Can you properly distinguish between a male and female crocodile? This research paper, published in 2007, will help — pointing out the sometimes subtle differences between external genitalia. It's chock full of pictures of erect crocodile penises, so you'll learn what those look like, but what particularly interested me was the diagram above.
Cloacas are sort of multi-purpose orifices found in certain species of birds and reptiles. Instead of having separate biological tools for poop, pee, and sex, these animals manage all three functions with the same hole. Males also have cloacas and will either have a penis or pseudo-penis that comes out of it for mating. I've known this for a long time, but had a lot of trouble picturing how all of that anatomy fits together. This diagram (Figure 4 in the paper) is the first image that made the internal structure of cloacas really make sense to me. The more you know! Read the rest
Earlier this week, Republican representative Devin Nunes referred to his colleagues in the US House of Representatives as "lemmings with suicide vests". I would like to propose that this characterization is vastly unfair. To the lemmings.
That's because real lemmings, such as the adorable little creature pictured above, aren't actually suicidal. If anything, their problem is that they're just too damn horny. [Insert new political analogy here.] Read the rest
Fun fact you might not be aware of if you are not the owner of a uterus: Periods go hand-in-hand with pooping
. Not every person who gets a period will end up with diarrhea, but it's not uncommon because the same hormone that makes a uterus contract (a necessary step in the whole period process) can also end up making your intestines contract. Francie Diep explains this effect — as well as the other
hormone-related reason why periods and poops can be linked. Read the rest
First, neither the authors of the paper, nor the journal its published in, have the best track record for careful work, well-documented research, or non-hyperbolic results. More important, the actual paper, itself, makes claims it can't back up
. Case in point, says Phil Plait, the alien in question is a particle the authors assume is part of a diatom — a single-celled plant. The paper actually says "assume", and, from the sounds of things, they haven't even checked out that basic, important idea with a diatom expert. Read the rest
The opalescent inshore squid (which, if you've eaten squid in the US, then you've probably eaten before) can change color just like octopuses can. In fact, scientists found that female squid can give themselves a white stripe that looks an awful lot like the testicles of their male counterparts. It's probably some kind of defensive measure, but the scientists are more interested in how the squid change color, not why
. That's because the mechanism is unique, and fascinating. Read the rest
Wait But Why has a fantastic series of graphs that aim to help us wrap our heads around the enormous timescales on which forces like history, biology, geography and astronomy operate. By carefully building up graphs that show the relationship between longer and longer timescales, the series provides a moment's worth of emotional understanding of the otherwise incomprehensible. Read the rest
Meet Issus coleoptratus, an insect whose larva have interlocking meshed gears connecting their back legs. The gears help coordinate leg movements, helping the larva to jump fast and far.
Video Link Read the rest
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Science journalist John Rennie is an amazing story teller. In this recording from Story Collider, he explains how he became the lab safety officer in his post-undergrad biology laboratory in the early 1980s (it involves being the only person who was concerned when other people started scooping up mercury with their bare hands). The peak of his experience: The day he stuck his arm, up past the elbow, into a barrel of liquid nitrogen. Good times.
Audio link Read the rest
Given that people are going around doing things like cutting off octopus limbs
in order to understand their distributed neuron processing system, it's worth asking some questions about how octopuses perceive pain
, as well. That's more complicated than you might think. As Katherine Harmon explains, it's likely that octopuses have some kind of awareness of when they're touching something unpleasant. But just how that works, and how similar it might be to the way we vertebrates understand "pain", is a big mystery. Read the rest
Valérie Choumet at Paris's Institut Pasteur anaesthetized a mouse, stuck a microscope in a flap of its skin, and induced a mosquito to bite it. The result is the best footage yet of the weird, flexible, questing mouth of a mosquito, which can bend and twist and fork as it seeks out blood vessels.
Read the rest
The complicated process
that allows your brain to quickly cancel an order and replace it with another. Read the rest
Yesterday, Rob told you about the first public tasting of a burger that was grown in a laboratory
, from strips of flesh built up from muscle stem cells. I found a couple of great links today that build on that news. First: The secret ingredient in lab-grown meat
is fetal cow blood. (It's both a significant part of the high price of lab meat, and a reason why your vegan friend won't be eating lab meat anytime soon.) Also be sure to check out synthetic biologist Christina Agapakis' perspective
— she tones down some of the hype while making it clear why lab meat is still pretty impressive. Read the rest
What is a species? That's not a simple question.
And it's even harder to answer after you've had a few.
Intrepid science journalist Charles Q. Choi takes inspiration from both the Drunk History series of videos and a really awful lot of whiskey to try and help you better understand a scientific concept (and also the finer points of orc biology). This was an idea I had, which came together with the help of several science journalist friends during the Science Online conference back in January. I'm still impressed with how accurate Charles was on the science while in that state. I can't speak to the Tolkien mythology.
Video Link (Note: This seems to play softly on some computers. If you're having trouble hearing it, plug in headphones or turn up your speakers.)
Thanks to Rose Eveleth, Colin Schultz, and Jennifer Honn — whose work on editing and producing this video was invaluable. Also thanks to John Rennie, Steve Ashley, Olivia Koski, Maki Naro, and Stephen Granade — whose input and assistance made this possible. And, of course, special thanks to Charles, who really was fully recovered by the next morning.
Image: Orc, a Creative Commons Attribution (2.0) image from ton's photostream Read the rest
Researchers at Children's Hospital of Philadelphia have been following and studying the brains and lives of so-called "crack babies" for more than 20 years. Now, they're beginning to publish their findings, and what they're finding is not what they expected
. The researchers saw few statistical differences between kids exposed to crack in utero and those who weren't. But they did find big differences between the exposed babies and the controls when compared to children who grew up in wealthier families. Now, they're coming to the conclusion that it's poverty — not crack — that may present the biggest risk to children's neurological development and their later opportunities in life. Read the rest
If you seem to be the target of bloodsucking attention, there are two biological systems you can blame
— your microbial flora, and/or your immune system. Your particular mix of skin bacteria play a big role in determining how well mosquitoes can smell you (and whether you smell delicious). Meanwhile, your immune system controls your allergic response — or lack thereof — to mosquito bites. If you never get red welts to go with the biting, it's easy to think that you're not getting bitten as often as someone who does. Read the rest
I'm reading a ton of baby and pregnancy books right now, preparing both for the October birth of my daughter and an upcoming BoingBoing feature about evidence-based books for science-minded soon-to-be-parents. After reading this interview at The New Inquiry
, I really want to check out The Motherhood Archives
— a documentary about the ways culture shapes and reshapes how we understand the biology of birth and the growth of an infant. From the Marxist origins of Lamaze, to the early-20th-century feminists who pushed for pain-free birth, to the rise of the birth center, The Motherhood Archives
sounds like a fascinating exploration of how different generations think and rethink the same ideas and an anthropological assessment of what "the right way" to give birth and raise children really means. (Thanks, Emile Snyder!) Read the rest
At The Conversation, neuroscientist Melissa Hines talks about what little biological basis there is behind the idea of heavily gender-coded toys for children
. It's true that male and female fetuses are exposed to different hormones before birth and that might affect what kinds of toys they're interested in later. But it's also true that there is natural variability in both hormone levels and interests within
the sexes and (intriguingly) human babies all
prefer reds and pinks, regardless of their sex. (Meanwhile, human adults prefer blue colors, regardless of sex.) Read the rest