Patterns in the Fossil Record

Science Daily has a post on research about patterns in the fossil record that comes out of the Santa Fe Institute.  They write:

Throughout life's history on earth, biological diversity has gone through ebbs and flows -- periods of rapid evolution and of dramatic extinctions. We know this, at least in part, through the fossil record of marine invertebrates left behind since the Cambrian period. Remarkably, extreme events of diversification and extinction happen more frequently than a typical, Gaussian, distribution would predict. Instead of the typical bell-shaped curve, the fossil record shows a fat-tailed distribution, with extreme, outlier, events occurring with higher-than-expected probability.

While scientists have long known about this unusual pattern in the fossil record, they have struggled to explain it. 

Now, at last, there is something of an answer.

“Within a lineage of closely related organisms, there should be a conserved evolutionary dynamic. Between different lineages, that dynamic can change,” says [Andy] Rominger. “That is, within clades, related organisms tend to find an effective adaptive strategy and never stray too far. But between these clade-specific fitness peaks are valleys of metaphorically uninhabited space. It turns out, just invoking that simple idea, with some very simple mathematics, described the patterns in the fossil record very well.”

Sometimes, it just pays to rethink something from a different angle. This may open up doors to understanding other patterns in the fossil record.

Oldest Complex Fossil Found in Newfoundland

CNN is reporting that a 560 million year-old fossil with muscular tissue has been found in Newfoundland.  I can't embed the video so here is the link.

BioLogos, Ken Ham and David Menton—A Response, Part II

Point 3:

Because of the rarity of fossil hominids, even many of those who specialize in the evolution of man have never actually seen an original hominid fossil, and far fewer have ever had the opportunity to handle or study one. Most scientific papers on human evolution are based on casts of original specimens (or even on published photos, measurements, and descriptions of them).

So?  Menton seems to think that there is a problem with performing analyses based on measurements that other people have taken.  That is nonsense.  A few years back, I was at a conference where a paper was given in which the author was attempting to show the differences between subtle details on various fossil crania.   The striking criticism of the study was that it was based on casts, not on original fossils and, because of this, the analysis was questionable.  When I did my dissertation on the origins of modern human crania, I had measurements of almost all of the original crania that had been taken either by my advisor or by other researchers in the field, who had then published them.  Almost every paper done on human evolution is based on measurements from the original fossils.  The only examples where this is not happening is where the original skulls are missing, as with the Homo erectus remains from Zhoukoudian, which vanished during the run-up to the second world war, or the European Mladec remains, which were destroyed when the allies bombed the castle in which they were housed.  Even in those cases, copious measurements were taken of the originals and, in the case of the Zhoukoudian remains, comprehensive photos were taken. There is absolutely nothing wrong with doing analyses based on measurements from the original fossils, especially where the photos are clear and detailed. Bill Howells took detailed measurements of the Near Eastern Qafzeh 6 cranium and then kindly sent me the measurements for it.

All of science is built on what came before and the observations of the those scientists are absolutely invaluable.

Point 4:

Since there is much more prestige in finding an ancestor of man than an ancestor of living apes (or worse yet, merely an extinct ape), there is immense pressure on paleoanthropologists to declare almost any ape fossil to be a “hominid.” As a result, the living apes have pretty much been left to find their own ancestors. 

More nonsense.   There are palaeoprimatologists that spend their entire lives researching the prehistory of non-human primates.  A check of Google Scholar revealed over forty-nine thousand papers dealing with non-human fossil primates.  One of the most productive and exciting aspects of fossil primate studies is the search for the last common ancestor (LCA).  This involves an in-depth study of Miocene apes.  Another area of important study is the origin of the large-bodied primates and the split between the Old World and New World monkeys.  When Menton states that the living apes have been left to find their own ancestors, he forgets the media circus that surrounded the find of the fossil primate Ida, which shed light on the origin of primates as a group. 

Point 5:

In contrast to man, apes tend to have incisor and canine teeth that are relatively larger than their molars. Ape teeth usually have thin enamel (the hardest surface layer of the tooth), while humans generally have thicker enamel. Finally, the jaws tend to be more U-shaped in apes and more parabolic in man.

The problem in declaring a fossil ape to be a human ancestor (i.e., a hominid) on the basis of certain humanlike features of the teeth is that some living apes have these same features and they are not considered to be ancestors of man. Some species of modern baboons, for example, have relatively small canines and incisors and relatively large molars. While most apes do have thin enamel, some apes, such as the orangutans, have relatively thick enamel. Clearly, teeth tell us more about an animal’s diet and feeding habits than its supposed evolution. Nonetheless, thick enamel is one of the most commonly cited criteria for declaring an ape fossil to be a hominid. 

Menton may be correct in his statements about enamel thickness.  Enamel thickness may be a better indicator of dietary adaptations than of morphology, but, where primates are concerned, that is only true of enamel thickness.  It is not true of tooth morphology.  Primatologists have no trouble telling baboons from humans.  They do not have the same features.  Fossil and modern baboons are quite different from humans, even human ancestors.

In 1924, when the well-trained anatomist Raymond Dart was given the deposits that had the Taung child in them, he knew immediately that the teeth did not belong to any fossil baboon.  It wasn't the thickness of the enamel that tipped him off.  The dimensions were similar to those of an infant human and the morphology of the canine and the premolars was like that of humans. Remember, at this time, there were very few other prehuman ancestors with which to compare it, and no australopithecines.

Teeth are, actually, one of the most conservative features on a skeleton and change very little over time.  For example, the Y-5 molar pattern that we have in our mouths is first found in Aegyptopithecus, from the Oligocene epoch, some 30 million years ago. Furthermore, one of the ways we can tell the new world primates from the Old World primates is the number of teeth they have.  New World monkeys have two incisors, one canine, three premolars and three molars in each quarter of the mouth.  All Old World monkeys and apes are lacking the extra premolar (bicuspid, if you are a dentist).  We have this same pattern. 

These differences are either glossed over or not mentioned by Menton, who simply declares, based on enamel thickness, that the teeth are similar and completely disregards information that doesn't fit his narrative. 

Part III here.  

David MacMillan: Understanding creationism, VI: An insider’s guide by a former young-Earth creationist

Panda's Thumb has the sixth installment by David MacMillan on Understanding Creationism.  This one deals with the correspondence between fossil taxonomic studies and genetic evidence as well as the daunting task of constructing phylogenies.  He writes:

The more items you have in a given collection, the more ways they can be arranged. Just five items can be arranged in 120 different ways, and ten items can be arranged in a staggering 3.6 million ways. But the task of placing items into a branching tree is even more complex; for only five items, there are an unbelievable 6.6 × 10198 different possible branching trees. The number of possible trees for just five species is hundreds of orders of magnitude greater than the number of gene sequences that could be used to compare those five different species. So a researcher can’t simply “pick” the sequence that matches; there’s no chance of getting a match in any sequence unless there’s a real phylogeny to work with.

Most importantly, researchers don’t pick only a single sequence. Phylogenetic analysis is performed on many different sequences, and then all of the resulting trees are compared to each other to see which one appears most consistently. Trees produced by random noise will appear only once; accurate trees will appear in multiple sequences. All these clear facts are completely missing from the creationist understanding.

Read the whole thing, especially the response to the “common design” argument.

Rediscovery of a Lifetime

According to a story in Planet Earth Online, a large cache of fossils has been rediscovered at the British Geological Survey, some of which produced quite a surprise. Adele Rackley writes:

Dr. Howard Falcon-Lang, a palaeontologist at Royal Holloway, University of London was in the BGS archive looking for carboniferous fossil-wood specimens when he made the discovery.

"I spotted some drawers marked "unregistered fossil plants", he recalls. "I can't resist a mystery, so I pulled one open. What I found inside made my jaw drop!"Inside were hundreds of fossil plants, polished into thin translucent sheets known as 'thin sections' and captured in glass slides so they could be studied under a microscope.

Falcon-Lang's jaw dropped even further when he began to take out the slides. One of the first he looked at was labelled 'C. Darwin Esq.'

These were, in fact, some of the fossils that Charles Darwin had brought back from the trip aboard the Beagle. They had been given for safe keeping to Joseph Hooker and, somehow, just slipped through the cracks. It does give one a picture of the enormity of how much was being discovered even at that time. There is, in fact, a dirty secret in that most museums display only a fraction of what they actually have in their vaults, much of which is uncatalogued. Remember that the next time that someone tells you that the fossil record has gaps in it.

Nifty Video on Transitional Fossils

Karl, writing from the blog Athens and Jerusalem, has posted a long series on the "foundational falsehoods of creationism." Here is his video on transitional fossils.



He has a very good explanation of what a transitional fossil is as well as how many we actually have. The slides go past pretty quickly so you will probably need to pause the video to read them. The best line, regarding extinction: "practically everything that ever was, ain't no more."

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The Downside of Dinosaur Fossil Hunting

The war is on! In what is known as "Jurassic Coast," in southwest England, there is a war going on between professional fossil hunters and the National Trust as to who owns the fossils. ScienceDaily has the story. Michael Hanlon writes:

'This is, quite simply, the finest unbroken record of the Age of Dinosaurs anywhere in the world,' says Richard Edmonds, geologist and chief scientific officer for the Jurassic Coast, a world heritage site since 2001, which runs from Exmouth to Studland. The rock strata of this remarkable 95-mile stretch of coastline encompasses 180 million years of the Earth's history.

As such, it should prove to be a boon to scientists all over the world, right? Sadly, that is not what is going on. He continues:

If the wet, crumbling cliffs of Dorset are the coalface for fossil collectors, Dale Rogers's shop in Belgravia is the showcase. Ammonite 2000 is London's premium dealer in rare fossils and minerals, and relies heavily on the Dorset fossil-hunters for its supplies.

'We sell to interior designers, hotels, celebrities,' explains Rogers.

Here, Earth's treasures are freely available for those with oligarch levels of cash. Above the counter, a complete 4ft ichthyosaur is mounted on a wall. This one, also from Lyme, is perfect, every rib and vertebra, even the scales visible on its fins.

'Yours for £100,000,' says Rogers. 'I hope it will go to someone who knows what it is, but there's a good chance someone will come in and go, "Wow honey, that looks like a dolphin! I love dolphins, they are so cute... can we get it?"'

Rogers says his stock is all 'totally legal', but admits that in the trade 'a lot of stuff goes on'. The problem is that there are no clear rules.

The problem is, as Mr. Hanlon points out, many of these fossils, if not discovered by the hunters, would never be found because the necessary funds and manpower is not there to do it by the book. This is, in some senses, amateur salvage archaeology. That many of the more amazing fossils end up in private collections is regrettable, though.

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More on the Human-Orang Connexion

Here is a much longer article from Eurekalert! on the idea that humans are more closely related to orang-utans than to chimpanzees. They write:

Jeffrey H. Schwartz, professor of anthropology in Pitt's School of Arts and Sciences and president of the World Academy of Art and Science, and John Grehan, director of science at the Buffalo Museum, conducted a detailed analysis of the physical features of living and fossil apes that suggested humans, orangutans, and early apes belong to a group separate from chimpanzees and gorillas. They then constructed a scenario for how the human-orangutan common ancestor migrated between Southeast Asia—where modern orangutans are from—and other parts of the world and evolved into now-extinct apes and early humans. The study provides further evidence of the human-orangutan connection that Schwartz first proposed in his book The Red Ape: Orangutans and Human Origins, Revised and Updated (Westview Press, 2005).

Schwartz and Grehan scrutinized the hundreds of physical characteristics often cited as evidence of evolutionary relationships among humans and other great apes—chimps, gorillas, and orangutans—and selected 63 that could be verified as unique within this group (i.e., they do not appear in other primates). Of these features, the analysis found that humans shared 28 unique physical characteristics with orangutans, compared to only two features with chimpanzees, seven with gorillas, and seven with all three apes (chimpanzees, gorillas, and orangutans). Gorillas and chimpanzees shared 11 unique characteristics.

Schwartz and Grehan then examined 56 features uniquely shared among modern humans, fossil hominids—ancestral humans such as Australopithecus—and fossil apes. They found that orangutans shared eight features with early humans and Australopithecus and seven with Australopithecus alone. The occurrence of orangutan features in Australopithecus contradicts the expectation generated by DNA analysis that ancestral humans should have chimpanzee similarities, Schwartz and Grehan write. Chimpanzees and gorillas were found to share only those features found in all great apes.

Schwartz and Grehan pooled humans, orangutans, and the fossil apes into a new group called "dental hominoids," named for their similarly thick-enameled teeth. They labeled chimpanzees and gorillas as African apes and wrote in Biogeography that although they are a sister group of dental hominoids, "the African apes are not only less closely related to humans than are orangutans, but also less closely related to humans than are many" fossil apes.

As they, themselves acknowledge, the earliest hominid material is in Africa, which is where chimpanzees are and where orangs are not. They suggest that there was a migration between 12-13 mya of hominoids between east Asia and Africa before there was a separation of the different groups that eventually became chimpanzees and orang-utans. Peter Andrews seems to like the idea. I wonder how many others will sign on?

Ancient Hippos in North America

Randy Boswell of Canwest has a story of some hippo remains that have been discovered in Ellesmere Island (a hotbed of temperate fossils), shedding light on the migration of the modern precursors into North America some 50 million years ago:

Researchers have long known that Canada’s northernmost Arctic islands were once relatively warm, lush environments inhabited by alligators and other creatures associated today with southerly latitudes.

But the latest findings, according to Canadian and U.S. researchers who’ve published a study in the latest issue of the journal Geology, shed new light on the diets and movements of Arctic animals in the post-dinosaur age and “may provide the behavioural smoking gun for how modern groups of mammals like ungulates — ancestors of today’s horses and cattle — and true primates arrived in North America.”

Are they actually hippos? Well, not really:

Among the remains analyzed were teeth from the extinct Coryphodon, a semi-aquatic mammal resembling the modern hippopotamus. Teeth from two other species — an extinct ancestor of today’s tapirs and a rhinoceros-like animal called brontothere — also were examined and confirmed the team’s findings.

Another piece of the puzzle.

Ida and the Importance of Fossils

Jasmine Williams of the New York Post has a piece on Ida and also how fossils form and why they are important. She write:

Fossils can be found all over the world and range in size from the largest dinosaur bones -- more than 10 feet in length -- to plant spores that are a few 100ths of an inch across. The Earth's landscape is always changing and driving up long-buried fossils. While you may not find an Ida or Lucy, traces of ancient life are all around.

She also partakes in the kind of nonsense that generates problems for all concerned:

Until this discovery, the oldest known fossil linked to humans was that of Lucy, a 3-million-year-old adult female discovered in Ethiopia in 1974. However, Lucy was just 40 percent intact.

Ida lived 47 million years ago. She isn't a link to humans. She might not even be a link to modern-day lemurs and lorises. For crying out loud, we don't even know for sure which Miocene ape is the link to humans, and they lived within the last 10-15 million years. Ida is a neat fossil that tells us a great deal about EARLY primate evolution. It tells us zip about where humans came from.

Ah, the Intrigue of Palaeontology!

Here is some back story about the disovery of Ida and how it came into the hands of the scientists. It is the stuff of Nick Danger:

Hunched around a table at a vodka bar in Hamburg, Jørn Hurum, a palaeontologist, was about to make the scientific gamble of his life. Thomas Perner, a fossil dealer whom he knew well, had insisted they met; he had something very special to show him.

Looking nervously over his shoulder for prying glances, Perner put three ­photographs of a fossil on the bar table. "My heart started beating extremely fast," said Hurum. "I knew that the dealer had a world sensation in his hands. I could not sleep for two nights."

Rumours had been flying around for years in the palaeontological community about a spectacular primate fossil specimen. Now Hurum was one of the first people in the world to see it.

Read the whole thing.