Our choco­late ad­dic­tion de­pends per­ilously on a coy re­pro­duc­tive sys­tem

The Woolwich Observer - - LIVING HERE - ABOUT THE AU­THORS Bill is a jour­nal­ist, Rich holds a doc­tor­ate in physics. To­gether the broth­ers bring you “Strange But True.” Send your ques­tions to strangetrue@com­puserve.com. WEIRD NOTES

Q. News re­ports on air and wa­ter pol­lu­tion are rel­a­tively com­mon but not so for light pol­lu­tion. What can be said about this al­most ubiq­ui­tous form of pol­lu­tion? A. Let’s start by not­ing that “elec­tric­ity’s eclipse of the nightly fir­ma­ment is a dis­tinc­tively mod­ern phe­nom­e­non,” says Heather Smith in “Sierra” mag­a­zine. Pub­lic light­ing was first in­tro­duced in the early 20th cen­tury in ur­ban ar­eas con­cerned about crimes com­mit­ted af­ter dark: Oil lamps gave way to gaslights, which were re­placed by “moon tow­ers,” il­lu­mi­nated when there was no full moon. Lit by arcs of raw elec­tric­ity, they were “built as high as pos­si­ble, both be­cause they were so bright and be­cause shorter ver­sions had a his­tory of elec­tro­cut­ing peo­ple who used them to light cigars.” Fi­nally, the tow­ers gave way to light­bulbs and, ac­cord­ing to one sci­en­tific pa­per, “the United States, on av­er­age, be­came 6% brighter each year be­tween 1947 and 2000.”

Other il­lu­mi­nat­ing stats from the mag­a­zine: 99% of peo­ple in Europe and the U.S. ex­pe­ri­ence some form of light pol­lu­tion; 88% of North Amer­i­cans can’t see the Milky Way from their home re­gion; and Los Angeles’s glow on a clear night can be seen from 270 miles away. Fi­nally, coun­tries with the great­est lev­els of light pol­lu­tion are Kuwait, Sin­ga­pore and Qatar; those with the most pris­tine night skies are Chad, Cen­tral African Repub­lic and Mada­gas­car. Q. We think of BFF (“Best Friends For­ever”) as a hu­man thing but per­haps it’s not ex­clu­sively so. Do you know an­other an­i­mal that might also have a BFF? A. “Bovine Friends For­ever” may also be true, says Dan Lewis on his “Now I Know” web site. One study found that cows, be­ing nat­u­rally so­cial, may even “pair off — pla­ton­i­cally speak­ing,” find­ing them­selves a bestie to hang out with. Ac­cord­ing to Uni­ver­sity of Northamp­ton, Eng­land, re­searcher Krista McLen­nan, for a cow, a good friend may be a good thing to have around. First, she iso­lated some cows for 30 min­utes, mea­sur­ing their heart­beats through­out, then paired each of them with an un­fa­mil­iar cow and again took read­ings. Fi­nally, the cows were mea­sured af­ter be­ing put with their “best friends.” As McLen­nan told the BBC, “When heifers have their pre­ferred part­ner with them…, their stress lev­els in terms of their heart rates are re­duced com­pared with if they were with a ran­dom in­di­vid­ual.”

Ex­trap­o­lat­ing from this, Lewis says, it’s likely that “hap­pier, less stressed cows make more milk.” Farm­ers and cow lovers, take note. Q. It’s a won­der we have choco­late at all, given the ca­cao tree’s “coy re­pro­duc­tive sys­tem.” What’s the story here? A. “Ar­guably some of the most im­por­tant seeds on the planet — they give us candy bars and hot co­coa, af­ter all — come from pods cre­ated by dime-sized flow­ers on ca­cao trees,” says Su­san Mil­ius in “Sci­ence News” mag­a­zine. With Emily Kear­ney of the Uni­ver­sity of Cal­i­for­nia, Berke­ley, as our guide, imag­ine a bloom­ing ca­cao tree with most of the flow­ers com­ing not from branches but di­rectly out of the trunk. The male, pollen-mak­ing struc­ture is fit­ted with a tiny hood and curv­ing petals. Tiny midges no big­ger than a poppy seed crawl into the hood, but what hap­pens next is un­clear. But here’s what is clear: The pol­li­na­tor needs to ex­tract 100-250 pollen grains to fer­til­ize the 40-60 seeds of a ca­cao pod, then fly some dis­tance away and de­posit the pollen into the fe­male part grow­ing on un­re­lated trees. This of­fers a bet­ter chance of crosspol­li­na­tion.

To Kear­ney, it’s un­likely that the frail midges are up to the task. Per­haps, she muses, there could be “a clan­des­tine, strong-fly­ing na­tive pol­li­na­tor species that sci­en­tists just haven’t no­ticed.”

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