Dolphins (probably) can’t recogize each other’s voices

[Above: Two bottlenose dolphins swimming around. Image via Max Pixel and Creative Commons CC0 license.]

Human speaking voices come in a dizzying array of tones. They can be raspy or reedy, lilting or monotone, chirpy or sonorous, nasal or throaty, breathy or booming, and that’s before we even start describing accents.

Most mammals, including humans, use their vocal tracts to make noise, and so slight variations in the anatomies of our voice boxes, throats, mouths, and nasal passages give our voices unique timbres.

Perhaps, not surprisingly, we can use variation in vocal qualities to tell people apart. (Some people have a lot more acuity at this than others, but most of us can recognize our favorite singers, even on songs we haven’t heard before, and distinguish our dog’s bark from the neighbors’ yapping.)

Animals do the same. Mother bats can recognize their babies’ voices.  (Anyone else remember Stellaluna?) So can fur seals, rhesus monkeys, and sheep.

“If you answer the phone, and it’s someone you know very well, you know the voice, and they don’t have to tell you their name,” explains behavioral biologist Laela Sayigh of Hampshire College. “That’s how really every other mammal that has ever been studied identifies each other.”

With one notable exception–dolphins.

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Meet WTF4: A Gene So Selfish It Poisons All Its Offspring

[Image by Wokandapix via Pixabay and Creative Commons 2.0 License.] 

Imagine you’ve been invited to a fancy dinner at a millionaire’s house. The table is set. The silverware gleams. The guests are chitchating about who does what for work and the season finale of Game of Thrones when the dinner host arrives and announces that he has poisoned himself.

The confusion turns to terror when the dinner party host reveals that he has not only poisioned himself but everyone else in the room.

Such a scenario sounds silly, but if you’re a gene in the game of inheritance, “you win or you die.” (Or at least, risk disappearing from the gene pool.) And sometimes the most extremely “selfish genes” are the ones that survive.

Case in point: Some strains of kombucha yeast, the friendly fungus that makes fermented kombucha tea,  carry a gene called “wtf4“. (Yes. That is its real, technical name.) 

 

[A jar full of mature kombucha tea. Image via Wikimedia Commons] 

As far as scientists know, wtf4 offers no benefits to its carrier. It doesn’t help kombucha ferment tea leaves or survive refrigeration. It doesn’t boost tendril growth or amp up spore production or even coast along as a neutral passenger. In fact, wtf4 is poisonous to the sex cells (aka “gametes”) of the yeast it lives in. (But not to humans.)

wtf4‘s poisonous nature mainly comes into play during meiosis–the process of typical cells dividing into sex cells with only half the total complement of chromosomes.

Genetics researchers at the Stowers Institute noticed that when yeasts that had just one copy of wtf4 (as opposed to 2 copies) went through meiosis, over 90% of the viable sex cells came out carrying wtf4.

All else being equal, you would expect the sex cells to have a 50-50 chance of inheriting wtf4 from a heterozygous parent. Something was killing off the gametes that didn’t inherit wtf4

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Biology for Worldbuilding: Immutably Mutable Genetics of Octopuses

[Above: Drawing of Octopus vulgaris by  Comingio Merculiano (1845-1915) circa 1896, published in Jatta Giuseppe (1860-1903). Public Domain via Wikimedia Commons.] 

This post is the first in the series aimed at people who write speculative fiction–sci-fi, fantasy, horror, etc–and are looking for worldbuilding inspiration. In each post, we’ll take a look at a biological trait and explore how that trait might shape a species and the cultures/societies said species might form. Since these posts are mostly about hypothetical alien or fantasy worlds, I want to stress that these posts are thought experiments and highly spectulative.

Humans cultures are obsessed with the idea of inheriting fixed traits–such as nobility, honesty, and magical abilities–from ancestors.  It’s the basis of feudalism and hereditary rule. It’s at the root of the Nature vs. Nurture debate. And today, it’s one of the main reasons why people get their genomes sequenced.  The concepts of DNA and bloodlines will probably be used to justify racism, power grabs, and high fantasy plot twists for decades to come.

Thanks to DNA sequencing studies, the evidence is pretty clear: many traits and predispositions to certain traits can be passed down from parent to parent. People still tend to assume that traits–especially physical ones and “innate” abilities–are more or less determined by DNA and that the environment’s role, if it has one, is secondary.  After all, you can’t just rewrite your own genetic code, right?

Well…if you’re an octopus, squid, or cuttlefish, you kind of can…at the RNA level, anyway.

That, imho, would be an interesting trait for a sci-fi alien or fantasy beastie to have, and in sentient, society-forming life forms, it could have a profound impact on how they behave and see themselves.

[Flamboyant cuttlefish doesn’t care who Jon Snow’s parents are.] via GIPHY

First, some science explanation:

Octopuses, squid, and cutteflish–collectively known as the “coleoid cephalopods“–transcribe the sequences in their DNA into RNA pretty much the way everyone else does, but then, they add an extra step that allows them to make proteins that aren’t encoded in their genomes: They have enzymes that pull As, Gs, Cs, and Ts off of the RNA backbone and replace them with new base pairs in a process called RNA editing.

Mammals and other animals can edit our RNAs and do have the RNA-editing enzymes floating around in our cells, but we don’t use the ability very often. RNA-editor enzymes are very picky and can only edit base pairs that are flanked by specific sequences. (If you want to get especially specific about it, an RNA-editing target has to be surrounded by base pairs that allow the RNA to tie itself up in a knot with the target sticking out.)  For our purposes, the thing you need to remember is that: octopuses and company can alter the proteins their cells are making very rapidly by rewriting their RNA, and they do it all the time.  

That ability can be useful for quickly adjusting to cold water or in neurons that need to be able to respond to cues quickly in general. But it comes with a catch.

Continue reading “Biology for Worldbuilding: Immutably Mutable Genetics of Octopuses” »

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Best Shortform Science Writing: January-March 2017

(A Highly Subjective Round-up of Standout Science News)

[Above:  Header from an 1884 science magazine called Knowledge, led by British astronomer Richard Anthony Proctor. Its tagline reads: “A magazine of science: plainly worded – exactly described.”  Image via Wikimedia Commons & public domain.]

Late January 2017 saw a shift in science journalism so subtle that you probably wouldn’t notice it unless you make your living writing press releases. I happened to be interning in the press office of a prominent family of scientific journals that publishes basic research almost exclusively, so I felt it. And since our press office tracks the coverage of all studies from its journals, I saw data, too.

What we noticed is coverage of our papers in the first half of January 2017 looked a lot like the first half of January 2016. But on January 20, 2017, coverage of our journals’ papers saw a drop. Our February 2017 coverage stats were below our February 2016 numbers, both in terms of the percentage of studies covered and in the number of outlets that covered the popular studies. The numbers improved since then.

We’re biased, but we think it’s unlikely that our press releases suddenly got worse. The journal family is focused basic biology and chemistry (y’know–octopus RNA, flu-killing peptides in frog mucus, stuff like that), and it seems that science journalists, in aggregate, weren’t writing as many stories about basic research as they did in February-early March last year.

That’s neither a good thing nor a bad thing, and it may be the standard science journalism community response to a new administration, regardless of party. But in my mind, it raises the question: How do we decide what counts as “science writing”? Where do we draw the distinction between “health policy” stories and “science of health” stories? Is there a distinction to be drawn at all?

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10 Women of Color in Science History: Medicine

It’s Women’s History Month, and in the Science Twitterverse, that means it’s a time for collages, lists, and black-and-white photos of famous women from science history.

Universities, non-profits, and journalists all love to honor the month by highlighting women’s contribution’s to science. This year it feels especially poignant due to the recent passing of Vera Rubin and Mildred Dresselhaus, both of whom were on shortlists for “Most Likely to Break the 54-Year Streak of Women Not Winning the Nobel Prize for Physics.” However, most #WomeninSTEM tributes largely leave out a key group of people: the women of color who have contributed to STEM. 

Some tributes–like the two below–do a decent job of including key women from underrepresented minorities in STEM history.

 

 

Others not so much…

Continue reading “10 Women of Color in Science History: Medicine” »

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The (Mostly) Untold Story of the Oxygen Revolution

[Cyanobacteria–green, brown, and orange streaks–grow in hot spring at Yellowstone National Park. Photo by Harvey Barrison via Flickr & Creative Commons 2.0] 

The troublemakers were hardly new to the neighborhood. For 300 million years, they had lived in the water column, floating in the sunlight near the surface, sending tiny plumes of toxic gas into the air. That was how they ate: sunlight in, poison out. But it was nothing the ecosystem couldn’t handle. The atmosphere was vast, and the troublemakers were microscopic. The poison diffused. Life went on.  

Until something changed. For some reason, there were more of the green troublemakers. Quadrillions more. So many more that their poison became the air itself. An entire world’s atmosphere transformed. Those that could tolerate the miasma grew and spread. Others survived in pockets of the planet where the new air couldn’t reach them. Uncountable numbers died.

The sunlight-eating oxygen-makers inherited the Earth.

In other words, 2.3 billion years ago, photosynthesis caused a mass extinction.

Continue reading “The (Mostly) Untold Story of the Oxygen Revolution” »

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Best Shortform Science Writing October-December 2016

Best Shortform Science Writing October-December 2016

(A Highly Subjective Round-up of Standout Science News)

[Above: A fish-eyed view of a newsstand in Paris. Photo by Mark Mitchell via Flickr & Creative Commons 2.0 License] 

Science writing at its best doesn’t just impart facts; it has the potential to change the way we think about issues and phenomena. And yet, the vast majority of pieces on science writing–especially the short news stories designed to be consumed on a daily basis–simply focus on telling stories to people who are already interested in science.

The shortforms–the daily news briefs, front-of-book blurbs, and succinct blog posts– are the training grounds for emerging science writing writers, but they’re also underused as a place for experimenting with new ways to convey science, environment, and health stories to the public.

So my writing New Year’s Resolution is to experiment more, both in my blogging and in the sorts of stories I nominate for the 2017 @SciShortform round-ups. I hope you’ll join me by carrying out some experiments of your own and sharing them with the shortform editors.

You can nominate stories via this Google form or simply by tagging us at @SciShortform on Twitter. (Be sure to include a link to the piece you’re nominating in your tweet!)

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NIH scientists identify a genetic disorder that may affect 1 in 20

[Mast cells from a sinus stained in blue. Image via Wikimedia Commons & CC 2.0] 

On July 10, 2010, a DC restauranteur came down with what seemed to be food poisoning. He had no energy and no appetite. Rashes flared up. He could barely get out of bed. First hours and then days dragged by without any relief from the symptoms.

The restauranteur’s family sought out doctor after doctor, until finally they were referred to a lab at the NIH (National Institutes of Health) that studies how allergies pass down through families. 

His symptoms fit a diagnosis of Mast Cell Activation Syndrome, (MCAS)  a disorder where a type of immune cells called mast cells release chemicals that send other immune cells into a destructive frenzy. Ideally, mast cells detect infection and spur other immune cells into action. However, some people’s mast cells have a hair trigger. When mast cells release their chemical contents too often, immune cells end up attacking healthy tissue, causing allergies, stomach issues, and heart palpitations. 

[Above: An NIH-produced video about MCAS and Milner’s research into mast cell activation genetics.] 

Unfortunately, most treatments for MCAS aim at the symptoms, not the root cause.  But the NIH team delved deeper into the genetics and found a pattern:  many MCAS-related symptoms run in families.

And oddly enough, hyperflexible joints, dysautonomia, and baby teeth that fail to fall out also ran in many of those families.  [Correction 6/15: A commenter has pointed out that “hyperflexible” and “hypermobile” are not interchangeable terms. The term “hypermobile” refers to joints that can move outside the typical range of motion due to laxness in ligaments. “Hypermobility” is also sometimes called “double-jointedness.”]  Many of these symptoms skipped generations, only showing up occasionally in individuals, but genetic sequencing revealed the correlation wasn’t coincidence.

In October, NIH scientist Joshua Milner and his team described the  genetic disorder in a paper in Nature Genetics. According to the team’s paper, 4-6% of the U.S. population has the genes that predispose them to this syndrome–which has been tentatively named alpha-tryptasemia or “alpha-T”.

The symptoms can be cryptic and unrelenting: Dizziness, chronic pain, irritable bowels, and fainting. For many patients with these conditions, there’s no explanation and no treatment. “These [symptoms] are really all triggers to get an eyeroll from a doctor,” said Milner. But for a sizeable portion of population, these seemingly unrelated problems might be part of the previously undiscovered genetic disorder.

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Cachexia: How Cancer Sabotages Patients’ Metabolism

[A cancer patient rests in a hospital bed. Photo by Christine Gleason via Creative Commons 2.0 & Flickr

Tumors are master manipulators. They have to be in order to escape human immune systems. Scientists have found evidence that tumors hide by wearing biochemical disguises and some tumors can even recruit turncoat immune cells to their cause.

And now scientists have found evidence that some tumors alter the whole body’s metabolism by “reprogramming” the liver,  according to a study in the journal Cell Metabolism. [Full disclosure: I have an accepted an internship position at Cell Press’s media relations office, but I don’t start until January. I conducted the interviews this post is based on prior to accepting the internship.] The consequences of that reprogramming are often deadly. 

It’s no secret that many cancer patients waste away. They lose weight, including lean muscle mass.  Many lose their appetites, too. Food doesn’t seem to nourish them anymore. They grow weaker.  Breathing gets harder.  And, too often, they die.

This wasting syndrome is called cachexia.  

“The wasting can get so severe in so many patients that it’s estimated to account for 30% of all deaths due to cancer,” explains study co-author Thomas Flint of University of Cambridge. “Lots of people are saying [the cause of death] is the metastasis; it’s this and that, but about 30% of the deaths don’t seem to be directly explained by the tumor.”  Continue reading “Cachexia: How Cancer Sabotages Patients’ Metabolism” »

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7 Things To Know About Mitochondria: 2016 edition

Mitochondria: To most people, they’re little more than a ghostly memory fragment from middle school biology. However, these tiny “powerhouse(s) of the cell” are much more than they seem.

They’re actually the shape-shifting descendants of ancient bacteria that were eaten by a larger archaebacterium billions of years ago. . (If you want to know more about that theory, check out my recent Lateral magazine piece on the scientist who developed that theory.)  Mitochondria have complex relationships with other organelles, swim around in our neurons, and make up 1/3rd of the mass of heart cells.  In the past year, scientists have learned how to add and remove them with cellular surgeries and how to manipulate them directly.

Mitochondria live in every cell in your body and are essential for human life. As University of California post doc Samantha Lewis pointed out to me: “There’s mitochondrial involvement in almost every disease.” 

Yet, we rarely hear of or think about our cells’ powerhouses.

Here are seven facts you probably haven’t heard about mitochondria:

1:  Mitochondria are interconnected shape-shifters.

18962944788_bb79ca413b_k

[A bone cancer cell with stringy mitochondria highlighted in yellow. Photo by NICHD via Flickr & CC 2.0 License.] 

We say “Mitochondria is the powerhouse of the cell” as if mitochondria is a singular word, but actually it’s plural. (The singular of mitochondria is mitochondrion.)  However, in most cells mitochondria act as a collective, passing electrons and genetic information from mitochondrion to mitochondrion.

“They’re [descended from] bacteria that divide in a binary fashion,” explained UC Davis cell biologist and mitochondria specialist Jodi Nunnari. “During the course of evolution [the mitochondrial] genome has been greatly reduced. As a consequence of that and the fact that they were reproducing in a new environment, a few of those do mitochondrial fusion.” Mitochondria’s habit of merging sets them apart from all known bacteria. “Bacteria divide, but they don’t fuse,” Nunnari added.

In fact, mitochondria are so tightly connected that many scientists think of them as a membrane network rather than a series of jelly-bean shaped organelles.

Continue reading “7 Things To Know About Mitochondria: 2016 edition” »

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