Sunday, May 31, 2009
Saturday, May 30, 2009
The name “mangrove tree” can refer to any number of species common to the world’s brackish habitats, however here in Florida, the term generally refers to one of three species, the “red mangrove” (Rhizophora mangle), “white mangrove” (Laguncularia racemosa) or the “Black Mangrove” (Avicennia germinans). In order to survive and prosper in the plant hostile environments found within coastal areas, natural selection has provided the mangrove trees with highly specialized morphological adaptations.
The evolutionary history of mangrove trees stretches back more than 100-million years to the Lower Cretaceous of Southeast Asia – a geographic area where they currently exhibit a species diversity and range greater than anywhere else on the planet. Having had emerged from tropical and subtropical intertidal zones with excesses of salinity, temperature and erosion - and having deficiencies of freshwater and aerobic soils - mangrove trees demonstrated tolerances and strategies that enabled them to quickly expand their range around the globe. These adaptations include a mode of viviparous reproduction in which energetically independent seedlings remain attached to the parent tree following germination; remaining there attached until sufficiently mature to drop to the waters below as propagules for dispersion to far-off localities. From the plants ability to turn its leaves away from the intense midday tropic sun, to its skill in fine filtrating sodium from available marine waters, the mangrove is a dynamo of the brackish way of life.
Another adaptation to intertidal existence was the advent of soil accumulating suberised prop roots, which elevate the tree, filter salts and permit mangroves to construct their own islands. The roots are critical to the mangrove’s ecology for several reasons. One is that being immersed in a saline hydrology requires balance of sodium between the plant’s internal environment and that of the surrounding marine waters; this is critical for maintaining osmotic pressures and nutrient uptake in a world where the potential for desiccation is omnipresent. The roots also provide physical stability and support to the tree during frequent and intense wave bombardment and during high wind events such as tropical cyclones. Though amazingly adapted, the roots of mangrove trees may have met their match in anthropogenic nutrient loading…
Nutrient enrichment of plants through the addition of Nitrogen and Phosphorus loads, rather occurring naturally - or as more common – of anthropogenic origins, leads to growth in most species. These are simply the principles of fertilization in action; “more nutrients equals more growth.” However, as an important aside, “more growth” does not necessarily mean that the entire plant from root-to-canopy grows uniformly. In fact, in most cases fertilization leads to expansion of above ground plant structures only. Thought of from the plant’s perspective, “if there is currently adequate, or more than adequate, nutrients available, why should I invest in additional nutrient up-taking roots – I already have what I need from the soil, so I’ll invest in stems and leaves instead!” Such a “plant’s perspective” appears to be the one implemented by mangroves in the presence of increasing levels of eutrophication.
Using Florida and the Gulf of Mexico as one example of many from around the world, run-off carrying excesses of fertilizer from the “Bread Basket” of the United States is finding its way into the tributaries of the Mississippi, and in turn, into the Gulf of Mexico where explosions of algae growth have resulted in hypoxic conditions and the creation of a massive Dead Zone. Surges in the growth of algae and other noxious plants resulting from Nitrogen and Phosphorous loading is called eutrophication; eutrophication leads to de-oxygenated environments, the death of all organisms requiring oxygen and the total loss of ecosystem function. To make matters worse, far from being stationary, the dead zones move or “creep” from their epicenters, corrupting ecosystems both far and wide. For Florida, the Gulf of Mexico Dead Zone may contribute to “Red Tide” and the death of everything from phytoplankton to manatees in the State’s waters. Now, in addition to all of these previously known adverse effects, eutrophication has the potential to fertilize Florida’s coastal mangrove forests, causing rapid tree growth – but only of canopy components, not of roots.
As described above, the roots of mangrove trees are essential for multiple reasons and any increase in above surface foliage that is not accompanied by a proportional increase in rooting not only makes the trees more susceptible to desiccation, but also makes them directly vulnerable to mortality by frequent onslaught of wind and wave. If the current research is accurate, additional Nitrogen in coastal aquatic ecosystems may translate to a short-term growth of tree canopy followed by a long-term increase in the rate of mangrove tree death.
Lovelock, C., Ball, M., Martin, K., & C. Feller, I. (2009). Nutrient Enrichment Increases Mortality of Mangroves PLoS ONE, 4 (5) DOI: 10.1371/journal.pone.0005600
Friday, May 29, 2009
Sea Oxeye is an Obligate member of the Asteraceae family and is native to salt water wetlands in Florida, the Bahamas, and the Caribbean. Often found in and around Mangroves, its fleshy gray-green leaves and large yellow composite flowers make it easy to identify.
I photographed this one yesterday near the Chassahowitzka National Wildlife Refuge.
Central to the model is the presence or absence of “tags” that are recognizable to the players. Tags can be thought of as phenotypic gauges of “likeness” or “kin proximity” that can be identified by the individuals involved and factored into the decision to cooperate or defect - think, “Greenbeard Effect”.
Essentially, when the model is provided with relatively high rates of phenotypic plasticity by way of elevated rates of mutation, cooperation appears to be positively selected.
My initial assessment of the model is that increased mutational rates of phenotypic characteristics when expressed in a single-trait environment simultaneously provide positive feedback (reward) and restrain (penalize) preferences for strategy based advantage both within and between populations; mock-ups such as this go a long way towards improving our understanding of selection relative to mutualism and altruism, but it’s important to bear in mind that these models are necessary simplified representations of highly complex interactions.
Antal, T., Ohtsuki, H., Wakeley, J., Taylor, P., & Nowak, M. (2009). From the Cover: Evolution of cooperation by phenotypic similarity Proceedings of the National Academy of Sciences, 106 (21), 8597-8600 DOI: 10.1073/pnas.0902528106
Wednesday, May 27, 2009
Weighing as much as fifteen pounds and sporting a wingspan greater than nine-feet in length, the Bearded Vulture (Gypaetus barbatus) is a massive bird. First described by Linnaeus in his Systema Naturae, it’s found throughout Eurasia and Africa where it nests at mountainous elevations beyond 1300 feet. Although becoming rarer within most of its natural European range, the huge bird is experiencing population growth and overcrowding in the Pyrenees and as a result has opted for co-occupancy with rival males.
Within un-crowded habitats, single male Bearded Vultures stake claim to territories and take-up with female members of the species; however with the population growth currently experienced in the Pyrenees, there just isn’t enough available habitat for free roaming males to settle down and raise families of their own. Having little other option, the roving males are beginning to invade the established territories of attached rivals where they move-in with the conventional male-female pair. The resulting trio of vultures, consisting of two males and one female, is leading to disharmony between the established pair-bond and is diminishing their reproductive success.
Typical Bearded Vulture male-female pairs breed between December and February and produce one or two eggs, but with the addition of the second male in the territory, the frequency of copulations is decreasing. This is happening for a couple of reasons. Firstly, the males are constantly fighting each other for access to the female. With time and energy being invested in combat and deterrence of rivals, the males simply don’t have the time or energy to get romantic. Exasperating this situation even further, when one male does find an opportunity to copulate with the female, the rival male will often physically interrupt the act and stop them mid-coitus!
In addition to the obvious and expected interlude brought on by the intrusion of a combative third party in sexual congress, the female is often put-off by the mere presence of a second male and will terminate copulation independently of any physical altercation.
Fortunately, there is hope for the Pyrenees populations. As with the cliché, “time heals all wounds,” it turns-out that over long enough periods, the polyandrous model can work for the Bearded Vulture. Key to success in the multi-male regime is a habitat of sufficient quality to sustain additional numbers and the willingness of the beta bird – usually the previously roving male – to demonstrate submission to the resident alpha through male-male copulations, which appear to curtail the aggression of the alpha.
Bertran, J., Margalida, A., & Arroyo, B. (2009). Agonistic Behaviour and Sexual Conflict in Atypical Reproductive Groups: The Case of Bearded Vulture Polyandrous Trios
Ethology, 115 (5), 429-438 DOI: 10.1111/j.1439-0310.2009.01628.x
Tuesday, May 26, 2009
Interesting discussion on NPR’s Science Friday last week – Download the MP3 or LISTEN HERE.
Myotragus balearicus Credit: Duke University
Myotragus balearicus is distinctive among the caprinae due to the presence of several features that are uncharacteristic for the group as a whole. Included with these unique anatomic morphologies are small stature (about 20-inches tall), forward looking eyes (stereoscopic vision) and dentition lacking upper incisors. Having evolved on the Spanish islands of Majorca and Minorca, the cave goat possesses an exceptional phylogenetic history and may hold important clues in its DNA as to how evolution functions in geographically isolated regions such as islands.
A challenge to past attempts at recovering and sequencing the genome of extinct animals is that DNA readily breaks down at elevated temperatures; so animals, such as the cave goat, which lived, perished and fossilized in warm temperate climates rarely maintained genetic remnants of sufficient quantity or quality to process in the lab.
Now that high-throughput DNA sequencing technologies are being developed and brought to bear, unique phylogenetic stories can be read from long extinct animals that were biogeographically located in warmer climes.
Monday, May 25, 2009
Presidential News by Michael Palin on 22 May 2009 2:02pm
Eagle-eyed Palin's Travellers, or those desperate for any kind of cheap sensation, may have read or heard reports that Michael Palin (that's the real one, not the one who Twitters) has been romantically linked with the Royal Geographical Society. Well, for once, what you've read is true. I've been asked to be President of the RGS for the next three years, starting at the beginning of June. The only other time I've been President of anything was when they invented the position for me at the Campaign For Better Transport. Of which I am still President and very proud of it too.
Why did I agree to become President of such an august and celebrated body as the Royal Geographical Society ? Well, basically (and I'm quoting Monty Python here for we once invented a spokesman for the British "Well Basically" Society) because I have always been a great enthusiast for geography, as those of you who visit the site know. As well as doing everything to preserve the excellence of the RGS, I hope that I can transmit some of my enthusiasm to those who might be the geographers of the future.
This site has always encouraged travel, contact and better understanding between the people of the world. The Royal Geographical Society represents and embodies nearly 180 years of wisdom and experience of those whose lives have been dedicated to understanding our world better.I see the Presidency as a way of continuing the work I've been doing these past twenty years of travels. I shall treasure the opportunities to learn more myself and I'll let you know how it's all going. Please don't be put off by the "augustness" of the Society's title. It survives by being open to the curious and welcoming to everyone. Check out the RGS website (http://www.rgs.org/) and come and see us.
Oh and by the way, it doesn't mean I'm hanging up my boots - look out for my Kolkata (Calcutta) article in Conde Nast Traveller (October edition, I'm told). Photos by Basil Pao. And I shall be at the Palestine Literary Festival for the next few days, then off to a travel writing festival at St Malo in France to talk about Around The World In Eighty Days in a new French translation. Zut ! Alors ! It's true I shan't be planning any long TV journeys for a while, but that's more to do with Archie than the RGS ! And another grand-child due in the summer. Watch this space !
I've so much to learn about my new role that I'm not in any position to deliver heavyweight statements of intent, but I'll be putting up a press release on the site very soon. Meanwhile, keep travelling, and if you're in Ramallah next Tuesday, come and say hello.
Michael P, May 22, 2009.
The fossil Materpiscis attenboroughi is a 380-million year old placoderm that was found with an intact umbilical cord!According to Dr. John Long of the Museum Victoria,“The discovery is certainly one of the most extraordinary fossil finds ever made. It is not only the first time ever that a fossil embryo has been found with an umbilical cord, but it is also the oldest known example of any creature giving birth to live young. The existence of the embryo and umbilical cord within the specimen provides scientists with the first ever example of internal fertilisation - i.e sex - confirming that some placoderms had remarkably advanced reproductive biology. This discovery changes our understanding of the evolution of vertebrates.”
Here's a Youtube Video (originally from Nature):
Long, J., Trinajstic, K., & Johanson, Z. (2009). Devonian arthrodire embryos and the origin of internal fertilization in vertebrates Nature, 457 (7233), 1124-1127 DOI: 10.1038/nature07732
Abstract: Evidence of reproductive biology is extremely rare in the fossil record. Recently the first known embryos were discovered within the Placodermi, an extinct class of armoured fish, indicating a viviparous mode of reproduction in a vertebrate group outside the crown-group Gnathostomata (Chondrichthyes and Osteichthyes). These embryos were found in ptyctodontids, a small group of placoderms phylogenetically basal to the largest group, the Arthrodira. Here we report the discovery of embryos in the Arthrodira inside specimens of Incisoscutum ritchiei from the Upper Devonian Gogo Formation of
Check out the Museum Victoria's Website for more info on Mother Materpiscis.
The second Devonian fish story that slipped away is one that has been retold since 1892 and really has some teeth to it!
In fact, teeth are all that it has to it – fossil teeth. Back in 1892 Woodward described the Devonian chondrichthyan Protodus jexi from the Lower Devonian Campbellton Formation in New Brunswick based on teeth recovered from the site. Several months ago, Susan Turner and Randall Miller published a follow-up examination of these teeth in Acta Geologica Polonica and determined the fish to be representative of the first predatory fish.
Here’s their conclusion:
Protodus jexi is known from one locality on the Campbellton shoreline of northern New Brunswick and represents the first chondrichthyan with predator style teeth. Given the nature of shark dentitions, the known 60 or so teeth might belong to one dentition. The paratypes and probably the syntypes include a tooth file of four associated dagger-like teeth with serrated cristae. The large subrectangular to D-shaped Protodus toothbase is similar and might be phylogenetically related to the cladodont type. Contemporaries Celtiberina and Stigmodus might be closely related or the similar tooth features might reflect functionality, with large laterally extended bases providing such ‘protodontidid’ teeth with a ‘solid’ root resisting movement and assisting an efficient predatory bite.
A Couple of Fossil Protodus jexi Teeth. Source Turner & Miller Article
SUSAN TURNER,RANDALL F. MILLER (2008). Protodus jexiWoodward, 1892 (Chondrichthyes),from the Lower Devonian Campbellton Formation, New Brunswick, Canada Acta Geologica Polonica, 58 (2), 133-145
The article is available HERE.
Sunday, May 24, 2009
With all of the fanfare over human origins and primate evolution the last few days, I thought that it would be appropriate to take a quick look at an article recently published in The American Journal of Physical Anthropology. The article, “Plio-Pleistocene eagle predation on fossil cercopithecids from the Humpata Plateau, southern Angola,” discusses the taphonomic evidence for the taking of primates by predatory bird around the Pliocene/Pleistocene boundary at the renowned Taung site in South Africa – including the taking of a hominin.
NOTE: For those of you that may be familiar with the “Bird of Prey Hypothesis,” this article - to the best of my knowledge – represents the most recent support of Berger’s 1995 publication in The Journal of Human Evolution (Berger LR, Clarke RJ 1995).
The current article’s authors, Christopher Gilbert, W. Scott McGraw and Eric Delson, assessed the signatures of raptorial predation on cranial fragments recovered from the Taung site through direct comparison of the fossils with the cranial remains of extant primates from Tai National Park on the Ivory Coast.
The old world monkeys of Tai National Park, predominantly Chlorocebus sp, are heavily preyed on by Crowned Eagles (Stephanoaetus coronatus), which weigh about nine-pounds and have a wing span upwards three feet in length. Ninety-eight percent of the eagles’ diet is derived from mammals, and the majority of that is supplied by monkey flesh. As might be expected, the eagles are fearsome predators with talons that typically pierce the skull of their prey – thereby leaving a unique signature that can be readily identified by scientists.
Of special interest in regards to human evolution is that in addition to the numerous skulls of Cercopithecoides shown to bear evidence of avian predation, a hominin fossil from the Taung site, a specimen of Australopithecus africanus estimated to be a child of about three, also displays the tell-tale punctures of predation from above.
Comparison of "Taung Child" (left) with monkey skull (right). Source Berger
Checkout the Discovery of Early Hominins site from Palomar College, San Marcos, California for additional info on hominin evolution, and the two Berger articles for more on the "Bird of Prey Hypothesis."
Berger, L. (2006). Brief communication: Predatory bird damage to the Taung type-skull ofAustralopithecus africanus Dart 1925 American Journal of Physical Anthropology, 131 (2), 166-168 DOI: 10.1002/ajpa.20415
Berger LR, Clarke RJ. (1995). Eagle involvement in accumulation of the Taung child fauna The Journal of Human Evolution (29), 275-279.
Saturday, May 23, 2009
Onsite assessment, analysis and classification of natural areas and natural communities is the job of the community ecologist while infield. Depending on specialty and employer, the variables measured by these scientists could range from the organic content of soils, to tree canopy invertebrate biodiversity, or anything in between; it’s a physical job and deals with evaluation of natural systems, organic and inorganic, as they exist and function contemporaneously - or at least that’s the traditional role of these scientists. Currently things may be changing; no longer are community ecologists limited to the quantitative and qualitative assessment of systems as they exist at hand, now, thanks to advances in our understanding of genomics and phylogeny, evolution is entering into the equations of ecology.
Charles Darwin recognized that phenotypic and ecological similarity existed between species with shared ancestry. This relationship between environmental fit and evolutionary history created a paradox in his mind; if ecologically and genealogically similar, shouldn’t species exhibit the same resource needs and be found coexisting in habitats where those resources are present? But at the same time, shouldn’t direct competition for those resources of mutual necessity push the organisms in different directions and towards acquisition of divergent characteristics?
Does the phylogenic history of a species factor into a currently evaluated ecological system, or are hydrology, soil chemistry, biodiversity, trophic interaction and anthropogenic effects the only variables of concern to the community ecologist?
This dilemma has been evident throughout the history of ecology. It has effectively resulted in a linear continuum of thought in which one side supports a model of ecological assembly that accounts for the interplay of species through evolutionary time; at the other side of the spectrum, ecological systems are viewed as a minute snapshot of the temporal range with organismal and physical components that are to be measured in situ, without a concern for past or future directionality. On the whole, this continuum is now showing bias towards the inclusion of evolution.
More and more ecologists are coming to place value on the interaction of species within the temporarily fluctuating biological and physical environments in which they are submersed. Through complex nutrient cycling and resource accusation processes organisms alter the physical world around them and in so doing interact with other organisms via competitive and mutualistic dynamics. These newly altered physical environments, freshly acquired mutualisms and recently incepted rivalries provide direct feedback to the original organism forcing additional change and adaptation – just as the ecological picture was becoming clear, it changes again.
Recognizing the links between biological organisms and the physical environment as they exist over deep time and with respect given to spatial biogeography, dispersion and phylogeny is essential to the future of the field. Further developing of methodologies and techniques that incorporate these highly complex dynamics into tools that can be utilized by in-field ecologists should be – will be – an important step in conserving the world’s biota well into the future, particularly on a planet with a rapidly expanding human population and a quickly changing climate.
Cavender-Bares, J., Kozak, K., Fine, P., & Kembel, S. (2009). The merging of community ecology and phylogenetic biology Ecology Letters DOI: 10.1111/j.1461-0248.2009.01314.x
Harmon, L., Matthews, B., Des Roches, S., Chase, J., Shurin, J., & Schluter, D. (2009). Evolutionary diversification in stickleback affects ecosystem functioning Nature, 458 (7242), 1167-1170 DOI: 10.1038/nature07974
The Florida Virtual School is a government funded online program in which students in grades 6 through 12 can get credit for studying from home. It's nationally accessible component, the Florida Virtual Global School, is available in 44 states and 38 countries – though it’s most popular in Florida’s and its fundamentalist sister state, Texas.
The article “Christian working mom homeschools – on state's dime; Program allows full-time market analyst to reject evolution, sex ed assignments” breaks the story here.
Elaine McCall, principal of Florida Virtual Global Schools says:
"If you have a homeschooled student, we have alternative assignments or we would excuse the student from those assignments and they wouldn't be counted in the grade book…"
“[We] do accommodate Christian homeschoolers if the need should arise.”
As one ignorant parent explains:
When a biology project dealing with evolution was brought up in one of the classes, "I spoke to the teacher and told her we don't believe in evolution. We believe in creation,"
She further details, "I told her my daughter was going to do this assignment in terms of creationism, which she did. The teacher had no problem with it, and she got an 'A.'"
"My kids don't have to put up with bullying. They don't have to put up with indoctrination. They don't have to have sex education. We're allowed to pray all we want at home," she said. "It's really a lifesaver for Christian parents."
Well, I understand that parental “flexibility” is inherit within home schooling curricula, but in this case its endorsed and paid for by the government – and how in the world can a student get credit, much less an “A,” for putting together a creationist project for a biology class???
As with Florida Citizens for Science, I cordially invite you to join me in filling a complaint with this virtual school, that’s virtually not a school at all:
Florida Virtual School
Toll Free Tech Support: 1-866-322-8324
Address: Suite 2002145 MetroCenter Blvd Orlando, FL 32835
Directions:Use the map below or click here for directions (pdf).
Friday, May 22, 2009
Apparently I'm suspected of being a spam blog as described at their help page here. Well actually its not "me" that's accused, but rather Ecographica.
Based on the email received from Google, evil spam blogs such as Ecographica "...can be recognized by their irrelevant, repetitive, or nonsensical text..."
Hold on, now their just being mean!
As detailed in the Blogosphere Prime Directives, Volume 71, Chapter 374, Section 13, Paragraph 12, Line 2 - if Ecographica doesn't pass a formally requested content review, it will be a demolished by Vogans in 20 Earth days.
I hope that Ecographica makes it through the review, if not - it's goodbye cruel blogosphere...
Oooooyaaaa, one more thing before I'm destroyed:
Ha-HAA! The virus has been transmitted -You've been infected!
Thursday, May 21, 2009
Wednesday, May 20, 2009
Their impact on plants combined with the ability to reproduce parthenogenetically makes the aphid a formidable foe – but there is a defense.
Here's a stare down between an aphid and the seven-spot ladybug Coccinella septempunctata:
The predatory attack of Coccinella septempunctata - the aphid hunter:
Coccinella septempunctata is one of several ladybeetles found in Florida, for a listing click HERE.
Throughout the United States non-native coccinellid populations are on the rise. The primary reason for this increase is most likely the establishment of exotic ladybeetles with the ability to out compete, the locals for vital food resources.
For native Florida ladybugs, those food resources are aphids, and with the exception of Neoharmonia venusta, which is a predator of psyllids (jumping plant lice), all of beetles listed above find them quite delicious.
Another contributing factor to native beetle strife may be the commercial sale and transport of ladybeetles for the purpose of agricultural defense. Although the beetles are a tremendous aid in protecting crops, the increased cross-regional exchange of fauna may be accelerating the spread of pathogenic and parasitic organisms that prey on the ladybugs.
In regards to natives being out competed for food resources, Susan Moser and John Obrycki of the University of Kentucky found that when food resources are plentiful exotic ladybeetle species, such as Harmonia axyridis and Coccinella septempunctata experience higher fecundity than the locales and can expand their numbers very quickly. When food resources aren’t as accessible the natives prove to be a heartier species and sustain reproductive rates that out pace the immigrants.
Moser, S., & Obrycki, J. (2009). Competition and Intraguild Predation Among Three Species of Coccinellids (Coleoptera: Coccinellidae) Annals of the Entomological Society of America, 102 (3), 419-425 DOI: 10.1603/008.102.0310
A derivative of the words “paleontologist” and “prostitute;” referring generally to a scientist whom allows money, fame or notoriety to interfere with scientific study or the established methods of scientific research.
Example: "After receiving a handsome stipend from the local church, the paleostitute provided research data which clearly demonstrated tiktaalik to be a golden retriever with scoliosis.”
The wildtype paleostitutes typically exists as one of two species:
A species of scientist specializing in the subject areas of paleontology, paleoecology or paleoanthropology that willingly and fraudulently alters, modifies or misrepresents research for purpose of receiving direct payment.
A species of scientist specializing in the subject areas of paleontology, paleoecology or paleoanthropology that willingly exaggerates the significance of scientific evidence for the purpose of publishing a popular work, reinforcing previously held hypotheses, creating a documentary on the History Channel, receiving free drinks at a tavern or impressing members of the opposite sex.
Though after only a cursory flip through, I find myself rather confused...? The article in hand appears to be of a scientific nature, with an abstract, introduction and discussion section – what’s the deal? Based on recent hype I was of the understanding that Ida was a scarcely clothed partygoer and heiress to the Hilton Hotel chain?
Ok, well maybe Ida isn’t all that, but I must admit, based on the photographs glanced so far, “daddy likes what he sees.” Talk about sexy…
Darwinius masillae (AKA “Ida”) may very well represent the most complete fossil primate yet discovered and boasts a full skeleton, a soft body outline and even the contents of the digestive tract - an absolutely amazing fossil!
Although the concerns expressed by Brian Switek in his post A Discovery That Will Change Everything (!!!) ... Or Not are perfectly valid, in this instance I find myself torn between two opposing views of Ida’s coverage…
On one hand, the cheapening of the discovery through exaggeration and media hype may be indicative of a peer review process that is becoming more susceptible to commercialization and influence by those not in the know – a situation in which the public’s scientific understanding is purchased at cost via movie-of-the-week deals instead of from knowledgeable and articulate sources.
On the other hand, having spent time on my hands-and-knees, under a southwestern Wyoming sun, meticulously scanning every inch of Wasatch for the most minuscule of dentary fragments, I find the fossil itself absolutely astonishing! Indeed, so astonishing that I have little doubt that there are young men and women today flipping on the TV and upon viewing Ida’s images becoming motivated – inspired even – to pursue careers in the natural sciences.
As I’m sure Paris Hilton would agree, even bad media can be good media. And like a theatrical movie that is woefully inaccurate but still has the power to thrill an audience or capture the imagination, Ida’s coverage is a two sided sword. The “Jurassic Park Effect” may initially result in misunderstanding, but ultimately it leads the masses to a world they may have never known otherwise. I just hope that the majority are bright enough to seek “truth” and not to accept popular media as fact.
As for the real science behind Ida’s fame, I don’t know; I’ve yet to read the paper. But what I can attest to is that Jens, Philip, Jorg, Jørn, Wighart and Holly have put their research to paper and have been published. Irregardless of where Ida’s phylogeny may be found on the History Channel, it is in the scientific community that her history will ultimately be judged – and that is exactly how it is supposed to work.
I'm not suggesting that there isn't some "paleostitution" here, but the current media situation could always be worse, instead of Ida we could be inundated with coverage of the other scarcely clothed partygoers and heiresses…
Poor, poor Ida, Or: "Overselling an Adapid" @ Laelaps
Darwinius masillae @ Pharyngula
Darwinius: It delivers a pizza, and it lengthens, and it strengthens, and it finds that slipper that’s been at large under the chaise lounge for several weeks… @ The Loom
Franzen, J., Gingerich, P., Habersetzer, J., Hurum, J., von Koenigswald, W., & Smith, B. (2009). Complete Primate Skeleton from the Middle Eocene of Messel in Germany: Morphology and Paleobiology PLoS ONE, 4 (5) DOI: 10.1371/journal.pone.0005723
Tuesday, May 19, 2009
By ED KEMMICK – Billings Gazette
Charles Darwin, who fundamentally altered the way scientists view the world and whose ideas are nearly as inflammatory today as they were when he announced them to the world 150 years ago, was a quiet, kindly homebody who was literally sickened by excitement and dispute.
And though he is known now for one big idea, the theory of evolution by natural selection, Darwin spent his life, in the words of David Quammen, immersed "in the beautiful significance of tiny details."
Quammen [at right] is a science writer who lives in Bozeman. Having spent most of February and March delivering lectures on Darwin around the country, Quammen said he sometimes felt a little presumptuous, given that Darwin apparently never gave a single public talk on evolution.
"It was hard for him even to have a really animated discussion with one of his friends without being sick the next day," Quammen said.
Darwin is the subject of renewed interest this year because it is the 150th anniversary of the publication of "On the Origin of Species" and the bicentenary of his birth in England on Feb. 12, 1809.
Quammen is in demand because he has spent much of his career writing about evolutionary biology. He delivered a speech on Darwin at the Library of Congress in 2002, and in 2006 he wrote "The Reluctant Mr. Darwin," a short biography. He also served as general editor and wrote an introduction for a big, new illustrated edition of "The Origin" published in October.
He has lived in Bozeman since the 1970s and is now in his third and final year as the Wallace Stegner Distinguished Professor of Western American Studies at Montana State University.
He said he has been surprised "to find myself sort of a tinpot Darwin expert. ... I'm not trained as a scientist myself. I'm not an evolutionary biologist. But I've been in love with this guy and his work for a long time." ................
Monday, May 18, 2009
Sunday, May 17, 2009
Thanks to the vector of modern media, Angelo’s meme is still infectious today (among populations of H. sapiens) and has probably met with some limited success; however there are several species that have found competitive advantage in strategies other that those associated with an increased body size – one such animal is the redback spider of Australia.
The redback, Latrodectus hasselti, is a polyandrous species in which intrasexual selection relies less on choosey females and more on males competing for access to un-mated –“virgin” - females. Virgins are preferred by the male redbacks because, as with many other spiders, the males introduce a post copulatory plug to the female following sex, this has the effect of decreasing the likelihood of secondary male suitors successfully transferring genetic material – to have the best probability of forwarding their germ line to future generations, male redbacks seek out virgins. The virgin status of redbacks is identified by the males through a pheromone signal emitted by the female; within hours of mating, these chemo-signals cease being produced and the female becomes less attractive as a potential mate.
Typically, sexually mature males of the species, having converged on the virginal pheromone, will find themselves geographically amassed at the female’s web with as many as five other males vying for mating access. When this occurs, the males combatively engage each other until a single victor remains. To the victor goes the mate.
When it comes down to brute force, generally the male with the best weapons, most strength or greatest mass has the advantage in combat. This polyandrous scenario is familiar to most, but generally images of big horn sheep ramming each other, or gladiatorial deer with interlocked antlers are called to mind; the spiders are little different… Little different - except for an alternative intrasexual strategy to which some males find themselves better adapted.
By way of sexual and natural selection, some male redbacks have decided that because of the dynamic between pheromone signaling, male-to-male competition and copulatory plugs, that it may be better to focus more on being the first to achieve sexual maturity via rapid development than to spend extra effort and time in growing to a larger size. In this way they would have first access to females, avoid web-sparring with males and because of the pheromones, even discourage rivals post copulation. Even Charles Atlas could respect that!
KASUMOVIC, M., & ANDRADE, M. (2009). A change in competitive context reverses sexual selection on male size Journal of Evolutionary Biology, 22 (2), 324-333 DOI: 10.1111/j.1420-9101.2008.01648.x
Saturday, May 16, 2009
Superficially, Aletris farinosa resembles Wetland Plant #16 from last week’s post; however A. farinosa isn’t an orchid but rather a lily (Liliaceae). Although classified as Facultative in Florida, colicroot is adapted to hydric flatwoods and marginal areas of marshes and bogs. A. farinose is a perennial with a spike-like raceme of flowers arranged along the leafless stem and displays a flat rosette of leaves at the base.
“Jay the Banjo Picken’ Botanist” photographed this one in Levy County, Florida.
Friday, May 15, 2009
Cool fossil… Here’s the background section of the article:
Termites are one of the most successful eusocial insect groups today and certainly the most notorious as a result of their damage to human dwellings. Their success can be attributed in large part to microbial (especially protozoa and bacterial) symbionts harbored in their alimentary tract. Especially important are gut protists, which are essential for the survival of termites feeding on lignocelluloses. While termites do produce endogenous cellulases from salivary glands and gut cells, cellulolytic protists are crucial for the complete digestion of cellulose in wood-feeding termites. In the lower termites, these symbionts are mostly flagellates belonging to the Oxymonadida, Trichomonada and Hypermastigida. Flagellates associated with an Early Cretaceous lower termite of the family Kalotermitidae are described and compared with mutualistic flagellates of extant kalotermitids. This discovery shows that, while the protist species represent different genera and species, mutualistic associations between protists and termites had already been established some 100 million years ago. The present study represents the earliest fossil record of mutualism between microorganisms and animals.
The full text and several images can be found free HERE.
George O Poinar Jr. Description of an early Cretaceous termite (Isoptera: Kalotermitidae) and its associated intestinal protozoa, with comments on their co-evolution. Parasites & Vectors, 2009; 2 (12) DOI: 10.1186/1756-3305-2-12
Thursday, May 14, 2009
One, I provided much needed sustenance for thousands of apparently starving mosquitoes and horse flies, and two, I was able to view – and photograph – the greatest topography transition I’ve seen since relocating to Florida six years ago. It’s a bluff along the Bells River near the Georgia-Florida State line.
Might not look like much, but for Florida it’s not too shabby…
Sunday, May 10, 2009
"You look at the frog and can see it is vocalizing — you can tell because their vocal pouches pulsate — but you don't hear any sound. It's amazing. Then you look down at the recording equipment and see the lights flashing, indicating sound. I have never seen that before. In a frog, it's unprecedented to have purely ultrasonic vocalizations." Victoria Arch, UCLA grad student.
The “hole-in-the- head” frog (Huia cavitympanum) - so called because of its recessed ear drums- resides in hillside forest ecosystems of Borneo and Southeast Asia at elevations between 250 and 1000 meters. It is unique among the Ranidae for its ability to vocalize and hear ultrasound calls – well outside of the human range of hearing.
According to Victoria Arch, one of the authors of a recent paper published at PLoS One describing the communication of Huia cavitympanum, "Our hypothesis is that these frogs have shifted to use higher frequencies in their communication to avoid the interference of sound produced by rushing water in the lower-frequency range. However, high-frequency sounds do not transmit as far. By producing some lower-frequency calls, they can transmit calls over a greater distance, so they can communicate with frogs that are farther away. But by also producing some calls that are high-frequency — all ultrasonic — they may be able to communicate better over that background noise. Producing both types of calls might be a bet-hedging strategy to be heard," Arch said. "This is how males attract females, communicate with one another and establish territorial boundaries."
H. cavitympanum relies on fast moving streams for reproduction; these sometimes torrential waters may have necessitated enhanced communication tactics in order to affectively stake out territories and attract potential mates. The tadpoles of the species have also adapted to streamside existence - they’ve developed huge abdominal suckers in order to suction-cup themselves to the sides of rocks.
Abstract (Full Article Here)
Huia cavitympanum, an endemic Bornean frog, is the first amphibian species known to emit exclusively ultrasonic (i.e., >20 kHz) vocal signals. To test the hypothesis that these frogs use purely ultrasonic vocalizations for intraspecific communication, we performed playback experiments with male frogs in their natural calling sites. We found that the frogs respond with increased calling to broadcasts of conspecific calls containing only ultrasound. The field study was complemented by electrophysiological recordings from the auditory midbrain and by laser Doppler vibrometer measurements of the tympanic membrane's response to acoustic stimulation. These measurements revealed that the frog's auditory system is broadly tuned over high frequencies, with peak sensitivity occurring within the ultrasonic frequency range. Our results demonstrate that H. cavitympanum is the first non-mammalian vertebrate described to communicate with purely ultrasonic acoustic signals. These data suggest that further examination of the similarities and differences in the high-frequency/ultrasonic communication systems of H. cavitympanum and Odorrana tormota, an unrelated frog species that produces and detects ultrasound but does not emit exclusively ultrasonic calls, will afford new insights into the mechanisms underlying vertebrate high-frequency communication.
Photographic Credits: Frogs of Borneo
Arch, V., Grafe, T., Gridi-Papp, M., & Narins, P. (2009). Pure Ultrasonic Communication in an Endemic Bornean Frog PLoS ONE, 4 (4) DOI: 10.1371/journal.pone.0005413
University of California, Los Angeles (2009, May 9). Ultrasonic Communication Among Frogs. ScienceDaily. Retrieved May 9, 2009, from http://www.sciencedaily.com/releases/2009/05/090508192231.htm
Posted by Johnny at 5:45 PM 0 comments
Friday, May 8, 2009
Photographed yesterday near the Ochlockonee River Wildlife Management Area in Leon County, Florida.
Here is a nifty video from Louisiana State University describing the anatomy and habitat of Spiranthes praecox:
Saturday, May 2, 2009
Through examination of vertebrate remains associated with the archaeological sites of Levant, scientists were able to piece together patterns of ungulate biogeography that point to over hunting and environmental degradation as the impetus for the extinction of hartebeests, aurochs, hippopotami and several species of deer. Additionally, a direct correlation was found between the body mass of the hunted species and the rate at which the animal went extinct – presumably, larger animals were of greater value (provided more meat) and were easier to hunt (bigger = slower).
Figure: Body mass of ungulates that became extinct at end of Iron Age (by 586 BCE), at end of Mamluk period (12th century CE), at end of 19th century CE, as well as body mass of extant ungulate species. Three species became extinct during the Iron Age (1,Hippopotamus amphibius; 2, Bos primigenius; 3, Alcelaphus buselaphus), one species during the 12th century CE (4, Cervus elaphus), and six species during the 19th century CE (5, Dama mesopotamica; 6, Capra aegagrus; 7, Capreolus capreolus; 8, Gazella subgutturosa; 18 9, Equus hemionus; 10, Oryx leucoryx). Four species still exist (11, Sus scrofa; 12,Gazella gazelle; 13, Capra ibex nubiana; 14, Gazella dorcas). Because only one species become extinct during the 12th century this period could not be included in the ANOVA analysis. Horizontal broken line indicates average body mass of the 14 ungulates in Natufian Period (13,000–9,500 years BCE). Letters above bars indicate a significant difference between groups (Bonferroni Multiple Comparison Test, P,0.05). doi:10.1371/journal.pone.0005316.g011
According to the researchers, “It thus appears that during the Holocene period in the southern Levant, the most important causes of ungulate extinctions were habitat destruction and uncontrolled hunting.” They further detail, “Based on the data of this study we assume that overkill in the southern Levant operated in two stages: 1) slow overkill by ancient hunting methods, that caused the disappearance of the larger species and 2) modern blitzkrieg, which was made possible by the use of modern firearms, such blitzkrieg differed drastically from the prehistoric hunting of naive large fauna in other continents and islands, where human hunters were never encountered.”
Tsahar, E., Izhaki, I., Lev-Yadun, S., & Bar-Oz, G. (2009). Distribution and Extinction of Ungulates during the Holocene of the Southern Levant PLoS ONE, 4 (4) DOI: 10.1371/journal.pone.0005316