Scientists filled in the details of some famous evolutionary tales in 2016 — and discovered a few surprises about creatures large and small.
By studying a gene family important for toxin production, researchers found that modern rattlesnakes have pared down their venom arsenal over time (SN: 10/15/16, p. 9). Rattlers now have a smaller repertoire of toxins, perhaps more specialized to their prey.
Small tweaks to a gene that makes a protein important for skeletal development may have led to the big toe and helped shape the human foot for bipedalism (SN: 2/6/16, p. 15).
A gut microbe collected from chinchilla droppings appears to have no mitochondria, making it the first known complex life without the supposedly universal organelle (SN: 6/11/16, p. 14).
Studies of prototurtle fossils suggest that, instead of serving as natural armor, turtle shells might have got their start by aiding in burrowing (SN: 8/6/16, p. 15). The idea could help explain how turtle ancestors survived a mass extinction 252 million years ago.
Scientists pinned down the genetic changes that, in a famous example of natural selection, made peppered moths soot-colored (SN: 6/25/16, p. 6).
Giraffes should thank genes that regulate embryonic development for their long necks and strong hearts (SN: 6/11/16, p. 9).
Evolution at speed
A study of Darwin’s finches found that medium ground finches with smaller beaks survived better than big-beaked counterparts during a drought. The advantage was linked to a key gene, offering insight into the birds’ speedy evolution (SN: 5/28/16, p. 7).
Scientists have crowned a Greenland shark as the vertebrate with the longest known life span. Their analysis suggests the predator lived to an age of 392 years (SN: 9/17/16, p. 13).