The Anatomical Record Marches on by Exploring Evolution in the Second Part of Our Special Issue on the Human Pelvis.

Abstract

How fitting that this Editorial is penned (will anyone even know what this means in twenty years?) on February 12. That day is special for so many, particularly those who seek to understand our biological world, as it was on this day in 1809 that Charles Darwin was born in Shrewsbury, England. Darwin is, of course, the name that has become most associated with ideas of species change through processes of natural selection, what is now generally referred to as evolution. While Charles Darwin was not the first to advance the ideas that a species could change—often referred to as “transmutation of species” by those before him—he did articulate a process and empower it with that handy compendium of facts (real, not alternative, that is) known as “data” to accompany his ideas. While the exact processes and mechanisms of evolution remain topics of study, the general concept that species have temporally changed has been repeatedly, and robustly, demonstrated scientifically. Whether it is through the geologic and paleontologic record, or the almost-daily insights from genetics and genomics, documentation of evolution has been copiously documented in nature for all whose eyes are sufficiently open to see. Evolution is the foundation upon which those of us who seek to comprehend the narrative of vertebrate anatomy, and its inherent function, is built. With the above as prelude, The Anatomical Record has been a fertile and creative home for studies that explore the natural past and/or test hypotheses on evolutionary mechanisms that have effectuated extant vertebrate morphology. Indeed, nary an issue of our journal sees the press that does not contain such, and we have featured many Special Issues on evolutionary topics, such as those on: “The Evolution of Primate Special Senses” (Dominy et al., 2004; Laitman, 2004); “Anatomical Adaptations of Aquatic Mammals” (Laitman, 2007; Reidenberg, 2007); “Unearthing the Anatomy of Dinosaurs” (Dodson, 2009; Laitman, 2009); “Evolutionary and Functional Morphology of New World Primates” (Laitman, 2011; Rosenberger, 2011); “The Vertebrate Nose: Evolution, Structure and Function” (Laitman, 2014; Van Valkenburgh et al., 2014); “Understanding the Zygoma: A Key Morphological Partition in the Craniofacial Skeleton, Evolution” (Dechow and Wang, 2017; Laitman, 2017.) Indeed, our cup runneth over! It is with great pride that we now continue our Special Issue on “The Human Pelvis,” Guest Edited by Karen Rosenberg of the University of Delaware and Jeremy DeSilva of Dartmouth College. The first part, focusing on “Anatomy, Function, and Development” appeared last month in our April, 2017 issue (DeSilva and Rosenberg, 2017.) This month, our intrepid duo built upon the cutting edge science and reviews in the first issue, now probing both back in time and through comparative studies with their second act, lifting up the curtain on the “Evolution” of this extraordinary region (Rosenberg and DeSilva, 2017.) Again, our Anatomical Record archives are rich with many fine studies that have explored aspects of functional pelvic morphology. While our prior Editorial to the first Special Issue on the Pelvis (Laitman and Albertine, 2017) reviewed many of our older contributions (indeed, going back to “horse-and-buggy” doctors and ancestors of Aaron Burr!) this editorial offers some recent contributions that addressed, or provided, insights from comparative anatomy or paleontology that bear directly upon evolutionary questions. These include studies on a range of species that create a window into functional changes and evolutionary relationships, such as those by: Walthall and Ashley-Ross (2006) on the post-cranial myology of the California newt; Urben et al.'s (2014) study on the homology of pelvic elements of Zygaspis quadrifrons; the insightful, global observations on tetrapod forelimb and hindlimb homologies by Rui Diogo, one of the leading evolutionary-focused anatomists of our day (Diogo and Molinar, 2014); a comparative study of hip and thigh anatomy in leopards and domestic cats, and its implications for evolutionary changes by Carlon and Hubbard (2015); and a study by Toledo and colleagues (Toledo et al., 2015) on the reconstructions, and functional morphology, of the hindlimb region of Early Miocene sloths from Patagonia. Many studies in The Anatomical Record focused directly on aspects of pelvic comparative anatomy, or the fossil record, of our primate relatives. Notable amongst these are: Been and colleagues’ (Been et al., 2010) new model for lumbar lordosis angle estimation, and what this means for assessment of early hominids and their lower limb and locomotor behaviors; the insightful, virtual dissection study of the pelvic region and femur in humans and great apes by a team of Swiss and Japanese anthropologists (Morimoto et al., 2011) and their interpretations for evolutionary relationships; a strong, but scholarly and civil response by a team of leading paleoanthropologists, and locomotion experts, Gen Suwa, Owen Lovejoy, Behane Asfaw, and Tim White, to the above 2011 Morimoto study (Suwa et al., 2012); Yusof et al.'s (2013) study of the distinctive nature of the human ilium and sacro-iliac joint; and Lewton's (2015) study of pelvic form and locomotor adaptation in strepsirrhine primates. We began this essay by noting that it was being written on Charles Darwin's birthday, February 12. How fitting, we thought, for a prelude to an Issue exploring the morphings and changings of a region that houses so many features that distinguish our kind. Yet there was another person of great importance also born on this day and year, an occurrence of either serendipity or design we will never know. The second birthday child was not born in Darwinian comfort, but rather in the more humble trappings of a one-room log cabin in Harden County, Kentucky. The child was Abraham Lincoln, for many of us one of, if not the, greatest President of the United States. Indeed, he may be the reason there still is a United States. While Darwin's relevance to our scientific mission is unmistakable, Lincoln's may be a tad harder to see for some. But not really, if one only looks a little. In 1858, upon accepting his party's nomination to run for the United States Senate against Illinois Senator Stephen A. Douglas, Lincoln, against advice, gave a speech that has resonated through the centuries. It began, “A house divided against itself cannot stand.” While Lincoln lost the race to the always angry, fiery Douglas, Lincoln did go on to win the Presidency two years later. In his Second Inaugural Address, on March 4, 1865, as the incomprehensible horrors of a war on our own soil was mercifully coming to a close, no harshness or vindictiveness came from his lips. Lincoln told a people that could have gleefully danced in victory over a vanquished foe, “With malice toward none, with charity for all…” His Inauguration spoke to elevate a nation, to uplift. He would belong to the ages on April 15, 1865, a scant five weeks later. Both Darwin and Lincoln were transformative figures: Darwin, through his intersection of hypothesis-testing incorporating the need for factual accrual was a pillar upon which Evolutionary Science, and our very understanding of life itself, was built; and Lincoln, through his never-wavering understanding that humans cannot exist without adherence to the basic laws of human civility, mutuality of respect, inclusiveness, and rights distributed to all, was the pillar upon which a re-born nation arose. This Special Issue on “The Human Pelvis,” arguably more than many others we have birthed, has gone to the very core of our being. Studies within these two volumes have explored aspects of much in the region, particularly, our distinctive birth, posture, locomotion, and how it all came to be; so much at the center of who and what we are. To accomplish this, colleagues from around the globe needed to contribute and produce together, a hallmark of modern, collaborative science. Indeed, without the free exchange of people and ideas, science can shrivel and rot like untended fruit on a vine. Neither The Anatomical Record nor its scientist/authors live in a vacuum; we are well aware of the complexities and difficulties of our nation and our world. As we present this extraordinary compendium of science, we are also most cognizant of the words, spirit, and lessons of those remarkable “twins” born on February 12, 1809. We only hope that leaders today hear their message as well.