have come first.
But this answer sidesteps the question, doesn't it? What we really want to know is: Which came first, the chicken or the chicken egg? Even phrased liked this, the egg wins out.
Chickens have a labyrinthine genealogy. The earliest fossil evidence for the species' domestication appears in northeastern China and dates to around 5,400 BCE; however, the chicken's wild ancestors were likely the junglefowl of southeast Asia.
Its primary progenitor includes the red junglefowl (Gallus gallus), but scientists have identified other species that bred with G. gallus on its way to chickenhood. One of them, the grey junglefowl of southern India, is thought to have given the modern chicken its yellow skin — leaving scientists befuddled as to whether chickens were domesticated in southeast Asia before spreading outward, or if their progenitors were domesticated in several locations before being brought together.4
Either way, the chicken lineage is one of many wild and domesticated fowl being interbred. At one point in this history, two chicken-like birds — let's call them a proto-rooster and proto-hen — mated, and the proto-hen laid a clutch of eggs. One of these eggs housed an offspring with DNA mutations, resulting in what we would consider the first chicken.5
In time, this offspring's offspring would diverge enough for speciation, but since the proto-hen produced the egg the chicken was born from, we can safety say the egg came first.
Or, as Neil DeGrasse Tyson succinctly put it: "Just to settle it once and for all: Which came first the Chicken or the Egg? The Egg – laid by a bird that was not a Chicken[.]"
Chicken Prime or the Cosmic Egg?
Thanks to science, we know the egg came before the chicken, but we haven't really settled the debate that led Plutarch to raise the question millennia ago.
We've discovered many links in the causal chain of the universe. We know that life on Earth came to be through a process called evolution and that the Earth accreted from rocks and debris orbiting the Sun and that the Sun formed when gravity pulled in immense amounts of dust and gas together and that the universe sprang forth from a high-density, high-temperature state. But that's as far back as we can manage.
As astrophysicist Paul Sutter wrote: "Earlier than 10^-36 seconds, we simply don't understand the nature of the universe. The Big Bang theory is fantastic at describing everything after that, but before it, we're a bit lost. Get this: At small enough scales, we don't even know if the word 'before' even makes sense!"
Even with our accumulated knowledge, there's always another link in the causal chain, another first cause in need of a mover, another egg in need of a chicken.
As such, children and philosophers can still get mileage out of the chicken-and-egg problem. They just need to tweak the wording a bit. How about this: Which came first, Chicken Prime or the Cosmic Egg?
1. Symposiacs (Book II: Question 3). Plutarch. The University of Adelaide Library. Last updated Dec. 17, 2014. Retrieved on Aug. 10, from https://ebooks.adelaide.edu.au/p/plutarch/symposiacs/complete.html#section15.
2. Oxford Dictionary of Philosophy. Simon Blackburn. Oxford University Press; Oxford. 2008. Pg. 135.
3. The origin of birds. Understanding Evolution, UC Berkley website. Retrieved on Aug. 9, from https://evolution.berkeley.edu/evolibrary/article/evograms_06.
4. How the chicken conquered the world. Andrew Lawler and Jerry Adler. Smithsonian.com. Retrieved on Aug. 9, from https://www.smithsonianmag.com/history/how-the-chicken-conquered-the-world-87583657/
5. FYI: Which came first, the chicken or the egg? Daniel Engher. Popular Science. Retrieved on Aug. 9, from https://www.popsci.com/science/article/2013-02/fyi-which-came-first-c
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All this from a wad of gum?
- Researchers recently uncovered a piece of chewed-on birch pitch in an archaeological dig in Denmark.
- Conducting a genetic analysis of the material left in the birch pitch offered a plethora of insights into the individual who last chewed it.
- The gum-chewer has been dubbed Lola. She lived 5,700 years ago; and she had dark skin, dark hair, and blue eyes.
Five thousand and seven hundred years ago, "Lola" — a blue-eyed woman with dark skin and hair — was chewing on a piece of pitch derived from heating birch bark. Then, this women spit her chewing gum out into the mud on an island in Denmark that we call Syltholm today, where it was unearthed by archaeologists thousands of years later. A genetic analysis of the chewing gum has provided us with a wealth of information on this nearly six-thousand-year-old Violet Beauregarde.
This represents the first time that the human genome has been extracted from material such as this. "It is amazing to have gotten a complete ancient human genome from anything other than bone," said lead researcher Hannes Schroeder in a statement.
"What is more," he added, "we also retrieved DNA from oral microbes and several important human pathogens, which makes this a very valuable source of ancient DNA, especially for time periods where we have no human remains."
In the pitch, researchers identified the DNA of the Epstein-Barr virus, which infects about 90 percent of adults. They also found DNA belonging to hazelnuts and mallards, which were likely the most recent meal that Lola had eaten before spitting out her chewing gum.
Insights into ancient peoples
The birch pitch was found on the island of Lolland (the inspiration for Lola's name) at a site called Syltholm. "Syltholm is completely unique," said Theis Jensen, who worked on the study for his PhD. "Almost everything is sealed in mud, which means that the preservation of organic remains is absolutely phenomenal.
"It is the biggest Stone Age site in Denmark and the archaeological finds suggest that the people who occupied the site were heavily exploiting wild resources well into the Neolithic, which is the period when farming and domesticated animals were first introduced into southern Scandinavia."
Since Lola's genome doesn't show any of the markers associated with the agricultural populations that had begun to appear in this region around her time, she provides evidence for a growing idea that hunter-gatherers persisted alongside agricultural communities in northern Europe longer than previously thought.
Her genome supports additional theories on northern European peoples. For example, her dark skin bolsters the idea that northern populations only recently acquired their light-skinned adaptation to the low sunlight in the winter months. She was also lactose intolerant, which researchers believe was the norm for most humans prior to the agricultural revolution. Most mammals lose their tolerance for lactose once they've weaned off of their mother's milk, but once humans began keeping cows, goats, and other dairy animals, their tolerance for lactose persisted into adulthood. As a descendent of hunter-gatherers, Lola wouldn't have needed this adaptation.
A hardworking piece of gum
A photo of the birch pitch used as chewing gum.
These findings are encouraging for researchers focusing on ancient peoples from this part of the world. Before this study, ancient genomes were really only ever recovered from human remains, but now, scientists have another tool in their kit. Birch pitch is commonly found in archaeological sites, often with tooth imprints.
Ancient peoples used and chewed on birch pitch for a variety of reasons. It was commonly heated up to make it pliable, enabling it to be molded as an adhesive or hafting agent before it settled. Chewing the pitch may have kept it pliable as it cooled down. It also contains a natural antiseptic, and so chewing birch pitch may have been a folk medicine for dental issues. And, considering that we chew gum today for no other reason than to pass the time, it may be that ancient peoples chewed pitch for fun.
Whatever their reasons, chewed and discarded pieces of birch pitch offer us the mind-boggling option of learning what someone several thousands of years ago ate for lunch, or what the color of their hair was, their health, where their ancestors came from, and more. It's an unlikely treasure trove of information to be found in a mere piece of gum.
The non-contact technique could someday be used to lift much heavier objects — maybe even humans.
- Since the 1980s, researchers have been using sound waves to move matter through a technique called acoustic trapping.
- Acoustic trapping devices move bits of matter by emitting strategically designed sound waves, which interact in such a way that the matter becomes "trapped" in areas of particular velocity and pressure.
- Acoustic and optical trapping devices are already used in various fields, including medicine, nanotechnology, and biological research.
Sound can have powerful effects on matter. After all, sound strikes our world in waves — vibrations of air molecules that bounce off of, get absorbed by, or pass through matter around us. Sound waves from a trained opera singer can shatter a wine glass. From a jet, they can collapse a stone wall. But sound can also be harnessed for delicate interactions with matter.
Since the 1980s, researchers have been using sound to move matter through a phenomenon called acoustic trapping. The method is based on the fact that sound waves produce an acoustic radiation force.
"When an acoustic wave interacts with a particle, it exerts both an oscillatory force and a much smaller steady-state 'radiation' force," wrote the American Physical Society. "This latter force is the one used for trapping and manipulation. Radiation forces are generated by the scattering of a traveling sound wave, or by energy gradients within the sound field."
When tiny particles encounter this radiation, they tend to be drawn toward regions of certain pressure and velocity within the sound field. Researchers can exploit this tendency by engineering sound waves that "trap" — or suspend — tiny particles in the air. Devices that do this are often called "acoustic tweezers."
Building a better tweezer
A study recently published in the Japanese Journal of Applied Physics describes how researchers created a new type of acoustic tweezer that was able to lift a small polystyrene ball into the air.
Tweezers of Sound: Acoustic Manipulation off a Reflective Surface youtu.be
It is not the first example of a successful "acoustic tweezer" device, but the new method is likely the first to overcome a common problem in acoustic trapping: sound waves bouncing off reflective surfaces, which disrupts acoustic traps.
To minimize the problems of reflectivity, the team behind the recent study configured ultrasonic transducers such that the sound waves that they produce overlap in a strategic way that is able to lift a small bit of polystyrene from a reflective surface. By changing how the transducers emit sound waves, the team can move the acoustic trap through space, which moves the bit of matter.
Move, but don't touch
So far, the device is only able to move millimeter-sized pieces of matter with varying degrees of success. "When we move a particle, it sometimes scatters away," the team noted. Still, improved acoustic trapping and other no-contact lifting technologies — like optical tweezers, commonly used in medicine — could prove useful in many future applications, including cell separation, nanotechnologies, and biological research.
Could future acoustic-trapping devices lift large and heavy objects, maybe even humans? It seems possible. In 2018, researchers from the University of Bristol managed to acoustically trap particles whose diameters were larger than the sound wavelength, which was a breakthrough because it surpassed "the classical Rayleigh scattering limit that has previously restricted stable acoustic particle trapping," the researchers wrote in their study.
In other words, the technique — which involved suspending matter in tornado-like acoustic traps — showed that it is possible to scale up acoustic trapping.
"Acoustic tractor beams have huge potential in many applications," Bruce Drinkwater, co-author of the 2018 study, said in a statement. "I'm particularly excited by the idea of contactless production lines where delicate objects are assembled without touching them."
Australian parrots have worked out how to open trash bins, and the trick is spreading across Sydney.
- If sharing learned knowledge is a form of culture, Australian cockatoos are one cultured bunch of birds.
- A cockatoo trick for opening trash bins to get at food has been spreading rapidly through Sydney's neighborhoods.
- But not all cockatoos open the bins; some just stay close to those that do.
Dumpster-diving trash parrots
In a study about these smart birds just published in Science, researchers define animal culture as "population-specific behaviors acquired via social learning from knowledgeable individuals."
Co-lead author of the study Barbara Klump of the Max Planck Institute of Animal Behavior in Konstanz, Germany says, "[C]ompared to humans, there are few known examples of animals learning from each other. Demonstrating that food scavenging behavior is not due to genetics is a challenge."
An opportunity presented itself in a video that co-author Richard Major of the Australian Museum shared with Klump and the other co-authors. In the video, a sulphur-crested cockatoo used its beak to pull up the handle of a closed garbage bin — using its foot as a wedge — and then walked back the lid sufficiently to flip it open, exposing the bin's edible contents.
Major has been studying Cacatua galerita for 20 years and says, "Like many Australian birds, sulphur-crested cockatoos are loud and aggressive." The study describes them as a "large-brained, long-lived, and highly social parrot." Says Major, "They are also incredibly smart, persistent, and have adapted brilliantly to living with humans."(Research regarding some of the ways in which wild animals adapt to the presence of humans has already produced some fascinating results and is ongoing.)
Clever cockie opens bin - 01 youtu.be
The researchers became curious about how widespread this behavior might be and saw a research opportunity. After all, says John Martin, a researcher at Taronga Conservation Society, "Australian garbage bins have a uniform design across the country, and sulphur-crested cockatoos are common across the entire east coast."
Martin continues, "In 2018, we launched an online survey in various areas across Sydney and Australia with questions such as, 'What area are you from, have you seen this behavior before, and if so, when?'"
Word gets around
Credit: magspace/Adobe Stock
Although the cockatoos' maneuver was reported in only three suburbs before 2018, by the end of 2019, people in 44 areas reported observing the behavior. Clearly, more and more cockatoos were learning how to successfully dumpster dive.
As further proof, says Klump, "We observed that the birds do not open the garbage bins in the same way, but rather used different opening techniques in different suburbs, suggesting that the behavior is learned by observing others." One individual bird in north Sydney invented its own method, and the scientists saw it grow in popularity throughout the local population.
To track individual birds, the researchers marked 500 cockatoos with small red dots. Subsequent observations revealed that not all cockatoos are bin-openers. Only about 10 percent of them are, and they are mostly males. The other cockatoos apparently restrict their education to a different lesson: hang around with a bin-opener, and you will get supper.
Thanks to the surveys, the researchers consider the entire project to be a valuable citizen-science experiment. "By studying this behavior with the help of local residents, we are uncovering the unique and complex cultures of their neighborhood birds."
The few seconds of nuclear explosion opening shots in Godzilla alone required more than 6.5 times the entire budget of the monster movie they ended up in.