WOLF
The lone wolf’s howl has long been chosen as a symbol of melancholy and
loss. Now researchers have demonstrated that the choice was accurate.
Howling is not related to the stress
level of the crying canine or the dominance status of the departing
wolf; the best predictor of a wolf’s howl is the closeness of the
howler’s relationship with the wolf leaving its side. The study is in
the journal Current Biology. [Francesco Mazzini et al., Wolf howling is mediated by relationship quality rather than underlying emotional stress]
The researchers separated individuals living in Austria’s Wolf Science
Center. They recorded the resulting howls for 20 minutes after
separation. Then the scientists took a sample of saliva from the howling
wolves to measure circulating levels of cortisol, a hormonal stress
indicator.
Cortisol levels increased during all separations, whether a preferred
partner or any other pack mate was taken away. But howling was much more
pronounced when a close partner was removed.
The researchers thus concluded that the level of howling was determined
by the relationship of the howler with the separated wolf, regardless of
the removed wolf’s rank. Because even a wolf, apparently, can have a
best friend.
—Arielle Duhaime-Ross
GUTS
Everywhere you go, the trillions of microbes in your gut go too. And that's a comforting thought. Because according to a new study, a more diverse population of intestinal bacteria is linked to better health. The work is in the journal Nature. [Emmanuelle Le Chatelier et al., Richness of human gut microbiome correlates with metabolic markers]
Danish researchers gathered gut microbes from almost 300 obese and
nonobese adults. The intestines of roughly one in four participants
contained fewer and less diverse bacteria than average. And members of
this group were more likely to be obese and to suffer from gut
inflammation.
By looking for only a few specific bacteria, researchers could predict
whether a subject fell into the low-diversity group. Certain species
could even indicate whether an individual was slim or overweight. And
these microbial markers might also serve as signs of future health
risks—because low-diversity participants who were obese were more likely
to gain additional weight over time.
But a low-diversity gut won't necessarily doom your health. According to another study
in the same journal, it's possible to increase microbial diversity by
developing a decent diet. Remember, you’re eating for trillions.
—Sophie Bushwick
