JOST A MON

In the first few days following the announcement of this edition of the Giant's Shoulders carnival, I received a few articles that appeared to strike off completely from the subject matter of the previous edition. To wit, I hoped that I might be able to do for geophysics what The Primate Diaries had done so ably for Charles Darwin. Over the ensuing days, though, I realised that there would not be such a concentration in one topic as before, and that this carnival would end up being as motley as its readers like to see. And so we have not only geophysics, but also (as we expect) evolutionary theory, palaeontology, quantum physics, astronomy, epidemiology, and a remarkable treasure-trove of resources for the science of food.

Before Darwin could come up with On The Origin of Species, someone had to rigorously define what a 'species' is. Indeed, before Linnaeus, someone had to come up with a coherent system of biological classification. The man to do both these things was John Ray. The Renaissance Mathematicus discusses Ray's contributions in A Boy From Essex Who Made Good, pointing out that the first definition of 'species' in a strictly biological context was made by Ray, who published a magisterial study of the flora of Cambridgeshire with his student Francis Willughby. Whilst in many an account of the scientific explosion in the 17th and 18th centuries the hat is tipped towards astronomy and physics, The Renaissance Mathematicus insists that this is unfair towards the other sciences, which also advanced greatly during the period. And, he adds, in a fair world in which the history of scientific development were not defined as the history of physics [.] Ray would be acknowledged as standing on a level with Galileo or Newton, and not be regarded as some obscure biologist. [via gg]

Before he got busy usurping credit for the idea of vaccination, Edward Jenner was a keen ornithologist who took it upon himself to answer a question that had puzzled natural historians since antiquity. The Common Cuckoo had been known to be a nest parasite, that is, it would lay an egg in the nests of birds of other species; when the egg hatched, the chick would be raised by the unwitting hosts. It would be the sole survivor in that nest - all other fledglings and eggs would vanish. Who was responsible for their disappearance? That was the puzzle, and Edward Jenner was responsible for its resolution in a seminal paper published in 1788, as revealed by John in his A Historic Paper on Cuckoo Behavior posted at A DC Birding Blog. John adds that this paper was written long before Origin of Species, and the lack of a concept of natural selection is evident in several passages ... Instead, Jenner refers several times to nature's design, a concept that he does not have much elaboration.

Brian Switek has been notably prolific this past month, and so we have three paleontological contributions from him [all via gg]. First, in The Species that Domesticated Itself, he discusses Louis Leakey's attempt to identify the earliest hominid ancestor and the various blind alleys and tight spots he put himself in when he made hurried claims that this fossil or the other was exactly that ancestor. When in 1959 his wife Mary reconstructed a skull that appeared at once familiar (like an australopithecine) and alien, Leakey insisted that this was a new ancestral species that he dubbed Zinjanthropus. But dating techniques cast doubt on this conclusion. Brian adds: It seems that in Louis' view he and his team discovered our ancestors while everyone else was puttering about with evolutionary dead-ends. Once he had in mind that something was an ancestor, such as Zinj, he forcefully made the case that it was so, even if he had to abandon the very notion he had just popularized.

When a field of study is pursued in completely different ways by two camps of scientists, it shouldn't surprise us that major differences of opinion should arise between them, not only with respect to methodology but also in the conclusions and in the resulting establishment of a foundational theory. In the second of his posts featuring in this carnival, Riding the Bicycle posted at Laelaps, Brian Switek draws our attention to one such schism: geneticists in their laboratories were observing a slow-and-steady pace of evolutionary change, while palaeontologists were demonstrating that evolutionary change occurred in bursts followed by periods of stasis. Brian describes an attempt in 1980 to reconcile these two strands of science that has now come to be known as a palaeobiological synthesis, but laments that in many popular portrayals of evolution the contributions of palaeontology still take a backseat to genetics: thanks for the fossils, but don't worry so much about the theory next time. Authors seem grateful that there are fossils with transitional features to demonstrate the fact of evolution, yet evolution is still often presented as being a uniformitarian march from simple to complex.

The third piece from Brian is The Witness of the Deluge, in which he reveals how the discovery in 1725 of a supposedly humanoid skeleton was taken as definitive proof for the Biblical flood, and hence as validation by devout Christians of their faith. To the Swiss naturalist Jacob Johann Scheuchzer, the skeleton appeared to have, as Brian writes, a distinctively human appearance. The remains primarily consisted of a backbone and a semicircular skull with two eyes in it, and the fact that the remains of an antediluvian human had been discovered was so astounding that Scheuchzer described it the following year and again in his 1731 work Physica Sacra. He called it Homo diluvii testis, commonly translated as "Man, a witness of the Deluge." But, of course, it was no such thing. We'd like to say that the story proves yet again that it pays to keep one's dogmas out of one's science. But in the 18th century, naturalists were generally in agreement that terrestrial geology had been shaped by Noah's Flood. So why pillory poor Scheuchzer?

We take this opportunity to segue from palaeontology to geophysics, and what better way to do so than to learn how the California Thrasher led a biologist Joseph Grinnell to his understanding of climate change. In a three-part post at Ecographica, Johnny says that the first post introduces the idea of the 'ecological niche' and then discusses [Grinnell's] papers introducing the concept. The second post (linked at bottom of the first) details his life's work and then transitions to the third and final post in which Grinnell's research is used in modern studies.

What effect do the eccentricities of the Earth's orbit around the Sun have on its climate? I use 'eccentricity' not only in its mathematical meaning, although the elliptical orbit, as is well known, does contribute to seasonal climatic change. But this elliptical orbit rotates such that its axes shift over time; simultaneously, the Earth itself precesses; and, finally, the tilt of its axis away from the perpendicular changes in a long cycle. Together, these effects cause periodic ice-ages over 100,000 years, and these are called Milanković Cycles. The Russian science site Elementy explains the Cycles, and I took the liberty of translating the article into English at Sundry Translations and Other Tangentialia.