- Denisovans, Neanderthals: People Acting Like Humans?
- A Mammal, But Not Quite
- Why Bother With Beaks?
- Toothpicks: The Case of the Mangled Mandibles
(From Fernando Correia, Universidade de Aveiro, via Sci-News, used w/o permission)
"Niassodon mfumukasi. Image credit: Fernando Correia, Universidade de Aveiro."
If the plants behind beak-face in that picture don't look familiar, I'm not surprised. That mammal-like animal lived almost a quarter of a billion years ago, near what's now the southeast coast of Africa. The area was farther inland then, part of Earth's only continent.
(From scotese.com, used w/o permission.)
A short time later, by cosmic standards, about nine tenths of Earth's animals died. Scientists are still trying to figure out what happened. (November 29, 2013)
We've learned a great deal about Earth and the universe over the last few centuries. If anything, we're collecting and analyzing data faster now, than when the first science academy was founded: in 1603, by the Vatican. (October 2, 2011)
In 1650, an English king's Primate of all Ireland published his estimate of the time elapsed since Earth began. James Ussher's chronology, based on analysis of an English translation of the Bible, placed the beginning at nightfall before October 23, 4004 BC.
This was a reasonable estimate of Earth's age at the time. As scientists learned more about Earth, though, assuming that Ussher was right became harder.
In 1862, a physicist used available data and calculated an age of Earth at somewhere between 20,000,000 and 400,000,000 years.
This wasn't even close to Ussher's 'Biblical' chronology, which upset quite a few folks at the time.
Some claimed that an orderly Creator can't exist: because the universe is orderly, and changes in predictable ways. I think it's a silly idea, but ever since the mid-19th century quite a few folks enthusiastically supported it.
Even more remarkable, quite a few loudly-Christian folks do too, although they take a different approach. They apparently assume that folks living in and near ancient Mesopotamia knew everything there is to know about the cosmos.
(From "The Three-Story Universe," © N. F. Gier, God, Reason, and the Evangelicals (1987), via Nick Gier, University of Idaho, used w/o permission.)
This doesn't bother me. I believe that God created the universe, designed us with the curiosity, and expects us to use our brains.
As a Catholic, I have to believe that truth can't contradict truth, and that methodical study of creation cannot work against faith. (Catechism of the Catholic Church, 159)
Not-so-methodical jumping to daft conclusions, based on a little new data and a lot of imagination, is something else.
I think part of the problem folks have with the idea of a constantly changing universe is what we've learned about our ancestors. We've been changing, too: and apparently still are.
I don't have a problem with that. Even if I did, it wouldn't do much good. God is large and in charge: and created a universe that's moving toward perfection, but isn't there yet. (Catechism, 271, 302)
Genesis 2:7; Catechism, 302, 303)
I've been around animals enough to realize that human beings are animals. But I don't think that human are nothing but animals. We're made in the image of God, created with reason and free will. (Catechism, 1951, 1700-1706, 1730)
We don't use our ability to reason consistently, and occasionally make monumentally bad decisions: and that's another topic. Topics.
More about being human and being Catholic:
- "Communion and Stewardship: Human Persons Created in the Image of God"
International Theological Commission (2004)
(From Javier Trueba, Madrid Scientific Films, via National Geographic Daily News, used w/o permission.)
"Discovery of Oldest DNA Scrambles Human Origins Picture""Scrambles" isn't a particularly accurate way to describe what new data about humanity's past does to "the scientific picture" of our remote ancestors. What we're learning complicates the picture, but also lets scientists draw more accurate conclusions. That's not 'scrambling,' in the sense of making something more disordered.
"Scientists reveal the surprising genetic identity of early human remains from roughly 400,000 years ago in Spain."
Karl Gruber, National Geographic Daily News (December 4, 2013)
"New tests on human bones hidden in a Spanish cave for some 400,000 years set a new record for the oldest human DNA sequence ever decoded — and may scramble the scientific picture of our early relatives.
"Analysis of the bones challenges conventional thinking about the geographical spread of our ancient cousins, the early human species called Neanderthals and Denisovans. Until now, these sister families of early humans were thought to have resided in prehistoric Europe and Siberia, respectively...."
I suppose that National Geographic's editors place more importance on grabbing a reader's interest in the headlines than strict semantic rigor: which is what headlines are supposed to do. Since I'm being picky, "strict semantic rigor" is redundant, and yet another topic.
"...'Our results suggest that the evolutionary history of Neanderthals and Denisovans may be very complicated and possibly involved mixing between different archaic human groups,' he said.Our knowledge of humanity's past is growing: but very far from complete. If this was a Golden Age whodunit, we'd be on the page where the detective discovers that the obvious suspect couldn't be guilty: but that everyone else in Motley Manor had motive, means, and opportunity.
"Neanderthals and Denisovans arose hundreds of thousands of years before modern-looking humans spread worldwide from Africa more than 60,000 years ago. The small traces of their genes now found in modern humans are signs of interbreeding among ancient human groups.
"Previously, the oldest human DNA sequenced came from bones that were less than 120,000 years old.
"For humanity's tangled past, the new mitochondrial DNA results raise an unexpected question: How does a Spanish early human species end up with Siberian DNA?..."
(Karl Gruber, National Geographic Daily News)
That point in a story can be frustrating, since a straightforward explanation has been replaced by fragments of many explanations: none of which is particularly simple.
On the other hand, it brings the reader closer to the mystery's solution: or, in this case, answers to the puzzle of how our distant ancestors lived, and who they were.
"...The authors propose several possible scenarios. For instance, Sima hominins could simply be close relatives of the Denisovans. But that would mean they lived right alongside Neanderthals without having close genetic ties to them.I think Linnaeus made a great contribution to our understanding of life on Earth when he sorted critters by species, genus, and so on. I've also noticed that the more we learn about living creatures, the harder it is to define just what a "species" is.
"The Sima hominins could also be a completely independent group that mingled with Denisovans, passing on their mitochondrial DNA, but it would be hard to explain why they also have Neanderthal features.
"Another possibility, suggested by anthropologist Chris Stringer of the Natural History Museum in London, is that mitochondrial DNA from the Sima people reached the Denisovans thanks to interspecies sexual adventures among early humans, which introduced the DNA to both the Sima and Denisovans...."
(Karl Gruber, National Geographic Daily News)
A century from now, scientists may see "interspecies sexual adventures" involving humans with different hereditary traits about the same way many now see 'interracial' marriages.
I'll admit to a personal bias here. I'm what happened, a few generations later, when a decent young lady married an Irishman. By now, my wife and I are raising kids who are German, Dutch, Norwegian, Irish, and Scots. Granted, all our ancestors spent the last several centuries, at least, in northwestern Europe: and that's not another topic, really. (November 13, 2008)
Something nearly all human beings have in common is that part of a community is going to get fed up, driven out, or simply curious: and head for the horizon. Humans travel, a lot.
Although mixing with the "wrong" sort seems to horrify some of us, many seem far more willing to welcome someone new into the family.
That's a good thing, considering what the Hapsburgs did to themselves.
Part of my take on tolerance and the Hapsburg disaster:
- "Halloween's Coming: Why aren't I Ranting?"
(October 29, 2009)
- "Aspergers, Meditation, Tolerance and a Loud Pump"
(September 3, 2010)
- "Charles II of Spain and a Seriously Messed-Up Family"
Apathetic Lemming of the North (April 19, 2009)
(From Fernando Correia, Universidade de Aveiro, via Sci-News, used w/o permission)
"Niassodon mfumukasi: Fossil of New Mammal-Like Reptile Found in Mozambique"Interestingly, the word synapsid has little to do with synapse. Synapsid comes from Greek words meaning "fused arch," and refers to critters I've known as theropsids: which means "beast face."
Sci-News.com (December 5, 2013)
"Paleontologists have discovered a new genus and species of dicynodont that lived in what is now modern Mozambique during the Late Permian period, about 256 million years ago.
"The prehistoric animal has been named Niassodon mfumukasi, which means the 'Queen of Lake Niassa' in local languages Chiyao and Nyanja.
" 'The name is a tribute to the Yao matriarchal society, to the women of Mozambique and to the beauty of Lake Niassa,' explained Dr Fabian Wilde of Helmholtz-Zentrum Geesthacht with colleagues.
"Niassodon mfumukasi is a dicynodont - an herbivorous mammal-like reptile (Synapsida). Its skull and much of the skeleton were unearthed during fieldwork in the remote province of Niassa, Mozambique, in 2009.
"By using micro-computed tomography, Dr Wilde and his co-authors digitally reconstructed the bones of the ancient creature and created a virtual model of its brain. The model reveals new information on the brain anatomy of early synapsids, which is important for understanding the evolution of many features of the mammalian brain...."
Not that I knew any theropsids personally.
Actually, I do, since I'm a theropsid myself. More specifically, I'm a mammal, a primate, and a human: and I'm getting a bit off-topic.
What I meant was that I wasn't around when critters like beak-face there lived. That was the late Permian, 252,000,000 years ago or so. Mammals wouldn't show up for maybe 50,000,000 years: more or less, depending on how "mammal" gets defined.
niassodon's skull. After nearly a quarter of a billion years, it had come apart: so what they started with was a three dimensional jigsaw puzzle.
Since the critter's brain filled most of the space reserved for it, they could 'see' what that organ's shape was. The skull had openings and channels for nerves and blood vessels, too: which gave more information.
The niassodon's brain was shaped like reptilian, avian, and mammalian brains: which helped Dr. Wilde and the others identify its layout. It was narrow, with the cerebellum wider than the forebrain. That's the way reptiles' brains are today, but the paraflocculi were about the size we'd expect to see in birds. The 'para-' things are lobes on the cerebellum.
This sort of thing isn't useful as a conversation starter at a party: but it's important for folks who study how our brains work, and how they've developed.
Our cerebellum is tucked under the back of our cerebrum. The cerebrum is what we do most of our thinking with, and has most of the circuits for image processing, among other things. The cerebellum is important, too, since we use it when we move and learn how to move.
More about beak-face:
- "Bringing Dicynodonts Back to Life: Paleobiology and Anatomy of a New Emydopoid Genus from the Upper Permian of Mozambique"
Rui Castanhinha, Ricardo Araújo, Luís C. Júnior, Kenneth D. Angielczyk, Gabriel G. Martins, Rui M. S. Martins, Claudine Chaouiya, Felix Beckmann, Fabian Wilde; PLOS ONE (December 4, 2013)
(From Dinosaur-world.com, via Sci-News.com, used w/o permission.)
"Research Reveals Role of Dinosaur Beaks"Words like "keratinous" and "therizinosaurs" aren't part of everyday conversation, unless you're a paleontologist or even more interested in Cretaceous fauna or structural proteins than I am.
Sci-News.com (December 3, 2013)
"By using CT scanning technology combined with computer simulations, paleontologists have revealed what role keratinous beaks of some dinosaurs played in their life.
"The study, published in the Proceedings of the National Academy of Sciences, is focused on the skull of Erlikosaurus andrewsi, a 4-m-long herbivorous dinosaur called a therizinosaur.
"Erlikosaurus lived in what is today Mongolia during Cretaceous, about 90 million years ago. Fossil evidence shows that the snout of this dinosaur was covered by a keratinous beak.
"The findings of the new study show that the beak of Erlikosaurus played an important role in stabilizing its skeletal structure during feeding, making the skull less susceptible to bending and deformation...."
Looking at that picture, someone might think that keratinous meant a beak shaped like the ones on today's graniverous avians: which are also words you don't see every day. Or hear, for that matter.
Keratin is a sort of fibrous structural protein used in hair, horns, beaks claws, fingernails, and the outer layer of our skin.
What's really interesting about an Erlikosaurus beak is that it may not have developed as a substitute for teeth.
By the way, therizinosaurs have nothing to do with theremins.
"...'It has classically been assumed that beaks evolved to replace teeth and thus save weight, as a requirement for the evolution of flight. Our results, however, indicate that keratin beaks were in fact beneficial to enhance the stability of the skull during biting and feeding,' said study lead author Dr Stephan Lautenschlager from the University of Bristol, UK.I'm not at all sure that Dr. Lautenschlager's team has shown that beaks didn't develop as a weight-saving feature: but they've shown that there's more to learn about the evolution of beaks.
" 'Using Finite Element Analysis, a computer modeling technique routinely used in engineering, we were able to deduce very accurately how bite and muscle forces affected the skull of Erlikosaurus during the feeding process. This further allowed us to identify the importance of soft-tissue structures, such as the keratinous beak, which are normally not preserved in fossils,' added study co-author Dr Emily Rayfield, also from the University of Bristol...."
It's likely enough that reduced weight was a factor. Most of the times when beaks evolved on the way from dinosaur to bird the critters lost their teeth, too. Maybe more to the point: since beaks reinforced skulls, their heads didn't have to have as much bone: which left more room for a brain.
(From Georgian National Museum, via LiveScience, used w/o permission.)
"Human Ancestors' Oral Hygiene: The Toothpick"Make no mistake: toothpicks can be dangerous. Agathocles, who ran Syracuse a little less than two dozen centuries back, died after using a toothpick. I think toothpicks are probably safe for dental hygiene, though: Agathocles' fatal pick had been dipped in poison.
Charles Q. Choi, LiveScience (October 7, 2013)
" Overuse of toothpicks might be one reason that explains the mystery of why the jaws of the oldest-known extinct human relatives found outside Africa could vary so much, researchers say.
"These findings suggest tool use could have helped to alter drastically how these ancient members of the human family tree ate and survived. In addition, the evidence suggests human ancestors may have overused the toothpick in some instances, possibly leading to swelling and infection.
"The origin of the human family tree is rooted in Africa. The earliest known remains of hominids — humans and all their extinct relatives after they split from the ancestors of chimpanzees — that researchers have unearthed yet outside of Africa are nearly 1.8-million-year-old fossils discovered at the site of Dmanisi in the Republic of Georgia.
"The remains of several hominids were previously discovered at Dmanisi, which ranged from adolescence to old age. Included within these fossils were four lower jaws, or mandibles...."
The Syracuse he led was the one on the island we call Sicily, not the one in the state of New York. There's a fellow in Illinois who made a replica of the Lusitania out of toothpicks, and that's yet again another topic.
More about toothpicks:
- "Let us now praise the romantic, artful, versatile toothpick"
Sue Hubbell, Smithsonian magazine (January 1997)
"Flirting, scale modeling, putting on the dog through the ages, the device has been used for a lot more than dental hygiene"
"...'Fossil findings in human evolution are often represented by mandibles, because typically they are better preserved than any other parts of the skeleton except teeth during fossilization processes,' said researcher Ann Margvelashvili, a paleoanthropologist at the University of Zurich's Anthropological Institute and Museum in Switzerland.Again, I think scientists will be re-defining "species" in the next few decades. It's a convenient term, and may reflect real distinctions between animals, plants, and other critters. But we've learned a lot since the days of Linnaeus.
"Mysteriously, these jaws varied widely in shape from each other, more than scientists could satisfactorily explain up to now. Some researchers suggested the discrepancies might reflect ones between the sexes within a species; others proposed they represented disparities between different species.
"To help solve this puzzle, scientists analyzed how jawbones from modern hunter-gatherers from Australia and Greenland could vary and compared them with Dmanisi teeth and jaws. They relied on X-rays and microscopic analysis of these samples, focusing on the wear on teeth and the resulting changes in jawbones.
"Based on their data, the researchers suggest the amount of variation seen in the Dmanisi jaws reflects the differences one might normally expect within a species. Tooth wear could, in theory, greatly augment differences between individuals by reshaping features of jawbones, such as how the rows of teeth are shaped and the height and angle of the jaws...."
(Charles Q. Choi, LiveScience)
About early hominids, species, and dental hygiene: I think it's quite likely that some of the different "species" may turn out to be individuals from different cultures.
Today, I don't think many folks would seriously think that a Chinese-American office worker in Seattle and a German-American stevedore in Chicago belong to different species. But those two people wouldn't look exactly alike, partly due to their way of life: and 1,800,000 years from now someone might be astonished that both are among his or her ancestors.
- Being human
- Seeking truth
- "Collagen: 68,000,000 Years Old, and Still Soft"
(December 6, 2013)
- "Three Es: Exoplanets, Exobiology, and Evolution"
(October 4, 2013)
- "Lowbrow to Highbrow in Four Centuries, Paleolithic Pitchers, and a Fantastic Elastic Echinoderm"
(July 5, 2013)
- "DNA, Voyager 1, Habitable Worlds, and the Universe"
(March 22, 2013)
- " 'In a State of Journeying' "
(January 18, 2012)
- "Collagen: 68,000,000 Years Old, and Still Soft"