From beer to coffee, bitter flavors are things that most of us have to learn to enjoy over multiple tastings. Scientists have long assumed that our ability to even taste those flavors is rooted in self-defense — a way to root out and avoid potentially poisonous plants in the diet of our hunting and gathering ancestors. But new research suggests that the ability to taste bitter flavors isn't strongly tied to hunting and gathering
lifestyles, which leaves researchers at a loss for why the skill might have evolved. My hypothesis, based on experience with espresso and IPA lovers: Perhaps there's an evolutionary advantage to beverage pretentiousness. Read the rest
More than 90% of land plants have symbiotic relationships with fungus and those relationships seem to date back hundreds of millions of years. At Topologic Oceans, Charles Soeder explains how this fact has become a jumping off point for an interesting theory about the evolution of land plants
— maybe all the plants we see in our daily land-locked lives are the result of symbiotic blending of algae and fungus, similar to the way our own cells now depend on the offspring of a bacterial invasion in order to function. Read the rest
Male fiddler crabs are famous for their mismatched front claws — one great big and threatening, one eensy-weensy. (I used to use this as a metaphor for the split in my SAT scores.) But what's really interesting about this lopsided look is that it seems to serve multiple purposes. The big claw can be used to attract lady crabs — wave it around and it becomes the crabby equivalent of, "Yo! Adrian!" But the big claw can also be used as a practical weapon, where two male crabs go at each other like fancy fencers with one arm behind their backs.
And the extent to which the big claw is for looks or for violence seems to vary a lot depending on the species of fiddler crab, writes scientist John Christy. Some have a lightweight claw that's better for waving at the girls, but weaksauce in a fight. Others have a heavy, dangerous claw that's difficult to use for long-distance flirting. Christy and his team are in the process of trying to figure out what selection forces leave some crabs optimized for love and others for the battlefield. In the meantime, though, they made this awesome crab fight video, set to a stirring, John Williams-esque soundtrack.
Video Link Read the rest
It's not too early to plan for next semester. John Hawks
, a fantastic science blogger and professor of anthropology at the University of Wisconsin-Madison is offering a Coursera class on Human Evolution: Past and Future
. Seems like just the thing for curious Happy Mutants! Read the rest
More than a quarter of primate species form male-female pair bonds that scientists describe as "monogamous". That's much higher than the overall mammal average of 9 percent. But those statistics don't mean that humans are somehow "meant" to be monogamous. In fact, scientists are still debating — and publishing conflicting theories — on why monogamy would have evolved at all
. Carl Zimmer has an interesting column at The New York Times looking at two recent papers, and how they fit into an ongoing scientific fascination with our own sex lives. Read the rest
Good news for humanity's sense of shiny special uniqueness! Sure, other animals use tools. Chimpanzees and bonobos might even have behaviors that can be classified as cultural. But those damn dirty apes still can't throw a fastball to save their lives.
Becky Lang at Discover magazine has an interesting story on this research, which centers around the biology that allows fast pitches to happen, and how we developed it, while our closest relatives did not.
Video Link Read the rest
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. Read the rest
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.
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. Read the rest
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
. Read the rest
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
. Read the rest
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 Read the rest
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. Read the rest
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). Read the rest
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. Read the rest
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. Read the rest
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. Read the rest