Scientists at the University of Copenhagen sequenced the oldest genome yet — 700,000-year-old DNA
from an ancient ancestor of the horse. The Nature Podcast explains why doing this is valuable
(and, no, it's not about creating a cloned ancient horse park) and how you go about sequencing such elderly, and thus degraded, DNA.
History has shown us that even some of the greatest scientific luminaries, towering figures such as the naturalist Charles Darwin, the twice-Nobel-Laureate chemist Linus Pauling, and the embodiment of genius — Albert Einstein — have made some serious blunders.Read the rest
As we all know by now, ducks have penises
. Rather epic penises
, in fact. Chickens, though, are penis-less. In fact, most birds don't have them. In an important update in duck sex news, Ed Yong follows the work of several scientists who are trying to better understand how genitals evolve and why they differ so much between species and genuses
. Bonus new fact: A dissected goose penis looks surprisingly like a less-colorful Man-O-War jellyfish.
Sure, you've got those great opposable thumbs, complex culture, and the ability to walk on two legs. But don't let those facts lull you into thinking that evolution is on your side. It's not. It's not really on anybody's side. Which is why the same process that produces super-smart, super-creative apes (like us) is also responsible for helping cockroaches evade our attempts to murder them
There doesn't have to be a pre-ordained meaning to the universe in order for it to mean something. That's one of the fun things about being human — we get to make meaning for ourselves. With that in mind, please read this lovely essay by Brian Switek about finding wonder and joy in the oft-denigrated idea of being "just" a product of time and chance
Entomologist Piotr Naskrecki found this fantastic centipede hiding under the smushy bark of a fallen log in Mozambique. You can see more photographs of it, and read more about its discovery at his blog, The Smaller Majority.
What makes this centipede particularly interesting (besides that great handlebar moustache it's sporting) is the long, fuchsia appendages on its rear end, each one topped with a feathery, yellow bit, like a flag on a pole. According to Naskrecki, nobody knows what those appendages are for. They seem to have evolved from the animal's rear-most legs, but their function is a total mystery.
Via Why Evolution is True
It could just be cultural connections that make us identify one song as happy and another as sad. But, explains Joe Hanson, there's evidence that our emotional connections to music are more universal than that.
In this video about evolution, music, and smooshy feelings, Hanson describes a study that asked participants to create short lines of music that matched specific emotions. The results were surprisingly similar, whether the participants were Americans, or people from an isolated village in Cambodia.
My dad calls the first few months of a baby's life "the necessary larval stage". I've heard other people refer to it as "the fourth trimester". Basically, newborn human babies are pretty useless, as far as baby animals go
. This is especially true in comparison to baby apes, who come out of the womb at a much higher level of development. Scientific American has an excerpt from an upcoming book by Chip Walter that talks about this fact and its connection to two key moments in human evolution — the development of bigger brains (and thus, bigger heads) and walking upright (which has the side effect of creating a narrower birth canal).
The populations at lowest risk for developing gestational diabetes — namely, ladies of European decent — come from cultures that eat (and have eaten, for thousands of years) dairy and wheat-heavy diets that would, normally, increase your risk. Meanwhile, writes Carl Zimmer at The Loom, Bangladeshi women, who have one of the highest risks for gestational diabetes, come from a culture that traditionally ate a low-carb, low-sugar diet. What's going on here? The answer might lie in evolution
. It's a particularly interesting read given the ongoing pop-culture debate about whether 10,000 years is enough time for humans to adapt to eating certain foods. This data on pregnant ladies would suggest the answer is, at least in some respects, yes.
Writer Darren Naish, who blogs at Tretrapod Zoology, took this photo of a Larus gull attempting to chow down on an awkwardly shaped starfish. (And, really, are there any other kind of starfish? Especially when you're trying to fit them in your mouth whole?)
You might remember Larus gulls from a recent piece I wrote on speciation and evolution. According to Naish, they might have another place in the story of evolution, as well. Regardless of how Sisyphean this gull's dinner plans may appear, Larus gulls actually (successfully) eat a lot of starfish. So many, in fact, that, as Naish explains in a recent post, they might be prompting one species of starfish to slowly turn a different color — an adaptation that makes the species less visible to gulls.
The coelacanth is one of a small handful of living fishes that are probably closely related much more ancient, extinct creatures — including, the first fish to haul itself up onto land. Now scientists have sequenced its genes and are digging through the data in search of genetic clues to how fish and land-dwelling animals are connected to one another
. Among the finds so far, a gene that seems to be connected to how animals grow placentas. Coelacanths don't have placentas, but they do have eggs that hatch inside their own bodies.
First: When shown images like the one above and asked to choose which men they found more attractive, women cared significantly more about body shape than penis size. (Also, it's worth noting that the image above is meant to show you an average, actual human guy in the middle and the extremes of body shape and penis size that were shown to the women on either side of him. In reality, the women were shown a full spectrum of images mixing different body types and penis sizes).
Second: The hypothesis (that human women sexually selected human males to have the larger-than-other-primates junk they are blessed with today) comes with some big questions, including the obvious — flaccid penis size does not correlate well to erect penis size.
Third: As Faye Flam points out at The Knight Science Journalism Tracker, the journal Proceedings of the National Academy of Sciences might need a new acronym (or, at least, different subject matter).
Here's a link to the actual study
I'm contributing to Voice, a new group column on environmental science at Ensia. My first piece is about those swallows in Nebraska
that seem to have adapted to highway traffic and what they can teach us about the speed of evolution and the way invasive species adapt to new homelands.
Imaginary letters, in which giraffes, angora rabbits, and emperor penguins air their grievances against the forces of natural selection
In Tulsa, Oklahoma, over the last 30 years, the number of cliff swallows killed by moving vehicles has drastically decreased. That change can't be accounted for by alterations in traffic patterns or swallow populations, say scientists. Instead, they think it's tied to the fact that the birds' wingspan is also decreasing
. This adaptation — whether selected for by vehicular birdicide and/or other factors — helps swallows be more nimble in the air at high speeds, making it easier for them to avoid oncoming traffic. (EDIT: Sorry guys, I made an error here. Some of the researchers were from Tulsa, but study actually happened in Nebraska. Evolution takes place throughout the plains states.)
By studying the way it has mutated and changed over time, scientists can trace human mitochondrial DNA — the DNA that is passed from mother to daughter — back to a single woman. Basically, everybody alive is descended from her. But that's not the same thing as saying that Mitochondrial Eve was once the only woman alive. In a very nice piece — with helpful illustrations — the Christian (but evolution-accepting) scientists at BioLogos explain what Mitochondrial Eve really means and why she can't be used as an argument for creationism
. Whether or not you've ever found yourself arguing this point with a family member or friend, the piece is really useful for deepening your understanding of a pop-science concept that's often thrown around without a clear explanation behind it.