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7 myths you learned in biology class that you probably still believe
You’ll be surprised how many commonly known science “facts” are actually total misconceptions.
Science classes are supposed to give students not only the most up-to-date knowledge and information but also a belief in the scientific method and perhaps imbue them with the logic and reasoning skills associated with it. Trouble is, there are a lot of myths out there that sabotage these lofty goals. In fact, many of them originate in science classes themselves, taught over and over by teachers too lazy to look them up. Despite already being debunked, they persist. Here are 7 commonly held myths from biology class you probably still believe.
1. Humans sit atop the food chain
Food web. Credit: Socratic.
Sometimes you’ll hear the carnivorous among us exclaim, “I didn’t fight my way to the top of the food chain to eat a salad.” Though we may understand their meaning, the concept behind it is dead wrong. That’s because the food chain metaphor itself is too simplistic. It’s more like a food web, which more accurately portrays how energy is passed among organisms in a certain ecosystem.
Food webs are made up of food chains, which are when energy is transferred up in a linear fashion. The trouble with the food chain is, there are usually multiple organisms who are both predator and prey. Many organisms can eat multiple things and conversely be consumed by multiple predators. The food chain model also often ignores the producers at the bottom. As such, a food web, although still imperfect, is a far more precise model.
2. Respiration is synonymous with breathing
Cellular respiration. Credit: Sheri Amsel, Exploring Nature.
Most people think respiration and breathing are the same thing. That is, sadly, nowhere near true. While we’ve got a good handle on what breathing is, respiration is when muscles release glucose during physical activity, like exercise. Glucose is the body’s fuel. We use it for energy. This misconception may be due to the fact that study of the respiratory system focuses mainly on breathing. And therein lies the confusion.
3. Cats and dogs are colorblind
Credit: Stocksnap, Pixababy.
The reason for the pervasiveness of this myth might be due to the fact that vision in these species works much differently than ours. Shockingly, recent research finds both dogs and cats can see the colors green and blue. But not quite like us. The color in a dog's vision is 1/7th less vivid than ours due to the fact they have fewer cone cells.
They do, however, have more rod cells in their eyes than humans. These cells sense light. This means dogs have better night vision than we have. With cats, colors look completely different. Purple, for instance, may look more blue to them, while red and pink appear as different shades of green.
4. Sugar is as addictive as cocaine
Credit: Getty Images.
This comes from the bestselling book by Dr. Robert Lustig, Fat Chance. First published in 2009, it claimed that sugar stimulates the brain’s reward system in much the same way as drugs do, such as cocaine, heroin, and alcohol. One problem though, although sugar may, in fact, trigger dopamine, no scientific studies using neuroimaging have ever backed up this claim. While it may be proven to be accurate in the near future, there’s no way currently to substantiate this statement.
5. Daughters inherit traits from their mothers and sons from their fathers
Autosomal recessive inheritance. Credit: Cburnett, Wikipedia Commons.
Genetics is fun, isn’t it? It can also be a tad confusing. Most people carry this misconception from when they learned how we inherit traits. It’s true that an offspring inherits an allele from each parent.
But the characteristic that is taken by the organism happens to be the dominant one, regardless of which parent it came from or the sex of the offspring. Another common misconception is that we get half of our characteristics from each parent. The truth, all that matters is which alleles are dominant.
6. Sharks can smell one drop of blood in the water from a mile away
A great white shark. Credit: Skeeze, Pixababy.
It’s a scary thought, but does the claim stand up under scientific scrutiny? Just know that no shark is darting for your swim trunks from miles away. Sharks have highly developed brain regions for sensing odors. They can pick up 1 part of blood per 10 billion parts of water. But while this might conjure up the image of a shark honing in from miles away, it's useful to know what 1 in 10 billion parts of water actually is. A good way to visualize this is the ball of a ball-point pen in an Olympic swimming pool (still impressive nevertheless). Molecules, of course, scatter and drift in the water and there are loads of them in the ocean. The best a shark could do is pick up blood from a couple of football fields away if the currents and other conditions are just right.
7. Humans evolved from chimps
A chimpanzee in the Leipzig Zoo. Credit: Thomas Lersch, Wikipedia Commons.
While the chimpanzee may be our closest living relative (homo sapiens are equidistant from them and bonobos), we didn’t evolve from them per se. Rather, chimps, gorillas, and humans share a common ancestor that walked the Earth some 6-10 million years ago. A recently unearthed fossil from Kenya’s Rift Valley may be the common thread. This has tentatively been identified as the Nakali ape (Nakalipithecus nakayamai). So how closely related are we to chimps? We share 98.8% of the same genes.
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>
With just a few strategical tweaks, the Nazis could have won one of World War II's most decisive battles.
- The Battle of Britain is widely recognized as one of the most significant battles that occurred during World War II. It marked the first major victory of the Allied forces and shifted the tide of the war.
- Historians, however, have long debated the deciding factor in the British victory and German defeat.
- A new mathematical model took into account numerous alternative tactics that the German's could have made and found that just two tweaks stood between them and victory over Britain.
Two strategic blunders<p>Now, historians and mathematicians from York St. John University have collaborated to produce <a href="http://www-users.york.ac.uk/~nm15/bootstrapBoB%20AAMS.docx" target="_blank">a statistical model (docx download)</a> capable of calculating what the likely outcomes of the Battle of Britain would have been had the circumstances been different. </p><p>Would the German war effort have fared better had they not bombed Britain at all? What if Hitler had begun his bombing campaign earlier, even by just a few weeks? What if they had focused their targets on RAF airfields for the entire course of the battle? Using a statistical technique called weighted bootstrapping, the researchers studied these and other alternatives.</p><p>"The weighted bootstrap technique allowed us to model alternative campaigns in which the Luftwaffe prolongs or contracts the different phases of the battle and varies its targets," said co-author Dr. Jaime Wood in a <a href="https://www.york.ac.uk/news-and-events/news/2020/research/mathematicians-battle-britain-what-if-scenarios/" target="_blank">statement</a>. Based on the different strategic decisions that the German forces could have made, the researchers' model enabled them to predict the likelihood that the events of a given day of fighting would or would not occur.</p><p>"The Luftwaffe would only have been able to make the necessary bases in France available to launch an air attack on Britain in June at the earliest, so our alternative campaign brings forward the air campaign by three weeks," continued Wood. "We tested the impact of this and the other counterfactuals by varying the probabilities with which we choose individual days."</p><p>Ultimately, two strategic tweaks shifted the odds significantly towards the Germans' favor. Had the German forces started their campaign earlier in the year and had they consistently targeted RAF airfields, an Allied victory would have been extremely unlikely.</p><p>Say the odds of a British victory in the real-world Battle of Britain stood at 50-50 (there's no real way of knowing what the actual odds are, so we'll just have to select an arbitrary figure). If this were the case, changing the start date of the campaign and focusing only on airfields would have reduced British chances at victory to just 10 percent. Even if a British victory stood at 98 percent, these changes would have cut them down to just 34 percent.</p>
A tool for understanding history<p>This technique, said co-author Niall Mackay, "demonstrates just how finely-balanced the outcomes of some of the biggest moments of history were. Even when we use the actual days' events of the battle, make a small change of timing or emphasis to the arrangement of those days and things might have turned out very differently."</p><p>The researchers also claimed that their technique could be applied to other uncertain historical events. "Weighted bootstrapping can provide a natural and intuitive tool for historians to investigate unrealized possibilities, informing historical controversies and debates," said Mackay.</p><p>Using this technique, researchers can evaluate other what-ifs and gain insight into how differently influential events could have turned out if only the slightest things had changed. For now, at least, we can all be thankful that Hitler underestimated Britain's grit.</p>
A new study shows our planet is much closer to the supermassive black hole at the galaxy's center than previously estimated.
Arrows on this map show position and velocity data for the 224 objects utilized to model the Milky Way Galaxy. The solid black lines point to the positions of the spiral arms of the Galaxy. Colors reflect groups of objects that are part of the same arm, while the background is a simulation image.
Apple sold its first iPod in 2001, and six years later it introduced the iPhone, which ushered in a new era of personal technology.