Category Archives: Fossil record
A shorter version of this review has appeared on 3 Quarks Daily.
This book will be of interest to anyone who is interested in the way in which evolution actually proceeds, and the insights that we are now gaining into the genome, which controls the process. The author, Neil Shubin, has made major contributions to our understanding, using in turn the traditional methods of palaeontology and comparative anatomy, and the newer methods of molecular biology that have emerged in the last few decades. He is writing about subject matter that he knows intimately, often describing the contributions of scientists that he knows personally. Like Shubin’s earlier writings, the book is a pleasure to read, and I was not surprised to learn here that Shubin was a teaching assistant in Stephen Jay Gould’s lectures on the history of life.
Shubin is among other things Professor of Organismal Biology and Anatomy at the University of Chicago. He first came to the attention of a wider public for the discovery of Tiktaalik, completing the bridge between lungfish and terrestrial tetrapods, and that work is described and placed in context in his earlier book, Your Inner Fish. The present volume is an overview, from his unique perspective, of our understanding of evolutionary change, from Darwin, through detailed palaeontological studies, and into the current era of molecular biology, a transition that, as he reminds us, parallels his own intellectual evolution.
18 March 2020, this just in: https://edition.cnn.com/2020/03/18/world/fish-finger-fossil-scn/index.html Fish finger fossils show the beginnings of hands;
This weekend sees the 93rd anniversary of the Scopes Trial, and I am reposting this and its companion piece to celebrate.
I would point out two things. One is that the actual William Jennings Bryan was nothing like the ogre of Inherit the Wind, which was an allegory of McCarthyism. The other is how remarkably well the scientific evidence has stood up to almost a century of examination. There is even a mention, based on serological evidence, of how closely related whales are to hoofed land animals.
Darrow: Did you ever discover where Cain got his wife?
Bryan: No, sir; I leave the agnostics to hunt for her.
Both sides, I will argue, were long-term loses in this exchange. But why were such matters being discussed in Tennessee court of law in the first place?
Part 1: the story so far: An extraordinary case indeed, where a school teacher, with the encouragement of his own superintendent, volunteers to go on trial in the State court for the crime of teaching from the State’s approved textbook, and where that same superintendent will be the first witness called against him. And where a mere misdemeanour case, with a maximum penalty of $500, could attract the participation of William Jennings Bryan, former US Secretary of State, and Clarence Darrow, America’s most famous trial lawyer and an agnostic.
In the run-up to the case, we even have the…
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From Old Earth Ministries by way of my friend Michael Roberts. Covers the scientific bases clearly and comprehensively, before exposing the contorted theology of Young Earth Creationism, and the arrogant presumption of its claim that evolution is incompatible with Christianity.
Disclosure: I see difficulties with religious beliefs, but these are not increased (perhaps the contrary) by our knowledge of evolution, and since they are not my difficulties it is not my place to comment on them, other than to point out that the YECist claim to “own” Christianity (or any other religion) is plainly false
This is for a planned wide-audience writing project on evolution, in which I pre-empt (rather than respond to) creationists’ counter-arguments, such as their downplaying of historical science. I would greatly value comments on this approach.
There are sciences, such as physics and chemistry, where we can perform experiments. There are other sciences, such as the science of planetary motion (and astronomy in general) where we cannot do this, but we can still carry out repeated observations in well-controlled circumstances, and devise theories with whose help we can make definite predictions. All of these are what I will call rule-seeking sciences. At the other extreme, we have sciences such as palaeontology and much of geology, which one might call historical sciences.1 With these, the aim is not so much to establish general rules, as to unravel and explain the specifics of what happened in the past. It is usual to regard the rule-seeking sciences as the most rigorous, to which the others should defer. This shows a deep misunderstanding of how science works, and, time and time again, when historical and rule-seeking sciences have come into conflict, it is historical science that has triumphed.
Quite a challenge, I expect, to the local Free Presbyterians.
My friend Kim Johnson commented on the strange appearance of the footprints, Steve Drury (author of the blog of which this is just an annotated repost) referred me to Paige Depolo, senior author of the paper on which Steve’s post is based, and Paige replied as follows:
When it comes to the depositional environment, the tracks were formed in a low-energy lagoon and are generally preserved today as impressions into shaley limestone. Later, additional limestone layers were laid down at the site and in-filled the impressions. Those layers form the casts that we can still observe for some of the tracks today. In some cases at this site, the cast remains while the surrounding impression which it was originally infilling has been almost completely eroded. These rocks were deposited during the Middle Jurassic. Later, likely during the Paleogene, a sill was intruded immediately below the track bearing layer and the surrounding rocks were baked. The low-level contact metamorphism of the track-bearing layers definitely makes for some interesting looking exposures!
h/t Kim and Steve, and many thanks to Paige
The Isle of Skye off the northwest coast of Scotland is known largely as a prime tourist destination, such as Dunvegan Castle with a real clan chief (The MacLeod of MacLeod) and its Faerie Flag; Britain’s only truly challenging mountains of the Black Cuillin; and, of course, the romantic connection with the Young Pretender, Charles Edward Stuart and his escape, in drag, from the clutches of the Duke ‘Butcher’ Cumberland, hence the Skye Boat Song. Geologists know it best for its flood basalts with classic stepped topography and the exhumed guts of a massive central volcano (the Cuillin), relics of the Palaeocene-Eocene (62 to 54 Ma) North Atlantic Large Igneous Province. The spectacular Loch Coruisk, a glacial corrie drowned by the sea, exposes the deepest part of the main magma chamber. It is also the lair of Scotland’s lesser…
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No one, so far as I know, has any religious objection to the Periodic Table and the unifying concepts of chemistry. But some people do have religious objections to the geological record, and to the unifying concepts of geology, because these don’t agree with what the most learned men of their time and place wrote down some two and a half thousand years ago.1 And as I argued in my last post, such people will seize on real or imagined anomalies as evidence that the entire intellectual structure is unsound. By contrast, the scientist’s response to such anomalies is to regard them as a potential source of new knowledge, far more likely to extend the framework in a mature discipline than to destroy it.
Example 1: Superposition and overthrusts
It is more than 350 years since Steno (who eventually became a bishop) proposed that strata consisted of layers of rock laid down one on top of another, newest on top. We have known for over two hundred years that both the London and Paris basins are filled with relatively recent sediment, on top of marine deposits (chalk or limestone) that emerge in hills to the North and South, that these in turn rest on an older basement, and that the more recent sediments were laid down in layers. The familiar geological sequence, Precambrian upwards (click to enlarge), was established in something like its present form before 1860, by merging the overlapping but incomplete local rock columns, although it was not until the 20th Century that it was recognised that the Precambrian occupied far more of the Earth’s history than everything since that time.
One major disruption of the usual order occurs in the northwest of Scotland, where older rocks lie above younger along a 200 km front. The resulting confusion (the “Highlands Controversy“, fuller account here) was not resolved until the 1880s, with the recognition of what is now known as the Moine Thrust. Read the rest of this entry
EVOLUTION: What the Fossils Say and why it Matters, Donald R. Prothero (2nd edition)
If you are interested in evolution, get this book. And make sure that your library gets it. And your children’s highschool library. Incidentally, it’s incredible value; list price $35.00/£27.95 from Columbia University Press, with over 400 lavishly illustrated pages.
The book is a comprehensive survey of the fossil record, supplemented at times with other evidence, and framed as one long argument against creationism. It opens with a general discussion of the ideas behind current evolutionary thinking, moves on to a survey of specific topics in (mainly animal) evolution, from the origins of life to the emergence of humanity, and concludes with a brief discussion of the threat that creationism poses to rational thinking. The argument is laid out clearly in the seemingly artless prose of an accomplished writer in love with his subject matter, with plain language explanations that presume no prior knowledge, while the detailed discussions of specific topics give enough detail to be of value, I would imagine, even to a professional in the field. The author is an experienced educator and researcher, with thirty books ranging from the highly technical to the popular, some 300 research papers, and numerous public appearances to his credit, and the work is copiously illustrated with photos, diagrams, and drawings by the author’s colleague, Carl Buell. These illustrations are an integral part of the work, graphically displaying the richness of the data at the heart of the argument. Read the rest of this entry
“The wise learn from everyone.”1 The freak success (half a million reads) of my recent piece How to slam dunk creationists, and the subsequent discussion, have again set me thinking about how to learn from creationists. It is not enough to say, as Dawkins notoriously said, “[I]f you meet somebody who claims not to believe in evolution, that person is ignorant, stupid or insane (or wicked, but I’d rather not consider that).” Conversation is a two-way street, I have certainly learnt from creationists’ attacks on evolution, and if I am learning from them it is at least possible that they are learning from me.
Types of comment
Comments I have had from creationists fall into three broad groups (and note that contrary to what Dawkins says, some of these are at least partly informed, highly intelligent, and completely rational):
1) Simple misstatements
2) Appeal to the Bible
3) Purportedly scientific arguments, some without merit, while others refer to important issues.
From simple misstatements, not very much can be learnt, except perhaps the source of the misinformation. Remember that if someone quotes wrong information, the burden of proof is not on you but on them. Leave it there, as in this actual exchange: Read the rest of this entry
Ten minutes difference, and Earth would still be Planet of the Dinosaurs
We have suspected for some decades that the dinosaurs1 became extinct as the result of a massive meteorite, an asteroid, hitting the Earth. We have known where the impact site was since 1990, if not before. But it is only last year that we successfully drilled into the impact site, and only now, for the first time, do we really understand why the impact was so fatal. And if the meteorite had arrived ten minutes earlier, or ten minutes later, it would still no doubt have inflicted devastation, but the dinosaurs would still be here and you wouldn’t.
66.1 million years ago, dinosaurs covered the Earth. 66 million years ago, there were none. And not only the dinosaurs, but the pterosaurs in the skies, the long necked plesiosaurs and even the ammonites in the oceans, and 75% of all complex animal life. No terrestrial vertebrate heavier than around 25 kg seems to have survived. What happened? Read the rest of this entry