The ‘Minden Monster,’ a whacking great carnivore that lived about a hundred million years before T. Rex, is in the news again. Studying it will help scientists work out details of megalosaur development.
I’m fascinated by that sort of thing. Your experience may vary.
Other scientists think they know what killed Lucy, our name for a famous Australopithecus afarensis skeleton. It looks like Australopithecus afarensis was a little more at home in trees than we are.
- The Minden Monster
- What Killed Lucy?
But first, (quite) a few words about Adam, Eve, and getting a grip.
We are created in the image of God, male and female. Each of us is a person: not something, but someone; made from the stuff of this world, and filled with God’s ‘breath:’ matter and spirit, body and soul. (Genesis 2:7; Catechism of the Catholic Church, 355, 357, 362–368)
I read Genesis 1:1–2:4 and 2:4–25 as an explanation of God’s role in our existence: among other things. As far as I’m concerned, all that’s changed in the last few centuries is how much we know about the “clay” God used.
I learned about hominids when that term didn’t mean quite what it does today, and didn’t run into “hominin” until fairly recently.
Around the 1960s, when I was in high school, scientists were rethinking primate taxonomy: again.
Carl Linnaeus set up a taxonomic system that’s still in use — with considerable tweaking. Taxonomy is what we call classifying organisms: and by extension, anything else that’ll sort out in a nested hierarchy.
Folks like Anaximander and Empedocles speculated that today’s critters — humans included — had changed since the world’s beginning. Folks like Pierre Louis Maupertuis and Louis Leclerc, Comte de Buffon wrote about more-or-less-systematic change in the 1700s.
Comte de Buffon also used experimental data to estimate Earth’s age. He was wrong by several orders of magnitude: but in the 1700s it was a good educated guess. (August 28, 2016)
Charles Darwin didn’t single-handedly start the idea that organisms change in a rational way: but his “On the Origin of Species” (1859) was an important contribution to evolutionary theory. It also dropped “evolution” into popular culture.
We’ve learned quite a bit since then, much of it in my lifetime: and there’s a great deal left to learn.
I’m okay with that, and even if I wasn’t: it wouldn’t matter.
“Our God is in heaven; whatever God wills is done.”
As my father once told me, ‘at a certain level of authority, argument becomes pointless.’
I figure my job is appreciating God’s handiwork: not telling the Almighty how it should have been designed.
That’s because there is not an 11th Commandment against using the brains God gave us.
Scientific discoveries are invitations “to even greater admiration for the greatness of the Creator.” (Catechism, 283)
Honest and methodical study of this wonder-filled creation cannot interfere with an informed faith, because “the things of the world and the things of faith derive from the same God.” (Catechism, 159)
What we learn sometimes obliges us to reexamine preconceived notions: but I’m okay with that.
Some of my high school science textbooks talked about Haeckel’s “ontogeny recapitulates phylogeny” theory. It’s the idea that an embryo goes through the critter’s entire evolutionary history. It’s not quite accurate, but there’s some truth to it.
Getting back to pharyngeal arches, I had them when I was about four weeks old. By the time I was born the first arch had developed into my upper and lower jaws and hard palate. In fish, pharyngeal arches become branchial/gill arches.
Turns out that they were right.
(From Ernst Haeckel, via Wikimedia Commons, used w/o permission.)
(Ernst Haeckel’s 1868 illustration in “Natürliche Schöpfungsgeschichte,” showing similarities between embryos of a dog (hund) and human (mensch).)
Haeckel’s illustrations are more nearly accurate than Percival Lowell’s maps of Mars: but Haeckel apparently de-emphasized features that didn’t agree with his theory — while his critics emphasized those features in their drawings.
I figure Haeckel believed that he was drawing what he was observing, and compensating for limitations of available technology: a reflecting microscope.
Haeckel could, in principle, have used micrography for his research. But let’s remember that this was the 19th century.
Haeckel was right, too, but we’ve learned that life is a whole lot more “intricate and quirky:”
“…Embryos do reflect the course of evolution, but that course is far more intricate and quirky than Haeckel claimed. Different parts of the same embryo can even evolve in different directions. As a result, the Biogenetic Law was abandoned, and its fall freed scientists to appreciate the full range of embryonic changes that evolution can produce — an appreciation that has yielded spectacular results in recent years as scientists have discovered some of the specific genes that control development.”
(“Early Evolution and Development: Ernst Haeckel,” The History of Evolutionary Thought, Understanding Evolution, U. C. Berkeley)
(From Joschua Knüppe, via Phys.org, used w/o permission.)
(“Artist’s impression of W. albati. The dinosaur is shown together with other organisms whose fossil remains were recovered in the same locality.”
“A Middle Jurassic monster put in its taxonomic place”
Phys.org (September 1, 2016)
“An analysis of the fossil known as the Minden Monster has enabled paleontologists to assign the largest predatory dinosaur ever found in Germany to a previously unknown genus, among a group that underwent rapid diversification in the Middle Jurassic.
“This huge dinosaur dates to about 163 million years ago, in the Middle Jurassic. And it is not only the first carnivorous dinosaur from this period to be unearthed in Germany, it is also the largest ever found in the country: Based on the remains so far recovered, the specimen is estimated to have been between 8 and 10 meters in length. In comparison with other carnivorous dinosaurs, the animal was very sturdily built, weighed more than 2 tons – and was probably not fully grown when it died.
“…The first fossilized bones and teeth were discovered in 1999 during a routine surface survey in an abandoned quarry in the Wiehengebirge, a range of low hills south of Minden. Although the fossil clearly represents a terrestrial form, the remains were embedded in marine sediments. It is however known that, in the Middle Jurassic, large areas of what is now Central Europe lay below sea level, and the shallow waters of this sea were dotted with islands….”
Pangea, our name for a continent that formed some 300,000,000 years back, was splitting into Laurasia (north) and Gondwana (south) during the Middle Jurassic. Ichthyosaurs had been joined by pliosaurs.
We still don’t know why so many carnivores were so much larger then.
The Minden Monster is a big deal to scientists because dinosaurs like it were rapidly diversifying during the Middle Jurassic.
Part of the article I didn’t quote mentions phylogenetic analysis, which isn’t just about genetics. Phylogenetics studies how critters are related to each other: sort of like an evolutionary family tree. That’s probably why a phylogeny is called a phylogenetic tree.
I put links to more ‘Minden Monster’ information near the end of this post.3
“Early human ancestor Lucy ‘died falling out of a tree’ ”
Jonathan Webb, BBC News (August 29, 2016)
“New evidence suggests that the famous fossilised human ancestor dubbed “Lucy” by scientists died falling from a great height – probably out of a tree.
“CT scans have shown injuries to her bones similar to those suffered by modern humans in similar falls.
“The 3.2 million-year-old hominin was found on a treed flood plain, making a branch her most likely final perch.
“It bolsters the view that her species – Australopithecus afarensis – spent at least some of its life in the trees….”
Australopithecus afarensis is our name for a hominin species — I talked about taxonomy earlier, and put a mess of resource links near the end of this post.4 They lived in eastern Africa between 3,900,000 and 2,900,000 years ago.
Or maybe it’s who lived: I don’t think we can tell whether Lucy was a critter who looked a lot like us, or a person who’d have a terrible time trying to fit in today.
We’ve also learned that there’s less than a 2% difference between human and chimpanzee genes. That doesn’t make us chimps, or chimps human, though. The chimp-human genetic difference is about 20 times the difference between any two humans.
This particular genetic module apparently goes back about 3,4000,000 years: and it’s one of 23 that are uniquely human.
Anatomically modern humans, humanity’s current model, don’t just have an oversized brain. Our version of the SRGAP2 gene helps determine how our brains are wired. Among other things, it boosts the density of dendritic spines.
We’re wired differently: which I think helps explain why we’re so good at making flint arrowheads, steam engines, and cochlear implants.
All mammals have the SRGAP2 gene. Our version’s prototype showed up some 3,400,000 years back: very roughly 200,000 years before Lucy lived and died. Does that make her “human,” a person? I don’t know.
“…’We weren’t there – we didn’t see it – but the subset of fractures that we’ve identified are fully consistent with what’s reported in a voluminous orthopaedic surgical literature about fall victims who have come down from height,” said lead author John Kappelman from the University of Texas at Austin.
” ‘It’s tested every day in emergency rooms all around the planet.’
“Discovered in Ethiopia’s Afar region in 1974, Lucy’s 40%-complete skeleton is one of the world’s best known fossils. She was around 1.1m (3ft 7in) tall and is thought to have been a young adult when she died.
“Her species, Australopithecus afarensis, shows signs of having walked upright on the ground and had lost her ancestors’ ape-like, grasping feet – but also had an upper body well-suited to climbing….”Jonathan Webb, BBC News)
My knee-jerk reaction to “…an upper body well-suited to climbing…” was the thought that whoever wrote it hadn’t seen, or didn’t remember, kids on a jungle gym.
Humans spend most of our time on the ground: but we can climb pretty well.
Then I did a little checking. Sure enough, Australopithecus afarensis had longish arms, compared to today’s model; and their shoulder joints were mounted higher than ours. Both features would make climbing trees easier.
On top of that, scans show that their bony labyrinth, housing their semicircular canals, wasn’t optimized for walking upright. They most likely were more at home in trees than we can be, and maybe a bit less steady on their feet.
We’ve been learning that quite a few non-human animals use tools, but it’s still a very “human” thing.
Someone was using stone tools in Lucy’s part of the world about 3,300,000 years ago: roughly 100,000 years before her day.
They weren’t particularly efficient tools, certainly not up to the standard we expect to see in Lowe’s: but that “human brain” gene had been around a hundred thousand years by then. My guess is that they were used by someone: not something.
On the other hand, we’ve changed in the 3,200,000 years since Lucy lived.
For starters, she was 1.1 meters, three feet, seven inches, tall.
She’d be looking up at just about everyone, since her eyes would be only slightly above the top of your typical cummerbund.
The view would be — strange. Our heads, compared to her family’s, have ‘too much’ forehead and nowhere near enough face.
‘Human brain’ gene or not, her head had room for about a third of the neural circuitry we use. There’s more to intelligence than brain size: but my guess is that she’d have trouble passing the ACT or SAT.
Scientists are still wrapping their minds around the idea that Neanderthals may have buried their dead with as much care as the British.5 We know much less about the folks whose bones were interred, or just happened to end up, in Rising Star Cave. I won’t be surprised if we learn that burial customs go further back than folks who look like us.
That might explain why there’s only one mark on her bones from a carnivore’s tooth. That’s not typical of a body left in the open.
If Lucy’s people were people, and even remotely like us, they’d have noticed when she didn’t return from whatever errand she was on. As the University of Texas at Austin’s John Kappelman said — “We weren’t there – we didn’t see it….” But I suspect that we found so many of Lucy’s bones because someone found her body, and brought it home for burial.
Then again, maybe not. We don’t know.
More of our continuing search for knowledge, and why I think that’s okay:
- “Space Aliens and Life’s Ladder”
(September 18, 2016)
- “Faith, the Universe, and Wisdom”
(August 28, 2016)
- “Brogdar, Öetzi, and Piltdown Man”
(August 26, 2016)
- “Humility isn’t Being Delusional”
(July 31, 2016)
1 Maybe you’ve read that August Weismann and 68 white mice finally demonstrated that Lamarckism didn’t work. Folks have pointed out that amputating a mouse’s tail is hardly a case of “disuse,” but we’ve learned that Gregor Mendel was on the right track.
- “Photographing microscopic preparations in the nineteenth century”
Scientific Instruments in the History of Science: Studies in transfer, use and preservation, pp 299-318
Maria Estela Jardim, Marila Peres; via Museu de Astronomica
- “German Jurassic megalosaurid”
Oliver W. M. Rauhut, Tom R. Hübner, Klaus-Peter Lanser, Palaeontological Association; via palaeo-electronica.org (August 2016)
- “Perimortem fractures in Lucy suggest mortality from fall out of tall tree”
John Kappelman, Richard A. Ketcham, Stephen Pearce, Lawrence Todd, Wiley Akins, Matthew W. Colbert, Mulugeta Feseha, Jessica A. Maisano, Adrienne Witzel; Nature (2016)
- “Human-specific evolution of novel SRGAP2 genes by incomplete segmental duplication”
Megan Y. Dennis, Xander Nuttle, Peter H. Sudmant, Francesca Antonacci, Tina A. Graves, Mikhail Nefedov, Jill A. Rosenfeld, Saba Sajjadian, Maika Malig, Holland Kotkiewicz, Cynthia J. Curry, Susan Shafer, Lisa G. Shaffer, Pieter J. de Jong, Richard K. Wilson, Evan E. Eichler; Cell; via PMC, NIH (May 11, 2012)
- “Paleoecological patterns at the Hadar hominin site, Afar Regional State, Ethiopia.”
K. E, Reed, Journal of Human Evolution; via PubMed/NIH (June 2008)
5 Neanderthal burial practices are still debated. Some scientists say evidence of flowers buried with the Shanidar IV skeleton indicate ritual burial. Others insist that it can’t be so, since the evidence might have been planted by rodents. I think we’re still not certain: but that Neanderthals have been looking more ‘human,’ the more we learn about them.
“Neanderthal reconstruction by F. Kupka, Illustrated London News, 1909. This reconstruction has practically become iconic as an example of the bias of early-twentieth-century understanding of Neanderthals.”
(Caption for František Kupka’s illustration, “Seven Skeletons: The Evolution of the World’s Most Famous Human Fossils,” p. 32, Lydia V. Pyne (2016) via Google Books.)