Word: bacterias
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Dates: during 1990-1999
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...there is also a small chance that the technology that allows people like Getty to receive tissues from animals could someday unleash a medical disaster. The danger is that patients could receive a previously unknown microbe along with their transplants. When viruses or bacteria have made the jump from animals to humans in the past, they have often proved exceedingly virulent: HIV, which causes AIDS; Ebola virus; and hantavirus are all chilling precedents. In a worst-case scenario, such transplants could introduce humanity to a plague that would make all of those look tame. "This is a serious mistake," says...
...fossils. Under bright lights and powerful microscopes, they coaxed fine-grain anatomical detail from the shale's stony secrets: the remains of small but substantial animals that were overtaken by a roaring underwater mudslide 515 million years ago and swept into water so deep and oxygen-free that the bacteria that should have decayed their tissues couldn't survive. Preserved were not just the hard-shelled creatures familiar to Darwin and his contemporaries but also the fossilized remains of soft-bodied beasts like Aysheaia and Ottoia. More astonishing still were remnants of delicate interior structures, like Ottoia's gut with...
...divide their bodies into cells, believes Seilacher, but into compartments so plumped with protoplasm that they resembled air mattresses. They appear to have had no predators, says Seilacher, and led a placid existence on the ocean floor, absorbing nutrients from seawater or manufacturing them with the help of symbiotic bacteria...
...oxygen through photosynthesis - the metabolic alchemy that allowed primordial algae to turn carbon dioxide, water and sunlight into energy - was almost perfectly balanced by oxygen-depleting processes, especially organic decay. Indeed, the vast populations of algae that smothered the Precambrian oceans generated tons of vegetative debris, and as bacteria decomposed this slimy detritus, they performed photosynthesis in reverse, consuming oxygen and releasing carbon dioxide, the greenhouse gas that traps heat and helps warm the planet...
...take food in at one end and expel wastes at the other, may be the key to the Cambrian explosion. Their reasoning goes something like this: animals grazed on the algae, packaging the leftover organic material into fecal pellets. These pellets dropped to the ocean depths, depriving oxygen-depleting bacteria of their principal food source. The evidence? Organic lipids in ancient rocks, notes Hayes, underwent a striking change in carbon-isotope ratios around 550 million years ago. Again, the change suggests that food sources rich in carbon 12, like algae, were being "express mailed" to the ocean floor...