A, B, C

2

Sometimes the uses of evolutionary developments seem obvious. Far more often, though, they are invisible and their uses not necessarily comprehended by the creatures — including humans — who possess them. (This is why the notion that sex is only for reproduction is, itself, an antievolutionary notion.) What are earlobes for? Well, they are blood collectors that help supply the ear with blood and keep the inner ear warm in very cold weather. That’s probably why they developed first in northern climates and why smaller earlobes developed nearer the equator. Well, then why don’t all northerners have large earlobes and all equatorial people have small ones? Because, over the last four hundred years, quite enough intermixing has occurred in both the north and south to rearrange the genetic distribution, which rearrangements can be considered a natural response to the interbreeding of peoples and the movement that goes along with it and is also a long-ago established evolutionary advantage of genetic reproduction itself, which allows such rearrangements in diploid genetic species for blending-inheritance aspects. (Haploid species — some stages of amoeba and paramecia — can mix genes through a process called syzygy, but that’s much rarer and takes even more time to develop anything evolutionary — although it does, some. A science-fiction writer who was most fascinated by that process — and one of the great short fiction writers of the middle of the last century — is Theodore Sturgeon. Read him. He’s wonderful.) Two evolutionary ideas to keep in mind: first, by the time anything develops evolutionarily, it always has many uses; and that includes earlobes, large and small. No matter how scientists talk about them, anyone who believes that any evolutionary development has only one use basically misunderstands how evolution works: because the development is slow and gradual, at each stage the development must be useful enough to give a large-scale statistical survival advantage to a group. Those uses change as the aspect develops but the older uses they met don’t necessarily go away. (Humans’ external ears are highly erogenous — whether individuals use that aspect or not.) If it isn’t useful at all, it breeds out eventually. Carrying around excess still isn’t an advantage — though sometimes it only looks excessive to us. Second, any aspect of us that is widespread and has been around for a long time almost certainly has some functional use(s), even if we have never stopped to consider what it might be. Humans had developed a circulatory system with veins, arteries, valves, and a complex heart multiple millions of years before the Egyptians in the sixteenth century BCE and with observations by Romans and Arabs over three thousand years contributed to William Harvey’s assembling a viable model of the whole human circulatory system (as well as discussing a few of its uses, but by no means all) in his 1628 publication, De Motu Cordis. And we are still discovering aspects of the circulatory system that have been in place since before we branched off the general evolutionary line along with the other great apes, many of which are common to all mammals, birds, amphibians, and fish. In many of their variant forms they do lots of things very well, and a staggering percentage of the greater “us” (almost all of us who aren’t plants or worms — and worms are the major planetary population, remember; though we share still other things with them, such as muscles and an alimentary canal) utilize them to interact with the cities, the caves, the rural areas in which they live or have lived, the prairies, the grasses and brambles and ferns, the seas, the seabeds and trenches and shallow reefs, the deserts, the hills, the tundra, the mountains, the jungles, and forests.