February 28, 2007
February 27, 2007
It's hosted by our United Campus Ministry, and the panel includes three clergymen and three students; conspicuously missing from the panel are any prominent atheists (though in this area, I'm not sure if they would publicly attest to the fact).
BTW, the new e-mail they sent out acknowledges the living writer of The End of Faith.
This should be a familiar scene for anyone with a passing interest in wildlife films; the great African savannas are often filmed to illustrate with detail the great theater of competition and predation in the wild. Visibility plays a large factor in this choice; the savannas have very few trees, and are home to some of the largest groups of the largest mammals in the world, not only in Africa, but also in South America, India and Australia. The same drama could not be effectively captured in a rain forest; animals are much less visible generally.
But that does not mean that the creatures of the savannas are immediately apparent. Most are well camouflaged, especially the predators, matching the golds, browns and sage greens of the flora, or appearing as a distant rock, as in the case of rhinos. Huge herds of ungulates pound the hard earth of the savanna, following the summer rains as they sweep across the enormous stretches of land that savannas occupy. As in all biomes, the climate sets the standard of living.
Like the tropical dry forests, the savanna is doused with rain in the summer seasons (often in just a few weeks depending on the year), and suffers from extreme drought for the rest of the year. What keeps dense plant growth at bay? Well, the answer to that question is threefold:
- Fire: After the five month long dry season, lightning storms swirl violently over the plains, igniting the parched vegetation. These fires can be prolific, clearing huge tracks of grasses and saplings. The grasses grow back quickly, but millennia of fires like these have selected a small number of fire resistant trees and shrubs that are constantly kept in check by the annual fires.
- Soil: The soils of the tropical grasslands are relatively impermeable, causing the heavy rains to skim along the surface instead of soaking deeply into the ground.
- Herbivory: Animals also keep the density of non-poacean plants at a relatively low level. The herbivores of the African savanna, for example, have evolved to fill specific niches* (the specific factors that influence a species existence, in this case feeding) in which they consume plant material at different levels of the ecosystem. Giraffes and elephants browse the upper and middle levels of leafy trees, respectively, while wildebeests and zebras graze on different levels of grasses. The large herds of ungulates roaming the plains are also restrictive to growth.
Insects, as usual, play a large part in recycling nutrients from dead and dying tissue. Termites are perhaps the most visible of these detritivores (detritus eating) in just about every savanna across the world, living in mounds in excess of two meters high, each home to millions of foraging termites. In the Cerrado Savanna of South America, the giant anteater plays Godzilla, wandering through entire cities of termite mounds and dismantling them with its powerful claws to expose tunnels full of workers and lapping them up with its sticky tongue (links to video of anteater feeding).
Modern humans are believed to have originated in the African savanna before trekking out to inhabit every other biome in one way or another. The savanna is used for supporting non-native livestock in most cases, but there is a movement for domesticating antelope and other ungulates due to the naturally higher feed to meat ratio observed in these animals.
Next we'll move out of the tropics and into the desert.
*We will return to niche theory in a later post; Cheetah image courtesy of schani
This post is part of a series of Basic Concepts: Ecology (Intro, Biomes I, II, III). For the entire list of Basic Concepts in Science, visit Evolving Thoughts.
February 26, 2007
Starting a few months ago our phones started to ring... and the message was clear. Americans from across the country were calling our offices offering their energy and enthusiasm to help send the message to Congress that it is time to stop global warming and permanently protect the Coastal Plain of the Arctic Refuge in Alaska. We heard you, but in order to reach this goal we need your help.
Climate Crisis Action Day is your opportunity to ensure that Congress hears your concerns about your climate, your quality of life, and America's fragile Arctic wilderness.
Action day will begin at 11 AM with an inspiring lineup of speakers including celebrities, well known US representatives and senators, and leaders from faith organizations, labor groups, sporting and business organizations, and conservation groups. Alaska Natives and members of the Canadian First Nation will also share their firsthand experiences about the challenges of global warming and the threat of oil drilling in the arctic. Following this inspirational two hour program, attendees will have the opportunity to meet with their members of Congress and urge them to support the Arctic Wilderness Act and legislation that will combat global warming and support clean energy.
All the big NGO's are sponsoring the event: Union of Concerned Scientists, Audubon, NWF, Sierra Club, etc. Sign up for the event here, spread the word with some posters, mark it as an event on Facebook or link to this post to spread the word.
I would like to know if any other bloggers/activists plan on attending; perhaps a car pool or meeting place could be set up beforehand. E-mail me at thevoltagegate [at] gmail.com or leave a comment on this thread to let me know.
I took some nice fall pics while walking through this forest a couple of years ago; it's literally right down the street from our complex.
February 24, 2007
Eugenie Scott gave a brief history of creationism/evolution with respect to citizen science organizations, noting that the internet has given these groups a greater platform from which to distribute information. I finished E.O. Wilson's The Creation before I left for San Francisco, and he devoted the entire last chapter to "Citizen Science", encouraging (and relishing in the thought of) nonscientists - business persons, lawyers, chefs, moms, dads and kids, etc. - helping in bioassays, bioblitzes, compiling data, volunteering at labs and conservation organizations to not only get people outside, but to open wide the doors of science and make it accessible. If education is indeed the end goal, the coup de grâce to creationism and pseudoscience, hands on learning like this is far superior to any other form. Giving science a face (as with blogging), making it personal, without jeopardizing its objective integrity might ease some of the difficulties the general public has with science (and math, for that matter).
Michael Zimmerman, founder of the Clergy Letter Project talked about Evolution Sunday and its successes for a bit, seeking to reframe the dialogue between evolution accepting people and the believers of creationism (There was much talk of knee jerk reactions to creationist assertions and of setting the parameters of the argument between all of us at The Stinking Rose on the previous night.) Zimmerman had 612 congregations participate in Evolution Sunday this year, a 30% increase from last year.
Other measures of success? "Lots of people have been calling me offensive," said Zimmerman.
Evolution Sunday leaves room for the pastor/congregation to decide how to celebrate, one of the greatest aspects of the event, said Zimmerman. One congregation from Colorado constructed a sort of labyrinth of science and distributed rosaries depicting the scientific events of the formation of the universe/earth/life.
In the future he plans to include congregations from other religions, specifically Judaism and Islam.
A couple of organizers from the AAAS Dialogue on Science, Ethics and Religion (DoSER) spoke at the symposium, and one of the most poignant criticisms of the Clergy Letter Project came from Connie Bertka, program director of the DoSER.
Bertka's concern was that Evolution Sunday was too limited to be a comprehensive solution to the anti-evolution movement.
"Evolution Sunday will not reach evangelicals," said Bertka, the main religious group denying the evidence for evolution and condemning the faithful that embrace the idea. She's right; of the 612 congregations that signed on to participate in Evolution Sunday, only one signatory was evangelical.
Bertka said the main problem with Evolution Sunday is that it is not framed in the context of religious discussion. She questioned whether the choice of Darwin's birthday as the day for discussion among churches was "wise", suggesting that even this small detail could lead to polarization in the current climate.
Bertka also promoted a "contact" model between science and religion (as opposed to a NOMA style model), encouraging the admission that the two "fields" do intersect, and a continuing dialogue is the only immediate solution.
Rev. Henry Green, an evangelical Baptist minister straight out of my hometown of Annapolis, Maryland, shared his experiences with Evolution Sunday and the culture wars in his area. Very early he made a distinction between fundamentalists and evangelicals, saying that, at his church, "We don't check our brains at the door."
Green believes that fundamentalism is a result of fear; xenophobia, the fear of technology and the loss of tribalism ("gangs") are all threats to fundamentalists. They see themselves as victims, define themselves by oppression. "They are the new puritans," said Green.
Finally, Jon King of the Darwin Festival in Shrewsbury, England gave a PowerPoint tour of Darwin's birthplace, while Bob Stephens of the Darwin Day Celebration spoke a bit about his organization and the event. (I might be taking a little trip to England next year if time and money permits. Shrewsbury looks like a lovely place.)
With eight speakers and one moderator (Irv Wainer from the National Institute on Aging and the Alliance for Science), there was little time for questions, but several teachers were able to address the issue of evolution in the classroom and discuss the potential for change in the future. The gears are starting to rotate, but it will take a constant effort to build up momentum for this movement in the public forum.
*An incriminating photo did surface over at Aetiology...
February 23, 2007
The American College & University Presidents Climate Commitment is a high-visibility effort to address global warming by garnering institutional commitments to neutralize greenhouse gas emissions, and to accelerate the research and educational efforts of higher education to equip society to re-stabilize the earth’s climate.
Building on the growing momentum for leadership and action on climate change, the Presidents Climate Commitment provides a framework and support for America’s colleges and universities to go climate neutral. The Commitment recognizes the unique responsibility that institutions of higher education have as role models for their communities and in training the people who will develop the social, economic and technological solutions to reverse global warming.
Presidents signing the Commitment are pledging to eliminate their campuses’ greenhouse gas emissions over time. This involves:
- Completing an emissions inventory
- Within two years, setting a target date and interim milestones for becoming climate neutral.
- Taking immediate steps to reduce greenhouse gas emissions by choosing from a list of short-term actions.
- Integrating sustainability into the curriculum and making it part of the educational experience.
- Making the action plan, inventory and progress reports publicly available.
I wonder if Gibralter and company would put themselves on the spot like that. They are currently slashing and burning a large portion of the forest across the street from me to found a new technology center and plan to demolish two of the larger buildings on campus within the next decade to build a new student union and a mass comm building. Don't get me wrong; FSU needs these sort of advancements to keep up in the higher ed market. But does progress always have to come at the cost of the environment? It might be interesting to talk about alternatives...
February 21, 2007
Jablonski argument could be summed up in a word: Flexibility. Human behavior driven by a big brain and great mobility has brought us to where we are today, though this very expansion of our niche might cause our extinction, wrote Jablonski.
Like our ape-like ancestors, we are long lived and complex, maturing to reproductive age slowly and nurturing our young with similar patience. Jablonski called the summation of these factors our "slow life history".
Slow life histories began to develop in our ancestors about 10 to 20 million years ago in the consistent warmth of tropical forests, where fruits and nuts could be gathered, providing the energy rich sugars and fatty acids needed to build bigger and bigger brains. Bigger brains meant more flexibility.
Jablonski attributes much of our intellectual success to both the food availability in ancient forests and our capacity to procure the food. Humans are different now. We have cultivated a "rain forest in our heads," wrote Jablonski, in the form of the ingenious techniques of cooking and storing food (not to mention techniques for caring and nurturing children).
Jablonski described the two major extinctions of hominids, that of the "robust australopithicenes" (Paranthropus) and the early members of the genus Homo, H. erectus and H. neanderthalis (a good chronology of human evolution can be found here). Basically, Homo was better suited than Paranthropus to range widely for food and generally not limited to a particular area (with the exception of H. neanderthalis; it is generally accepted that they became trapped in a refugium of southern France and ran out of food). It wasn't just better bipedal movement that assisted Homo in this feat. The naked skin of Homo and the subsequent ability to efficiently dissipate heat also allowed for the capacity of our closest ancestors to move to their food.
Jablonski was recently featured in an interview with the NY Times about her latest book, Skin: A Natural History.
I'll finish up the series in a fourth part hopefully tomorrow, and moving on to one more symposium about the evolution movement at the grassroots.
WVU students who had trouble making the trip to campus last Wednesday did not have trouble because it was too warm outside or because they were taking a stand against the University's decision not to cancel classes. They had trouble because there was ice and snow falling and area roads were too hazardous to drive on. Once again, I am just taking a shot in the dark, but when I think of ice and snow, I don't think of warming or any other warm thoughts.
At least he admits that he's full of it.
February 20, 2007
Thud has a new website flag suggestion in honor of the Dark Lord's trip.
Dum, dum, dum, dum-dee-dum, dum-dee-dum...
The soils are often relics of the ancient continent Gondwana, especially in directly detached, isolated systems like New Caledonia. The soils are more fertile than that of the rain forests, but erosion is higher, especially in deforested areas.
The dichotomous nature of the climate in the dry forest drives life to cope with the extreme seasonality of precipitation in different ways. The driest areas are dominated by deciduous trees that drop their moisture-exuding leaves once the rains stop, allowing sunlight to pass through the once-thick canopy, to reach the lower levels of the forest. Wetter areas, like Southeastern Indochina, are home to large forests of dipterocarps (pdf) and other evergreens, able to utilize the blessings of the monsoon rain season to keep growing throughout the year. And, unlike the plants of the rain forests, that rely almost entirely on animals to disperse seeds, seeds in the dry forest are swept through open areas by strong winds.
Wildlife is diverse in the dry forests, but necessarily migratory in some areas due to the extreme seasons. During the dry season, many animals will travel to a certain area in the neighboring rain forest to subsist, waiting for the rains to return to their home. This extra level of complexity has given ecologists a new challenge: Tracing the migratory paths of animals reliant on both tropical dry and wet forests. How much do these species rely on each biome for subsistence?
Dry forest systems are not quite as biologically diverse as rain forests, but they are home to many rare species found nowhere else: tigers, leopards and jaguars, sloth bears, a myriad of kingfishers and flycatchers, the Komodo dragon, the maned wolf, the elusive Javan rhino and unique plants like Gouania and Cycas beddomei. The Madagascar dry forests are home to seven species of baobab tree. The whole of Africa can claim only one.
While I'm generally working under the assumption that the reader knows the dangers faced by each biome, the dry forest has been massively altered by human influences. There is a huge difference in human population between tropical wet and dry forests. Murphy and Lugo provided an estimate in 1986: In Central America, only 7 percent of the people lived in wet forest areas, while 79 percent live in dry forest areas. The relatively fertile soil drives deforestation for agricultural purposes, and has whittled dry forests down to just about 2 percent of their former area in places like Central America.
Guanacaste National Park in Costa Rica is usually hailed as the prevailing example of how dry forests can be saved and care of them placed in capable, educated hands of native peoples. Ecologist Dan Janzen began with a simple problem - why does the guanacaste tree produce so much fruit if it just lays around - found a simple answer - it had evolved to rely on herbivores like camel and ground sloths to disperse its seeds; unfortunately, those animals were hunted to extinction 10,000 years ago - and then used this knowledge to set up a system to save the tree - by introducing domesticated herbivores to the park - and encouraging the Costa Rican people to preserve their lands. Janzen called it a "biocultural restoration."
Next in the order of increasing latitude is the savanna, tropical grasslands that actually cross the boundaries with dry forests. More on that later.
February 19, 2007
"The biological extinction of a society is rare," said Redman, describing social extinction as more of a cultural rollover - certain social orders become antiquated and irrelevant and tend to be replaced.
"At some point, the old ways just die out. In some cases," he said, "the language still exists, but the society may not."
Redman questioned the importance of the collapse of societies in reference to the central theme of the AAAS meeting, sustainable science. The loss of a species is unequivocally deemed morally important, but is the loss of society? What causes societies to fail? Is there such a thing as a truly sustainable society?
Redman answered himself simply. "The only thing that is certain is that change is ubiquitous."
He detailed briefly and necessarily the Easter Island paradigm of cultural collapse and the succession of regimes in Mesopotamia as examples, following with a concise definition of societal "resilience," the ability of a society, biologically and culturally, to remain in a desirable state or to be able to change in a desirable way. Redman never exactly defined "desirability," but I think we can assume that state generally involves nonviolent shifts in society.
Redman sees two major threats to a society: environmental changes and the capacity for response in problem solving, either through greater mobility, technology or sweeping social transformations. He pointed out that the simplest and often the most effective response, greater mobility, is no longer feasible. People are generally stuffed into particular nations where travel between is at best, a bureaucratic paper race and at worst, absolutely forbidden. This problem is especially puzzling in this time of globalization, where goods are brought to people across the world. Redman would like to see more people brought to the goods, evening things out a bit more.
I think one of Redman's more poignant statements was "sustainability is not always good" when you're speaking from a societal perspective. The longest lived, strongest governments in human history were not democracies, but totalitarian monarchies and theocracies. Redman questioned the power of democracy to create a lasting, sustainable, resilient society. No answer was implied in the statement; he just wondered if there was potential.
He questioned the value of information to a society, wondering if the availability of information was as much a detriment as a boon, offering too many options, leading to indecision and confusion faced with so many choices. Unlike biological diversity, which is essential in prolonged stabilization in evolved living systems, cultural diversity may lead to gridlock on senate floors, each group holding firm to subcultural principles.
So I'd like to throw a couple of questions that Redman asked out to the blogosphere. Please, spread them around if you would, on your blog, through e-mail, asking friends:
- When a society is on the verge of extinction, are we morally obligated to save it?
- Do you agree with Redman about diversity and information in today's society?
- Is a sustainable, "resilient" society possible? Does in involve greater globalization, as Redman suggests?
"Star Trek: Beyond the Final Frontier" initially takes die-hard Trekkers where many have gone before. For two hours, a History Channel press release promises, the documentary "examines the series as a global cultural phenomenon." This mostly entails familiar episode clips, trite sound bites from the actors (George Takei, Nichelle Nichols, Patrick Stewart, Jonathan Frakes, Avery Brooks, Kate Mulgrew), and tired glimpses of costumed Klingons from the fan conventions that provide the performers with a steady stream of older-age income.
Trekkers have seen it all dozens of times before. So maybe "Beyond" is meant for newbies, should there be any in our beam-me-up soaked culture. OK, the aforementioned might make a semi-informative primer. But that effort compromises perhaps half the program's airtime, while the remaining focus is on something only devotees could love staff preparation for the October sale of 1,000 "Trek" props, costumes and other production relics at Christie's auction house.
So half the show is designed to bore Trekkers, while the other half should send nonfans fleeing. Great job, guys.
The two angles are interwoven randomly throughout the show's extreme length, too, just to drive every viewer batty. You know you're in for a long night when host Leonard "Spock" Nimoy takes an introductory stroll through a warehouse opining about the auction: "How did this happen, why did it happen, and what were the results?"
Dull enough. But then, after showing costumes being appraised and props being uncrated, the program doesn't answer those questions. Supposedly the idea was to get these collectibles into the hands of the fans. Oh, really? It had nothing to do with making money? And who got the proceeds? How much did it total? You won't find out here.
Instead, you'll learn that a Picard uniform sold for $9,000, a McCoy space suit expected to fetch $6,000 to $8,000 was bid up to $120,000, and a 5-foot Enterprise-D spaceship model used for special effects went for a whopping $500,000. You'll hear series participants intone how their work has "become part of the American mythos," opine on the show's "morality plays," and, lest we forget about that sale, extol how every fiber of the production has "recognizable emotional value."
You also get to see a '60s clip of McCoy saying, "I'm a doctor, not a bricklayer," and to watch the auction buyers drooling over pricey purchases as shipments arrive in London and Sweden. If only we could also see their faces when the credit card bills arrive.
February 18, 2007
February 17, 2007
Ecologist Jim Collins of the NSF and Arizona State University kicked off the discussion with an analysis of global amphibian decline as an indicator of extinction, and also a type of living experiment. It is usually the job of paleontologists to analyze fossil and climate records, correlating extinctions with major environmental change.
"At this moment, however," said Collins. "Extinction is right in front of us. We actually get to peer through the window this time."
And amphibians are the perfect example, a model class, said Collins. It's easy to see why. Thirty-three percent of amphibians are endangered, with 7.4 percent of those considered critically so, compared with 23/3.8 percent of all mammals and 12/1.8 percent of all birds. It is striking that we're talking about an entire class of animals that are being pushed to the brink, not just a particular family or genus.
Collins listed the different threats that may lead to extinction in these animals, including the "historic" threats,
- Introduced species
- Habitat reduction
- Climate change
- Infectious agents
But commercial harvesting is still a major threat for amphibians, especially frogs. The frog leg industry is especially destructive, concentrating their harvests on only 11 species of frogs, 95 percent of the time harvested from natural habitats, not farms.
Toxins are hard to label as a concrete cause of because of the stratified and highly variable distribution of contaminants in biological systems, especially those bound to aquatic environments. Collins suggested that the deformities caused by parasites in frogs may be due indirectly to an increase in fertilizers, though that idea has not been confirmed.
Collins instead concentrated on his own work with Central American frog populations and the potential for a type of fungus, Chytrid to extinguish about 100 species of frogs in the area. Chytrid attacks the kerotin-rich skin of the frog, and since these animals respirate through their skin, advanced cases cause cardiac arrest and death. Chytrid has also been known to disrupt normal behaviors in frogs.
The idea of a pathogen driving its host to extinction seems contradictory; where's the benefit for the pathogen?
There are a few species of Chytrid resistant frogs in these communities that act as a reservoir species for the fungus. In other words, these frogs show no symptoms of infection, but still maintain the ability to spread the disease (a kind of Typhoid Mary). It's easy to see how this might cause a large extinction of frogs from the constant exchange of Chytrid between susceptible and resistant species.
And the whole bit might be caused by climate change, at least on the local level. As the microclimate shifts, certain pathogens seem to spread more effectively (as in the case of avian malaria in Hawaiian birds).
Collins and company were also able to predict the spread of the fungus to the next location south, more or less confirming the climatic/pathogenic threat of extinction. He has shipped over 100 different species of the most endangered frogs to a zoo in New York (not sure if it was Brooklyn or not) to try to protect and preserve them.
The question is, does this count? If the animal only exists in a zoo, are we truly preserving diversity? More questions were raised in the ethical implications of extinction: When should we intervene? How do we know when the cause of endangerment is natural or artificial? How to define was is natural or artificial?
Collins urged the philosophers of science to step up and engage questions like these, weighing the importance of value systems in ecology, intrinsic value vs. utilitarian value. He feels that we need a more clear philosophy of what should be preserved and how, all the while keeping in mind what exactly our role is in this process.
Back later with more tidbits from this symposium.
After that I perused the exhibition hall (I think AAAS got a up close and personal of me behind the cutting ribbon as it opened - whee!) and picked up bags of freebies, including some useful pubs from PNAS, Science and Nature, among others.
After that was a review of emerging grassroots campaigns in evolution education (thoughts on that later) and this evening, a meeting with my NASW mentor followed by the NASW science journalism awards ceremony aboard the bay ferry, complete with booze, food and a few hundred science writers - generally, not a bad combo.
Last night I had the pleasure of meeting Tara, John and Janet from Scienceblogs. Nice to put a face to the writings, so to speak (there might even be some incriminating photos surfacing in the next couple of days).
I'll be attending a symposium on new mathematical systems in ecology and evolution tomorrow morning, and I hope to have something substantial posted by the evening.
GG [to bed]
February 15, 2007
This week marks two important days. The twelfth was Charles Darwin's birthday, Darwin Day, celebrating his conception of the governing principle of biology, evolution. Today, Valentine's Day, is the day where men everywhere strive to impress their significant other with a gaudy plumage of pretty paper, tasty treats and innuendo (a.k.a. sweet nothings).
Their intentions are dubious at best. Admit it, ladies.
Sex is the driving force behind every relationship in the natural world. The origin, evolution and persistence of sex may be a bit less exciting than the act itself, but no less interesting.
Since sex produces offspring with a more varied genome, the descendents of an infected organism have a better chance of evolving defenses against the parasites. In an infected asexual organism, the offspring will be copies of the parent, with only a relatively slim chance of mutating measures of avoidance.
In an experiment involving a type of snail from New Zealand, scientists were able to test the hypothesis. These snails, like many other organisms, can reproduce sexually or asexually, depending on the environmental conditions. When reproducing asexually, female snails of this particular species go through a process called parthenogenesis, in which they generate viable female offspring identical to themselves.
Scientists have recently traced the evolutionary lineage of the Y chromosome, leading them 300 million years into the past, to our distant ancestors. They have found evidence that the male determining Y chromosome is a mutant of the X chromosome. All humans have 23 pairs of chromosomes housing our genetic code, with the last pair determining sex. This pairing is another advantage of sexual reproduction, allowing the code within to make repairs more easily. If one is damaged, the other can provide the template.
The problem is that male chromosomes are not all paired. The Y chromosome stands alone, among the set and is susceptible to damage without a backup. Three hundred million years ago, the Y chromosome had some 1,000 genes; today the chromosome is down to a few dozen.
I just arrived in San Francisco after eight hours of planes, airports and grumpy people. It might be time for a little snooze. I'll probably be back tonight talking about the tropical dry forests as part III of the biome basics posts.
February 13, 2007
Check out (and download if you wish) a couple of these: A storm, a tawny owl, ambient sound in a forest, pond frogs, waves crashing in an offshore cave, gulls or one of hundreds of Sample Packs, compiled sounds of a certain type.
Psh... Hovind's a Chump and his CC is way too high to be useful. Besides, I've got my own Fattie:
His logic is impeccable.
Go and give Alun some props.
February 12, 2007
"Dynamics of Extinction"
The evolving character of the world permits new phenomena to emerge but places other phenomena at risk. Across a range of scientific fields, attention in recent decades has increasingly focused on phenomena that are endangered or that have already become extinct. This symposium will examine different kinds of extinction: the loss of biological species, including the reduction in the number of hominid species; the disappearance of distinctive cultures; and the vanishing of specific human languages. Scientists will examine the processes that have led to the extinction of phenomena on which their fields focus, synthesizing the results from a range of studies to identify broader ranging contexts, trends, and issues. Through this set of presentations, the speakers and participants can explore more fundamental issues that range across different phenomena, such as the factors that result in endangerment and extinction, the timing of the processes through which endangerment and extinction occur, the proximity in space and time of processes endangering different phenomena, and the factors and interventions that may delay and even end threats to specific phenomena. Special emphasis will be placed on integrating insights into the processes of endangerment and extinction from different disciplines, time periods, and geographic locations.
"Supporting Evolution at the Grass-Roots: Building Better Bridges"
Using a variety of strategies, the antievolution movement continues to push for acceptance of its ideas, including the teaching of the “controversy in evolution” within the classroom. Many scientists and most scientific organizations have publicly and unequivocally stated their support for the teaching of evolution. Organizations such as the National Center for Science Education and the Clergy Letter Project have also played key roles in debates as well as the resulting court cases. The efforts by proevolution supporters produced a broad array of activities, many of which were successful in increasing the support for the teaching of evolution in public school classrooms. These efforts also produced a vast amount of practical experience and educational materials designed to educate the public on differences between science and religion. This symposium's objective is to summarize, analyze, and draw lessons from these experiences so that they can be used to help promote the general population's understanding of evolution. Its aim is to build on these experiences to develop a common strategy to educate the public about the different but complementary roles of science and religion; to improve the teaching of science in our public schools; and to restore the excitement about science and discovery that once characterized the United States.
Strange. The last presenter in this symposium is the pastor of a Baptist church literally five minutes from where I grew up.
"Renewable Energy from Biomass: Technology, Policy, and Sustainability"
Renewable energy from biomass has the potential to significantly contribute to a more diverse and secure domestic energy portfolio for the United States. There are policy, economic, and technical barriers to achieving the potential of energy from forests and agricultural lands. However, with focused research and development and market incentives that reflect the multiple ecological and social benefits of energy from biomass, the goals of providing 25 percent of energy from renewable sources by 2025 or replacing 30 percent of imported oil by 2030 are attainable. Scientists from forestry, agriculture, and energy sectors will describe the state of the science, economics and policy and provide a challenge for broader cross-disciplinary engagement on this issue.
"Canary in the Coal Mine: Mountains and Climate Change"
Unstable glacier conditions are threatening freshwater supplies in areas across the globe, raising the risk of catastrophic mountain lake failures and resulting floods, and creating risky conditions for climbing, trekking, and scientific expeditions. This session compares the current and past state of mid-latitude mountains at various time-scales and offers glimpses of the future. Topics will include glaciers and ice core record data, tree-ring chronologies, and global instrument records, and a world-famous mountain climber will summarize the session. Panelists will discuss ongoing and future monitoring of the accelerating loss of high-mountain glaciers, in conjunction with an examination of the state-of-the-art in terms of predicting individual glacier retreat and unstable glacier conditions. Mountain flora and fauna are also under pressure as climate zones slowly shift upward in response to warming trends and species are driven into smaller habitat or those near mountain summits are driven into extinction. The symposium will address the potential of tree-ring studies to quantify such impact. Finally, the discussion will address the fact that instrument records in mountain regions are notoriously unreliable due to microclimate effects and the dearth of stations directly located at high elevation.
"New Vistas in the Mathematics of Ecology and Evolution"
Sustainability has many dimensions, from basic biology to coupled biological and socioeconomic systems. This symposium will explore a range of issues, from fisheries to ecosystem services, but with special emphasis on infectious diseases and the dynamics of collectives. It will view ecological, epidemiological, and socioeconomic systems as complex adaptive systems, where macroscopic phenomena emerge from collective actions of individual agents.
I will be blogging from the conference on Friday and Saturday evening if everything goes as planned.
But, leave it to Bora to cheer me up. He's compiled a glut of links to different Darwin Day centered posts: news, history, science and personal reflections. Good stuff.
February 11, 2007
As with many systems of classification in science, there are different classifications of biomes; you may run across lists shorter or in excess of the one described in this series of posts. I will detail the most expansive terrestrial biomes here, though later we may delve into some of the more obscure classifications.
The tropical rain forest (tropical wet forest, tropical moist broadleaf forest) is probably the most well-known biome to the non-biologist, immediately recognizable for its garish displays of color, shape and texture. Evolution has produced a nearly unlimited array of plants, animals, fungi and microbes, all interwoven in an intricate organic tapestry.
The source of the density and richness of the tropical rain forest is two fold: temperatures are relatively constant throughout the year and these areas are drenched by rain almost daily. Rainfall can exceed 400 cm in a single year in these forests (temperate forests rarely exceed 100 cm of rain), draining the soil of nutrients and leaving it acidic.
Not all rain forests have soils that are poor in nutrients; those along rivers are consistently rejuvenated by flooding, while those rooted in the soil of young volcanoes have yet to be leached by steady rains.
Nutrients are rapidly recycled in a rain forest system. With as many as 300 tree species inhabiting a single hectare and as many as 1,000 species of insects on a single tree, not to mention the high density of other organisms, it is easy to see how the nutrient budget in the forest would be tight, and how organisms rely on one another to perpetuate. Bacteria, mites and other soil creatures quickly break down organic matter from dead organisms which is absorbed by other animals or by the shallow, twisted roots systems of trees and plants. Mutualistic fungi called mycorrhizae often assist these root systems in acquiring elusive elements like nitrogen and phosphorous. Termites break down tough cellulose with the help of microbes in their guts. Leaf cutting ants slice up plant material and cultivate a nutritious fungi for the colony that aids in decomposition. And, since the density of plant life within the forest almost negates the effects of wind, plants are almost completely reliant on insects for fertilization and frugivorous (fruit-eating) animals for the dispersal of seeds.
If you want to find most of the life in a rain forest, it might be best to look up. The canopy is home not only to countless species of birds, monkeys, amphibians and snakes, but also to thick draping vines called lianas. Epiphytes, plants that live on other plants, make homes out of the crooks and crannies of trees that can reach 80 meters in height.
Rain forests make up only about 2% of the Earth's terrestrial surface, but contain about half of the planet's land-loving species. On a macroscopic level, these forests are the taxonomist's last great frontier of discovery, especially in entomology; low estimates predict tens of millions of unclassified insects.
The thick web of life, the behavior guiding (sometimes forcing) interaction and the underlying genetics of it all that constitutes the tropical rain forest system is the quintessential representation of biodiversity. While other biomes on the planet may not by as dense, the biological relationships of each provide a fresh view of the diversity of life on Earth.
Some authors skip the tropical dry forest when listing biomes, but due to its peculiar (and extreme) double life of wet and dry seasons, we'll give it a nod, next time.
Our new Office of Public Policy has organized a special viewing of the documentary film, Flock of Dodos: The Evolution/Intelligent Design Circus, at 8:00 p.m. at the historic Avalon Theater, located in D.C. at 5612 Connecticut Avenue, NW.
The highlight of the evening is sure to be the panel discussion following the film. Panelists include professor Paul Kurtz, Chairman of the Center for Inquiry, professor Barbara Forrest, expert witness at the Dover evolution/Intelligent Design trial, Randy Olson, the Flock of Dodos filmmaker, and Jack Cashill, the Intelligent Design advocate featured in the Dodos film.
If you're in the area, be sure to drop by for the film and the panel (and let me know how it was!).
February 9, 2007
A frank and honest dialogue, questions such as "Is religion relevant or irrelevant, helpful or harmful, empowering or restrictive, the cause of wars and divisions or a hope of peace?"
Are these questions absurd or inane, futile or impotent, unavailing or trivial, the cause of further sophomoric attempts at poignancy or the product of several recent, well-argued, published criticisms of religion?
Let's see... Yes, yes, yes and yes. Wait, there's more:
Current bestsellers such as The End of Faith by Richard Harris take a negative view. What do you think?
Richard Harris wrote The End of Faith? Well, I think at this point he would know of all people whether or not we should be spending more time in church.
February 7, 2007
The park trail winds close to the Youghiogheny River, moving up and down the slope. There was about six inches of snow on the ground, and the lacy limbs of the hemlocks still bore a hefty load of it. It was cold, about 20 degrees or so, but the scenery more than made up for rosy cheeks and frosty toes.
The forest was relatively empty that day, with just a few hikers nosing around the forest. The sign points the way to each of the park's waterfalls. We turned right.
The trees were untouched in the park; even tiny limbs had pencil thin traces of snow. Heather stole my sweatshirt because she was "cold" or something.
This walkway leads you down to the rushing waters of the smaller waterfall. It used to be a bit more treacherous here in the winter with no railing to guide you.
An Eastern hemlock limb, lightly dusted.
Apparently, Swallow Falls got its name because of the flocks of swallows that would roost on this rock formation. The view is downriver from the smaller waterfall.
The smaller of the two waterfalls, taken from downriver.
The hemlocks grow anywhere and everywhere along the Youghiogheny.
Fifty-three foot Muddy Creek Falls gets its name from all of the detritus washed down from Cranesville Swamp in West Virginia. It flows down from here and join the Youghiogheny.
The icicles were enormous.
The sky started to gray over again as we left, bringing a bit more snow to Garrett County.
One way for ecologists to define and correlate these varied environments is by categorizing these areas by the types of plants that inhabit them. These categories are called biomes. Categorizing each biome by plant life is not an end in itself; instead, indigenous plant life acts as an indicator of the animal life, soil composition and the climate of an area.
Most of us already know the biomes - desert, rain forest, savannah, tundra, etc. - but how exactly are they defined?
Life within a terrestrial biome is founded by its soil. Soil is created by the weathering of rock (inorganic content) and by the decay of tissue from animal, plant and microbial life (organic content). A mature soil - one that has been undisturbed by geologic or human activity - is characterized by distinct layers called soil horizons that will vary from biome to biome. Deserts have a very different soil stratification than rain forests due to the varying organic and inorganic composition of the biome. The horizons will be immediately apparent and distinct with a deep core sample.
In Western Maryland, there are large swaths of land reclaimed from strip mining operations and repopulated with native or analogous plant life. If you take a core sample in these reclaimed areas, there is no stratification. You will see the same trend in park land that was once used for agriculture. The soil will not become mature again for some centuries, perhaps even millennia.
Soil horizons are typically defined as such:
- The O horizon, as shown above, is the "organic" layer, a mixed bag of leaf litter and other organic bits found on the biome floor. This layer will vary with particular biomes, obviously, with deserts or tundra having very little litter at all.
- In the topsoil layer, or A horizon, is usually associated with humus, mostly decayed organics that have been compacted and mixed with fine inorganic particulates such as clay, silt and sand.
- The B and C horizons are mostly composed of inorganic rock in different sizes; C will have larger "chunks" than B.
- Below C is the bedrock.
Climate is also an essential factor in understanding the distinctions made between environments. The Earth's "average" climate is determined by an enormous number of factors, but generally speaking, we can zero in on a few.
Heat from the sun is what drives the circulation of air on Earth, and with the circulation of air, the factors of precipitation. Much of the basis of climatic variation seen between biomes is created by uneven heat from the sun due to the Earth's tilt on its axis and its ovoid orbit around the sun. In short, these variations combined with the ever changing geology have created our extant biomes, which lie within more or less predictable latitudes.
Take a look at the map below:
The middle dotted line is the equator, while the outer two both lie at 30 degrees. Notice that the dark green areas (tropical rain forest) are pretty much bound to the equator, while the yellow areas (deserts, generally) skirt along the 30 degrees north and south. This is caused by the constant heating and cooling of air at the equator leading to almost daily rainfall.
With the moisture expelled in the form of rain, this now dry air mass rises, moving north and/or south. It sinks into the areas at 30 degrees N & S, reabsorbing moisture, and in the process, robbing the area of rain. The mass continues its journey, eventually dumping moisture into the temperate zones. This is a generalized model, but it proves the point.
So, biomes are categorized by the plants that live within certain areas, but those plants exist in their present state only because of the atmospheric and geologic pressures placed upon ancestral organisms. With recent evidence confirming that human beings are indeed causing the global climate to rise prematurely, ecologists will rely on plants to continue their role in indicating climatic influences.
In the next few posts, we'll briefly review the different types of biomes on Earth, making distinctions in precipitation levels, geography and indigenous life.
February 6, 2007
Spread the word and contribute! Seed Media Group (the host of Scienceblogs) has agreed to create a home for all of the compiled posts. This "living textbook" of sorts has the potential to be a far greater resource than Wikipedia for its accessibility, personality and depth.
The term ecology comes from the Greek root words oikos logos, literally “the study of household,” first combined by Ernst Haeckel in 1866. Haeckel was referring to the interactions within the house of nature, and we have used the word ecology (translated from the German Oekologie or Ökologie) to describe complex systems of life both extant and extinct.
The shear range of fields that the term "ecology" encompasses is staggering. Why? Think about how many levels of biological interaction can be described by focusing on one animal, a red panda (Ailurus fulgens).
At the individual level, the red panda itself, an ecologist could look at a particular panda's ability to thermoregulate, or absorb and expel heat within its environment. Within a population of red pandas, the next step up, an ecologist could analyze the gene flow within the population and how this particular group of red pandas is distinct in adaptations from a neighboring one.
Communities of organisms are composed of two or more populations. At this level, an ecologist could take a closer look at the cohabitation of red pandas and giant pandas in a certain area, studying how the animals share food and space.
The distinction between a community and an ecosystem is slight, but essential to understand. While a community describes interaction between organisms in an area, an ecosystem describes the entirety of the area, including chemical and physical factors. Research at this level would concentrate on things like nutrient cycling (i.e. the phosphorus or carbon cycle) or the distribution of energy within the slope forests of the Himalayas.
As we expand, things become more generalized. We are not longer talking specifically about the red panda, but about the living/nonliving system of which the red panda is a part. Landscape ecology looks at a certain heterogeneous conglomerate of ecosystems, their composition ("patches" of forests, plains, etc.) and the interaction between these ecosystems. (I will zero in on this level and be a bit more descriptive in a later post.)
A geographic ecologist (who studies regions of interaction) might take a look at the geologic history of an island or lake and try to explain the distribution of organisms in that area due to the large scale geologic activity or other environmental variables. R.H. MacArthur (an associate of E.O. Wilson) thought that geographic ecology could be described as the "search for patterns of plant and animal life that can be put on a map."
Finally, ecologists can look at biological interaction through the widest scope by analyzing the biosphere, or the entirety of life's systems on the globe. Ecology at this level usually involves major atmospheric phenomena like the long term effects of climate change or El Niño on the Earth's living systems.
At each of these levels of organization, there are near infinite examples of questions to ask about interaction. Those are just a few examples. Additionally, we have not even considered narrowing the focus to the levels of physiological, cellular and molecular interaction.
In the next posts in the Basic Concepts: Ecology series will discuss terrestrial biomes, but in order to appreciate the distinction and formation of these regions across the Earth, we'll delve into some basics about climate distribution and soil composition.
February 5, 2007
How does inert nitrogen become useful as fertilizer? Find out here.
DNA sure is tasty... for marine bottom feeders.
Carnival of the Godless #59 is up.
Oh yeah, Just Science week begins today.
February 4, 2007
February 1, 2007
Like Darwin’s famous finches, crossbills have evolved unique bill sizes, bill shapes and body sizes depending on the kind of conifer seeds they eat. There’s a crossbill that specializes on ponderosa pine seeds, one that’s equipped to eat lodgepole pine seeds and another that feeds on western hemlock. While the birds may all look alike to a casual human observer, they seem to recognize their own kind. Each type of crossbill has a different call and refrains from breeding with other types, for example. Although the American Ornithologists’ Union officially recognizes just one red crossbill species today, biologists have proposed as many as nine.
In the South Hills of Idaho, University of Wyoming biologist Craig Benkman has been studying one type of crossbill for more than a decade. He believes the birds are in the process of evolving into a new species, with speciation driven by what he calls an “evolutionary arms race” between crossbills and the lodgepole pines the birds feed on.
Throughout most of the red crossbill’s Rocky Mountain range, says Benkman, red squirrels have the upper hand in seed retrieval, because they harvest and cache whole cones in early fall while crossbills must mine seeds from the cones that remain on trees. The squirrel’s taste for lodgepole seeds has encouraged the trees to evolve short, wide cones—more difficult for the rodents to bite off—with thick scales at the base. In Idaho’s South Hills, however, there are no squirrels. Lodgepole pines there have longer, thinner cones whose scales are thicker at the tips where seeds are housed. To pry open these cones, South Hills crossbills have developed bigger bills than other crossbills.
The absence of squirrels also means a steadier supply of conifer seeds. This has allowed South Hills birds to establish a more regular pattern of breeding than crossbills elsewhere in the Rockies, which breed irregularly and opportunistically whenever food is available. Fueling the evolution of a separate species, crossbills that fly into the South Hills from other areas rarely stay long enough to breed with the locals because they cannot extract seeds from the tougher cones.
Well organized and impossibly huge, Tangled Bank #72
Have you sent in your entry for Oekologie #2? Jane will be hosting the second ecology and environmental science blog carnival at Perceiving Wholes on the 15th of February, so start getting your submissions in now!