43% of people think they can get a sense of someone's personality by their picture.
If you've used a dating app, you'll know the importance of choosing good profile pics.
An intriguing theory explains animals' magnetic sense.
- Some animals can navigate via magnetism, though scientists aren't sure how.
- Research shows that some of these animals contain magnetotactic bacteria.
- These bacteria align themselves along the magnetic field's grid lines.
Magnetotactic bacteria hosts<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQyMTQ2Ny9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY2MDcwMTYxMn0.BZ-cpaTejm38_HCvVoSZ92k58dxnQETahNmKOmB14X4/img.jpg?width=980" id="c6097" class="rm-shortcode" data-rm-shortcode-id="a9f01b7583442ad92a05927c79754f50" data-rm-shortcode-name="rebelmouse-image" alt="whale mother and calf" />
A right whale mother and calf
Credit: wildestanimal/Shutterstock<p>One of the paper's authors, Geneticist <a href="https://sciences.ucf.edu/biology/person/robert-fitak/" target="_blank">Robert Fitak</a>,<a href="https://sciences.ucf.edu/biology/person/robert-fitak/" target="_blank" rel="noopener noreferrer"></a> is affiliated with the biology department of the <a href="https://www.ucf.edu" target="_blank">University of Central Florida</a> in (UCF) Orlando. Prior to joining the department, he spent four years as a postdoctoral researcher at Duke University investigating the genomic mechanisms responsible for magnetic perception in fish and lobsters.</p><p>Fitak tells <a href="https://www.ucf.edu/news/animals-magnetic-sixth-sense-may-come-from-bacteria-new-paper-suggests/" target="_blank">UFC Today</a>, "The search for a mechanism has been proposed as one of the last major frontiers in sensory biology and described as if we are 'searching for a needle in a needle stack.'"</p><p>That metaphorical needle stack may well be the scientific community's largest database of microbes, the <a href="https://bmcgenomics.biomedcentral.com/articles/10.1186/1471-2164-9-75" target="_blank" rel="noopener noreferrer">Metagenomic Rapid Annotations using Subsystems Technology database</a>. It lists the animal samples in which magnetotactic bacteria have been found.</p><p>The primary use of the database, says Fitak, has been the measurement of bacterial diversity in entire phyla. An accounting of the appearance of magnetotactic bacteria in individual species is something that has previously be unexplored. "The presence of these magnetotactic bacteria had been largely overlooked, or 'lost in the mud' amongst the massive scale of these datasets," he reports.</p><p>Fitak dug into the database and discovered that magnetotactic bacteria have indeed been identified in a number of species known to navigate by magnetism, among them loggerhead sea turtles, Atlantic right whales, bats, and penguins. <em>Candidatus Magnetobacterium bavaricum</em> is regularly found in loggerheads and penguins, while <em>Magnetospirillum</em> and <em>Magnetococcus</em> are common among right whales and bats.</p><p>As for other magnetic-field-sensitive animals, he says, "I'm working with the co-authors and local UCF researchers to develop a genetic test for these bacteria, and we plan to subsequently screen various animals and specific tissues, such as in sea turtles, fish, spiny lobsters and birds."</p>
The bacteria-host relationship<p>While the presence of the bacteria in these particular species is intriguing, further study is needed to be sure they're responsible for other animals' magnetic navigation. Their presence in these species <em>could</em> be just a coincidence.</p><p>Fitak also notes that he doesn't know at this point exactly where in the host animal the magnetotactic bacteria would reside, or other details of their symbiotic relationship. He suggests that they might be found in nervous tissue associated with navigation, such as that found in the brain or eye.</p><p>If confirmed, Fitak's hypothesis could suggest that our own sensitivity to the Earth's magnetic field might one day be enhanced via magnetotactic bacteria in our own individual microbiomes, should they be benign to us as hosts.</p>
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.
The true apex predator<p>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.</p><p>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 <em>one </em>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. </p>
Why are they doing this?<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="14ccb270e8cc6888b69118539a29b63b"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/B7GHCJXwLw8?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>Orcas have been known to eat great whites. The remains of the sharks are a grotesque sight to behold and are always missing their <a href="https://www.nationalgeographic.com/animals/2019/07/killer-whales-orcas-eat-great-white-sharks/#:~:text=By%20Emma%20Rigney&text=In%20October%201997%2C%20tourists%20in,killer%20whales%20eating%20white%20sharks." target="_blank">livers</a>, 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 <a href="https://youtu.be/bHoqL7DFevc?t=28" target="_blank">time</a>.</p><p>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.</p><p>Before this gets too frightening, there are no known cases of wild orcas killing <a href="https://en.wikipedia.org/wiki/Killer_whale_attack" target="_blank">humans</a>, and only a few examples of injuries being caused by these interactions. <a href="https://bigthink.com/surprising-science/orcas-and-stress" target="_blank">Orcas kept in tiny boxes</a> for long periods can be a bit more violent, but that's another story. </p>
A new study bases its calculations on more than the great white shark.
- Previous estimates of the megalodon's size were based solely on its teeth compared to the star of "Jaws."
- The prehistoric monster is as closely related to other sharks.
- Imagine just a dorsal fin as tall as you are.
What’s different about this analysis<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzg3MjU5OS9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYxNDc2MTQyNn0.K38h9qHeCM7jtYLA2Z25W7ZC9NiekmvL6CkQy82szzU/img.png?width=980" id="24ad8" class="rm-shortcode" data-rm-shortcode-id="fbc76e6dc6f82d299c7828a80272eede" data-rm-shortcode-name="rebelmouse-image" alt="megalodon compared to a school bus" />
The megalodon’s revised measurements<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzg0OTAwMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNTM4MjA4M30.uArVFW_ithOZuZ1_oTKCg0y1-2Zue2VRD_C_j2KJVk4/img.jpg?width=980" id="98366" class="rm-shortcode" data-rm-shortcode-id="8caf88dda090ba04f0aac156e15b7a27" data-rm-shortcode-name="rebelmouse-image" alt="shark and diver illustration" />
Credit: Reconstruction by Oliver E. Demuth/Scientific Reports<p>The study proposes the following approximate measurements for a full-grown megalodon:</p><ul><li>Length: about 16 meters (52.5 feet). A full-size school bus is just 45 feet long</li><li>Head size: about 4.65 meters long (15.3 feet) </li><li>Dorsal fin: about 1.62 meters tall (5.3 feet). A person could stand on the back of a megalodon and be about as tall as the fin.</li><li>Tail fin: about 3.85 meters high (12.6 feet) </li></ul><p>Let's just hope this sucker is really extinct. </p>
On the list of animals at risk are several endangered species.
- SARS-CoV-2 enters our cells by binding with ACE2 receptors.
- A study finds many animals may provide a similar point of entry for the infection.
- COVID-19 has already been seen in a range of non-humans.
ACE2<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzU4MTgwMC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyMTI3NDU4NH0.BceDb6l6wcwImHgniUPCNX_F5NeJ8vSsrAWNH7DG-x0/img.jpg?width=980" id="2fb6e" class="rm-shortcode" data-rm-shortcode-id="77a7d2b0d83cfc72479f2b9089e512ac" data-rm-shortcode-name="rebelmouse-image" alt="3D illustration of SARS-CoV-2 binding with ACE2 receptors" />
3D illustration of SARS-CoV-2 binding with ACE2 receptors
Image source: Kateryna Kon/Shutterstock<p>SARS-CoV-2's main point of entry into our systems, its main cellular receptor, is an angiotensin converting enzyme-2 known as ACE2. There are many types of cells and tissues in humans that contain ACE2, including the epithelial cells found in the mouth, nose, and lungs. SARS-CoV-2 binds to 25 ACE2 amino acids to get into our cells.</p><p>The researchers investigated the presence of these amino acids in other organisms on the assumption that their presence would provide SARS-CoV-2 entry to their cells as they do in ours. Says first author of the study <a href="https://www.ucdavis.edu/person/articles/27275" target="_blank">Joana Dama</a> of UC Davis, "Animals with all 25 amino acid residues matching the human protein are predicted to be at the highest risk for contracting SARS-CoV-2 via ACE2."</p><p>The precise mechanism by which SARS-CoV-2 infections occur and lead to COVID-19 is still under exploration. Nonetheless, the study operates on the principle that more of the 25 amino acids an animal has, the higher its risk of infection. "The risk is predicted to decrease the more the species' ACE2 binding residues differ from humans," says Dama.</p>
Which species are at risk?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzU4MTgwMi9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYwMzA5ODY4Nn0.oZHKdhpvHJjihgp2R3E23hMotY-yazjh0vCw5S_L2F8/img.png?width=980" id="3130d" class="rm-shortcode" data-rm-shortcode-id="8edb6a4f609576554b9067ee019ab08b" data-rm-shortcode-name="rebelmouse-image" alt="species risk chart" />
Image source: Matt Verdolivo/UC Davis<p>Their analysis leads Dama and her co-authors to the conclusion that about 40 percent of the species at risk of SARS-CoV-2 infection are on the International Union for Conservation of Nature's <a href="https://www.iucn.org/resources/conservation-tools/iucn-red-list-threatened-species" target="_blank">"threatened" list</a>.</p><p>Sumatran orangutans, Northern white-cheeked gibbons, and the Western lowland gorillas are all critically endangered and are vulnerable to infection. Some marine animals are also at high risk, including bottlenose dolphins and gray whales.</p><p><span></span>The study asserts that many animals most likely to live among humans are apparently at low risk, including cats, dogs, cattle, sheep, horses, and pigs. Chinese hamsters carry a high risk.</p><p>It's worth noting, however, that there <em>are</em> cases on record of SARS-CoV-2 infections in <a href="https://www.statnews.com/2020/05/13/cats-can-catch-covid-19-from-one-another-study-finds-the-question-is-can-we/" target="_blank">cats</a> and <a href="https://www.aphis.usda.gov/aphis/newsroom/stakeholder-info/sa_by_date/sa-2020/sa-06/sars-cov-2-dog" target="_blank">dogs</a>. <a href="https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa325/5811871" target="_blank">Hamsters</a>, too. Less likely house pets like <a href="https://www.aphis.usda.gov/aphis/newsroom/news/sa_by_date/sa-2020/ny-zoo-covid-19" target="_blank" rel="noopener noreferrer dofollow">lions, tigers</a>, and <a href="https://www.npr.org/sections/goatsandsoda/2020/06/25/882095588/dutch-minks-contract-covid-19-and-appear-to-infect-humans" target="_blank">mink</a> have also been infected.</p><p>Bats, the presumed <a href="https://www.nature.com/articles/s41586-020-2012-7" target="_blank" rel="noopener noreferrer dofollow">source of SARS-CoV-2</a>, are found by the study to be at very low risk of infection due to a lack of ACE2 receptors. Other experimental data lines up with the study's finding, which suggests that spread of SARS-CoV-2 from bats is likely to have involved intermediate hosts en route to infecting humans.</p><p>The authors have made available for <a href="https://www.pnas.org/highwire/filestream/945399/field_highwire_adjunct_files/1/pnas.2010146117.sd01.xlsx" target="_blank">download</a> the full list of animals its authors find may be susceptible to SARS-CoV-2 infection.</p>