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What Makes "Psycho Killers" Tick?

Neuroscientist Jim Fallon studies psychopathic killers, and why they do what they do. Is there something different about their brains genetically, due to damage, or is their behavior (murder) caused by environment? Interestingly, psychopathic murderers often have damage to their orbital cortex -- a part of the brain just above the eyes -- as well as certain genetic markers. Fallon explains in a fascinating, brief TED Talk what his research has revealed -- including a personal connection to his work, as it turns out he's related to a long line of murderers (uh-oh).

Discussed: why more men than women are psychopathic killers, how overdoses of serotonin in the womb desensitize young brains, how early trauma interacts with a particular "killer gene," how Fallon's cousin is Lizzi Borden (and other murderous family connections), and how Fallon is watching for more murderers to pop up in his own family.

You can also watch in high-resolution MP4 format (plays in QuickTime, Windows Media, etc.). Also, read more about Jim Fallon and psychopaths.

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Why Can Parrots Talk and Other Birds Can't?
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If you've ever seen a pirate movie (or had the privilege of listening to this avian-fronted metal band), you're aware that parrots have the gift of human-sounding gab. Their brains—not their beaks—might be behind the birds' ability to produce mock-human voices, the Sci Show's latest video explains below.

While parrots do have articulate tongues, they also appear to be hardwired to mimic other species, and to create new vocalizations. The only other birds that are capable of vocal learning are hummingbirds and songbirds. While examining the brains of these avians, researchers noted that their brains contain clusters of neurons, which they've dubbed song nuclei. Since other birds don't possess song nuclei, they think that these structures probably play a key role in vocal learning.

Parrots might be better at mimicry than hummingbirds and songbirds thanks to a variation in these neurons: a special shell layer that surrounds each one. Birds with larger shell regions appear to be better at imitating other creatures, although it's still unclear why.

Learn more about parrot speech below (after you're done jamming out to Hatebeak).

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Prehistoric Ticks Once Drank Dinosaur Blood, Fossil Evidence Shows
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Ticks plagued the dinosaurs, too, as evidenced by a 99-million-year old parasite preserved inside a hunk of ancient amber. Entomologists who examined the Cretaceous period fossil noticed that the tiny arachnid was latched to a dinosaur feather—the first evidence that the bloodsuckers dined on dinos, according to The New York Times. These findings were recently published in the journal Nature Communications.

Ticks are one of the most common blood-feeding parasites. But experts didn’t know what they ate in prehistoric times, as parasites and their hosts are rarely found together in the fossil record. Scientists assumed they chowed down on early amphibians, reptiles, and mammals, according to NPR. They didn’t have hard evidence until study co-author David Grimaldi, an entomologist at the American Museum of History, and his colleagues spotted the tick while perusing a private collection of Myanmar amber.

A 99-million-year-old tick encased in amber, grasping a dinosaur feather.
Cornupalpatum burmanicum hard tick entangled in a feather. a Photograph of the Burmese amber piece (Bu JZC-F18) showing a semicomplete pennaceous feather. Scale bar, 5 mm. b Detail of the nymphal tick in dorsal view and barbs (inset in a). Scale bar, 1 mm. c Detail of the tick’s capitulum (mouthparts), showing palpi and hypostome with teeth (arrow). Scale bar, 0.1 mm. d Detail of a barb. Scale bar, 0.2 mm. e Drawing of the tick in dorsal view indicating the point of entanglement. Scale bar, 0.2 mm. f Detached barbule pennulum showing hooklets on one of its sides (arrow in a indicates its location but in the opposite side of the amber piece). Scale bar, 0.2 mm
Peñalver et al., Nature Communications

The tick is a nymph, meaning it was in the second stage of its short three-stage life cycle when it died. The dinosaur it fed on was a “nanoraptor,” or a tiny dino that was roughly the size of a hummingbird, Grimaldi told The Times. These creatures lived in tree nests, and sometimes met a sticky end after tumbling from their perches into hunks of gooey resin. But just because the nanoraptor lived in a nest didn’t mean it was a bird: Molecular dating pinpointed the specimen as being at least 25 million years older than modern-day avians.

In addition to ticks, dinosaurs likely also had to deal with another nest pest: skin beetles. Grimaldi’s team located several additional preserved ticks, and two were covered in the insect’s fine hairs. Skin beetles—which are still around today—are scavengers that live in aerial bird homes and consume molted feathers.

“These findings shed light on early tick evolution and ecology, and provide insights into the parasitic relationship between ticks and ancient relatives of birds, which persists today for modern birds,” researchers concluded in a news release.

[h/t The New York Times]

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