ecology
voltagegate | July 18, 2007
Welcome to the Tangled Bank and to The Voltage Gate. The theme of this 84th edition of TB is science in Ancient Greece, so we'll be exploring what that meant to them, and jumping ahead a couple millenia to find out what it means to us.
I want to begin this edition with an important announcement. Aetiology's Tara Smith has some news about the Clergy Letter Project (and Evolution Sunday). This founder, Mike Zimmerman, is trying to create a list of scientists who would be willing to answer the more technical questions posed about science and evolution by participating clergy. Tara has all the…
clock | July 17, 2007A very interesting new paper was published today in PLoS Biology:
Flight Speeds among Bird Species: Allometric and Phylogenetic Effects by Thomas Alerstam, Mikael Rosen, Johan Backman, Per G. P. Ericson and Olof Hellgren:
Analysing the variation in flight speed among bird species is important in understanding flight. We tested if the cruising speed of different migrating bird species in flapping flight scales with body mass and wing loading according to predictions from aerodynamic theory and to what extent phylogeny provides an additional explanation for variation in speed. Flight speeds…
mikethemadbiologist | July 17, 2007Inspired by Quixote's excellent post about ascidians--my firstest study organism EVAH--I've decided to delve into the archives and repost something of my own about ascidians.
I used to study botrylloid ascidians (Botrylloides diegensis to be exact). Ascidians are one of our closest invertebrate relatives. In their larval stage, they look like little tadpoles and even have a notochord (picture taken from here):
Within a few hours, the tadpole settles on a flat surface, and resorbs its tail, and essentially turns itself into a giant pair of vocal chords that are wrapped in mucus. The whole…
mikethemadbiologist | July 16, 2007Over the weekend, there was a lot of discussion of those ridiculous conservative faithtank graphs that were rerun in the Wall Street Journal. Several of my fellow ScienceBloglings have debunked the analysis that claims these data support the Laffer curve, although my favorite criticism is by Brad DeLong who points out that to prove something the editorial writers like (the Laffer curve), the Wall Street Journal editors use the the Norwegian data, and to weaken something they don't (increased corporate taxes lead to increased tax revenue), they remove the same data.
Is there any question how…
voltagegate | July 16, 2007At least they're letting some students finish up before they pull the entire rug out from under them:
The beleaguered Savannah River Ecology Lab hopes to remain open - but with vastly reduced staff and resources - through the end of the year due to commitments that require some scientists and graduate students to fulfill obligations associated with research grants.
"One of our main concerns right now is with these students," said Whit Gibbons, a senior ecologist and University of Georgia professor who has spent decades at the Aiken County lab.
The university, he said, has agreed to support…
voltagegate | July 13, 2007So far we have established that spiders are distinct from insects for two reasons: physiology (mouth parts, body plan, respiratory structures) and more importantly, evolutionary history (or phylogeny, as scientists call it).
But where did spider's come from? How did they come to speciate ?
The answer, like many in invertebrate paleontology, is cloudy. Organisms without hard, thick shells rarely become fossilized. In fact, for any organism's parts to become fossilized, even vertebrates, is a profound rarity, as Bill Bryson illustrates in A Short History of Nearly Everything:
Only about one…
clock | July 11, 2007You really don't want to be an enemy of the aphids - two papers today! The first is quite straightforward:
Aphids Make 'Chemical Weapons' To Fight Off Killer Ladybirds:
Cabbage aphids have developed an internal chemical defence system which enables them to disable attacking predators by setting off a mustard oil 'bomb', says new research. The study shows for the first time how aphids use a chemical found in the plants they eat to emit a deadly burst of mustard oil when they're attacked by a predator, for example a ladybird. This mustard oil kills, injures or repels the ladybird, which then…
mikethemadbiologist | July 11, 2007...and the Mad Biologist answers. Over at the World's Fair, David asks scientists:
1. What's your current scientific specialty?
Microbial population biology.
2. Were you originally pursuing a different academic course? If so, what was it?
Yep. I was originally a marine evolutionary ecologist. I studied botrylloid ascidians (specifically, the evolution of histocompatibility). Sadly, I had far more cache than a microbiologist.
3. Do you happen to wish you were involved in another scientific field? If so, what one?
Nope. Given the crappy wages, long hours, and work to get to the point where…
mikethemadbiologist | July 5, 2007I've always thought if the evolutionary biologists who invented the term macroevolution--any evolutionary change at or above the level of species--knew the mischief that the creationists would do with it, they would have 'uninvented' the term right then and there.
I've been meaning to write about this for some time, but this post by ScienceBlogling Mike Dunford where he discusses a creationist who misuses macroevolution finally gave me the much needed kick in the assreason to do so. Creationists--some anyway--have built a cottage industry out of claiming that while they might accept '…
voltagegate | June 28, 2007The tropical dry forests of Madagascar are notoriously fragile. The plants and animals inhabiting these areas are highly endemic; 48% of the genera of plants in southern Madagascar are unique to the island. Clear cutting of these forests has escalated with the expansion of agriculture since 1970.
But to what extent? According to this paper recently published in PLoS One, recent literature on the subject has shown a less dramatic model of deforestation in the area. The researchers broaden the scope of analysis to include rates of stability and regeneration in these forests, as well as the…
chaoticutopia | June 26, 2007It isn't hard to spot the aphids in this picture:
Aphids feasting on a maple leaf.
But, we aren't the only ones checking them out:
The aphids are spotted. So is the lady beetle.
(Two-spotted Lady Beetle, aka Adalia bipuncta).
In a matter of minutes, the lady beetle devours half of the aphids.
If the lady beetle is lucky, it will keep on eating aphids. There are plenty more on other leaves in the tree. Of course, it is not alone. There are other lady beetles around, as well. There are also eggs and larvae, promising new swarms to come. They aren't exactly free to take over the tree…
mikethemadbiologist | June 25, 2007
Abandoned fourth century AD settlement. Photo by L. Laüt.
In the June 2007 issue of Ecology, Dambrine et al. have a fascinating article demonstrating that abandoned Roman settlements still affect the local abundance of plant communities. From the abstract (italics mine):
Combined archaeological and ecological investigations in a large ancient oak forest in Central France have revealed a dense network of ancient human settlements dating from the Roman period. We demonstrate a strong correlation between present-day forest plant diversity patterns and the location of Roman farm buildings.…
voltagegate | June 21, 2007Glaciation opening new niches? The bushbuck, Tragelaphus sciptus, is sure to fill them.
I finally had the chance to this paper on molecular biogeography, an interesting method of analyzing the biodiversity of widespread populations of organisms, their core habitats and their interconnectivity. The bushbuck is a perfect model; it populate most of Sub-Saharan Africa. Genetic data - from mitocondrial DNA and cytochrome b complimentary data - was contextualized and integrated with geomorphologic and climatic history. For those keeping track of the ecology basics posts, this is a perfect example…
mikethemadbiologist | June 20, 2007The Mad Biologist loves this experiment. In the April 2007 issue of Ecology, there's a nice article by Ellis et al. demonstrating how sea gull predation regulates community dynamics in the rocky intertidal. One of the methods used was the construction of exclusion cages. Essentially, these keep various critters of interest out of a patch of seashore (or in, if the researcher prefers).
For example, a cage might be constructed to let prey (e.g., snails) in, but keep predators (e.g., crabs) out. But that's hard to do with seagulls that eat large crabs: both organisms move long distances…
voltagegate | June 20, 2007Found this on ECOLOG this morning:
Dear Colleagues:
We are writing to invite your participation in a survey of wildlife
responses to climate change in the Rocky Mountains. Results of this
important project will help frame policy decision making, media reports to
the public, and the direction of future science and management programs.
Climate change is no longer a matter of "what if" or "when." The
scientific community agrees: a growing body of evidence indicates that
human activities are causing unprecedented disruptions to the global
climate system. Furthermore, it is clear that these…
mikethemadbiologist | June 19, 2007NIH, in about six months, will release a huge sum of money to fund the study of the human 'microbiome': those microorganisms that live on or in us. One of the things that will be done with this money is meta-genomics which is "the study of genomes recovered from environmental samples as opposed to from clonal cultures." (In this case, the samples would be fecal, vaginal, your mouth, etc.). In other words, we can sample the 'community' of genomes (or perhaps we should call it the community ecology of genomes). So I have a question: what do we learn from meta-genomics of the human…
voltagegate | June 16, 2007From the ESA blog:
All of this research is needed. But where is the balance? It is the ecologists who know about primary productivity, about the effects of harvests on biodiversity, and about designing sustainable systems. We know about fluxes of greenhouse gasses. We study the effects of biomass removal on biodiversity. In summary, it is the ecologists who should be the leaders in this debate. The Ecological Society of America and other representatives of the community of ecologists should demand that our science receive proportional attention. Otherwise, we will merely end up…
voltagegate | June 15, 2007Bora (and many others) reviewed the paper I've been meaning to get to all week, on climate change and land use impact projections on bird populations based on the Millenium Ecosystem Assessment. He has all the details and the links.
clock | June 14, 2007An interesting paper came out last week in PLoS-Biology: Projected Impacts of Climate and Land-Use Change on the Global Diversity of Birds by Walter Jetz, David S. Wilcove and Andrew P. Dobson. You can view some bloggers' responses on The DC Birding Blog, Field Of View and Living the Scientific Life and media coverage here, here and here.
The authors of the paper collected information about all known ranges of land birds and made a mathematical model for predicting how those ranges will be affected by global warming on one hand and the land-use on the other by years 2050 and 2100. They use…
voltagegate | June 11, 2007It's true. Ecosystem analyst Dr. Rand Knight is running for senate in Georgia:
From 2004 - 2006 Dr. Knight served as a Scientist for the National Ecological Observatory Network (NEON) and received a Postdoctoral Fellowship at the American Institute of Biological Sciences (AIBS). Dr. Knight was part of a team that worked with the National Science Foundation and Congress to develop a continental-scale research platform for discovering, understanding and predicting the impacts of climate change, land-use change, and invasive species in urban and wild ecosystems. Rand Knight is a member of the…