Year: 2022

NUMEROUS SIMILAR INVENTIONS. "Certain components of the eye, such as the visual pigments, appear to have a common ancestry: that is, they evolved once, before the animals radiated. However, complex, image-forming eyes evolved some 50 to 100 times – using many of the same proteins and genetic toolkits in their construction." https://lnkd.in/dgxtAku View in LinkedIn

PATCHED TOGETHER. "The eyes of many taxa record their evolutionary history in their imperfect design. The vertebrate eye, for instance, is built "backwards and upside down", requiring "photons of light to travel through the cornea, lens, aqueous fluid, blood vessels, ganglion cells, amacrine cells, horizontal cells, and bipolar cells before they reach the light-sensitive rods and cones that transduce the light signal into neural impulses, which are then sent to the visual cortex at the back of the brain for processing into meaningful patterns." https://lnkd.in/decez8M View in LinkedIn

PANDA'S THUMB. "Botched jobs are common, in fact. The classic example is the panda’s thumb, which it uses to grasp bamboo. “The panda’s true thumb is committed to another role. So the panda must…settle for an enlarged wrist bone and a somewhat clumsy, but quite workable, solution,” wrote Stephen Jay Gould in 1978." https://lnkd.in/dv-JiV6 View in LinkedIn

NOT DESIGNED FROM SCRATCH. "The origin of our feet dates back to lobe-finned fishes, and has evolved into five-rayed, weight supporting structures since." https://lnkd.in/esuQhhw View in LinkedIn

TALUS UPON THE CALCANEUS. "Schaeffer (1941) rightly stressed that the therapsid foot was converted into a mammalian one by superposition of the talus upon the calcaneus, correlated with a loss of weight-bearing contact between fibula and calcaneus; but little is known about how the complex articular surfaces and ligamentous apparatus of the mammalian foot came into being." https://lnkd.in/er98r8i View in LinkedIn

NOT ELEGANTLY SIMPLE. "The foot is a complex mechanical structure. It consists of 26 bones (not including the sesamoid and accessory bones), over 30 joints, about 100 ligaments and additional elements (fascia, skin, fat pads). Thirty one muscles are active in the foot, of which 12 are extrinsic and 19 intrinsic." A structure built by a committee? https://lnkd.in/e3bN-6u View in LinkedIn

PIECEMEAL ASSEMBLY. "The anatomical features seen in modern human feet seem to appear in a piecemeal fashion, and it has recently been proposed that there are different types of mosaic morphologies in the feet of several fossil hominin taxa, and potentially at different lineages with different types of bipedalism." https://lnkd.in/e8qSKap View in LinkedIn

VESTIGIAL STRUCTURES OF THE FOOT. "In numerous mammalian taxa one or more toes have become vestigial. In numerous others, one or more toes are lost and the associated metatarsals are reduced to a vestigial state. Locomotor changes may have provided the selective pressure that drove the evolution of vestigiality in many mammalian skeletal structures." https://lnkd.in/eMd4h72 View in LinkedIn

EXAPTATION. "Recent analyses have demonstrated that neofunctionalization of paralogs from ancient polyploidy have driven a chemical arms race between plants of the Brassicales and their pierid butterfly herbivores." https://lnkd.in/e5Q_ate View in LinkedIn

THE PINNACLE. "Almost invariably in these conversations, someone expresses the opinion – as though everyone there takes it for granted – that humans are the end point, the goal, or the pinnacle of evolution." https://lnkd.in/dq73Az6 View in LinkedIn