Tuesday, December 21, 2010

A Threatened Orchid

Stenorrhynchos lanceolatum, the leafless beaked orchid, is listed as a Threatened species in Florida. This hummingbird pollinated orchid is found throughout Florida, Puerto Rico, and Central America.

Snapshots taken this past summer near Bradenton, Florida.

Friday, November 12, 2010

Transgenic Veggies Go Wild

A newly published study from Penn State details what can happen when a genetically modified organism escapes from captivity and interbreeds with the wild members of its species.

Transgenic organisms are critters that have been genetically engineered to express characteristics unique to their species. By snipping, swapping and splicing DNA between different species, organisms can be designed to provide specific benefits to people. For example, bacteria can be engineered to synthesis human insulin for treating diabetes, tomatoes can be manipulated to have an improved shelf-life, and pigs can be designed to more efficiently digest phosphorus, thus easing both their own cost of feeding and the amount of phosphorus pollution discharged into the surrounding environment. But, despite the potential benefits to people, what trouble could ensue if a transgenic organism were to evade human controls and escape its confinement? Would the transgenic organism out-compete the wild type and push it to extinction?

Cucurbita pepo is a species of squash cultivated around the world as a popular food; common varieties of the species include the zucchini, yellow squash and gourd. In addition to being commonplace at dinner tables, Cucurbita also maintains fame as a widely utilized transgenic plant – a transgenic plant that has managed to pass its transplanted genes to wild populations.

Prior to their escape, the genes of the Cucurbita plant had been engineered to have resistance to a leaf-wilting virus transmitted by aphids. The reasoning behind the genetic transplant was simple, by reducing susceptibility to the aphid borne disease, the agricultural yield of squash could be increased and more humans could be fed; but, having escaped, would the disease-resistant plants replace their naturally more disease-susceptible counterparts?

Not necessarily.

According to a case study just published in the November issue of the International Journal of Plant Sciences, when mixed populations of transgenic and wild type squash were naturally exposed to the aphid borne disease, the transgenic members did indeed exhibit better health – at least at first. After initially showing better health, the condition and reproductive success of the transgenic squash later equalized and balanced to that of the non-transgenic type. The reason for the equalization was that the robust appearance of the transgenic plants attracted the attention of leaf-munching, and bacteria-transporting, beetles. The beetles’ preference for the healthy looking plants affectively buffered any benefit the plants received from their introduced viral resistance.

Sasu, M., Ferrari, M., & Stephenson, A. (2010). Interrelationships among a Virus-Resistance Transgene. International Journal of Plant Sciences, 171 (9), 1048-1058 DOI: 10.1086/656531

Monday, October 11, 2010

Field Photos: Eastern Coachwhip Snake

Masticophis flagellum flagellum - the eastern coachwhip
Photographed near Inglis, Florida two weeks back.

Monday, September 6, 2010

Field Photos: Fishing Spider in Nyssa Swamp

The fishing spider Dolomedes tenebrosus as found in a Nyssa swamp near Tallahassee, Florida.

Snapshots taken about a month ago.

Thursday, September 2, 2010

Alfred Russel Wallace, a Conspicuous Caterpillar and David Bowie

Prior to yesterday morning I had never contemplated the linkages between rock’n roller David Bowie and the co-founder of Natural Selection Alfred Russel Wallace. It turns-out that these famous Brits hold at least two things in common; the first and most obvious of which is the already mentioned fact that both Wallace and Bowie were born in the U.K. The second linkage between the two, as strange as this may sound, is caterpillars!

Yes, caterpillars!

The Bowie-Wallace-caterpillar connection became apparent to me yesterday morning as I was heading off to work. While stepping outside in route to the car, I noticed a rather strange looking creature attached to the exterior of the door frame (no, it wasn’t David Bowie!). In trying to figure-out what the creature was, my brain struggled to match its distinctive shape, color and pattern to familiar morphological templates filed away in the dark recesses of my memory. Then it hit me! Although the overall proportions of the beastie seemed diminutive in comparison to the model held in my head, its overall appearance reminded me of something from my adolescence back in the late 1980s – it reminded me of a mullet!

For those with a functional fashion sense (or a selective memory), Wikipedia defines a “mullet” as a “hairstyle that is short at the front and sides, and long in the back. Often ridiculed as a lowbrow and unappealing hairstyle, the mullet began to appear in popular media in the 1960s and 1970s but did not become generally well-known until the early 1980s.”

The tiny creature (which fortunately turned-out to be a caterpillar, not an outdated and free-living hairstyle) looked exactly like a mouse-sized mullet! In fact, it looked like a miniaturized version of the very mullet sported by David Bowie just a few decades ago.

Check it out:

As evidenced by the images shown above, both Bowie and the caterpillar exhibited a conspicuous, yet strangely similar, appearance. It’s this conspicuous appearance that brings us to Alfred Wallace; because, Wallace knew a thing or two about conspicuous caterpillars.

In 1889 Alfred Wallace published a book titled, “Darwinism: an Exposition of the Theory of Natural Selection with Some of its Applications.” In this work, Wallace expanded on one of his theories - a theory that he had previously presented to Charles Darwin and to members of the Entomological Society of London - the evolutionary phenomena now known as ‘aposematism.’

Aposematism refers to signaling adaptations exhibited by prey species that serve to dissuade would be predators from attacking. In other words, aposematic species are those organisms that intimidate, scare, or warn predators of their ‘unprofitability’ as potential prey items. Aposematic species are considered ‘unprofitable’ because in addition to the signaling adaptation, they also bear an underlying secondary defensive mechanism. For example, a coral snake could be considered an aposematic species because in addition to its secondary defense mechanism (a venomous bite), it also warns predators of this lethal capacity through the use of visual cues; in this case, warning coloration via strongly contrasting yellow, red and black colored bands along the length of its body.

Speaking to warning displays, Wallace wrote, “…instead of serving to conceal the animals that posses them or as recognition marks to their associates, they are developed for the express purpose of rendering the species conspicuous. The reason of this is that the animals in question are either possessors of some deadly weapons, as stings or poison fangs, or they are uneatable, and are thus so disagreeable to the usual enemies of their kind that they are never attacked when their peculiar powers or properties are known.” (Chapter IX of Alfred Wallace’s 1889 book; my emphasis added)

As an alternative to Wallace’s quoted learned avoidance of prey due to ‘known’ risks (learned through prior bad/unprofitable encounters), predators could also facilitate the evolution of conspicuous prey by practicing dietary conservatism. By simply avoiding prey items that look weird or unusual, predators could thin populations of normal looking individuals, thereby contributing to a reproductive boom for the remaining strange-looking conspecifics. In the case of a predator of caterpillars, for example, by eating ‘normal’ hairless caterpillars a predator could open the door for a surge in ‘strange-looking’ caterpillars - like those caterpillars that flaunt mullets.

In fact, Wallace frequently used conspicuous caterpillars as examples in explaining the phenomena of warning signaling - caterpillars not dissimilar to the venomous Megalopyge opercularis found on the frame of my door yesterday morning.
Megalopyge opercularis, the asp caterpillar, is the larval form of the southern flannel mouth. Its range extends from the southern United States through tropical South America. Though its retro hairstyle may look cute and harmless, it packs a painful punch. The ‘hairs’ of the asp moth aren’t really even hairs at all; they’re actually bundles of venom injecting spikes! The spikes are the caterpillar’s secondary defensive mechanism, and its conspicuousness serves as its primary defense – it sends a warning signal to predators.

Looking strange can sometimes be advantageous - just ask David Bowie!

Wallace, A. R. 1889. Darwinism: an Exposition of the Theory of Natural Selection with Some of its Applications. London: MacMillan.

Lee, et al. (2010). Can dietary conservatism explain the primary evolution of aposematism? Animal Behaviour, 79 (1), 63-74 DOI: 10.1016/j.anbehav.2009.10.004

Sunday, August 29, 2010

Field Photos: White-eyed Vireo in Nest

Vireo griseus the white-eyed vireo; nested in a forked branch of Myrica cerifera (wax myrtle).

Snapshot taken a couple months back in Manatee County, Florida – where vireos nest year around.

Saturday, August 21, 2010

Field Photos: Jewel Beetle Vs Yellow-eyed Grass

A jewel beetle [Buprestis rufipes (?)] having a go at the wetland plant Xyris caroliniana.

Xyris caroliniana is a species of “yellow-eyed grass” belonging to the Xyridaceae Family of monocots. It’s an herbaceous perennial common to Florida’s marshes, hydric pine flatwoods, and wetland ecotones. They display a compact erect stem and ascending leaves. Its flowers are short lived with three yellow petals.

The iridescence shown by Buprestis rufipes isn’t due to pigmentation in the exoskeleton, but rather microscopic textures in its cuticle which reflect and scatter particular frequencies of light.

These photos were taken near Goethe State Forest back in April.

Thursday, August 19, 2010

Field Photos: An Endangered Fern

Below are a few snapshots of an endangered “hand fern” - Ophioglossum palmatum.

Members of the Ophioglossum palmatum are epiphytic ferns that take root in the humus that collects between the fronds and the trunks of palm trees.

These snapshots were taken last month during fieldwork near the Fakahatchee Preserve in south Florida.

Although, they’re listed by the State of Florida as an endangered species, the hand fern can also be found in Southeast Asia, South America and Madagascar.

A close-up showing the spore-bearing

sporangial spikes

Here are a few more specimens – these ones guarded by Toxicodendron radicans (Poison Ivy)

Tuesday, August 17, 2010

A Motivating Herd of Squirrel Frogs

I’ve really neglected this blog the last few months… There’s really no excuse for the lack of posts; I’ve just been tied-up with work, extra work (thanks for nothing BP) and personal commitments. In an effort to get things rolling again, I thought that posting a couple of snapshots would be a good idea. Small steps…

Despite a recent malaise brought about by incidents in the Gulf of Mexico, I was briefly inspired this weekend when I discovered a couple hundred juvenile frogs in my backyard. Yeah, a COUPLE HUNDRED!

Though, I’m not exactly certain where the deed went down (no ponds or puddles around), my best guess is that about 45-days ago (tadpole-to-froglet growth time) a couple (perhaps a few) of the squirrel frogs that reside in the rafters of my porch got “frisky” (i.e. mated). The result: hundreds of these guys in my yard:

Squirrel frogs (Hyla squirella) are common throughout the Southeastern United States. They’re terrestrial tree frogs that breed and undergo early development in water (puddles, ponds, ditches, etc…). Once sufficiently mature to undertake travel, they move to forested areas (or the exteriors of human dwellings) to live as adults. Eventually, the upland dwelling adult frogs return to water to reproduce and the cycle starts anew.

As another quick natural history note, Hyla squirella are at least bimodel when it comes to sexual selection. Like many frog species, the females home-in on distant males by converging on the sound of the male’s song; but, in addition to sound, female squirrel frogs also select mates based on appearance.

Squirrel frog in rafters of porch

Males with low-frequency and energetic calls are preferred by the females, but the females also consider the size of the yellow stripe that runs down the male’s side. The male’s yellow stripe may give some indication as to his overall health.

Sunday, July 25, 2010

Convergent Evolution and Intelligence

Measuring only about one-tenth of a millimeter in length, the female members of the wasp species Dicopomorpha echmepterygis are likely candidates for being the world’s smallest flying animal. Though accomplished fliers, these tiny parasitoid wasps are so minute that one could sit comfortably within the circumference of the period found at the end this sentence. Equally as versed in flight, but dramatically less petite than the insect aviators, were huge pterosaurs like Quetzalcoatlus. Though no human has ever laid eyes on a living specimen, fossil evidence clearly shows that some of these masters of the sky boasted wingspans well in access of thirty feet. In addition to the huge variety of aeronautically inclined insects and reptiles that have been identified, mammals too have converged on the adaptation of winged locomotion; mammals of the order Chiroptera have taken to the sky as moth hunting bats.

Like the adaptation of flight, eyes too have independently evolved in a number of different animal taxa. From the photoreceptive eyespots of a flatworm to the sharply focusing lenses of a great horned owl, eyes have arisen at least forty different times during the Earth’s biological history. ‘Convergent evolution’ is the phrase science uses to describe the common adaptations shared between different lineages of animals. For example, a case for convergent evolution could be made for the possum’s opposable thumb, which may very well represent an adaptation for improved grip; but, this enhanced grasping ability is hardly an indicator of a hereditary tie to primates. Rather than having been passed through genetic transmission from parent to offspring, the opposable thumb simply has an analogous structure and function for both possums and primates. So, just as flight isn’t unique to birds, the opposable thumb isn’t unique to primates.

If not opposable thumbs, is there a trait that is unique to primates? More to the point, is there a trait that is unique to the variety of apes called Homo sapiens? Perhaps intelligence is unique?

Maybe not as unique as we’d like to think:
de Waal, F., & Ferrari, P. (2010). Towards a bottom-up perspective on animal and human cognition Trends in Cognitive Sciences, 14 (5), 201-207 DOI: 10.1016/j.tics.2010.03.003

Monday, July 19, 2010

Tsunamis Hit Florida - Not!

I’ve been told that there is a rumor going around about methane gas bubbles causing a tsunami...

From Florida Department of Environmental Protection:

“Tsunamis are unlikely to occur as a result of the Deepwater Horizon incident. These rumors involve the naturally occurring methane beneath the seafloor in the Macondo Discovery, which is the petroleum reservoir into which the Deepwater Horizon production well was drilled. Scientists and engineers are aware of the physical and chemical behavior of methane in the earth and ocean, as well as during production of petroleum.

Science does not support the notion of a methane-induced tsunami resulting from Deepwater Horizon activities. However, while the possibility of an induced tsunami is extremely remote, DEP continues to take all concerns seriously and is consulting with experts in all related scientific fields.

View the following DEP fact sheet with more information about methane gas and the Deepwater Horizon incident: http://www.dep.state.fl.us/deepwaterhorizon/files/methane_fact_sheet.pdf

Tuesday, April 13, 2010

Cottonmouth Moccasins: Adapting to the Beach and Beyond

Could some pit vipers evolve the capacity to invade the world’s oceans?

Last Thursday, while doing some fieldwork in Levy County, I came across this Florida cottonmouth as it was sunning itself after an early morning swim:

The warning behavior being demonstrated in the last photo is how the ‘cottonmouth’ earned its common name; trespassers and would be predators can be caught off-guard and intimidated when the snake curtly flashes the white interior of its mouth. The warning was certainly well received by me – I’ll take being startled over enduring a venomous bite any day of the week!

The Florida cottonmouth Agkistrodon piscivorus conanti is one of three subspecies of water moccasin native to the United States; the other two varieties include the Eastern cottonmouth (Agkistrodon piscivorus piscivorus) and the Western cottonmouth (Agkistrodon piscivorus leucostoma). These three subspecies of semi-aquatic pit vipers are renowned for their exceptional swimming ability and their associated preference for habitats in and around the freshwater lakes, streams and swamps of the Southeast U.S. They have adapted to be masters of wetlands; well, masters of freshwater wetlands anyway…

Even though their preferred range places them in proximity to the Atlantic Ocean and the Gulf of Mexico, the conquest of marine ecosystems by the cottonmouths has been - as it has with most aquatically inclined reptiles - blockaded. The physiological demands of maintaining adequate hydration in a high-saline environment has constrained the Agkistrodon genus to a landward life. But things could change.

Could cottonmouths evolve to live in the sea, like kraits or sea snakes?

As mentioned previously, the above images show a cottonmouth from Levy County, Florida. Levy County is located in West Central Florida and boasts an impressive coastline along the Gulf of Mexico. The coastline even has barrier islands. In fact, one such barrier island, called Seahorse Key, has its very own population of cottonmouths - cottonmouths that have found a niche in the intertidal zone.

Generally considered opportunistic carnivores, the bulk of the average cottonmouth’s diet is derived through consumption of its wetland neighbors - frogs and fish - however, they have been known to occasionally snack on insects, lizards, birds, rats, or even other moccasins. The cottonmouths of Seahorse Key have taken their tastes for fish from the freshwater to the saltwater; there they eat marine fish scavenged from the intertidal zone or haphazardly dropped from the Key’s bird rookeries. In addition to marine fish, the cottonmouths of Seahorse Key will even eat SEAWEED if it has the odor of fish on its leaves.

So, the cottonmouths of Seahorse Key have a proven ability to eat, digest and process marine food resources. They posses elongate lungs to provide buoyancy and streamlined bodies capable of eel-like swimming locomotion. As with other pit vipers they have venom to aid in capture of fast moving fish. And, in regards to reproduction, cottonmouths give birth to live young, so there’s no need to go to shore to lay eggs…

It seems that the only other major factor restricting the cottonmouths’ sea-ward invasion is a limited tolerance for high-salinity…

If only there was a selective pressure for improved salt water tolerance; for instance, a selective pressure something like being stuck on an island that is subject to rising sea levels. What are the chances of that happening?

The behavioral and physiological adaptations required in order for a land animal to successfully undertake a conquest of the sea are undoubtedly both varied and numerous; but, with sufficient selection pressure, ample time, and an incremental, step-wise process it can and has happened.

For example, consider all of the behavioral and physiological changes that must have occurred in order for a few Devonian lobe-finned fish to find their way to shore as fully terrestrial tetrapods! Or, viewing the scenario in reverse, imagine the adaptations that permitted Eocene land mammals to re-enter the sea as a line of cetaceans!

Subtle cumulative changes over time can alter a lineage’s dietary preferences, reproductive rituals and even bodily mechanics.

Lillywhite, H., Sheehy, C., & Zaidan, F. (2008). Pitviper Scavenging at the Intertidal Zone: An Evolutionary Scenario for Invasion of the Sea BioScience, 58 (10) DOI: 10.1641/B581008

Sunday, April 11, 2010

What Spider is this?

Anyone know which species of spider this is?

It was in west central Florida - near Crystal River, Levy County.

I'm guessing Gea heptagon, but haven't seen one quite like this one - with so many numerous huge spines...

Tuesday, April 6, 2010

Awesome Picture: Florida Panthers in the Picayune

I was just emailed this picture of a mama panther and her cubs:

The email (from a reliable source) advises that the photo was recently taken during a fly-over of the Picayune Strand near Naples in South Florida.

Looks like three wild Florida panthers - cool!

Also pictured are what looks like a recently cleared road and stands of noxious Melaleuca – could be better! (As a matter of fact it is getting better - click here for info).

In addition to dealing with us ecosystem-altering and land-lusting apes, Florida panthers must also cope with other parasites – including highly specialized trematodes that have evolved a fancy for fare of the feline sort...

Trematodes are flukes of nature (sorry, couldn’t resist) in that they've evolved an astonishing, almost incomprehensible level of developmental plasticity. Most have evolved the ability to subtly manipulate their growth rates and sexual maturation to track the resources available in their environment. For parasitic nematodes, their environment is manifested by the internal chemistry of their victims. Id est, the digestive enzymes, hormones and antibodies expressed through the physiology of their hosts help the trematodes gauge the probability of reproductive success and to tune their own developmental process accordingly. This fantastic capacity for flexibility is of survival benefit because should a trematode happen to find itself immersed in the body of an unsuitable host, it can induce a state of arrested development and shift its metabolism to complete dormancy while awaiting transmission to a more favorable chemical climate. As a natural corollary, if the trematode succeeds in locating its target host (aka, its 'definitive host') it can quickly push development into overdrive and achieve reproductive adulthood in short order, thereby maximizing the opportunity to its individual advantage. Being unrestrained by the ticking-clock of reproductive efficacy, trematodes can migrate from host-to-host and even between species with relative ease. As a case study, consider the misadventures undertaken by the trematode species named Alaria marcianae.

Alaria marcianae is a fascinating organism known to target, as definitive hosts, the kittens of the Florida Panther (Puma concolor couguar). The Florida Panther holds a critically endangered status and, as the common name strongly suggests, resides in the state of Florida. The tawny colored Florida Panther is one variety of a widely recognized group of felids that are also known by the names cougar, mountain lion and puma. The panther-intersecting life cycle of Alaria marcianae is complex with several possible vectors of transmission, but in choosing an arbitrary starting point for the purpose of description, we can assume that its convoluted journey begins within the intestines of an adult panther.

Having recently been deposited in the intestinal tract of an adult feline, members of Alaria marcianae start their lifecycle as eggs. The eggs, unembryonated germ cells, intermix with the partially digested remnants of raccoons, armadillos and other common delicacies found in the panther's system, and are then excreted with the animal's feces. On being submerged in the inundated wetlands for which south Florida – and the Picayune Strand - is renowned, water stimulates the eggs to internally develop embryos. Once these embryos have achieved sufficient maturation, sunlight triggers the eggs to hatch free swimming, cilia-driven, paramecium-looking critters called miracidia.

The miracidia are not adult Alaria marcianae, rather they represent a sexually immature stage of development that is specialized for seeking out a very specific (obligate) intermediate host. To ultimately succeed in stalking a panther, the miracidia of Alaria marcianae must first locate and infect a ram's horn snail of the genus Helisoma.

On locating a ram's horn, the miracidium attaches itself to the soft exposed flesh of the snail, and by excreting tissue-degrading enzymes, it parts ways with its cilia-bearing outer layer. It then penetrates into the snail's body cavity. Shedding its ciliated epithelium, the miracidium becomes an immature sporocyst. Although sporocysts still lack the ability to reproduce sexually, by embedding in the snail's nutrient rich organs they acquire the power to produce additional replicates of themselves - clones called 'daughter sporocysts.'

Further advancing on the panther, the new daughters promptly leave their mother's side and venture to the snail's gonads. Mollusk hormones produced by the gonads fuel special cells within the daughters as they morph into tailed, tadpole-looking larval forms called cercariae. The cercariae swim to, and exit from, the snail's shell-producing mantle. From there, they return once again to the open water as free-swimmers.

Leaving the snail behind, the cercariae swim to the water's surface and hunt down the true tadpoles of the leopard frog (Rana pipiens) - their second intermediate host. Hijacking the leopard frog's tadpoles for transport, the cercariae drop their own tail and burrow into the tadpole's skin. There's no need for self-propulsion when riding inside a tadpole. Once inside the developing frog, Alaria marcianae, then at a stage where they're referred to as mesocercaria, cease further development and undergo another round of asexual cloning. As numbers continue to multiply, they patiently rest, waiting for the tadpoles to carry them landward as adult leopard frogs.

In time, the mesocercaria-bearing tadpoles grow into leopard frogs and move their parasitic cargo to land. On terra firma the leopard frogs are hunted by a wide range of predators; occasionally falling prey to yet another preferred host (aka, a 'paratenic host') of Alaria marcianae, the raccoon. After catching an infested frog, the raccoon's digestive enzymes make short work of the frog's flesh - in the process releasing the mesocercaria. As with its previous host, the mesocercaria multiply in the raccoon, but continue to maintain a state of arrested development - they are not yet adults.

Did I mention that raccoons in south Florida happen to be a favorite prey item of the endangered panther?

Utilizing methods similar to those during the frog-to-raccoon transmission, Alaria marcianae find their way into adult panthers by contaminating raccoons - panther prey. During the process of raccoon digestion, mesocercaria are liberated from tissue and enter the bloodstream by penetrating the intestinal wall.

Now, if the panther they find themselves parasitizing, by chance, turns out to be a lactating female, her hormones will stir the mesocercaria into migrating to her mammary glands where they will transmit (trans-mammary) to the digestive system of her kittens'. The term used to describe the situation in which a mother acts as a paratenic host to her own offspring is called 'amphiparatenesis.'

Here, amphiparatenesis results in the imbibing of mesocercaria-laden milk by the kittens. As with the mesocercaria residing within their mother, the parasites in the kittens will penetrate the intestinal wall and enter the blood stream. They'll surf the blood stream until reaching the lungs where they become metacercaria; as metacercaria they harden the surrounding lung tissue forming protective cysts. Having profitably acquired housing in their definitive host, the cysts in the lungs will eventually be coughed-up the trachea and then promptly swallowed into the esophagus. Once back in the intestines, Alaria marcianae accelerates its developmental process, achieves sexually reproductive adulthood (as sequential hermaphrodites), and deposits the next generation of eggs in the intestine.

Thus the cycle comes full circle.

Foster, G., Kinsella, J., Sheppard, B., & Cunningham, M. (2009). Transmammary Infection of Free-Ranging Florida Panther Neonates by Alaria marcianae (Trematoda: Diplostomatidae) Journal of Parasitology, 95 (1), 238-239 DOI: 10.1645/GE-1749.1

Saturday, April 3, 2010

Douglas Adams on Lemurs, Dolphins and other Wildlife

Cool just found this at TED - funny!

It's From back in 2001.

Douglas Adams' close encounters with these rare and unusual animals reveal that evolution, ever ingenious, can be fickle too -- in a University of California talk that sparkles with his trademark satiric wit.

Wednesday, March 31, 2010

Breaking News: Footprints challenge theory of evolution

Footprints challenge theory of evolution

At least according to a paper in Arizona, which proclaims that “Research by UA assistant anthropology professor David Raichlen and his colleagues provide evidence suggesting that 3.6 billion years ago, hominins walked with the same upright gait that humans do today...”

Link: Arizona Daily Wildcat

Really, upright hominins 3.6 BILLION years ago??? Bipedal locomotion is one thing, but upright walking during the Archean that’s impressive - especially considering the lack of oxygen.

Incidentally, the mentioned research actually makes an argument for hominin bipedalism first occurring around 3.6 MILLION years ago. And the research is not a challenge to evolution; in fact, it fully endorses it.

The research is available at PloS; here’s the abstract:
Debates over the evolution of hominin bipedalism, a defining human characteristic, revolve around whether early bipeds walked more like humans, with energetically efficient extended hind limbs, or more like apes with flexed hind limbs. The 3.6 million year old hominin footprints at Laetoli, Tanzania represent the earliest direct evidence of hominin bipedalism. Determining the kinematics of Laetoli hominins will allow us to understand whether selection acted to decrease energy costs of bipedalism by 3.6 Ma.

Methodology/Principal Findings
Using an experimental design, we show that the Laetoli hominins walked with weight transfer most similar to the economical extended limb bipedalism of humans. Humans walked through a sand trackway using both extended limb bipedalism, and more flexed limb bipedalism. Footprint morphology from extended limb trials matches weight distribution patterns found in the Laetoli footprints.

These results provide us with the earliest direct evidence of kinematically human-like bipedalism currently known, and show that extended limb bipedalism evolved long before the appearance of the genus Homo. Since extended-limb bipedalism is more energetically economical than ape-like bipedalism, energy expenditure was likely an important selection pressure on hominin bipeds by 3.6 Ma.

Raichlen, D., Gordon, A., Harcourt-Smith, W., Foster, A., & Haas, W. (2010). Laetoli Footprints Preserve Earliest Direct Evidence of Human-Like Bipedal Biomechanics PLoS ONE, 5 (3) DOI: 10.1371/journal.pone.0009769

Tuesday, March 30, 2010

The Views of Biology Teachers towards Teaching Evolution

In discussing Marco Rubio’s anti-science perspectives during the previous post, I mentioned Florida’s miserable (though improving) track record in regards to the teaching of evolution. As it turns out, the National Association of Biology Teachers has recently published the results of a survey which focused on the attitudes held by Florida’s biology teachers towards the teaching of evolution.

The survey’s data was derived from the responses of 353 Florida biology teachers; 28% of which taught biology in kindergarten through the fifth grade, 24% instructed biology in grades six through eight and 48% taught biology at the high school level (grades 9–12).

A Few of the Findings:
20% of Florida’s biology teachers are NOT COMFORTABLE with even INCLUDING evolution as a required science standard

17% of the teachers felt that biology COULD be taught and understood WITHOUT teaching evolution

17% DISAGREED that the earth is at least 4 billion years old (34% of those that disagreed believed that the earth is only between 4,000 and 40,000 years old)

34% felt that believing in God MEANS rejecting evolution

72% of the respondents reported that they HAD NEVER BEEN criticized by other teachers or school administrators in regards to HOW they taught evolution

44% of the teachers indicated that their teaching of evolution HAS BEEN criticized by students or parents

If the above numbers seem frightening consider this: The study’s respondents were solicited from the Building a Presence in Science (BaP) program of the National Science Teachers Association. Therefore, the numbers could be biased towards the "pro" science education end of the spectrum!!!

FOWLER and MEISELS (2010). Florida Teachers’ Attitudes about
Teaching Evolution The American Biology Teacher, 72 (2), 96-99 : 10.1525/abt.2010.72.2.8

Sunday, March 21, 2010

Tadpole Tails and Predator Induced Plasticity

Last Wednesday, while doing field work near Goethe State Forest, I happened onto the paths of a couple pinewoods tree frogs (Hyla femoralis). One frog was observed practicing evasive acrobatic skills between the leaves of a saw-palmetto dominated groundcover; the second frog, taking a more leisurely approach to the day, was found lazily stretched out on mid-swamp tree branch. Because of a recent environmentally-induced neglect of this blog on my part, I thought that the two frogs would serve as a good model for a post on how tadpoles can alter their developmental physiology in response to local ecological conditions.

Like many other frogs, the pinewoods tree frog undergoes a complex life cycle which carries them from the ephemeral waters of ponds, swamps and puddles to an adulthood existence in the trees. In response to the variability of selective pressures expressed by their environments, natural selection has shaped Hyla femoralis in such away as to be flexible. One example of this flexibility is the way in which their tadpoles can alter phenotype – their morphology - in response to the presence of predators. As opposed to their developmental processes rigidly rendering tadpoles displaying uniform and unchanging morphologies, the DNA of flatwoods tree frogs has been programmed to make size, growth rate and coloration malleable characteristics. The ability of an organism to change its physical characteristics to better fit local conditions is called ‘developmental plasticity.’

In addition to normal variations encountered at the regional level, or within individual populations, the colors and shapes exhibited by tadpole tails can differ from one location to another; this is because tail characteristics can be changed in response to cues in the environment. In waters lacking abundant predators, Hyla femoralis tadpole tails are generally colorless, or are of a dull brownish-red color. In contrast to relatively safer waters, the tadpoles hosted by puddles with abundant predators (predators like dragon fly larvae, for example) are often found bearing tails with distinct red-spot markings and an enhanced, taller shape and muscular robustness. Increased tail muscle provides greater propulsion, allowing the tadpoles to employ accelerated speeds as part of their predator evasion tactics. Though, it’s still an area for inquiry, changes in the pattern and coloration of tails may provide a crypsis function by either providing improved camouflage, or by directing predatory attacks tail-ward, away from the tadpoles’ main body mass – improved survival through either concealing or revealing.

The chemical signals that switch tail enhancement into overdrive include those compounds released by other tadpoles as warning pheromones during predatory attack and those molecules discharged by the predator while digesting prey-tadpole tissues. So, in other words, a predator’s attack and digestion of a conspecific tad liberates chemicals into the water that are received by other tadpoles during development; as a result, resources are directed away from ‘normal’ growth processes and are directed to tail augmentation.

Cool stuff!

A couple quick notes:

Pinewoods tree frogs display distinct orange or yellow spots on their inner side of their thighs, while in the field these spots help distinguish Hyla femoralis from other species with similar body color patterns. Though not pictured here, the leg spots were observed during the frogs’ recent attempts at evading a certain species of primate paparazzi. Their tadpole stage lasts for about two months, and the breeding season begins in March and runs through the summer months.

Although cypress swamps and pine flatwoods are distinct natural community types, they are both occupied by the pinewoods tree frog. The first snapshot above shows one Hyla femoralis precariously perched on the stem of a saw palmetto plant just a few inches off the ground in a well-drained upland flatwoods area. The second shows another individual leisurely laying on a tree branch about five feet above the surface waters of a swamp. In Florida, these communities are often directly adjacent to each other:

LaFiandra, E., & Babbitt, K. (2004). Predator induced phenotypic plasticity in the pinewoods tree frog, Hyla femoralis : necessary cues and the cost of development Oecologia, 138 (3), 350-359 DOI: 10.1007/s00442-003-1412-3

Saturday, March 13, 2010

Evolving from Promiscuity to Monogamy

New research has revealed how the process of evolution can result in sexually promiscuous animals undergoing adaptation for monogamy.

Reproduction is an expensive endeavor. Tremendous time and resources are invested in seeking-out healthy partners, in consummating relationships, and in rearing the resultant offspring. Luckily, evolution has resulted in life being programmed to strive for resource efficiency; to work towards maximum reproductive benefit at minimum personal expense. In regards to pair-bonding between the sexes, this biological imperative for reproductive economy has made promiscuity the rule and monogamy the exception. However, despite the fact that promiscuous mating systems are the prevailing strategy in nature, environmental factors can push typically promiscuous species towards monogamy.

As a case in point, a report published in the April issue of The American Naturalist details how the ‘mimic poison dart frog’ (Ranitomeya imitator) parted ways with promiscuity to adapt a lifestyle as the first scientifically recognized genetically monogamous amphibian.

Like other frog species, poison dart frogs incur a certain amount of risk by laying their eggs in water. Although water is a biological prerequisite for frog survival, ponds, lakes and puddles also house predatory fish and other animals that prey on vulnerable eggs and tadpoles. During its evolutionary past, the menace of predation pushed the mimic poison dart frogs away from larger, riskier ponds to the considerably smaller, but safer, pools held by leaves of large bromeliad plants. Unfortunately, although the tree-top bromeliads decreased the rate of frog young predation, the movement from the big ponds raised a separate issue – nutrient limitation.

The big ponds definitely had more predators; but, they also had substantially more food. In fact, the ponds had so much food that a single frog-parent (in this case the male) was able to handle the tadpoles all by himself – a single parent family arrangement was all that was necessary to raise the next generation. In contrast, the waters held by the bromeliads averaged only about 24 milliliters in volume, far too little to hold ample provisions for a startup tadpole. In order to maintain their newly acquired safe housing, the mimic dart frogs had to adapt a new tactic.

Male mimic dart frogs had previously evolved the capacity to both transport and guard young tadpoles, but having moved to the suburbs, the females needed to help-out with feeding; rearing had become too difficult a task for the males to handle on their own. If they were to ensure the survival of their young, the days of leaving dad to care for the kids were over – monogamy was the best option. Unlike males, female mimic darts have the ability to produce eggs. To do their part, mom frogs adopted a strategy called trophic egg feeding, a practice in which they lay unfertilized eggs in the bromeliad pools for the tadpoles to eat.

An absolutely amazing video of this monogamous behavior was recorded by the BBC during the dissertation work of Jason Brown. Jason was the lead author of the cited paper, and the mimic dart footage was included in the David Attenborough narrated documentary “Life in Cold Blood.”

This is awesome footage:

Brown, J., Morales, V., & Summers, K. (2010). A Key Ecological Trait Drove the Evolution of Biparental Care and Monogamy in an Amphibian The American Naturalist, 175 (4), 436-446 DOI: 10.1086/650727

Saturday, March 6, 2010

Ecographica is a Finalist: Conservation or Geosciences

Research Blogging Awards 2010 Finalist

I just received an email from Research Blogging requesting my votes for 2010’s best blog awards…

Working through the nominees, I was surprised to discover that Ecographica was selected as a finalist in the Conservation and Geosciences category – I had no idea!

My thanks to the readers and judges for supporting this blog!!!!

Since January of 2009, Ecographica has contributed 109 research related posts to Research Blogging. Vertebrate Proxies of Climate Change has been the most popular of the research postings; it reviews/summarizes some of the ways in which vertebrates can be used to study shifting climates.

Thanks again!

Saturday, February 20, 2010

How Enticing Viruses Manipulate Animals

Viruses are ubiquitous to life; they infect everything from the smallest of bacterial cells to the largest of whales. And though these these miniscule pathogens often bring illness, they do not contaminate our bodies out of malice or spite, rather they do so out of necessity. Lacking the prerequisite internal anatomy for self-reproduction, viruses invade the cells of the living as a means of insuring their posterity. They splice their DNA (or RNA) into the nucleus of the host’s cells and effectively subvert its cellular mechanics to meet viral reproductive ends. Hijacked cells are re-programmed by the viruses and become factories dedicated to the task of manufacturing more viruses; viruses which ultimately move on to other victims. In addition to hacking programming codes for the building of replicates, viruses often include sub-routines, or additional programming hacks, that facilitate their journey to new hosts.

By undermining the normal life-processes of the host’s cells, viruses are detriments to health; however, more than just illness can remain in the wake of a virus’s biological sabotage. Sometimes included with the observable symptoms of an ailment are other characteristics of viral infection that serve to promote the spread of disease. The genes that viruses splice into a host cell’s mainframe can code for phenotypes that manipulate unwitting vectors into exposing themselves – purely for the benefit of the virus.

For example, recent work out of Penn State University has shown that a virus common to the squash group of plants does more than just hack a virus-building program into the cells of its vegetative victims - it also includes a program that attracts insects. The cucumber mosaic virus (CMV) infects plants with a gene that causes the plant to synthesize and release chemicals that draw-in hungry aphids. Normally, aphids use their capacity to chemically sense plants as a way to zero-in on healthy and nutritious foodstuffs essential to their survival. By manipulating the aphids’ chemo-sense, the virus’s genes trick the insects into locating and then taking a bite from the diseased leaves of an infected plant. Even though the plant may emit a ‘delicious smell,’ because it has been subjected to disease, it lacks the nutrients needed by the aphids. Luckily for the aphids, after just one bite their tasting-sense overrides their smelling-sense and they’ll bugger-off in search of better food. Unfortunately for other squash plants, the aphids now have a mouthful of CMV virus! Thus, the virus spreads.

The genes of the cucumber mosaic virus can integrate into the DNA of a plant, causing it to produce a chemical compound that manipulates aphids into volunteering their time and services as vectors of disease. This scenario isn’t unique to viruses, plants and insects. Other studies have shown that a similar pathogen to chemo-attractant dynamic exists between sandflies and hamsters; the parasitic protozoa Leishmania causes infected hamsters to produce chemicals that attract sandflies as vectors. And in humans, there is some evidence that Plasmodium falciparum causes more than just malaria, it also hijacks human bodies to produce chemicals that attract more mosquitoes.

Mauck, K., De Moraes, C., & Mescher, M. (2010). Deceptive chemical signals induced by a plant virus attract insect vectors to inferior hosts Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0907191107

Friday, February 19, 2010

Communicating Science: Blogs and the Media

As newspapers and cable news cut science coverage, where can the science-curious get reliable science and technology news? Ira Flatow and guests discuss how the Internet — including blogs and social media — is filling the coverage gap.

Great conversation - Listen to the Audio!

Go to the NPR webpage and click on Communicating Science in the Recent Episodes column: Here

From NPR's Science Friday

Saturday, February 13, 2010

How to Study Invasive Species, a Conservation and Ecological Imperative

The January edition of The American Midland Naturalist includes an essay by Daniel Simberloff (University of Tennessee) that bears the questioning title “Invasions of Plant Communities – More of the Same, Something Very Different, or Both?” As alluded to by the interrogative title, the central theme of the piece is whether or not the ecological characteristics displayed by invasive plant species are similar to those demonstrated by native plants during the natural succession of a vegetative community. In other words, do the strategies and tactics employed by invasives during the conquest of new habitats follow similar patterns of recruitment and regeneration as those exhibited by native plants in moving a community towards maturation? Or, in contrast to natural succession patterns, do invasive species have unique biological or demographic qualities that require a novel or specialized approach to studying their dynamics?

Daniel poses great questions, because, recognizing that we live in a world of mass travel and shifting climates, the study of invasive dynamics is of critical importance to the conservation of biodiversity – protecting natural habitats and native species. In addition to conservation, by researching the interplay of native and non-native species during the establishment of ecosystems we will undoubtedly gain a wealth of knowledge in regards to the feedbacks between evolution and ecology (i.e. how do those species lacking a shared co-evolutionary history come to achieve a stable strategy for survival?).

So, with that in mind, here’s my answer to Daniel’s question: Both!

Cause’ in a nutshell: Although invasive species will exhibit some life-history strategies comparable to those of plants from the newly invaded habitat (growth pattern, time to reproductive maturity, etc…) they will also be subject to environmental factors of a temporal nature that do not influence the natives (at least to the same extent).

Said differently, because the growth, reproductive habits and resource needs of an invasive likely mirror those of at least one native plant, the invasive could theoretically replace the native with little ill effect to the ecosystem; the invasive could fill the niche left void by the out-competed native plant without disrupting the energetics of the plant community as a whole. BUT, at the same time, a newly arrived invasive species may have a distinct advantage over a native transient because it is completely foreign to the ecosystem. For example, being unrecognized by its new environment the invasive may, for a period of time, be buffered against attack by herbivores, parasites and other stressors that may be actively reducing the fitness of the locals.

Similar to the above potential advantages, the invasive could also be subject to the detrimental affects of being an outsider - brought about by a lack of co-evolved pollinators, ect…

I would also argue that the above temporal effects associated with being a novel addition to an ecosystem, though only short-lived, can be magnified greatly by stochastic events. I would suggest this because – generally – variability in initial survival rates contributes greatly to ultimate establishment; often more so than reproductive strategy, which is subject to greater phylogenetic constraint (i.e. initial survival is more important than in choosing to produce many low-quality seeds when young, or to conserve energy and produce fewer higher-quality seeds when older).

Daniel’s essay is a great read and offers plenty of real-world case studies to emphasize his points; definitely check it out!

Simberloff, D. (2010). Invasions of Plant Communities – More of the Same, Something Very Different, or Both? The American Midland Naturalist, 163 (1), 220-233 DOI: 10.1674/0003-0031-163.1.220

Thursday, February 11, 2010

Online Recommendations for Darwin Day

It’s Darwin’s birthday!

Linked below are a few videos, a website and a paper that I plan to enjoy today in celebration of the greatest scientist to have ever lived!

Charles Darwin (Born February 12, 1809)

"Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved. "

A biographical sketch of Darwin by John van Wyhe (Darwin Online)

E.O. Wilson on ‘Darwin’s Four Great Books’ (FSU Mediasite)

Richard Dawkins on 'There is grandeur in this view of life' (YouTube)

Sean Carroll on ‘Endless Forms Most Beautiful’ (Google Video)

Paper (Free, PDF)
Spencer C. H. Barrett. Darwin's legacy: the forms, function and sexual diversity of flowers. Phil. Trans. R. Soc. B February 12, 2010 365:351-368; doi:10.1098/rstb.2009.0212

Wednesday, February 10, 2010

Is the Evolution Debate Over?

A recent blog post at National Public Radio’s Cosmos And Culture by astrophysicist Adam Frank has raised my hackles. The post, titled “The Evolution Debate Is Over; It's Time To Move Forward,” argues that “it's time to put the prejudices that drag down discussion between science and the domains of human spiritual endeavor aside.”

I disagree with Adam Frank and believe that a false impression has caused him to misdiagnose and underestimate a serious problem; as stated in a recent psychology publication (cited below):

“Moreover, academics are largely nonreligious, a pattern anticipated by the negative correlation between education and religiosity. Being exposed to like-minded colleagues, academics may form the false impression that religion is a rather rare and marginal phenomenon.”

Furthermore, let me express that I have doubts as to Adam’s sincerity in this stated endeavor. Most would agree that the best way to “move forward” from a subject is to talk about something else – a different topic altogether. Adam chose a different tactic. He placed religion on even ground with science under the premise that both can “be sources of wisdom” and represent "...the many ways humans encounter the True and the Real." This fallacious pairing of religion and science to me seems more conducive to forming an argument than to dispelling one. That aside, the ‘can’t we all get along’ position is a great sentiment, and makes sense in regards to personal communication, but when it comes determining what is real, and what is true in nature, giving equal standing to relativistic mumbo-jumbo and spiritualism is a nonsensical move for anyone that values what is true.

What is real? What is true?

I am typing this piece from the comfort of my couch in Tallahassee, Florida. To type and transmit the text of the post, I’m using a manufactured conglomerate of silicon and plastic that is more commonly referred to as a “laptop computer.” Rather than detailing what precisely a laptop computer is, I am going to assume that the readers of this article are familiar with the technology. Of course, this is a big assumption…

If, for example, you happen to be reading this as a recently arrived member of a primitive tribe from the Amazon Basin or some remote island in Indonesia, a ‘computer’ may be a foreign notion; as would the internet, electricity and many other miracles that I treat as commonplace. In fact, due to its relative rarity in your homeland, your native tongue may not even have the words to describe the luminous rock at which I now peck. Taking it a bit further, the laptop’s ability to conjure light in the absence of fire might even earn it a descriptor with a magical or spiritual connotation! However, regardless if you consider my laptop to be magical or mundane, its nature remains unaltered by our differing languages. It is real - it exists independently of our individual perceptions and doesn’t require faith. It can be held in your hands, measured, weighed and contemplated. The laptop maintains the same physical attributes rather it is in my living room, or it’s placed at a Dani village in New Guinea for use as a backlit fish-cleaning station and object of worship. A laptop is a laptop, is a laptop; thinking that it’s anything other than a laptop is factually incorrect and an artifact of ignorance or self-deception. Believing a laptop to be magic is not insightful, “deep” or quant, quite the opposite - it is something to be remedied through education.

From a philosophical view, does science prove that my laptop is real or that it truly exists? No, science has never, nor will it ever, ‘prove’ anything. After all, it is possible that my laptop is only a figment of my imagination (just as it’s possible that it has magic); but, just because anything is possible, it doesn’t follow that everything is equally likely. There is an ‘objective reality.’ Individual phenomena are labeled as true or un-true based on that objective reality as measured by observation, rationality, discourse and methodical inquiry – reality is measured by science.

Science isn’t in the business of determining certainty; instead it applies a probability based on all available evidence. For example, it is not absolutely certain that humans reproduce through sexual congress. But, based on independent experimentation the stork hypothesis seems unviable, and sex appears to be a statistically significant contributing factor to human pregnancy; thus, sexual reproduction is considered a fact by medical professionals around the world.

In strong contrast to science, religion places subjectivity above objectivity, it requires no evidence, and need not be measurable or even rational. Religion affirms that what may be true for one person need not be true for another. Faith is belief in the absence of, or despite of, evidence. Its tenets are as variable as the range of human personality. With religion all things are possible - even human pregnancy without sex.

Superstitious beliefs are used to affront more than just science education. They’re also used daily as justification for sexism, domestic abuse, racism, killing children, terrorism and numerous other immoral behaviors the world over. Rationalizing these behaviors as different ways of experiencing reality or as acceptable consequences of cultural relativism is just as fallacious as staging a debate between legitimate biologists and creationists – it just serves to validate ignorance.

In closing, let me contrast my perspective from that of Mr. Frank one last time. In his post he writes, “it is clear that at this particular moment in history, when we face such obvious and overwhelming dangers, it's time to put the prejudices that drag down discussion between science and the domains of human spiritual endeavor aside.”

Because I fully agree that there are “overwhelming dangers” in the world, I would declare that the very worst thing we could do would be to offer safe heaven (or, safe haven) to ignorance, superstition and irrationality. Our best hope to prevail over danger is to aggressively combat ignorance with the greatest prejudice we can muster. We should strive to eliminate ignorance from every political office and every schoolhouse. There are some things that should not be tolerated or compromsed.

Sedikides, C. (2009). Why Does Religiosity Persist? Personality and Social Psychology Review, 14 (1), 3-6 DOI: 10.1177/1088868309352323

Friday, February 5, 2010

How Science Suppresses the Sex Lives of Republicans

According to Utah State Representative Mike Noel, global climate change is a conspiracy theory. He insists that the whole idea of shifting climates was put together by the world’s biologists, climatologists and other scientists as an elaborate effort to control his sex life.

Speaking to climate change, Republican Mike Noel (at left) explained recently that, “This is absolutely, in my mind, in fact a conspiracy to limit population not only in this country but across the globe."

Being both a Republican and an enthusiast of the equestrian arts, Noel isn’t the type to quietly lie down and let the lefties fondle his reproductive liberties! To the contrary, he has been an outspoken proponent of Utah’s House Joint Resolution 12; a proposition that aims to stop the Environmental Protection Agency from establishing policies that reduce carbon dioxide. Noel’s good friend, Republican Kerry Gibson, sponsored Resolution 12 because… Well…

Well, because there’s a global conspiracy going on!

Here are a few proofs of the conspiracy as listed in House Joint Resolution 12:

1. “…Climategate, indicate[s] a well organized and ongoing effort to manipulate and incorporate "tricks" related to global temperature data in order to produce a global warming outcome…”

2. “…there has been a concerted effort by climate change alarmists to marginalize those in the scientific community who are skeptical of global warming by manipulating or pressuring peer-reviewed publications to keep contrary or competing scientific viewpoints and findings on global warming from being reviewed and published…”

3. “…the Intergovernmental Panel on Climate Change (IPCC), a blend of government officials and scientists, does no independent climate research but relies on global climate researchers”

4. “…the climate change "gravy train," estimated at more than $7 billion annually in federal government grants, may have influenced the climate research focus and findings that have produced a "scientific consensus" at research institutions and universities”

In addition to deducing the above listed ‘hard facts,’ Noel and Gibson also arranged for a hired gun to testify as an expert witness at Utah’s legislative proceedings. The hired gun was non other than the infamous Roy “shunned by the system” Spencer, a climatologist from Alabama whose work has been continuously rejected by the scientific community – yet further evidence of the conspiracy!

Checking Roy's facts during the proceedings was a group of 18 scientists from Brigham Young University. The group unanimously concluded that he was full of crap and even “patently false.” Accordingly, they put their findings into an open letter (available here), which each scientists signed. The letter was mailed to the State legislature in hopes of dissuading them from passing the resolution.

What was the result of this unified effort?

Republican chairman of the Utah farm group Randy Parker publicly demanded a formal apology from Brigham Young University. Parker in part stated that, "I guess the bottom line here, from my perspective, is that science is an open process of ongoing research and debate, and a group of scientists should not make these kinds of statements about another scientist…” (Note: I couldn’t agree more with this sentiment. The art of debating without debating is under-appreciated.)

So unfortunately, it looks as though Mike Noel, Kerry Gibson, and Randy Parker’s fight for breeding rights has paid-off for the republicans. House Joint Resolution 12 passed committee yesterday morning. The state of Utah is about to tell the Federal Government that climate change is nothing but a conspiracy theory, take the EPA regulations and shove 'em!

This should be great for tourism: Welcome to Utah – the State of Denial!

References & Credits:
Sovacool, B., & Brown, M. (2009). Scaling the policy response to climate change Policy and Society, 27 (4), 317-328 DOI: 10.1016/j.polsoc.2009.01.003

Chris Vanocur-ABC Channel 4

Judy Fahys- Salt Lake Tribune

Photo: Mike Noel

Wednesday, February 3, 2010

Rush Limbaugh: How the existence of god disproves climate change

Yesterday, Rush Limbaugh - a proponent of creationism and intelligent design - detailed to his radio listeners that because his god wouldn’t have created us humans with a capacity to destroy our own environment, he doesn’t ‘believe’ in climate change.

As scientific evidence of this assertion, he explained that plants need carbon dioxide to produce oxygen for humans; thus, there is no way that carbon dioxide in the atmosphere could be a harmful thing…

Who needs science, when you have such astute republicans! I wonder if Rush would be willing to be sealed in a carbon dioxide filled chamber with a lovely bouquet of flowers to prove his point?

I hereby rest my case against the fallacy that evolution progresses towards human perfection.

Tree Plantations as Biological Deserts

If I had a nickel for every time a biologist told me that tree plantations are nothing but “biological deserts” I’d be a rich man!

Well, at least a rich-er man anyway…

Industrial tree plantations can be ugly places for those with an eye for the natural beauty offered by mature and diverse forested ecosystems. Plantations are more-often-than-not composed of crowded, densely spaced trees, predominantly of the same species, age, size and condition. The soil surface on which these monocultures stand is heavily disturbed, rutted, bedded & rowed, and laden with fertilizers and herbicides. The compounding effect of these characters alters hydrology, impedes the advance of recruiting plants and strongly restricts use by wildlife.

When compared to pristine natural forests, plantations are like ‘biological deserts;’ but what about when they’re compared to a sprawling urban landscape or an agricultural pasture? What if the plantation’s location in the landscape serves as a corridor for wildlife between a developed residential area and more pristine habitat at a distance?

Plantations do offer important ecosystem services and can often maintain critical ecological functions…

Replace natural forests with plantations? – No, I’ll fight you to my last breath!

Replace agricultural pasture, or a sprawling city-scape with plantations? – I’ll help you plant the trees!

A recently published review by Alain Paquette and Christian Messier has just found its way into a stack of papers I keep as ammunition against the overly broad characterization of plantations as worthless biological deserts (a claim usually made by biostitutes hired to devalue a chunk of land for the financial gain of the owners).

Check it out:
Paquette, A., & Messier, C. (2010). The role of plantations in managing the world's forests in the Anthropocene Frontiers in Ecology and the Environment, 8 (1), 27-34 DOI: 10.1890/080116

Tuesday, February 2, 2010

Buffalos and Birds: Flightless Wings from the KT Extinction to Darwin’s Dinner Plate

Although not an aficionado of fine cuisine by any measure, through persistence and voluminous sampling I have refined my palate to appreciate the delicate subtleties of several dishes. And, while I would admittedly be lost at a wine tasting, when it comes to cheeseburgers, pizza or Buffalo wings, I consider myself a gourmet of the highest standard. In calibrating my sophisticated taste buds, Friday night has been officially dubbed as ‘wing night’ with consumption of the deep-fried, cayenne laden morsels a matter of established ritual. This past Friday as my fiancé and I were blindly obliging our delectable dogma we were taken aback when our usual wing-purveyor served such diminutive wings that we jested they must have been taken from hummingbirds or from an assuredly flightless species. Luckily, the chicken wings’ lack of robustness was mitigated by an ice cold pitcher of beer and a nerd-ish banter about the evolutionary history of flightless birds and their place at the dinner tables long passed.

The current scientific “consensus” is that the vertebrate group we now refer to as birds had origins in the late Jurassic Period more than 145-million years ago. Having evolved from bipedal dinosaurs belonging to the theropod clade into an Archaeopteryx-type winged flyer, birds had conquered the air long before the infamous mass extinction event at the end of the Cretaceous Period. Often referred to as the ‘KT Extinction Event,’ a massive environmental upheaval approximately 65-million years ago wiped-out the majority of animal life on the planet, including what at that time was the dominant vertebrate group, the non-avian dinosaurs. The exact cause of the KT Extinction is still a topic for debate with asteroid impacts and volcanic activity viewed as the likely leading contributors, but what is absolutely certain is that the resulting mayhem collapsed the Earth’s ecosystems into complete chaos. Birds, the only members of the dino-clan to survive the cataclysm, emerged from the ruin to occupy a world in disarray but non-the-less rife with newly revealed opportunity.

In addition to leaving behind a ravaged planet, the KT Extinction also instigated the abandonment of numerous ecosystems that had previously been ruled over by the dinosaurs during their Mesozoic habitation. Though left in shambles, these ecosystems had also been vacated by many of the predators and competitors that initially pushed the theropods to the sky during the Jurassic Period. In the absence of rivalry, birds had been granted access to ‘open ecosystems’ and presented with the option to undertake a second conquest of the land. Several species of birds seized on the prospect of life on terra firma and through evolutionary time traded their wings for the physiology of sure-footedness. One modern grouping of these ground dwelling, flightless dinosaurs is called the ‘ratites’ and boasts the South American rheas among its extant members.

There are two species of rhea; the ‘Greater rhea and the ‘Darwin’s rhea,’ which is also known as the ‘Lesser rhea.’ Despite their flightless status, both the Greater (Rhea americana) and the Darwin’s (Rhea pennata) display wings as identifying anatomical features; however, due to the lack of a ‘keeled’ sternum to anchor to their already reduced breast muscles, as well as the presence of a diminished wishbone (furcula) to provide skeletal support, these South American natives are bound to a grounded existence. As an alternative to employment in the aviation industry, the process of natural selection has resulted in enhanced legs that have been optimized for a life on the run. While rhea’s legs have undergone adaptation for speed and agility, they have not yet evolved the ability to avoid entanglement by humans, or for that matter, to steer clear of the occasional dinner table.

On a more historical time scale, one of the most widely used implements of rhea leg entanglement were hunting weapons called ‘bolas.’ Bolas, derived from the Spanish word for ‘ball,’ refers to a weapon constructed with lengths of rope or braided cord with a weighted ‘ball’ attached on each end. The bolas are swung to build-up momentum and then thrown at the legs of fleeing game, tended cattle, or - more to the topic - a running rhea. The momentum of the weighted ends entangles the targeted animal by wrapping the adjoining ropes around its legs; this causes the animal to fall to the ground immobilized, or at least to be sufficiently slowed as to permit dispatch by other means (i.e. gun, knife or club).
Bolas are favorite tools of the South American ‘gauchos,’ which hold a societal role not unlike that of the North American cowboy; they work as ranch hands, hunters, and when the chance presents itself, as wilderness guides. In the year 1833 several South American gouchos were working as rhea-wrangling wilderness guides at the behest of a touring young naturalist from England. In August of that year, the naturalist Charles Darwin documented in his journal a humorous set of circumstances that lead to the dinner table identification of a new species of rhea – the bird now known as Darwin’s rhea.

Rendering of Darwin's rhea by John Gould.

Gould also identified 'Darwin's finches.'

While traversing South America during the voyage of the HMS Beagle, Darwin had observed Greater Rheas in the wild on many occasions. In fact, with the aid of a few gaucho guided bolas, the abundant Greater Rheas had become a mainstay of his diet.

In conversing with the gauchos in regards to habits of these ratites, Darwin had learned that there was a second variety of rhea roaming the continent. This second type, which the gauchos called ‘Avestruz Petise’ was reportedly a smaller version of the Greater and exhibited a darker plumage and skittishness behavior that made it readily distinguishable from the ones he had seen in the wild. Unfortunately, following Darwin’s discussion neither he nor the gauchos were able to collect a specimen of this “lesser” flightless bird for formal description, and in time it faded from Darwin’s attention. The lesser rhea went unspoken of until finally one evening Darwin was enjoying a quiet dinner with Mr. Marten, the Beagle’s contracted artist, who had shot and killed what they believed was a medium sized Greater rhea. As it turned out, the fully cooked ‘medium rhea’ that graced their plates as entrée on closer examination turned-out to be something else entirely; as Darwin himself detailed on pages 108 and 109 of Voyages of the Adventure and Beagle, Volume III:

“When at Port Desire, in Patagonia, Mr. Martens shot [a rhea]; and I looked at it, forgetting at the moment, in the most unaccountable manner, the whole subject of the Petises, and thought it was a two-third grown one of the common sort. The bird was cooked and eaten before my memory returned.”

Fortunately not all was lost. Recognizing the blunder, Darwin quickly gathered the table scraps and remaining carcass from the garbage. He continued,

“…the head, neck, legs, wings, many of the larger feathers, and a large part of the skin, had been preserved. From these a very nearly perfect specimen has been put together, and is now exhibited in the museum of the Zoological Society.”

Phillips, M., Gibb, G., Crimp, E., & Penny, D. (2009). Tinamous and Moa Flock Together: Mitochondrial Genome Sequence Analysis Reveals Independent Losses of Flight among Ratites Systematic Biology, 59 (1), 90-107 DOI: 10.1093/sysbio/syp079

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