Despite the snow, we didn’t get a chance to have any other posts this week other than the Monday Mystery fossil. We did, however, have three different school trips in the past couple of weeks to talk to kids about fossils, dinosaurs, and the skeletal system, as well as giving talks on the fossils telling us about the origins of crocodiles and dinosaurs, as well as attending a talk on the origins of birds. So a lot of paleo work, just not much showing up here. Fortunately, some of you had some time to examine our mystery fossil and congratulations to Laurenwritesscience for coming up with the correct answer.
It is indeed a stromatolite. Bruce Stinchcomb has a video on Youtube showing several examples of Ozark stromatolites and providing a good explanation of what they are.
Essentially, stromatolites are microbial ecosystems, built up of layer after layer of microbial mats. The general description is that of blue-green algae, which forms a sticky layer over the surface of a rocky surface in a shallow marine or coastal environment. Blue-green algae are not actually algae and are better referred to as cyanobacteria. These bacteria are photosynthetic, just like plants, so they need sunlight, thus limiting the depth at which they can be found. Actually, they are typically found right at the water’s edge in the tidal zone. This sticky substance, while maintaining their hold on the rock, also tends to collect sand, clay, and organic debris. Over time, all the stuff that sticks to the mat blocks the sunlight from the cyanobacteria and they migrate above the layer and build another mat, which collects more debris, which causes them to build another mat, etc. Stromatolites form much the same way as piles of laundry. By the time you finish washing one set, there is another pile forming in a neverending stream. The life of a cyanobacteria in a stromatolite is a depressing condition of always digging themselves out from under a pile just to get dumped on again. I am sure most people can empathize.
The sticky mucus (properly referred to as extrapolymeric substance, or EPS for short, but we can go with mucus here) forming the mat does more than just cause things to stick to it. The mat protects the bacteria in from ultraviolet radiation. It also allows the bacteria to control the microenvironment around them, keeping such things as pH levels in a good range. It also has an unfortunate aspect for the bacteria. The mucus allows the levels of calcium and carbonate ions to build up until they precipitate out of the water as calcium carbonate, also known as calcite (when referring to the mineral), or limestone (when referring to the rock). So not only are the poor bacteria constantly getting buried, they are getting turned to stone in their very own medusa nightmare. Life is hard as a cyanobacteria. But just wait, it gets worse.
These microbial mats are not just cyanobacteria, though. There are lots of other organisms that live in and on them. There are many other types of bacteria. There are sulfate reducing bacteria, which use sulfur like we use oxygen, only they release hydrogen sulfide instead of carbon dioxide, causing a nice rotten egg smell. There are purple sulfur bacteria that eat the hydrogen sulfide, as well as colorless sulfur bacteria that eat both the hydrogen sulfide and the oxygen released by the cyanobacteria, thus free-loading off of everyone. In addition to bacteria, there are plenty of prokaryotes (organisms without nuclei that holds their DNA) and eukaryotic (with nuclei) single-celled and multi-celled organisms living in the mat. Diatoms, single-celled photosynthetic organisms that grow their own shell, live on top, while nematodes burrow through the mat. In addition to all this, a wide variety of animals love to chow down on the mats. Everything from snails, sea urchins, crabs, crawfish, and just regular old fish happily eat them. As a result, there are not a lot of places left in the world you can find stromatolites growing. The Bahamas and Shark’s Bay, Australia are the best areas to find them.
They may be rare now, but at one time, they ruled the earth. As some of the oldest living communities in the world, they have been around for at least 3.5 billion years (that’s 3,500,000,000, or roughly 600,000 times the length of human civilization) and for more 2/3 of that time, they were the only game in town and in all probability served as the cradle for all eukaryotic and multi-cellular organism on the planet. These days, if you live in Arkansas, the only places you can find them are as fossils in the Cambrian age Cotter Formation and Ordovician age Everton Formation in the Ozark Plateau.
Many people have an issue with scientists, particularly those studying evolution and paleontology, for making statements they feel are pure speculation. I absolutely agree that people should be upfront about what is known and what is speculation. Most scientists ARE generally clear about that. If you ask most scientists, they will tell you what we know and don’t know. That is actually one of the biggest problems that scientists have with almost all of the shows and most of the books written for the public. Those outlets are not clear about what we really know and what we don’t, what is speculation. Most scientists I know work really hard at trying to clarify that sort of thing and get very frustrated when their words are twisted around. Many scientists have refused to work with film crews for precisely that reason. So please don’t blame the scientists. Write to the shows and demand they are clear about their speculations.
Sadly, I wish I could say all scientists act this way, but it is true, not all do. Scientists are only human after all. There are problems with some scientists. Believe me when I tell you that we recognize this and try to stop it. The lab I worked in to get my doctorate had a reputation for being spoilers, as it were, because a large portion of our research involved figuring out the limits of what the data really let us say and then telling others no, you can’t say that because the data do not extend that far. Our work was very much about separating speculation from reasonable interpretation and fact. But we were hardly alone in that regard, it is something most scientists work hard to do. Paleontology is admittedly one of those fields in which it is easy to take the fossils we have and in our excitement try to say too much about them. So we do our best to restrain ourselves and other workers from extrapolating too far. Go to a paleontology conference and you will see that on display in abundance.
Unfortunately, that rarely shows up in material done for the public. The film crews and honestly, most of the public, do not want to hear we don’t know. They want to hear the fanciful stories. Most people get annoyed with scientists when they equivocate and don’t give straight answers. We frequently hear from people, well which is it? Is it this way or that way? If you can’t say with absolute certainty one way or the other, you must not know ANYTHING, when in point of fact, there is a vast difference between not being sure and not knowing anything, I am sure most will agree. But most people don’t want to hear we don’t know with certainty, we can only say this much about it. I have even seen that in my college courses. Many students are uncomfortable with the material I cover in which there are no good answers everyone agrees on. They want definitive answers. A large part of that, I think, is that science is taught in schools very poorly, as a list of facts to memorize, not as a way of thinking and an expanding body of knowledge that is constantly re-examined, with large areas we don’t know yet. In fact, and what makes science fun and interesting for people doing it, is that science is more about what we don’t know than what we do. But happily, I can say that is changing in many areas, with the introduction of more hands-on, exploratory teaching methods.
One of the challenges though, is that many things the lay person thinks are pure speculation are not speculation at all, but are backed up by lots of evidence that there is simply not enough time to go into. Many computer programmers simply tell their clients what they do is magic because to answer their questions adequately would take months of training to even get them to the point they could understand the answer. Would you tell a computer programmer what they are doing is pure speculation simply because you don’t understand it? We aren’t trying to be elitest, there is just a lot of information we don’t have time to transmit. There is simply too much going on, too much data, too much research for anyone to keep track of it at all. Even professionals who try to keep up as part of their full-time job can’t do it. So it would be foolish to think anyone who doesn’t spend most of their time studying the research could possibly have a good grasp of the intricacies and quantity of data. It therefore becomes quite the annoyance when people say you can’t know something when they have no idea how much we do know. Many of those things people say we can’t know have been studied for decades by many people who have spent their lives figuring out how to go from speculation to concrete data and hard fact. Most people don’t realize the extreme levels of simplification it takes to get some concepts across because no one can provide all the data backing up those assertions without having their audience earn a graduate degree in the process.
Is all this me telling you to just trust whatever we say? Absolutely not. But don’t expect to come in on the ground floor and know what is going on at the top any more than you could expect to speak perfect French by catching someone speak a few words on TV. Understand that you are only getting the tip of the iceberg. What you see on TV is a seriously flawed transmission of a few grains of knowledge from a mountain range of data. Learn as much as you can from reliable sources. The more you know, the richer your interactions with professionals and the more in depth we can talk to you. We will be happy to share with you everything we know, that’s our job. But what we tell you is highly dependent on the level at which you come to us and the amount of time people are willing to spend. Also understand the quantity of data is more than any one person can understand, even those whose job it is to do so. That is why we have many people studying problems. No one can have all the answers. That is why we keep asking questions. Being open about what we know and what we don’t allows us the freedom to learn more and shows us the path about where to go next. Scientists don’t leave things at speculation, they try to figure out how can we go from speculation to understanding. But if you want to understand all the steps involved, may I suggest grad school?
I’m sorry, but I forgot to post the Mystery Monday fossil on the blog. I posted the fossil on the Facebook page, but somehow failed to get it posted here, for which I apologize. Here is the fossil I posted, including the identifying portion cropped from the original picture. This image was taken from trilobites.info, a great website for all things trilobite.
It was correctly identified as a trilobite, although this one is the species Irvingella, not Bristolia as was guessed. Irvingella is very similar, but lacks the tail spine and the second set of spines is a little farther down the body. They are both listed as “fast-moving low-level epifaunal” feeders by the Paleobiology Database, which means they scurried quickly about over the ocean floor. But whereas Bristolia is thought to have been a deposit feeder, much like a crawfish, Irvingella was a carnivore, preying on worms, bugs, and such. They both lived in offshore marine environments, but whereas Bristolia has been found mostly in shallower waters, Irvingella has been found widespread from offshore throughout the continental shelf and even deeper water. This may have more to do with Bristolia having only been found in a few places in the southwestern United States while Irvingella has a much broader range throughout much of North America and Asia. They both lived in the Cambrian Period, although Bristolia seems to have lived a little earlier than Irvingella (there are some discrepancies in the published records making it difficult to compare exactly, this is partly due to revisions of the time scale and refinements in age estimates over the decades making detailed comparisons problematic).
Since our last Forum Friday recap, we have started a new year. We have reviewed the Walking with Dinosaurs movie. We identified an Exogyra ponderosa oyster, Archimedes bryozoan, Aetobatus eagle ray, and this Irvingella trilobite.
Over on the Facebook page so far this year, we have seen some amazing animals, including sharks that glow in the dark, a fish that walks on land, and a caterpillar who’s tobacco breath repulses spiders. We even learned why sharks don’t make bone, but polygamous mice have big penis bones and an organism that changes its genetic structure seasonally.
We saw two articles on fighting dinosaurs. We learned how they took over the planet and discussed scaly dinosaurs for a change. We found out some ancient marine reptiles were black and Tiktaalik had legs.
A lot of articles hit the press on human evolution in 2013. We also found out (some) humans developed the ability to tolerate lactose to not starve and how we smell sickness in others. We also found a great book on Evolution & Medicine. We also saw evidence of how our actions affect the evolution of other animals and someone who thinks they can understand dog language.
We read that plants may have caused the Devonian extinction event, a genetic study saying placental mammals originated before the end-Cretaceous extinction event despite no fossils ever having been found, and that small mammals with flexible schedules handle climate change better than big mammals that keep a stricter schedule.
We found a great , concise explanation of evolution and three different short videos on the history of life on earth, two of them animated and set to music. We also heard Neal DeGrasse Tyson urge more scientists to do more science outreach (and how to cook a pizza in 3 seconds). Unfortunately, we also heard about the deplorable conditions during filming on Animal Planet and creationism in Texas public schools, as well as how the failure to take evolution into account can screw up conservation efforts.
In the upcoming year, we hope to expand the site, providing many more resources, along with continuing posts on Arkansas geology and fossils, including many more mystery fossils. Stick with us and you will learn about the history of Arkansas in a way that few people know. The site will be revamped to be more user-friendly and enticing to visitors. If plans materialize, we will be adding interactive activities, animations, and videos, many of which will be created by users of the site. Materials from workshops and talks will be posted for people to view and use. More scientists will be posted that have offered their services to teachers and students. We encourage you to contact them. They are there as a resource.
Of course, all of this does not come free. it takes money to provide quality services. Thus, more avenues of funding will be pursued, including other grant opportunities and likely a Kickstarter proposal. You may soon see a small button on the side of the website for Paypal donations. Any money donated will go first towards site maintenance. Other funds will go towards a student award for website design, a 3D laser scanner to put fully interactive 3D fossil images on the site, and materials for review and teacher workshops. If grant funding becomes available, additional money will be spent on research into the effectiveness and reach of the project. But even if no more funding becomes available, you can still look forward to continuing essays on Arkansas fossils, reviews of good books and websites, and curation of online resources suitable for teachers, students, and anyone else interested in learning about the endlessly fascinating history of life on planet earth.
Clue number 2: Many people think I’m a coral, but I’m not.
Clue number 3: I am named after a famous Greek mathematician and inventor.
What am I?
Digging for Bird-Dinosaurs was published in 2000, so it is not current, but is still topical and relevant and should stay so for some time. The only issues with the age of the book are new details that have been discovered, which further confirm the hypotheses presented in the book. When the book was written, most scientists had been convinced that birds evolve from dinosaurs for many reasons which are mentioned in the book. Since the book has been published, many new feathered dinosaurs have been found which clearly show the relationships in further detail. But the book is not really about the relationships between birds and non-avian dinosaurs, although it discusses them quite well, it is about the experience of the people on an expedition to Madagascar in 1998, what it is like being in the field and the study of some of the fossils that were discovered. If you want to know what it is like to go to another country and dig for dinosaurs, this book will be of interest and should make interesting reading for kids in elementary or middle school.
The expedition was led by Dr. David Krause, a professor at Stony Brook University in New York who has been running paleontological expeditions to Madagascar since the early 1990s and is still doing so, although the book is focused on his colleague, Dr. Cathy Forster, also of Stony Brook (at the time, but now an Associate Professor at George Washington University). She, like Krause, is a noted paleontologist and is likely the focus of the book because of the relative paucity of women in the field sciences. These days, if one goes to a meeting of the Society of Vertebrate Paleontology, women are well represented, but in the 1990s, most of these women were still students looking to the few women like Dr. Forster who were forging careers.
The book follows their experiences in the field and the discovery of a particularly interesting bird-like creature they eventually name Rahonavis. The book continues with the team bringing the fossils back, preparing them out of the rock and studying them, coming to the conclusion that the animal was the closest known bird to Archaeopteryx, which is generally considered the earliest known bird. It is so close in fact, that many scientists today consider it actually closer in lineage to the dinosaurs known as dromeosaurs, which include animals like Velociraptor, than it is to birds. This placement is a great demonstration that birds really did evolve from dinosaurs. It is so hard to tell the difference between “dinosaur” and “bird” in the earliest bird-like forms because they are not distinct, separate groups. Birds are merely a subset, a type of dinosaur, in much the same way that mice are rodents, which are also mammals, which are also amniotes, which are also vertebrates, etc. Therefore, whether or not Rohanavis falls out before or after Archaeopteryx in the lineage is a mere detail, changing nothing of the story. It makes as much difference to the evolution of birds as it does which of a set of twins was born first or second, a matter of inconsequential minutes in evolutionary time.
One of the fascinating parts of the book is when Dr. Krause and Dr. Forster discuss the local people helping them. The villagers are very poor, with no access to healthcare or schools. Dr. Krause was concerned enough that he founded the nonprofit Madagascar Ankizy Fund, which supplies needed healthcare to the area, as well as building schools and providing teachers. Dr. Krause and Dr. Forster came to Madagascar to hunt for fossils. But while they have found a great many spectacular finds, perhaps their greatest accomplishment is in the humanitarian work on behalf of the people who live there.
In the first post, I outlined why I think evolution is important and a few reasons why I think people refuse to accept it. In this post, I will discuss a little more about why it is not taught much in Arkansas and the rest of the United States and what you can expect from this website to help change that.
Teachers make a difference in the classroom, what they teach and what they believe affects their students. Thus, it is disconcerting that only 28% of public school biology teachers consistently teach evolution according to the National Research Council science standards, with 13% actively teaching creationism, despite it being illegal. A full 60% ignore the topic altogether. This perhaps explains why the United States trails most other countries in science aptitude. Arkansas is on average a conservative state, with lower than average income and education levels, and so it is no surprise that Arkansas is below average in science aptitude as well.
So why do so many educators fail to teach evolution in their classes, particularly in Arkansas? There are several reasons. Educators often avoid teaching or only give a cursory introduction to these subjects out of personal ignorance and/or religious beliefs. Many of those who do teach it are unaware they are teaching highly inaccurate and out of date material and must contend with outright hostility from school administrators and parents who do not themselves understand or accept evolution. More than 20% of Arkansas secondary teachers are teaching out of their certified field and the requirements for certification are low to begin with (Arkansas is not alone in this and in fact is only marginally higher than the national average). For example, elementary teachers are often not required to have had any science beyond the minimum standards for their college education degree. Home schooling is also becoming more prevalent, with education provided by parents or informal educators with typically little training in either science or education. It’s also not enough to simply know the facts. There is a long path from the content to education. Getting students to learn accurate information requires passing through a number of filters. Even before that can happen, people have to realize that what they intuitively believe may not be right and their gut feelings may be wrong.
How can we combat this problem? We cannot expect educators with little training in schools or homes that are cash-strapped and lacking resources to do a good job on their own. So we help them by providing resources they can access online for free (preferably) or small fees (if necessary). The internet is full of resources to fill every need and educators in the know can access myriad sources of knowledge and lesson plans. But the key to this is “in the know.” The internet is also full of misleading and false information. How is an educator that feels insufficiently prepared (be that learning the material, just looking for new ways to teach it, or wanting to provide additional resources for students and parents) to sort through the chaff and find the kernels of quality material? That’s where we come in, we can help them be “in the know.”