Can all living things—plants, insects and bacteria—be albino?
Lilliana Hitchcock, Houston, Texas
If by “albino” you mean an organism lacking the pigment melanin, then loosely speaking, yes, says Carly Muletz Wolz, a research scientist at Smithsonian’s Center for Conservation Genomics. Albinism, which is caused by a hereditary genetic mutation, is noticeable among mammals because melanin is the only pigment they produce; without it, their hair, skin and eyes will lack color. But other life-forms produce a variety of pigments in addition to melanin; some specimens may be unable to produce melanin, but their other pigments will show, and they are more properly called “amelanistic.” In either case, an organism lacking melanin will be more susceptible to ultraviolet rays.
Why don’t they use artificial gravity on the International Space Station?
Pat Andérson, Shasta Lake, California
Creating artificial gravity on the space station is possible—but impractical, says Valerie Neal, a curator at the National Air and Space Museum’s Space History Department. To simulate gravity, you’d need to spin the station to produce a force that propels the astronauts outward; that force would enable them to walk on the walls. But keep in mind that the ISS is about the size of a football field, with solar panels and other delicate offshoots. Getting it to rotate, and keeping the rate of rotation constant, just isn’t feasible.
What happened to the rats that carried the fleas that carried the Black Death?
Joan J. Brown, Fairfax, Virginia
Many of them died. The bacterium believed to have caused that fearsome pandemic, Yersinia pestis, infects rodents as well as humans, notes Kali Holder, veterinary pathology fellow at the Smithsonian Conservation Biology Institute. Historical evidence indicates that the black rat (Rattus rattus) was more vulnerable than the brown rat (Rattus norvegicus), and black rats have traditionally taken the blame for spreading the Black Death in Europe. Recent research, however, suggests that a more complicated interplay of disease vectors and environmental factors led to the Black Death—successive waves of plague that killed scores of millions of people in 14th-century Europe and Asia.
Could Neanderthals talk? If so, what was their language like?
Rob Loughridge, Honolulu, Hawaii
We can be confident that Neanderthals could communicate vocally, says Rick Potts, director of the Human Origins Program at the National Museum of Natural History—all primates, our closest biological relatives, do. Unfortunately, words and grammar do not fossilize, so we can’t tell much about what they said. Differences between human and Neanderthal skulls suggest that the human larynx, or voice box, extends deeper into the throat, and it is our lower larynx that allows us to produce the miraculous diversity of consonants, vowels, clicks and other sounds that make up human speech. So it’s unlikely that Neanderthals spoke like us.