"Born in the caul" is a phrase that's connected with a lot of cross-cultural myths and superstitions — babies born in the caul are supposed to be destined for lives of fame and fortune (or, possibly, misfortune and grisly death, depending on which legends you're listening to). Biologically, though, it refers to a baby that's born with part of the amniotic sac — the bubble of fluid a fetus grows in inside the uterus — still attached. Usually, a piece of the sac is draped over the baby's head or face. These are called caul births, and they're rare. But, about once in every 80,000 births, you'll get something truly extraordinary — "en-caul", a baby born inside a completely intact amniotic sac, fluid and all.
There's a photo of a recent en-caul birth making the rounds online. The photo is being attributed to Greek obstetrician Aris Tsigris. It's fascinating. But it's also pretty graphic, so fair warning on that. (If the sight of newborn infants and blood gives you the vapors, you might also want to avoid most of the links in this post, as well.)
I've been linking Double X Science a lot lately. That's because they're great. It's rare to get such smart, fascinating, science-centered discussion about female anatomy and reproductive issues that goes beyond the surface dressing we all already kind of know. Case in point: This piece by Emily Willingham about the development of the human heart in utero. You've probably heard at one point or another that a fetus' heart starts beating around 6 weeks (an age which is, by the way, calculated from the date of the mother's last period, NOT from the date of actual conception; so the fetus itself is really only about 4 weeks old at this point, and its mother only missed her period two weeks ago). But what's the heart actually like at that point? Turns out, absolutely nothing like what you imagine. Very cool stuff. — Maggie
In a study of 6,455 semen samples (yup), scientists at Israel's Ben-Gurion University of the Negev found that human sperm were most atheletic — and were found in the highest concentrations — in winter. There was a marked decrease in sperm motility and numbers in spring, summer, and fall. It's an interesting and logical addendum to the fact that sperm counts and motility decrease in men who subject their testicles to warm conditions; in hot tubs, say, or a pair of overly tight underpants. — Maggie
There is definitely a seasonality to human births, writes Beth Skwarecki at Double X Science. The complicated bit is that human baby season isn't necessarily the same (or as strongly expressed) from place to place and culture to culture. In the United States, significantly more babies are born in July, August, and September. Meanwhile, in Europe, babies seem to make their way into the world in spring. So there's clearly a cultural component to this — but culture doesn't explain it, entirely. Skwarecki's piece explores a messy place where culture, genetics, and circadian rhythms intersect. — Maggie
This is a book about "doin' what comes naturally". Which is to say, sex. But what kind of sex? With whom? And to what purpose? At what point do things like gender expression, sex, reproduction, and child-rearing stop being "normal and natural" and start being something weird that humans do because we are diverse/perverted/sinful/creative (depending on your personal point of view)?
In reality, the word "natural" is mainly how we tell each other which behaviors and traits are the socially correct ones. Calling something natural is often more about specific human cultural standards than it is about what actually happens in nature. Crime Against Nature is artist Gwenn Seemel's attempt to correct that mistake. Filled with gorgeous, Klimt-esque illustrations, Seemel's book shows readers just how diverse nature can be and just how often it fails to conform to our ideas of what is normal — from girls who are bigger and tougher than boys; to boys who give birth; to boys and girls that don't have sex or reproduce at all (and don't seem to mind one bit).
The issues at play here are hefty and potentially uncomfortable, but the book itself is light, playful, and pleasantly un-preachy. It's also set up in a way that allows it to evolve with kids as their reading skills improve — pairing simple statements like "Boys can be the pretty ones" with longer but still easy-to-read paragraphs explaining, for instance, the most recent scientific theories about why male peacocks are so much more colorful than females.
Overall, the book is a great reminder that there are lots of ways to be a girl and lots of ways to be a boy. Nature is chock full of role models for every kid (and every adult). Just because you don't conform to the version of your gender that you see on TV it doesn't mean that you're defective. Last month, my husband and I navigated aisle after aisle of noxiously gendered toys, trying to find things for our niece and nephew that reflected those individual kids, rather than telling them who they were supposed to be and what they were supposed to like. In a world where even Legos come in pink boxes (with instructions for building cute little houses) and blue boxes (with instructions for building race cars), Crime Against Nature is a much-needed breath of fresh air.
Reading the stories about the baby panda's death, I noticed that zookeepers had tried to revive the baby using CPR. And that got me curious. Just how, exactly, do you give a panda CPR. At Slate, L.V. Anderson tackles this question. Turns out, the process isn't all that different from resuscitating a human.
CPR is appropriate when a patient’s heart has stopped (whether or not the patient is human), and the goal is to maximize the amount of blood flowing out of the patient’s heart into other vital organs and to get some air into the patient’s lungs so the patient’s blood will be oxygenated. Some animals, including humans and baby pandas, have bodies shaped in such a way that the best way to pump the heart is to directly compress the chest. Other animals, Iike most dogs and cats, have much rounder chests, which makes it harder to directly compress the heart. With these animals, vets recommend compressing the chest from the side, which puts secondary pressure on the heart.
As anyone who’s recently taken a human CPR course knows, the rate of compression recommended for humans is about 100 beats per minute. (Doctors recommend pumping the chest to the beat of the Bee Gees song “Stayin’ Alive.”) The same rate of compression is recommended for animals; even though dogs and cats have a higher resting heart rate than humans do, the rate of 100 compressions per minute gives the heart a chance to refill with blood between compressions.
Sea urchin egg undergoing mitosis with fluorescent-tagged/stained DNA (blue), microtubules (green).
Cells divide. One single piece of life tugs itself apart and splits in two. It sounds like a purely destructive process, reminiscent of medieval woodcuts where the hands and feet of some unfortunate thief are tied to horses heading in opposite directions. But that's the macro world. On the micro scale, to split is to live. A dividing cell doesn't just rip itself to pieces. Instead, the cell first makes a copy of its genetic information. When the cell splits, what it's really doing is making a new home for that copy to live in. Make enough copies—and enough copies of the copies—and you eventually end up with a living creature.
Back in May, I took part in the Marine Biological Laboratory Science Journalism Fellowship, a 10-day program that gives journalists hands-on experience in what it means to be a scientist. The program is split into two tracks. As part of the environmental track, I went to the Harvard Forest, where nature is one giant laboratory. But, at the same time, other journalists were busy in a different sort of lab.
Steven Ashley is a contributing editor at Scientific American and writes for a host of other publications. He took part in the fellowship's biomedical track. Ashley and the other journalists fertilized the eggs of sea urchins and other small ocean creatures, and then used specialized biomedical microscopes and cell imaging software to create brilliant photos and mesmerizing movies of cell division and growing animals.
Ashley was kind enough to send me some of those images and movies. In them, you can see the tiny structures and every day processes that form the basis of life.
This is not a geode. It's an animal. An apparently delicious animals with clear blood, whose body is accumulates surprisingly large amounts of a rare metal used to strengthen steel.
This is Pyura chilensis—an immobile ocean creature. Besides the other traits I mentioned, P. chilensis is also capable of both sexual and asexual reproduction. At the Running Ponies blog, Becky Crew explains the results of a 2005 study that detailed the creature's breeding habits for the first time.
The results showed that P. chilensis is born male, before becoming cosexual – having both male and female gonads – in its adolescence as it increased in size. The researchers also found that given the choice – that is, if situated around other individuals – these organisms prefer to breed via cross-fertilisation, writing, “Given that more events of natural egg spawning followed by successful settlement and metamorphosis were recorded in our paired specimens and in our manipulated cross trials … it appears that cross-fertilisation predominates in this species.”
Manríquez and Castilla also found that a greater number of fertilised eggs resulted from the paired specimens, which suggests that cross-fertilisation, or reproducing with another individual, predominates because it is more effective. This assumption was strengthened by the fact that individuals that had cross-fertilised before being put in isolation took at least two months before successfully producing offspring via selfing. However, they were careful to note that while cross-fertilisation was preferred, selfing did not produce inferior offspring. “No perceptible differences in fertilisation, settlement and metamorphosis success among self and outcross progeny were found,” they reported. This suggests that when stuck alone in the ocean, selfing provides an advantageous opportunity for loner P. chilensis individuals to still pass on their genes.
Earlier this week, the Smithsonian National Zoo live-tweeted their most recent attempt to knock up a giant panda. You can read the whole thing at Storify. And, seriously people, you should read it. I originally intended to just post a short link to this, almost as a joke, but it turns out that the process of inseminating a giant panda is actually really interesting.
Besides the photos, which are great, and the revelation that it takes 15-20 people to properly oversee the process (insert obvious jokes here), the Storify contains a lot of neat behind-the-scenes details about what it's like to perform a medical procedure on a large animal. You'll also learn a thing or two about the panda reproductive process.
On the gurney lay a young woman the color of white marble. The red pool between her legs, ominously free of clots, offered a silent explanation.
“She arrived a few minutes ago. Not even a note.” My resident was breathless with anger, adrenaline, and panic.
I had an idea who she went to. The same one the others did. The same one many more would visit. A doctor, but considering what I had seen he could’t have any formal gynecology training. The only thing he offered that the well-trained provers didn’t was a cut-rate price. If you don’t know to ask, well, a doctor is a doctor. That’s assuming you are empowered enough to have such a discussion. I was also pretty sure his office didn’t offer interpreters.
I needed equipment not available in an emergency room. I looked at the emergency room attending. “Call the OR and tell them we need a room. Now.” And then I turned to my resident. I was going to tell him to physically make sure a room, any room, was ready when we arrived, but he had already sprinted towards the stairs. He knew.
Required reading in this year of presidential elections in America, in which so many candidates would have us return to the dark era in which abortion was illegal. Outlawing abortion doesn't end abortion, it just makes scenes like this more common.
Here's a fascinating study that shines a bright spotlight of nuance on some of those maybe-too-simplistic assumptions we make about evolution, physical characteristics, and reproductive fitness.
If you've paid any attention to reporting on the science of what humans find attractive and why, you won't be surprised to learn that studies consistently show that deeper voices are associated with stereotypically manly-man characteristics such as hairier bodies and taller height, that men with these voices and characteristics are judged as being more attractive, and that deep-voiced dudes seem to get more action from more ladies.
Based on all of that, you might be tempted to speculate that a deeper voice is an outward sign of how fertile and virile a dude is and that ladies have evolved to be attracted to that show of baby-making prowess. And that makes sense ...
Except that men with deep voices also seem to have lower-quality sperm. At the Anthropology in Practice blog, Krystal D'Costa explains:
These assessments aren’t entirely made up. There is evidence that secondary sexual traits can predict health and fertility of a partner. Brilliant colors and showy displays have long been natural indicators of potential sexual fitness. For example, deer with bigger, more complex antlers also have larger testes and more motile sperm. Lower frequency sounds have been linked to larger body size across all primate species
However, semen analysis reveals that men with deeper voices have lower scores on seven motility parameters (7)—even when the lifestyle and environmental factors are accounted for. While men with deeper voices may have more sexual partners, they seem less prepared to pass on their genes. Researchers believe the lower sperm quality reflects a trade-off that comes with having to compete for mates:
“Animals have finite resources to partition amongst reproductive activities, and the theoretical models of sperm expenditure assume a basic trade-off between male investment in attracting mates and in gaining fertilizations. Recent studies of non-human animals are providing empirical evidence for this basic life-history trade-off. A number of studies have also reported short-term declines in semen quality associated with social dominance."