A Just-So Story Digest

For your weekend reading entertainment, here is a collection of recent science stories that rely more on imagination than evidence, in the tradition of Kipling’s Just-So Stories for children.

• How the Brown Dwarf Sowed Planet Seeds:  Apai et al. in Science found magic crystals, hidden by the six brown dwarfs, that turn into planets over time.  “These results indicate that the onset of planet formation extends to disks around brown dwarfs,” they said, “suggesting that planet formation is a robust process occurring in most young circumstellar disks.”  Now in paperback at JPL.
• The Ancient Tunnel that Led to Life:  Scientists found a secret passageway into the ribosome where all of life’s proteins are made.  ScienceDaily said, “In developing the project, the team identified a corridor inside the ribosome that the transfer RNA must pass through for the decoding to occur, and it appears to be constructed almost entirely of universal bases, implying that it is evolutionarily ancient.”
• How the Animals Learned Fairness:  Nowak and Sigmund continued their long-running Game Theory Tales with the next sequel, published in Nature, on the “Evolution of direct reciprocity.”  Their attention-grabbing intro asked, “How can natural selection promote unselfish behaviour?”  It’s all in how you play the game called, “I help you and somebody else helps me,” they say.  The rest is human history: “The evolution of cooperation by indirect reciprocity leads to reputation building, morality judgement and complex social interactions with ever-increasing cognitive demands.”
• How the Shark Kept Warm During Workouts:  A cold-water shark with tuna-like muscles?  How could this be?  They belong to different evolutionary families.  The Knight of Convergent Evolution to the rescue: Bernal et al. writing in Nature 10/27 found that salmon sharks and tunas both independently discovered the secret to keeping their body temperatures elevated enough in cold water to power their strong muscles.
• How the Molecule Developed a Sweet Tooth:  Michael Yarus wrote a story about how an ancient RNA molecule learned the secret of the aldol reaction, essential for sugar metabolism.  “Could this be similar to an ancestral catalyst that existed billions of years ago?” he asked in Nature 11/03.  Watch for the next exciting episode.
• How the First Stars Lit Up the Sky:  We can’t see them, but they must have been there, because there is a faint infrared echo of the first stars in the universe.  Kashlinsky et al. followed the invisible light and the reporters told the world the glad tidings of their success (BBC, Space.com).
• How the Early Peoples Learned to Share:  “The question of the coexistence and potential interaction between the last Neanderthal and the earliest intrusive populations of anatomically modern humans in Europe has recently emerged as a topic of lively debate in the archaeological and anthropological literature,” said scientists in Nature.  In the darkness of the cave, radiocarbon light revealed a surprising mystery: “The implication is clear that the site shows either a directly interstratified sequence of Neanderthal and anatomically modern human occupations, or at least a very close contact and interaction between these two populations within this particular region of France.”
• How the Frog Women Decoded the Music:  New species of frogs arose in less than 8,000 years in Australia, which is lightning-fast, said the storyteller in UC Berkeley News.  The frog women learned to distinguish calls in the dark and split into various tribes by “reinforcement,” an evolutionary mechanism that “has been controversial since the time of Charles Darwin” and was considered “too complicated” and “unnecessary,” according to critics.  But ah, the frog women have free will, and free will is unpredictable.  “Because the frogs in the isolated contact area had a distinctively different call, and because they were effectively isolated from surrounding populations by mating preference, Hoskin and colleagues concluded that female choice led to this new species.”  It’s “kinda cool,” said one storyteller.  “It gives us a mechanism for very rapid speciation.”
• How the Stem Cells Lost Their Pedigree:  “Forgotten by evolution?” asked the Max Planck Society about stem cells.  Assigned to the slavish work of repairing organs, adult stem cells seemed destined for drudgery.  But scientists may have found their long-lost royal blood: “at least some adult stem cells could be the mere remnants of former embryonal differentiation processes, or, in other words, ‘footprints’ of evolution,” reported the short story.
• How the Play-Dough Gave Birth:  The womb of the earth mother lay deep in the ocean depths, with a placenta of clay.  Billions of years ago, this protective layer brought forth molecules destined for fins, wings, brains and philosophers.  Read this fascinating tale in News@Nature.

Nighty-nite, children.  No questions, now; just close your eyes, and sweet dreams.  Good-night, sleep tight, and don’t let the Creationist Monsters bite.