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Sharks flee in terror when killer whales show up
Sharks fear killer whales. How does this impact the ecosystems they share?
- A new study finds that sharks will flee areas they met orcas in for up to a year.
- Killer whales are known to eat sharks, but it is unknown if the sharks are fleeing because they know that too.
- The discovery will change our understanding of how marine ecosystems evolve.
Orcas, also known as "killer whales," are pretty cool. They're usually friendly despite their nickname, and are in an elite club of animals with no natural predators. With a range that spans the world and a coloring reminiscent of an equally popular but much less capable land animal, their image permeates pop culture.
But a new study published in Scientific Reports offers another reason to be impressed by these majestic creatures; they are so intimidating to ocean life that even great white sharks flee in terror before them.
The true apex predator
The study, titled "Killer whales redistribute white shark foraging pressure on seals," results from years of investigations into the movements and behavior of 165 tagged great white sharks, observations and records of killer whale movements, and information on seal populations off the coast of California. They also looked to previous descriptions of shark and whale interactions to give context to their findings.
The sharks immediately turned tail and fled in every time they crossed paths with orcas. They'd also stay away from that place long afterward. Only one observed shark dared venture back to where it had just encountered the whales, and it didn't stick around. Most of the sharks merely fled a bit further up the coastline, while others went much further out to sea to avoid the whales.
Why are they doing this?
Orcas have been known to eat great whites. The remains of the sharks are a grotesque sight to behold and are always missing their livers, no matter how much else remains or is missing. If the orcas have discovered a source of Chianti to pair with them or not remains unknown at this time.
However, we don't currently know if the sharks are fleeing because they understand that risk, because they knew the orcas would fight them for the same food supply, because whales look big and scary to them, or some combination of the three.
Before this gets too frightening, there are no known cases of wild orcas killing humans, and only a few examples of injuries being caused by these interactions. Orcas kept in tiny boxes for long periods can be a bit more violent, but that's another story.
Anything that makes sharks flee in terror will have an impact on the ecosystem. In this case, elephant seals benefit.
Observations of seal populations show a decline in predation events after orcas that can last for an entire year. While orcas occasionally snack on elephant seals, they stick to fish most of the time. It's a boon for the seals in areas the sharks leave, though the seals in the places they flee to might not see it that way. The findings of this study will inform our understanding of seal population fluctuations.
As lead author Salvador Jorgensen explains, the study also demonstrates that "food chains are not always linear. So-called lateral interactions between top predators are fairly well known on land but are much harder to document in the ocean. And because this one happens so infrequently, it may take us a while longer to fully understand the dynamics."
For those wondering how much longer it may take to reach that understanding, this study relied on decades of data on shark, whale, and seal populations in addition to the recently collected information. While demonstrating the value of long-term datasets and the long-term importance of minor interactions is great for science, the impatient may be disappointed at the slow pace of progress.
But the most important take away of this study might be the obvious one:
Never made an orca angry, unless you're tougher than a great white shark.
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What is human dignity? Here's a primer, told through 200 years of great essays, lectures, and novels.
- Human dignity means that each of our lives have an unimpeachable value simply because we are human, and therefore we are deserving of a baseline level of respect.
- That baseline requires more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose.
- We look at incredible writings from the last 200 years that illustrate the push for human dignity in regards to slavery, equality, communism, free speech and education.
The inherent worth of all human beings<p>Human dignity is the inherent worth of each individual human being. Recognizing human dignity means respecting human beings' special value—value that sets us apart from other animals; value that is intrinsic and cannot be lost.</p> <p>Liberalism—the broad political philosophy that organizes society around liberty, justice, and equality—is rooted in the idea of human dignity. Liberalism assumes each of our lives, plans, and preferences have some unimpeachable value, not because of any objective evaluation or contribution to a greater good, but simply because they belong to a human being. We are human, and therefore deserving of a baseline level of respect. </p> <p>Because so many of us take human dignity for granted—just a fact of our humanness—it's usually only when someone's dignity is ignored or violated that we feel compelled to talk about it. </p> <p>But human dignity means more than the absence of violence, discrimination, and authoritarianism. It means giving individuals the freedom to pursue their own happiness and purpose—a freedom that can be hampered by restrictive social institutions or the tyranny of the majority. The liberal ideal of the good society is not just peaceful but also pluralistic: It is a society in which we respect others' right to think and live differently than we do.</p>
From the 19th century to today<p>With <a href="https://books.google.com/ngrams/graph?year_start=1800&year_end=2019&content=human+dignity&corpus=26&smoothing=3&direct_url=t1%3B%2Chuman%20dignity%3B%2Cc0" target="_blank" rel="noopener noreferrer">Google Books Ngram Viewer</a>, we can chart mentions of human dignity from 1800-2019.</p><img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDg0ODU0My9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY1MTUwMzE4MX0.bu0D_0uQuyNLyJjfRESNhu7twkJ5nxu8pQtfa1w3hZs/img.png?width=980" id="7ef38" class="rm-shortcode" data-rm-shortcode-id="9974c7bef3812fcb36858f325889e3c6" data-rm-shortcode-name="rebelmouse-image" />
American novelist, writer, playwright, poet, essayist and civil rights activist James Baldwin at his home in Saint-Paul-de-Vence, southern France, on November 6, 1979.
Credit: Ralph Gatti/AFP via Getty Images
The future of dignity<p>Around the world, people are still working toward the full and equal recognition of human dignity. Every year, new speeches and writings help us understand what dignity is—not only what it looks like when dignity is violated but also what it looks like when dignity is honored. In his posthumous essay, Congressman Lewis wrote, "When historians pick up their pens to write the story of the 21st century, let them say that it was your generation who laid down the heavy burdens of hate at last and that peace finally triumphed over violence, aggression and war."</p> <p>The more we talk about human dignity, the better we understand it. And the sooner we can make progress toward a shared vision of peace, freedom, and mutual respect for all. </p>
Scientists find that bursts of gamma rays may exceed the speed of light and cause time-reversibility.
- Astrophysicists propose that gamma-ray bursts may exceed the speed of light.
- The superluminal jets may also be responsible for time-reversibility.
- The finding doesn't go against Einstein's theory because this effect happens in the jet medium not a vacuum.
Jet bursting out of a blazar. Black-hole-powered galaxies called blazars are the most common sources detected by NASA's Fermi Gamma-ray Space Telescope.
Cosmic death beams: Understanding gamma ray bursts<div class="rm-shortcode" data-media_id="cu2knVEk" data-player_id="FvQKszTI" data-rm-shortcode-id="c6cfd20fdf31c82cb206ade8ce21ba3f"> <div id="botr_cu2knVEk_FvQKszTI_div" class="jwplayer-media" data-jwplayer-video-src="https://content.jwplatform.com/players/cu2knVEk-FvQKszTI.js"> <img src="https://cdn.jwplayer.com/thumbs/cu2knVEk-1920.jpg" class="jwplayer-media-preview" /> </div> <script src="https://content.jwplatform.com/players/cu2knVEk-FvQKszTI.js"></script> </div>
Philosophers have been asking the question for hundreds of years. Now neuroscientists are joining the quest to find out.
- The debate over whether or not humans have free will is centuries old and ongoing. While studies have confirmed that our brains perform many tasks without conscious effort, there remains the question of how much we control and when it matters.
- According to Dr. Uri Maoz, it comes down to what your definition of free will is and to learning more about how we make decisions versus when it is ok for our brain to subconsciously control our actions and movements.
- "If we understand the interplay between conscious and unconscious," says Maoz, "it might help us realize what we can control and what we can't."
Puerto Rico's iconic telescope facilitated important scientific discoveries while inspiring young scientists and the public imagination.
- The Arecibo Observatory's main telescope collapsed on Tuesday morning.
- Although officials had been planning to demolish the telescope, the accident marked an unceremonious end to a beloved astronomical tool.
- The Arecibo radio telescope has facilitated many discoveries in astronomy, including the mapping of near-Earth asteroids and the detection of exoplanets.
Bradley Rivera via twitter.com<p>In 1963, the concave dish was built into a natural sinkhole on the northern coast of Puerto Rico. The location was <a href="https://www.space.com/20984-arecibo-observatory.html" target="_blank">picked because it was near the equator,</a> providing scientists a clear view of planets passing overhead, and also of the ionosphere, which is the uniquely reactive layer of Earth's upper atmosphere where the northern lights form.</p><p>Since its construction, scientists have used the Arecibo telescope to map near-Earth asteroids, detect gravitational waves, study pulsars, detect exoplanets and <a href="https://www.seti.org/goodbye-arecibo" target="_blank">search for alien civilizations</a>, among other projects. Here's a brief look at some of the discoveries and accomplishments made using the Arecibo telescope:</p><ul><li>1964: Astronomer <a href="https://en.wikipedia.org/wiki/Gordon_Pettengill" target="_blank" rel="noopener noreferrer">Gordon Pettengill</a> discovers that Mercury's rotation period is 59 days, significantly shorter than the previous prediction of 88 days.</li><li>1974: Physicists Russell Alan Hulse and Joseph Hooton Taylor Jr. discovers the first binary pulsar, for which they won a Nobel Prize in Physics.</li><li>1974: Scientists use the telescope to transmit the "Arecibo message" to <a href="https://en.wikipedia.org/wiki/Great_Globular_Cluster_in_Hercules" target="_blank" rel="noopener noreferrer">globular star cluster M13</a>. The message, when translated into image form, contains basic information about humanity and human knowledge: the numbers one to 10, a map of our solar system, an illustration of a human being, and the atomic numbers of certain elements.</li><li>1989: Scientists use the telescope to image an asteroid for the first time.</li><li>1992: Astronomers Alex Wolszczan and Dale Frail become the first to discover exoplanets.</li></ul>
The Google-owned company developed a system that can reliably predict the 3D shapes of proteins.