Live Like Dirt

J. D. Hooker: Charles Darwin's best friend

2012-02-12T06:00:00.000-03:30

When Joseph Dalton Hooker published his third and final essay on the subject of Antarctic Botany, Introductory Essay to the Flora Tasmaniae, he became the first scientist to publicly back Charles Darwin's theory of evolution by means of natural selection. Although Thomas H. Huxley is more famously known as "Darwin's bulldog" Hooker played a much larger role in Darwin's personal life. It was Hooker who listened to, read, and criticized Darwin's s first thoughts on the subject of transmutation. Perhaps, even more importantly, it was Hooker, alongside Charles Lyell, who urged Darwin to publish On the Origins of Species, even though Darwin felt it was unfinished and not fully developed.

J. D. Hooker began to attend lectures by his famous botanist father, Sir William Jackson, at the age of seven years old. This undoubtedly had a large influence shaping his career as a botanist, as well as the founder of geographical botany. Much like Darwin, Hooker spent his younger years working as a naturalist on ships which took him around the world. It was while he was upon one such ship, the HMS Erebus, bound for Antarctica, that he first read Darwin's writings. He had been given an early draft of Voyage of the Beagle by the geologist Charles Lyell.

Upon his return from the HMS Erebus Darwin asked Hooker to help him identify some of the botanical material he had collected during his the Beagle voyage which still remained unclassified. They pair became fast friends and continued to consult each other for many years. On January 11, 1844 Darwin first presented his ideas about transmutation to Hooker. Althogh he did have some criticism of the theory, he was largely sympathetic to the idea, and found many of Darwin's thoughts on the subject intriguing.

Some years later in 1858 the naturalist Alfred Russel Wallace sent Darwin his own paper on the subject of evolution. Wallace had composed the paper based upon his own research he had conducted during his time working as a biological specimen collector in Malayasia. Wallace, who was not a part of the upper class like Darwin and Hooker and therefor not part of scientific community of Victorian England, was looking for support from respected an academic in the hope that someone might take his ideas seriously.

Both Darwin and Hooker took Wallace's ideas very seriously. Hooker arranged for Wallace's paper to be presented at the next Linnean Society meeting. However, Hooker also made sure Wallace's paper was accompanied by notes from Darwin that effected demonstrated Darwin had been previously aware of the theory natural selection. After the meeting Hooker instructed Darwin that he needed to put his pen to paper and write the definitive text on the subject of evolution. Darwin did the next best thing. He spent the following months composing an introductory text on the subject which he titled On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life.

Happy Darwin Day.

42,000 year old cave art in Spain?

2012-02-08T14:54:00.000-03:30

According to the few news sites I've been perusing this morning the cave paintings depicted above are arguably the oldest examples of parietal art in all of Spain. The date given is 42,000 BP. Sounds intriguing, but one of those "news" sources was the notoriously credulous Daily Mail. Needless to say my skeptical spidey senses are tingling. It's quite possible that these paintings could be 42,000 years old, but I'm yet to find a definitive creditable source on the matter. I'll see what my Pleistocene Art Professor has to say about these on Friday. Oh yeah, the paintings are from Cave Nerja which is down in Southern Spain - quite a distance from the painted caves of Cantabria. Also, this news site is reporting that the artists were Neanderthals. Again, although it's possible, it's probably a good idea to remain skeptical until we hear from some more credible sources.

Zoophycus

2012-02-07T10:45:00.001-03:30

Here's another ichnofossil (aka trace fossil) which I think is kinda rad. It's called Zoophycus and it's formed by feeding worms, or at least that's what most paleontologists think. Nobody knows for sure, but it seems like a fairly reasonable idea. To be a little more specific, zoophycus can also be considered an ichnofacie. An ichnofacie is an ichnofossil which provides an indication of the conditions that their formative organisms inhabited. In the case of zoophycus, it appears as though the sediment was a matrix of impure sands and silts deep in the water (likely a marine setting). So the fossil you see to your right was most likely formed by some feeding worms in a sandy sediment at the bottom of the ocean sometime in the past.

Brachiopods: Nature's Middle Finger

2012-02-07T10:19:00.000-03:30

Oh, brachiopods. You are one of the most confusing phylum of animals I have ever come across. And to think we are more closely related than any of the other invertebrates (protostome invertebrates that is, there might be some other deuterostome invertebrates to which I am more closely related). I came across these critters before in a class in invertebrate biology. As we didn't get around to the deuterostome until close to the end of the semester, I don't believe we really covered the brachippods in any greater detail. I vaguely remember writing this little blog about how they differ from similar looking molluscans.

Scientists used to divide brachipods up into two classes: Articulata and Inarticulata. Okay, so that method of classification has been discarded, but taxonomists are still arguing about how to classify them. The way we're dividing them up in my paleontology class (at least those fossils which I am responsible for memorizing) is into two sub-phylums: Linguliformea and Rhynchonelliformea. The first sub-phylum isn't that. There's only one brachipod I have to be concerned with and that's Lingula (Phylum: Brachiopoda, Sub-phylum: Linguliformea, Order: Lingulida, Genus: Lingula). The shape of Lingula's organophosphatic shell is remarkably different from those of Rhychonelliformea. These guys have been around since the Cambrian and they're still kicking.

Now, we get to the Rhynchonelliformeans. There are seven orders which I have know (Orthida, Strophomenida, Pentamerida, Rhynchonellida, Atrypida, Spiriferida, and Terebratulida), and a more few specific genera (Productus, Rafinesque, Prorochtofenia, Pentamerus). I've developed a few tricks for telling these guys apart, but I'm still working on it. So, I'm gonna go get back figuring these brachiopods out. See ya later, brachiopoderator.

Yee-haw! Welcome to Lake Volstok!

2012-02-06T17:03:00.000-03:30

It looks like Russia just gained access to Lake Volstok. In case you're wondering that's the Antarctica lake which has been trapped under 4 kilometers of ice for the past 20 million years. Apparently they reached the surface sometime yesterday. It's a pretty big deal. Scientists have been trying to reach Lake Volkstok for the past 30 years. I can't wait to see what kind of critters they find down there.

Although some news reports are saying the scientists are expecting to find primitive life sown there, that's not exactly true. First off, although 20 million years might sound like a long time to a human, it's a relatively short period of time geologically. Twenty million years only takes you back to early Miocene epoch. Dinosaurs had already been extinct for 45 million years, and apes were at their zenith.

Scientists aren't expecting to find primitive life, they're expecting to find life that evolved along an unknown trajectory within a confined space. They are interested in seeing how the critters which inhabit Lake Volkstock survived in such harsh conditions, and they're interested in seeing critters that share no close connection to anything which has evolved elsewhere on earth for the past 20 million years. These critters won't necessarily be primitive, just different.

More details on the discovery can be found here.

Archaeocyathida

2012-02-06T14:41:00.001-03:30

Back in the fall of 2009 I was writing about different invertebrate groups every Sunday. It was the logical progression my weekly series (From Wednesday Dinosaurs to Wednesday Megafauna to Sunday Primates to Sunday Inverts to Sunday Verts and back to a very infrequent Sunday Primates). So I thought I must have written something about sponges during that time, but I wasn’t able to find anything here on this blog. I’m not sure if that’s an indicator that I didn’t attach enough tags or that I ignored sponges. I must have written something about the three big extant classes (Demospongae, Calcarea, and Hexactinellida). It’s probably hidden out there in the ether of the LLD-Blogosphere matrix and it’s probably out of date.

Why am I bringing up sponges anyway? Well, because I wanted to write something about a class of sponge which is new to me, but old to the fossil record. Archaeocyathida are an extinct class of sponges which originated in Siberia during the early Cambrian period. They lived in shallow marine environments and are considered to be the first reef building organism. Although they diversified fairly rapidly and spread throughout the tropics during the early and middle Cambrian they disappear from the fossil record by the start of the Ordovician period. It is for this reason that they are known as an index species; their presence can immediately tell you are looking at a rock which formed in the Cambrian period.

Members of the Archaeocyathida class are colloquially known as “ancient cups” because they look like cups and they are really old (I tell ya, these paleontologists can be pretty creative sometimes). They used calcium carbonate to construct their cones. They have no living descendants anywhere on earth as their ecological role was taken over (and dominated) by coral reefs early in the Ordovician period.

A Plant Worth Dying For

2012-02-06T13:33:00.001-03:30

I was just reviewing some information about Glossopteris on Wikipedia when I came across this little tidbit at the very bottom of the page:

The first Antarctic specimens of Glossopteris were discovered by members of Scott's doomed Terra Nova Expedition. The expedition members abandoned much of their gear in an effort to reduce their load, but kept 35 pounds of Glossopteris fossils; these were found alongside their bodies.

The article cites Jerry Coyne’s book Why Evolution is True as the reference. I read that book a few years ago when it first came out. I undoubtedly read about this story before and in greater detail than is given in your average wikipedia article. Although it does sound mildly familiar, it sounds totally new to me at the same time. Funny how this brain works, I guess you can’t store everything you read indefinitely. That’s probably one the reasons I can never remember my phone number.

Glossopteris

2012-02-05T18:18:00.004-03:30

Early fossil animals are cool and all, but how about we talk about some early plants for a change? How about Glossopteris? It's only the most well know extinct plant genus of all time. Let's get a little taxonomic background outta the way first.

Kingdom: Plantae
Division: Tracheophyta
Class: Spermatopsida
Order: Glossopteridales
Genus: Glossopteris

Glossopteris begins to appear in the fossil record during the early Permian period, that's the last period in the Paleozoic era (right before the Triassic period of the Mesozoic era). Back in the early Permian, around 290 million years ago, all the southern continents on the planet earth were squished together into a super continent known as Gondwana. Actually, the distribution of Glossopteris fossils in the southern continents is what led geologist Eduard Suess (1831 - 1914) to originally suggest the idea of a Gondwana, long before plate tectonics was a widely accepted theory.

Gondwana: the early Permian fauna distribution hints at a super continent, but Glossopteris binds the idea together.

Originally, it was believed that Glossopteris was a fern. However, subsequent investigation and the discovery of more intact fossil specimens revealed that it was actually a Gymnosperm (seed bearing plants that include conifers, cycads, ginkgo, and gnetales). There was a lot of diversity among the 70 + Glossopteris species. Some were small, whereas others could be as tall as 30 m. There interior would have likely been something comparable to a softwood tree. I should probably point out that unlike most of the fossils I've been discussing over the past few days this one lived above water. Well, at least the majority of the plant lived above water, the roots were likely planted in some very wet soil. Despite their wide distribution, Glossopteris went extinct at the start of Triassic period around 250 million years ago.

Conulariids

2012-02-05T13:46:00.000-03:30

Okay, Scyphozoans are a class of Cnidarians. In fact they are "The Class of Cnidarians", in that this particular group are also called the "true jellyfish". Personally, I think it's too bad that Cnidarians got stuck with the popular name of jellyfish. First, there are the obvious reasons: cnidarians are neither composed of jelly, nor are they a fish. Secondly, Cnidarian just sounds way cooler than jellyfish. Jellyfish sounds like something a three year old would come up with. Bah, humbug.

So, there is this particular order of sycphozoans called the Conulariids (aka Conulata). They originated sometime in the Cambrian and went extinct in the Triassic. They are a rather mysterious marine creature, as all they left behind are ice cream coned shaped calcite fossils. Some conulariid fossils suggest that they could survive in anoxic (oxygen depleted) environments. Bizarrely, it looks like some conulariids were able to produce pearls, a trait not found among cindarians (it's usually the molluscans that make pearls).

Crinoids

2012-02-05T13:04:00.002-03:30

Crinoids have been around for a real long time. The earliest crinoid fossils date back to the Middle Cambrian period ( 513 ± 0.3 to 499 ± 1.7 million years ago). There's a bit of a debate about their evolutionary origins. Some folks think that crinoids evolved from the blastozoans (an otherwise extinct phylum of echinoderms). Other folks think that the crinoids diverged from the edrioasteroids (another otherwise extinct phylum of echinoderms). Trouble is, blastozoans and edrioasteroids share a lot of similarities with each other and the crinoids. Like much of the paleontological record it is rather murky relationship.

Although they kind of look like plants, crinoids are animals. It's an easy enough mistake to make. Crinoids are sessile, have stocks, roots, and live in dense clusters known as 'forests". So why do we call them animals? Well, there are probably a number of good reasons, but they first one that jumps to my mind is that they evolved within the echinoderm phylum some 400 million years ago. That's about 500 million years after plants and animals diverged. Anyway, crinoids seemingly reached their diversity and distribution peak towards the mid to late Paleozoic era, but they are still around today.

In rather uninteresting, but semi-related event I realized that for years I've been misspelling Ordovician as Ordovacian. Please take that into consideration when reading any blog entry I have composed over the past three and a half years which discusses the Paleozoic era.

Corals

2012-02-04T21:02:00.002-03:30

Back in 1842 Charles Darwin published his first monograph: The Structure and Distribution of Coral Reefs. Being the first part of the geology of the voyage of the Beagle, under the command of Capt. Fitzroy, R.N. during the years 1832 to 1836. Man, that guy liked long titles, but I guess it was the style. It was time in which nobody had really developed any good theories to explain how coral reefs formed. So, Chuck through his hat into the ring.

Darwin's theory followed from his understanding that coral polyps thrive in the clean seas of the tropics where the water is agitated, but can only live within a limited depth of water, starting just below low tide. Where the level of the underlying land stays the same, the corals grow around the coast to form what he called fringing reefs, and can eventually grow out from the shore to become a barrier reef. Where the land is rising, fringing reefs can grow around the coast, but coral raised above sea level dies and becomes white limestone. If the land subsides slowly, the fringing reefs keep pace by growing upwards on a base of dead coral, and form a barrier reef enclosing a lagoon between the reef and the land. A barrier reef can encircle an island, and once the island sinks below sea level a roughly circular atoll of growing coral continues to keep up with the sea level, forming a central lagoon. Should the land subside too quickly or sea level rise too fast, the coral dies as it is below its habitable depth.

To the best of my understanding Darwin pretty much got it right. Now, there were some things he didn't account for, or have knowledge of, like plate techtonics, but sitll he did a pretty good job. I haven't read the Coral book myself, I just perused the this article at wikipedia. I'm actually more interested in the creatures which form the reefs. I'm particularly interested in those corals which might show up on my paleontology midterm next week.

Corals are a type of Cnidarian (that's the same phylum which contains jellyfish). The class Anthozoa is a cnidarian group that contains subclasses of both corals (Zoantharia & Alyconaria) and sea anemones (Actiniaria). Right now I'm interested in three orders from the Zoantharia subclass: Tabulata, Rugosa, Scleractinia. Two features which are used in part to identify and distinguish these orders are the presence/absence of septa and tabulae. Septa are vertical partitions formed in radial arrangement which are secreted by a basal disc called a holotheca. Tabulae are horizontal partitions.

Tabulata

Tabulata is an subclass of Zoantharians which died out sometime around the big old Permian-Triassic extinction event. Poor buggers never made it past the Paleozoic. They were fairly characteristic of the type of coral found in the shallow waters of the Silurian and Devonian periods. Most of the species were colonial organisms made up from individual hexagonal cells. In the fossil record they are known by their calcite skeletons which kinda resemble a honey combs. One of the ways in which Tabulata are differentiated from other Paleozoic corals is that many species lack septa, but have extremely well developed tabulae.

Rugosa

Like Tabulata, Rugosa first appeared in the fossil record during the Ordovacian period and went extinct at the end of the Paleozoic era. They too had calcite skeletons. Although there were plenty of colonial forms, solitary Rugosa were far more common than solitary Tabulata. Their tabulae were not as well developed, but they did have well defined septa.

Scleractinia

So these guys pick up where Tabulata and Rugosa died off; the Triassic (the first period of Mesozoic era), and they are still alive today. Unlike Tabulata, Scleractinia have absolutely no tabulae, but like Rugosa they have well defined septa. Unlike either of these previously discussed classes, Scleratinia leave behind aragonite skeletons rather than calcite.

On the philosophy of science

2012-02-03T08:01:00.000-03:30

Over the course of human history many philosophers have speculated on the meaning of science and its importance in our society. Countless books have been written on the subject, countless lectures given, and so on. Despite all of this, I believe one man captured essence of scientific pursuit of knowledge in one short phrase. That man is Alun Anderson, former editor of New Scientist magazine. In a 2003 interview with Simon Kirk of the University of Sussex, Anderson gave the following reply when discussing how he had purposefully set off to change the tone of science journalism from dry, wimpy, and boring to one which exemplified an unapologetic and enthusiastic nature.

What's happening in science is the most interesting thing in the world, and if you don't agree with me just fuck off, because I'm not interested in talking to you.

Trilobite inchno fossils

2012-02-02T18:34:00.003-03:30

Ichnofossils (aka trace fossils) are fossils that shows signs of an organisms activity, but do not usually include the organism itself. A pretty well-known example are the Laetoli footprints, which show a path made by two Australopithecines as they walked across a muddy surface in Kenya about 2.5 million years ago.

Well guess what my trilobite loving friends! There are two pretty awesome examples of trilobite ichnofossils which I'm gonna blather on about for a few minutes.

Cruziana

Cruziana fossils are believed to show the movements made by trilobites when they were burrowing through the sand.

Rusophycus

Rusophycus are believed to be the resting counterpart of Cruziana. However, Rusophycus both pre-dates and post-dates the earliest and last known trilobite fossils, so it's quite possible that they were made by another arthropod.

See ya later trilobater.

Three little trilobites

2012-02-02T17:56:00.003-03:30

During the Paleozoic trilobites ruled the seas. Well, that’s not exactly correct. They had their fair share of predators and there were a lot of creatures much larger than trilobites, even back in the Cambrian period. Perhaps it is more suiting to call them a once glorious class (and sub-phylum) of marine arthropods which flourished for over 270 million years.

As you can imagine when a class of animals exists for over 270 million years they usually evolve into a lot of diverse shapes and forms. Presently, there are nine recognized orders of Trilobites that have been found in the fossil record (17,000 species). There are likely quite a few more that haven’t been found yet, as well as many that will never be found. But alas, such is paleontology. Today I want to look at three different orders of Trilobites. Why only three? Well, that’s because there are three specific orders which I am supposed to be familiar for my Palentology lab mid-term next week. These three are: Redlichiida , Phacopida,and Agnostida.

Maybe I should point out a few trilobite basics first. As their named suggests (Trilobite = three lobes) Trilobites can be divided into three sections: the cephalon, the thorax, and pygidium. Trilobites had a raised section in the middle of cephalon a called the glabella which contained a crop. That basically means trilobites had a stomach in their head. How cool is that? Alright, calm down. We still have plenty to get through. The thoracic segment of most trilobites is made up of about 40 segments (give or take). And pygidium? Well, the pygidium… hey, did I tell you that trilobites grew through the process of ecdysis (aka molting)? And how about those eyes? Trilobites have the earliest known form of eyes on the planet earth.

Redlichiida

Redlichiida are the first order of trilobites to appear in the fossil record (Lower Cambrian). As such they have a fairly primitive appearance compared to many the later trilobites. These primitve traits include a large semi-circular cephalon, a highly segmented thorax, and very small pygidium. Unlike some of the later trilobites, most notably Phacops, Redlichiida were incapable of defensive enrollment. Redlichiida had a world wide distribution and went extinct in the Mid-Cambrian period.

Phacopida

Phacopida lived between the Ordovacian and the Devonian periods. As such, it had some more advanced traits. The name Phacopida, roughly translated means "Lens-face", which helps me remembers that these are the trilobites with tons of eyes all over their cephalons. One particular genus of this order, Phacops, is fairly well described in the paleontological literature. He's the guy I alluded to above that had the ability to curl up into a little ball in order to evade predators. It is also believed that Phacops survived on a diet of detrius.

Agnostida

Agnostida had roughly the same temporal distribution in the geologic record as Redlichiida (Lower to Middle Cambrian period). However, Agnostida looked remarkly different. First of they were much smaller than either of the aforementioned orders. Secondly, they possessed only two thoraic segments, and thirdly, they were completely blind. There is a bit of debate about whether these critters were pelagic or benthic. On one hand, they had a world wide distribution, which is uncommon for benthic creatures. On the other hand their overall morphology suggests they would have been awkward swimmers (not to mention their lack of eyesight would be a real liability in the well lit surface waters of the Paleozoic.

Hooray for trilobites!

REVIEW The perfect marriage: the essential joining of ethnoarchaeology and experimental archaeology

2012-02-02T11:50:00.001-03:30

Introductory note: This is short essay I wrote on the William A. Longacre’s “The perfect marriage: the essential joining of ethnoarchaeology and experimental archaeology” (1992). Although this paper is bit dated it has become something of a much referenced classic among archaeological theorists. I had the unique reaction of actually enjoying archaeological theory while reading it, thus I thought I would share my thoughts.

The University of Arizona Kalinga Ethnoarchaeological Research Project (UAKERP) began in 1973 as way to study economics, sociology, and material culture through the analyses of ceramic manufacturing. Interestingly, the author of this article and co-founder of the project, William A. Longacre, began studying the Kalinga not because of any inherent interest of the people themselves, but because he believed their culture might provide some indirect insight into the archaeological record of the American southwest (Stark & Skibo, 2007). Longacre was searching for a culture that could serve as a political and social analogue for the pre-contact Pueblo people. He felt there was a great disconnect between the prehistoric Pueblo people and their modern day descendants who manufactured ceramics primarily for the tourist trade (Stark & Skibo, 2007). One of the more commendable aspects of this paper is that Longacre clearly and explicitly discusses the theoretical framework and the intentions of his work:

“To maximize archaeological interpretation, principles must be identified that link variation in material culture to specific aspects of human behaviour and organization” (Longacre, 1992: 16).

The bulk of this article explores how the combination of ethnoarchaeology and experimental archaeology has allowed researchers greater insight into Kalinga society and cultural practices. Additionally, Longacre demonstrates how knowledge obtained from this study can be applied to help understand the archaeological record of other areas and people. However, before exploring the specifics of this paper, Longacre takes a moment to first define ethnoarchaeology and experimental archaeology (Longacre, 1992:16)

Ethnoarchaeology: the study of variation in material culture and the exploration of the sources of that variation in behaviour and organization among living peoples.
Experimental archaeology: the analysis of material culture in a controlled laboratory context in which either the material under study is fabricated, permitting the study of particular variables or behaviours which are mimicked in order to explore the results on material variation.

Over the course of the article Longacre showcases a number different studies conducted by researchers involved with the UAKERP. He begins by examining some of the ethnoarchaeological research that was conducted in the late 1970s and early 1980s before an experimental archaeology approach was incorporated. Longacre was interested in the idea that social organization might be inferred from the distribution of microtraditions on pottery. He believed these microtradtions could be tied to specific “learning frameworks”. Longacre is not exactly clear on what comprises a “learning framework”. However, he does admit that this avenue of research had actually demonstrated that his original hypothesis was wrong and that birth cohorts had a much more profound effect on which patterns appeared on which ceramics.

During the 1970s the Kalinga were primarily a self-sufficient rice agriculturalist people who produced ceramics on a household basis. However, due to the effects of political conflicts within the Philippines, this began to change in the early 1980s. Some Kalinga villages became ceramic producers, whereas others became ceramic consumers. Researchers were on hand to witness the emergence of ceramic specialization. They noted that this change in social practices surrounding the production of ceramics was accompanied by changes in the pottery itself. Restrictions to the access of traditional sources of pine resin lead to the development of new decorative traditions. Prior to the development of specialized ceramic villages, water jars were completely covered in resin, inside and out, and their exteriors were painted entirely in red hematite. As these practices were no longer economically feasible, ceramic producers began to use resin solely on the interior surfaces of water jars. Similarly, instead of covering the entire exterior surface in red hematite, ceramic producers began to decorate the vessels with small images, such as flowers. Another interesting phenomenon that accompanied the development of ceramic specialization was that people began to produce non-tradtional items, such as piggy banks adorned with phrases like “God Bless Us” and “Happy Birthday Uncle Willy”. The Kalinga people referred to these items as Ay-ayam and they were created with intended purpose of selling them in the distant capital city of Tabuk.

Following these two examples of traditional ethnoarchaeology, Longacre launches into a discussion about some UAKERP studies which incorporated experimental archaeology. The first such study is one that tracked the use-life of thousands of vessels over a period of ten years. This included both new and used pots. At the end of the study these pots were collected and sent to Arizona State Museum with laboratory analysis for the intended purposes of studying the effects that cooking behaviours had upon surface alterations of pottery. Researchers were able to effectively demonstrate that specific types of carbon deposits could be used to identify ceramic pots that had been used for cooking rice. One of Longacre’s fellow researchers, Masashi Kobayashi, then used his information to search for signs of the advent of agriculture and rice cooking in the archaeological record of prehistoric Japan.

The second study which Longacre cites in regard to combining ethnoarchaeology and experimental archaeology is one that involved examining changes in rice cooking practices in the 1980s. The Kalinga people began using metal cooking vessels for rice, arguing that they were faster and less resistant to damage than traditional ceramic pots. However, they continued using ceramic pots preferentially for cooking meats and vegetables. Under laboratory conditions, researchers analysed the performance conditions of metal and ceramic rice cooking pots. They came to the conclusion that the claims made by the Kalinga could be backed up by empirical evidence. Yet, they could not explain why ceramic pots were still preferred for meats and vegetables. The answer to this problem came from the observations of the ethnoarchaeologists who noted the differences in cooking practices between rice and other items. Rice was brought to a boil and then removed from the fire, whereas meats and vegetables were simmered slowly over a longer period of time. Since ceramic pots did not conduct heat as well the metal pots they able to better cook meats and vegetables in the fashion that the Kaligna people were accustomed.

The third and final study which blends these two approaches examined specific cultural practices amongst pottery consumers. Villagers from the Guina-ang seemingly preferred ceramics from the village of Dangtalan if they were to be used as cooking vessels, but preferred the ceramics from Dalupa if they were to be used as water jars. The ethnoarchaeologists suggested that these cultural practices might have been related to the fact that there were stronger kinship ties between the people of Guina-ang and the people of Dangtalan. However, this explanation failed to account for the preference of Dalupa manufactured water jars. Laboratory analysis conducted by experimental archaeologists was able to help clarify this matter by examining the chemical compostion of the clay used in Dangtalan and Dalupa ceramics. Ceramics from Dangtalan were composed from clay that had a higher composition of potassium and iron oxide which effectively made them stronger pots compared to those from Dalupa. Inversely, this chemical makeup also made the Dangtalan ceramics heavier. As water vessels tend to be carried over long distances it makes perfect sense that the Kalinga would prefer water jars from Dalupa.

Longacre makes a convincing case that the marriage of ethnoarchaeology and experimental archaeology has been highly beneficial to understanding human behaviour and social organization. Furthermore, the discoveries made by researchers from the UAKERP have been proven to be useful for archaeologists researching prehistoric societies. Longacre has a clear, explicit, and highly effective writing style (with the notable exception of his discussion surrounding “learning frameworks”). In the often verbose world archaeological theory this type of writing is much welcomed and refreshing.

References

Lonagre, W.A. (1992). The perfect marriage: the essential joining of ethnoarchaeological and experimental archaeology. Ethnoarchéologie: Justification, Problèmes, Limites. XIIe Recontres Internationales d’Archéologie et d’Histoire d’Antibes Éditions APDCA, Juan-les Pins : 15 – 24.

Stark, M.T. and J. M. Skibo (2007). A History of the Kalinga Ethnoarchaeological Project. In Archaeological Anthropology: Perspectives on Method and Theory. J.M. Skibo; M. W. Graves; Miriam T. Stark (eds.): 93-110.

The Story of Anomalocaris

2012-02-01T18:08:00.004-03:30

The story of Anomalocaris is well known to most paleontologists. In fact I’m sure it’s a story that forces many a paleontologist to become immediately sleepy every time it is retold (much in the same way Kennewick Man causes many a young archaeologist to sigh with equal parts disdain and boredom). However, I had not heard of this interesting creature until fairly recently. Although after searching out some illustrations of the little bugger I must admit he does look quite familiar.

Okay, so the story goes something like this...

Back in 1892 an elder British paleontologist named Joseph Frederick Whiteaves published a short paper describing an interesting shrimp-like fossil he had recently discovered in British Columbia’s Burgess Shale. More specifically he discovered in a geological strata in Mount Stephen which dated to the Middle Cambrian period. He decided to call the fossil Anomalocaris, which means “abnormal shrimp”.

A short while later another paleontologist, Charles Doolittle Walcott, came across a fossil that looked quite similar to Anomalocaris. However, unaware of Whiteaves’ earlier discovery, Walcott believed it to be a tail from an extinct arthropod known as Sidneyia. At the same time Walcott also discovered another fossil which he believed to be ancient cnidarian, and thus placed in the genus Peytoia.

Then, quite sometime later, in the mid 1970s, another paleontologist, Simon Conway Morris, who was also working in the Burgess Shale, discovered another Peytoia fossil. This time it was found alongside a sponge-like creature he named Laggania.

A few years after this another paleontologist working in the Burgess Shale, Harry B. Whittington, made another discovery. He came across a fossil in which a shrimp-like tail was attached to something that looks like the mouth of a cnidarian. Then, after a few more years, and the subsequent discovery and review of a number of Middle Cambrian fossils, Whittington and his colleague, D.E.G. Briggs publish a paper that made a rather bold claim (The Largest Cambrian Animal, Anomalocaris, Burgess Shale, British Columbia, 1985). According to Whittington and Briggs, Anomalocaris and Sidneyia were the same animal. Actually, they were the same animal part, and not the tail either, but a frontal feeding appendage. Likewise Peytoia was not a cnidarian, but a mouth structure which attaches to Anomalocaris/Sidneyia appendage. Finally, Laggania was not a sponge, but the body of this weird creature. According to the International Commission on Zoological Nomenclature because the shrimp tail, Anomalocaris, was the first part of discovered, it became the name of this newly described species. Hooray for Anomalocaris!

Okay. Wake up Paleontologists. It’s all over now.

My first video blog: Epigenetics and Ancient DNA

2012-01-31T21:25:00.005-03:30

Looky here! Some jerk thinks he can video blog. He must be starved for attention, the sorry bugger.

Okay, I'm hoping my biologist/geneticist readers (if there are any) weigh in on this article in New Scientist and more specifically the original article from PLoS One upon which it is based. It's about epigenetic changes discovered in ancient DNA. I'm new to this whole video blogging thing, so you must excuse me if my eyes wander about. I'm still figuring out where to look. Next time I'll just stare into the cold, black, abysmal depths that constitutes your soul.

How to date Upper Paleolithic Cave Art. Part II.

2012-01-30T15:53:00.003-03:30

Alright. This is the second installment in my ongoing series dedicated to dating cave art. Check out Part I if you missed it and would like to get up to speed. Today I wanna to explore the wild world of direct dating, or more specifically, Accelerated Masss Spectometry (AMS). Don’t worry I’m not going to tie you down with all sorts of boring details about how it works. If you’d like to know that sorta stuff go to Wikipedia.

Okay, maybe a little background wouldn’t hurt. Suffice to say AMS differs from other forms of mass spectrometry in that it uses a cyclotron to accelerate ions to extraordinarily high kinetic energies before mass analysis. It’s able to separate stable isotopes from radioactive isotopes on the basis of their respective weights. The technology was first used in 1939 by L.W. Alvarez and Robert Cornog and was a method to differentiate which isotopes of helium were stable and which were radioactive. By 1977, due in part to advancements in accelerator technology, physicist Richard A. Muller demonstrated that AMS could be used to detect radioactive carbon (Carbon-14). Further advancements over the subsequent decade peaked the interest of archaeologists when they realized that this would allow them to use smaller samples in order to reliably date archaeological materials by determining the concentration of Carbon-14.

AMS began to be applied to charcoal from cave paintings in the early 1990s. To date, nearly all of the dating of parietal cave art has been conducted Gif-sur-Yvette laboratory in Paris. Pettit and Pike (2007) include two tables in their paper Dating European Palaeolithic Cave Art: Progress, Prospects, and Problems which summarize all of the available dates that were available to them at the time of publication. They note that many of the dates recovered from AMS analysis actually match up fairly well with the dates suggested by the relative stylistic schemes (see Part I).

That being said, there are still plenty of problems with AMS.

1. You’re not actually dating the age of the painting, but the age of the charcoal that was used to make the painting. This is doubly problematic, because:
A. The charcoal could be from a tree that died long before it was used in a fire. Cutting down a living tree would have been a fairly labour intensive job using the tools of the Upper Paleolithic. Therefore it’s not unreasonable to suggest that Upper Paleolithic hunter-gatherers may have preferred using wood from trees that had already fell due to natural events. Hence, the wood could be much older than the charcoal.
B. The charcoal could have been recovered from an old fire pit. Pettit and Pike remark that it is still possible to use charcoal recovered from an archaeological deposit to draw a new cave painting. Pettit and Pike bring up Chauvet cave in this example.

2. Humic contamination. Dates on humic fractions often disagree with dates from wood charcoal fractions. Bahn and Lorblancet (1993) argued that more petrological, chemical, and micro-biological studies needed to be conducted in order to properly account for contamination. Example: Altamira bison vs. El Castillo.

3. Limited sampling. Because of the destructive nature of retrieving samples for AMS it can be difficult to obtain enough samples to generate a statistically valid date. “One date is no date” (Clottes, 1993).

4. A need for a more rigorous and transparent methodology. This includes:
A. The need for double blinded and independent studies. Nearly all of the dating of Paleolithic cave art has been conducted by Gif-sur-Yvette laboratory. In the few instances where other laboratories have been allowed to date cave art – different dates have appeared. Are scientists at GSY simply confirming their own biases/pre-concieved notions?
B. Need for Standards - to date no AMS standards in regard to dating cave art have been published.
C. Lack of experimental details. GSY reports “failed samples” but don’t explain how or why some samples are considered to have failed.

Although AMS dating holds great potential there are still a number of hurdles which need to be overcome. To demonstrate that AMS can generate reliable results independent lines of evidence need to converge upon the same dates.

Albino hummingbird

2012-01-29T17:33:00.004-03:30

There are some cool pictures of an albino hummingbird over at Discovery News. I had to post this here so I could be sure my mom sees it. She likes birds. I like albino animals. This little guy has it all. Hat Tip to Why Evolution is True.

El Mirón: Old Bones, New Dates

2012-01-27T23:09:00.002-03:30

There's some exciting news from Spain pertaining to the skeletal remains that were excavated from El Mirón cave back in 2010 and 2011. Originally, the bones were dated indirectly - meaning they were assigned a date based on the stratigraphic level from which they were exhumed. That level was about 15,000 years old which placed it in the Lower Magdalenian period (Lower Magdalenian secondary human burial in El Mirón Cave, Cantabria, Spain, 2011. Lawrence Guy Straus, Manuel R. González Morales, and Jose Miguel Carretero).

Well, now the bones have been dated directly. It turns out they are actually closer to 18,500 years old. I think that would technically mean this individual could be considered to be from Solutrean period. Pretty awesome. Seeing as this date came from the Max Planck Institute in Germany I hope it means we'll be hearing about the genetic analyses soon. Yee haw.

Dormouse, more like dorkmouse.

2012-01-26T20:54:00.001-03:30

Okay. I know I said I'd try to slap up another post about dating European Upper Paleolithic cave art this evening, but alas I'm having too much fun writing a term paper on the zooarchaeological record of Cantabrian Spain. I tend to make almost all my papers about Upper Paleolithic Cantabrian Spain these days. That way I can cut out the good parts and stick 'em in my thesis later on. Bwa ha ha ha. So... in lieu of cave art please accept this snoring dormouse. She's hilarious!

Busy little beaver

2012-01-24T21:44:00.000-03:30

I had intended to post Part II of the dating Paleolithic Art series this evening, but I spent the evening reviewing zooarchaeological literature from El Mirón and the Cantabrian region in general. Now, I'm gonna try to get Part II up by Thursday evening. I must say, writing this thesis and doing four other fourth year courses and a paleontology lab is a bit time consuming. Now, I'm off to go get some groceries. In the meantime enjoy this lovely quote from Stephen Fry.

I am a lover of truth, a worshipper of freedom, a celebrant at the altar of language and purity and tolerance. That is my religion, and every day I am sorely, grossly, heinously and deeply offended, wounded, mortified and injured by a thousand different blasphemies against it. When the fundamental canons of truth, honesty, compassion and decency are hourly assaulted by fatuous bishops, pompous, illiberal and ignorant priests, politicians and prelates, sanctimonious censors, self-appointed moralists and busy-bodies, what recourse of ancient laws have I? None whatever. Nor would I ask for any. For unlike these blistering imbeciles my belief in my religion is strong and I know that lies will always fail and indecency and intolerance will always perish.

The evolution of wheels

2012-01-22T19:02:00.001-03:30

In How the Mind Works Stephen Pinker wrote the following:

Many textbooks point out that no animal has evolved wheels and cite the fact as an example of how evolution is often incapable of finding the optimal solution to an engineering problem. But it is not a good example at all. Even if nature could have evolved a moose on wheels, it surely would have opted not to. Wheels are good only in a world with roads and rails. They bog down in any terrain that is soft, slippery, steep, or uneven. Legs are better. Wheels have to roll along an unbroken supporting ridge, but legs can be placed on a series of separate footholds, an extreme example being a ladder. Legs can also be placed to minimize lurching and to step over obstacles. Even today, when it seems as if the world has become a parking lot, only about half of the earth's land is accessible to vehicles with wheels or tracks, but most of the earth's land is accessible to vehicles with feet: animals, the vehicles designed by natural selection.

Pinker makes a good case, and until today I found no fault with his argument. There are, however, two points that I did not take into consideration. The first being that wheels can be useful for purposes other than travelling along flat tracks of land. Wheels can be useful when travelling downhill. The second point is that although it might be impractical to evolve wheels as separate appendages, it could be practical to have the ability to transform oneself into a wheel when a situation called for such action. This little video is what lead me to reconsider Pinker (via Pharyngula).

This is nonsense

2012-01-21T20:08:00.000-03:30

It's been nearly a month since Christopher Hitchens died. In the immortal words of Hank Snow, I still miss someone. It makes me sad to think about how I won't be able read his columns anymore. I miss the way in which he would annihilate pseudo-intellectualism while simultaneously promoting dignity and better qualities of human nature. When he died I didn't write anything about him. There was nothing I could say that wasn't said better than those that knew him intimately. One of my favorite things he ever wrote was about the arrogant anthrocentrism inherent in religious thinking. Maybe it struck a particular chord because he invoked the very dear subject of hominid evolution while doing so.

Let's say that the consensus is that our species, being the higher primate, Homo Sapiens, has been on the planet for at least 100,000 years, maybe more. Francis Collins says maybe 100,000. Richard Dawkins thinks maybe a quarter-of-a-million. I'll take 100,000. In order to be a Christian, you have to believe that for 98,000 years, our species suffered and died, most of its children dying in childbirth, most other people having a life expectancy of about 25 years, dying of their teeth. Famine, struggle, bitterness, war, suffering, misery, all of that for 98,000 years. Heaven watches this with complete indifference. And then 2000 years ago, thinks "That's enough of that. It's time to intervene," and the best way to do this would be by condemning someone to a human sacrifice somewhere in the less literate parts of the Middle East. Don't appeal to the Chinese, for example, where people can read and study evidence and have a civilization. Let's go to the desert and have another revelation there. This is nonsense. It can't be believed by a thinking person.

Cheers, Mr. Hitchens.

Hard Charger - Chrome Lord

2012-01-21T13:51:00.000-03:30

This is last night. Hard Charger at Distortion, St. John's, NL.