Something stinks over at National Geographic…

18 06 2007

Update the 1st: In the interest of being accurate, I’ve posted what the article actually says below. I didn’t have it with me when I originally wrote the post, although there is little different from what I said. Expect a more in-depth post this week when I’ve finished Carson’s book and make sure I understand just what DDT and DDE is doing to people. The author of the article, Michael Finkel, writes;

Soon after the [malaria eradication program collapsed, mosquito control lost access to its crucial tool, DDT. The problem was overuse-not by malaria fighters but by farmers, especially cotton growers, trying to protect their crops. The spray was so cheap that many times the necessary doses were sometimes applied. The insecticide accumulated in the soil and tainted watercourses. Though non-toxic to humans, DDT harmed peregrine falcons, sea lions, and salmon [emphasis mine]. In 1962 Rachel Carson published Silent Spring, documenting this abuse and painting so damning a picture that the chemical was eventually outlawed by most of the world for agricultural use. Exceptions were made for malaria control, but DDT became nearly impossible to procure. “The ban on DDT,” says [Robert] Gwadz of the National Institutes of Health, “may have killed 20 million children.”

Straw man, anyone?
___________________________________________________________________________

As I mentioned this past weekend, the new issue of National Geographic features a cover-story on malaria. Reading over the story last night, the author makes some jabs at Rachel Carson’s Silent Spring (which I should finish tonight) and claims that not only did DDT only effect sea lions, salmon, and peregrine falcons, but that it has no harmful effects to humans, either. The author also included a quote from a researcher (I forget their name, I will include it when I do the final write-up) that says the ban on DDT may have killed 20 million children. I was quote outraged that National Geographic would print such drivel without any further clarification or facts to back up the assertions, so I decided to start looking through the technical literature to see what is known about DDT and organochloride toxicity. I’m going to do a longer write up tonight or tomorrow, but if you’re interested here are some resources you can check so you don’t have to wait for me.

Bug Girl has an entire serious of posts taking on recent attacks on Rachel Carson, Silent Spring, and environmentalists in general. They serve as wonderful primers and are well-worth the time to read;

DDT, Junk Science, and the attack on Rachel Carson
New York Times, DDT, and an asshole
Rachel Carson and Chemical News
DDT, Junk Science, Malaria, and the attack on Rachel Carson
Malarial Drug Resistance: exciting new development!

Wikipedia- Organochlorides: Toxicity
Wikipedia- DDT
[Note: The Wiki DDT page is a bit of a muddle, and you can definitely see the influence of people who do not consider DDT to be harmful at all. I’d skip down to the Effects on Human Health section, although I’d check the sources for the information there as well.]

Also, beware the so-called “100 things you should know about DDT” page (by the contemptible J. Gordon Edwards and Steven Milloy), which is crass enough to show a photoshopped picture of Rachel Carson wearing a shirt that says “DDT: A weapon of mass survival.” What this page is doing on the Wikipedia entry under “Toxicity” I don’t know.

Here is the Scorecard entry for DDT as well, but it seems to be out of date and does not list its sources.

PubMed Abstract – Chronic nervous-system effects of long-term occupational exposure to DDT.
The paper suggests that there are long-term neurological effects among those who have applied the chemical.

PubMed PDF- Concentration of Organochlorines in Human Brain, Liver, and Adipose Tissue
Autopsy Samples from Greenland

Not about DDT specifically, but it does contain interesting information about organochlorines (DDT is one) and how they accumulate in marine mammals and people who eat those mammals.

1999 NJ DEP Fact Sheet – Historic Pesticide Contamination
This page is old, but it does suggest that up to 5% of my home state may still be affected by past use of pesticides like arsenic and DDT

Undated PDF – Peregrine Falcon’s in New Jersey
This page does not list its sources, but it states that DDT was banned in New Jersey in 1968, but use of the product caused a major crash in predatory-bird populations in the state (I also know of anecdotal evidence from an ecologist who helped re-establish ospreys in the Barnegat Bay area)

PubMed Abstract – In utero p,p’-DDE exposure and infant neurodevelopment: a perinatal cohort in Mexico.
Study suggests that DDE exposure during the first trimester of pregnancy may affect developing human children.

Abstract – The human health effects of DDT and PCBs (polychlorinated biphenyls) and an overview of organochlorines in public health
Very general abstract, but does note that some organochlorides do have effects on liver and neurological functions.

PDF Paper – Association of DDT and DDE with Birth Weight and Length of Gestation in the Child Health and Development Studies, 1959–1967
The study did not appear to come up with any strong correlation for male infants, advising that more study is needed.

PDF LEtter – Invited Commentary: Why DDT Matters Now
Summation of two paper appearing in a 2005 issue of the American Journal of Epidemiology. While the letter (and papers) are far from being iron-clad evidence, I did find this admission interesting; “…almost no data are available on the health effects of DDT exposure at the levels experienced by those living in sprayed homes.” In places where malaria is still a threat, the insides of homes are sprayed with DDT and people ingest DDE (either through metabolizing DDT themselves or the environment metabolizing it, which is then ingested). This brings up an interesting point; given the propensity of DDT to concentrate in tissues and be passed along in mother’s milk, over the course of various generations will DDT concentrations in humans go up, and if so, what effect will this have on health?

Paper PDF – Reduced Seminal Parameters Associated With Environmental DDT Exposure and p,p9-DDE Concentrations in Men in Chiapas, Mexico:A Cross-Sectional Study
This Journal of Andrology paper echoes what seems to be the case with DDT and reproductive effects, summed up by the authors as follows; “…nonoccupational exposure to DDT, as assessed by plasma p,p9-DDE concentrations, is associated with poorer semen parameters in men, indicating adverse effects on testicular function and/or the regulation of reproductive hormones.” The percentage of motile sperm went down, tail defects went up, and some suffered incomplete DNA condensation.

Fulltext Paper –THE HUMAN HEALTH EFFECTS OF DDT (DICHLORODIPHENYLTRICHLOROETHANE) AND PCBS (POLYCHLORINATED BIPHENYLS) AND AN OVERVIEW OF ORGANOCHLORINES IN PUBLIC HEALTH
While the abstract states that there is “no convincing evidence that organochlorines cause a large excess number of cancers,” the section on DDT has some interested correlations between DDT exposure and some kinds of cancers.

JSTOR Paper 1st page – DDT and Wildlife
A pre-Silent Spring (1946) paper that seems to dismiss claims of conservationists that DDT is dangerous to wildlife and humans.

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Thoughts on global climate change

25 04 2007

While watching the documentary Who Killed the Electric Car? with my wife and in-laws last night, my father-in-law brought up a good point; global climate change is lacking a symbol. When many documentaries cover the issue, footage of intense storms or photographs of hurricanes (especially Katrina) are shown, but there doesn’t seem to be one particular image that really resonates. For me, the most powerful was the lone polar bear, starving to death and having to swim many miles to find anything it could catch, featured in the BBC’s Planet Earth series, but much like many scientific concepts it’s hard to sum up the whole of such a concept (much like evolution) with just one image.

There has been some attempt to make global climate change relevant to the people of the United States, primarily by using Hurricane Katrina to explain that global warming could cause more (and if not more, then more intense) storms. Some, however, aren’t too sure about this correlation and are worried that it might end up hurting those who want to make sure everyone realizes global climate change is real. Indeed, while I won’t reveal his name or affiliations (I don’t want to get anyone in trouble or put words in their mouth), a very skilled friend of mine who is a meteorologist has explained to me that the connection between global warming and stronger or more numerous hurricanes is still tenuous at best; there may be a correlation but we simply do not know enough to say that it’s scientific fact. Mind you, he accepts that global climate change is real and that it’s man-made, but he has pointed out that by tying global warming to stronger storms we might end up shooting ourselves in the foot; if it’s coincidence or such predictions do not come true, those trying to explain global climate change to others may lose some credibility.

In the wake of the deadly 2005 hurricane season, scientists were predicting more deadly storms for 2006. Everyone was worried about another Katrina, or worse, but this did not come to pass. In fact, 2006 seemed relatively quiet, with no storms hitting the US. What’s the forecast for the approaching 2007 season? More major and powerful storms, this time unaffected by factors that were said to weaken storm activity last year, but whether the weather will be consistent with the predictions remains to be seen. Indeed, even though the recent IPCC report says that storms and global warming are linked, there is much debate within the scientific community as to whether this is really the case (where the real controversy over global warming is, in fact). Personally, I don’t think we know enough yet to say the warming-hurricane connection is an open and shut case, and we would do well to be careful (and honest) when invoking such examples to convince people that global climate change is real. It’s not like there’s a lack of things to talk about as far as changes to ecology and people in already impoverished regions paying the price for our gas-guzzling, and although such examples may not be as “close to home” as stronger hurricanes in our neck of the woods, we shouldn’t trade in potential relevance for accuracy.

Interestingly enough, after I finished Hunting Dinosaurs I decided to finish Peter Ward’s book Rivers in Time. While Ward’s style can be a little tedious at times, Ward does make the important connection that it is immensely important to understand past extinctions, especially in respect to what’s going on today. In fact, I am curious as to why there has not been more discussion about the Permian/Triassic mass-extinction being that we have already seen what drastic global climate change (likely fueled, at least in part, by carbon dioxide making the ocean more acidic and being dumped into the air) can do to the planet. While there are competing theories and I believe that extinctions are more complex than the average person realizes (rarely, if ever, is there one “smoking gun” that explains it all), we have a record of what happened to life when the climate changed quickly, although there is an important difference. The P/T extinction could not be avoided, nor could it be avoided now; it was caused by natural phenomena involving continental drift, volcanism, recession of the oceans, continent makeup, etc. In contrast, global climate change today is being created by us and can be eventually stopped or its impact reduced; it is not something that is entirely out of our hands. I think the P/T extinction can serve as a very potent example of what may await the planet if we do nothing; life will go on, I’m sure, but we might not be part of it. Again, if we were to use the P/T extinction as a model to help people realize the grave consequences we may face, we should be honest and attempt to be accurate, but I think it would be an effective tool to relate past catastrophes with our current situation.

Sometimes I wonder if we’ve passed the point of no return with global climate change; everyone’s aware of it these days, but getting people to actually do something about it is where the battle really is. Recycling has been around since before I was born and yet there are plenty of people who don’t do it (even plenty of states that don’t recycle), so how are we going to motivate people to “do the right thing”? How many people are going to want to make the sacrifices necessary to stop global climate change? While I’m sure plenty have good intentions, I personally am a bit pessimistic; I think the technology is going to have to change so that it forces people to be more “green” as they’re not going to do it of their own initiative. Things are far too convenient and comfortable, and I think the battle here is not so much to convince people global warming is real but to actually do what is necessary to reduce our energy input and pollution output.





Grizzlies bounce back; the delisting continues…

23 03 2007

Apparently big predators are thriving in the United States, wolves, American crocodiles, and now grizzly bears all coming off the endangered species list (and others, like bobcats in the NJ Pine Barrens, are making a comeback). Coyotes and foxes are doing well in cities, mountain lions prowl McMansion developments west of the Mississippi, and predators of all sizes seem to have found their place in a world of suburban sprawl and ecological mismanagement. While I am heartened by the success of these species, it appears that the focus has swung from conservation to (over)active management, wolves, grizzlies, and other species being considered for culls or hunts now that they have established populations. These animals have survived the wrath of man and it seems that people want to go back out and hunt predators as a celebration of their removal from the endangered species listings, and of course this is absolutely foolish.

A stable and healthy population isn’t just about numbers, so merely because there are 500 grizzles in a given area or 300 wolves in all of Idaho does not mean those numbers are going to increase indefinitely (or conversely, are immune to population crashes due to disease or other factors). In the case of wolves, 300 is an awfully paltry number, and I would say the reducing that by 2/3 to 100 takes a step backward; it doesn’t make sense that once the population becomes stable we have the right to go out and start reducing the population again. It would be wonderful if, when a species is no longer endangered, they are given an extra 5 years or so of protection to establish territories, genetic diversity, and stable population numbers before “active management” of said population begins again. What many state governments are doing (I’m looking at you Idaho and Wyoming) is akin to patching up a relationship with a partner you abused, and the second the apologies are over you smack them in the face again. Indeed, “abusive” is perhaps the best word to describe the approach many state and local governments take towards wildlife, and while more people are aware of environmental issues these days the impetus to act is still minimal.

Now, I’m not naive enough to suggest that the bears should be given free reign, no matter what their population size. The wildnerness isn’t “wild” anymore and bears have shown great ingenuity in terms of finding garbage or alternate food sources to eat, thus there’s always a potential for population problems. Indeed, often the camps are polarized, those who don’t want any animals shot or interfered with on one side, those who perceive the predators as an imminent threat on the other, and wildlife management officials in the middle, the findings of actual scientists often coming in second to emotions and rhetoric. For my own part, I would love to see a wild America, but that is not to be (at least in my lifetime). We created so many ecological problems that we must be responsible for caring for and managing what’s left of the wild, and part of that management process may be culling animals if populations of predators get large enough that they become malnourished and begin to exclusively feed on garbage. Developers and residents should be held responsible for where housing is built and where anyone chooses to live, but I’m not going to say that if black bears are breaking into houses and cars in search of food because the natural population is so large that they’ve been pushed out that we should do nothing. Such is the debate going on in my state right now, and it’s become so polarized that depending on who you talk to or apply with, whether you agree or disagree with a regulated bear hunt you might not get the job.

In the case of crocs, grizzlies, and wolves, I don’t believe any of the populations are established enough and they need more time before hunting should be allowed. Hopefully, as wildlife repopulates now-developed areas and adapts to urban lifestyles, developers will take these issues into account and issues like bears getting into trash, coyotes running through pet doors, raccoons raiding the fridge, mountain lions taking a stroll through the streets, etc. will be able to be managed through design and responsibility taken by residents. We cannot live in a world where we can eliminate and contain everything wild; we might win the short battle but in the end we will only end up creating more efficient and wily animals, ones even more capable of becoming nuisances.





Take it easy Curious George… just put the stick down

23 02 2007

As if those darned chimpanzees hadn’t given creationists enough trouble with all their tool-use and intelligence, a new report in the journal Current Biology suggests that at least one group may have devised primitive “spears” (although from the way they use it it’s more like a probe/skewer) to get at bush babies slumbering in trees. I checked the journal’s website for the article but it does not appear to be available to non-subscribers as yet, although most news outlets are carrying the story. There is also some video from a forthcoming PBS NOVA documentary, although admittedly it does not illuminate much about the behavior.

Indeed, chimpanzees have featured in the news a number of times in the past few weeks, and here’s a quick rundown of the news in case anyone missed it;

February 10, 2007 – The American Museum of Natural History opens the Anne and Bernard Spitzer Hall of Human Origins to the public, featuring casts, reconstructions, and media-intensive displays to help educate people about hominid evolution. You can read my thoughts on the exhibit here.

February 12, 2007 – Oldest yet Chimpanzee tools found in Africa,
suggesting that chimpanzees have been using stone tools to crack open nuts for at least 4,000 years. We know from extant chimpanzees that youngsters are taught how to do this through observation, suggesting that this form of tool use has been taught for far longer than previously suspected (the oldest set of stone tools prior to this discovery were 100 years old). Have a look at the video below for a look at how it’s done.

It’s important to note that the piece of stone is not the only important part in the behavior; the nut must be held in place or else attempting to crack it will be fruitless. Usually another stone or piece of wood with a depression in it help keep the nut still so that full force of the stone can be exerted on it, an example of this on film seen in the BBC’s wonderful series, The Life of Mammals

February 23, 2007 – According to a new study published in PLoS Genetics, it is suggested that humans and chimpanzees split from their common ancestor about 4.1 million years ago. Bear in mind that the Laetoli footprints has been positively dated to 3.7 million years ago, so if these new figures for speciation times are correct, then the evolution from a common ancestor to Australopithecus must have been rather rapid in relative terms.

Anyway, back to the study that was produced yesterday about the “spears.” What seems to be the case is that immature and female chimps (individuals that usually don’t get much meat when hunting parties return and call first dibs on the pulverized monkeys) take a twig or stick and whittle the tip down to something of a point with their teeth, which they then “forcibly” stick the probe into holes in trees hoping to snag a snack, using enough power that if there is prey in their it would be impaled or injured by the motion according to the researchers. The chimps sniff and lick the probes upon retracting them, the behavior seeming reminiscent overall of chimp’s habit of “fishing” for termites or orangutans using sticks to get honey out of trees. Indeed, this seems to me almost like the modification of an already familiar behavior rather than something entirely new, although more study will certainly be needed to see if the chimpanzees are just probing to see what they get or they have an intent to stun or even potentially impale whatever is in the holes. Another scientist named Gilby said that Gombe chimpanzees will sometimes use a similar method to extract honey or birds from tree holes in this AP article, so again more research will need to be done to understand how “novel” this behavior is and all its details.

This also reminds me of some studies done of chimpanzees using sticks as weapons, the males wielding sticks to hurt females during some displays. I haven’t been able to find anything on the internet about this (the initial reference I found was in the book The Octopus and the Orangutan), but it appeared that as yet the males that did use the sticks had not extended them into use beyond beating up some of the females. A video I saw in my Behavioral Biology class last week also featured chimpanzees faced with a fake leopard, the chimpanzees attempting to use sticks to hurt the fake cat. From what the video showed, the chimpanzees had not figured out how to effectively use the sticks and branches to strike, throwing them about at odd angles that I’m sure would hurt, but certainly nothing like swinging a baseball bat. The fake leopard was decapitated by some means or another (it was not shown how), but again it seems that while some chimps may be using branches as offensive weapons they have not yet figured out how to use them efficiently enough for them to be useful.

Usage of tools for hunting, defense, or even offense is interesting as chimps seem to be quite proficient in using tools that could be used for weapons (rocks and sharp sticks) but have not extended the use of those tools as yet. I wonder what led to the first “weapons” or hunting tools, and I think to fully understand the answer we need to look at the paleoecology of where hominids arose. When the line that would lead to hominids split from the line leading to today’s extant apes, there were far more predators around, especially on the savanna that Australopithecenes and others would likely call home. In addition to big cats like we have today (leopards, lions, cheetahs), there were giant hyenas and saber-toothed cats and various horned and tusked herbivores, Africa being a pretty dangerous place to live at the time. If you were going to live on the plains, where there are few trees and you can’t run fast enough to escape, natural selection would certainly favor those who could protect themselves and use weapons most efficiently, pressures that are highly relaxed today. While I’m sure tool use among extant chimpanzees can help us gain insight into our own history,we must remember that we need to get the big picture of ecology, behavior, and morphology during the time hominids arose in order to successfully figure out what happened; evolution does not work in a vacuum.





Classic National Geographic… yikes….

18 01 2007

Tonight was the first recitation for my Behavioral Biology course, during which time the class watched Miss Goodall and the Wild Chimpanzees, which recounted the 5 years Dr. Goodall spent in Gombe studying the chimpanzees there. I had heard plenty about Jane Goodall during the course of my life (I’ve yet to read any of her books or research; it’s on my to-do list), her and Diane Fossey held up at the two paragons of virtue in behavioral studies, but while watching the film I was struck at how irresponsible some of Dr. Goodall’s interactions with her subjects were. The documentary as a whole was rather shoddy, clearly a re-enactment and not actual footage of Dr. Goodall’s research, and I even spied a faked behavior in the film; a leopard yawning in a tree was made to be roaring madly towards the beginning of the film, but anyone who owns a cat knows the difference between a yawn and a snarl. I also took issue with the narration and musical cues used in the film, put in to elicit “awwws” or laughs during certain showings of behavior by the chimps, aggressive displays made during a rain storm described as a “rain dance.” Ugh.

Back to the point. The Heisenberg Uncertainty Principle is most often discussed in terms of physics (or it’s misunderstood popular incarnations), stating that there is a mathematical limit to accuracy to what can be measured in a physical system. Although physics and behavioral biology are not the same by any means, I believe there is a similarity in that it is impossible to take into account everything needed to know to describe behavior with unlimited precision, past events, thoughts, genetics, unseen stimuli, and other variables that may not even be considered can affect research. This isn’t to say such behavioral studies are worthless (if they were, I would have essentially just convinced myself to pick a new area of research), but it’s important to account for such things and not underestimate what can change observed data. This can be paired with the “Observer Effect” (different from the Uncertainty Principle) whereby merely observing anything changes it to greater or lesser degrees, adding to the natural variations that we cannot account for. While many biologist go out into the field, we are not like ghosts, unable to influence our surroundings. No, we leave footprints, our scent carries on the wind, our presence disturbs various creatures and is the causation for behavior (regardless of whether it’s being studied or not) and such considerations should be taken into account when studying in the field. Be that as it may, we are not to simply throw our hands up and not study nature, but we would do well to consider as many factors as we can for the reasons of honesty, accuracy, and possible later illumination (perhaps that deer you scared out of the bush ran into the path of a tiger, giving it a meal it may not otherwise have had). Dr. Goodall’s work falls within these parameters for the first 1/2 of the documentary, but her desire to get close to the chimpanzees unsettled me a bit. Yes, she did make some amazing discoveries about chimpanzees diet, tool use, and social behavior, but when she was done were the animals still truly wild?

The documentary makes sure to show us Dr. Goodall playing around with her subjects, even stating that her behavior is possibly endangering herself (chimps are quite strong, and if they realize they’re stronger than you it can mean trouble if they find reason to be aggressive), but the sequence involving the bananas disturbed me most. The chimps come into the camp, whereby one is given a banana, and you know what that means; all the rest must have their own. As the narrator (Orson Wells, if I’m correct) points out, it’s a “banana orgy,” with chimps stuffing as many bananas as can fit into their mouths. It’s important to note here that the bananas given to the chimps are not found in Gombe, nor are they natural (bananas as seen in the supermarket were actually created by man, the natural fruit being quite disgusting on various levels), and the rucus caused by their delight soon attracts the more numerous baboons. I have not heard of chimps fighting with baboons previously (a good search came up with nothing so far), but the baboons want bananas as well and fight the chimps for a share, thus showing that Dr. Goodall created as unnatural a situation as there could possibly be.

I do not wish to be too rigid or uptight about Dr. Goodall’s work, and as I said before she made some wonderful observations, but I am concerned with the current state of wildlife conservation/ethology where the prevailing desire can be interaction rather than observation. Even darting and radio-collaring animals to track is altering their behavior (and probably the behavior exhibited to them by other animals), but we keep telling ourselves that these creatures are no less wild than those untouched. It is true that, like surgery, we must be somewhat invasive if we are to save our “patients” but it would at least be nice if the researcher’s effects on the subjects was taken into account and new methods developed that allowed animals to live more natural lives, rather than experiencing what to them might seem like an alien abduction (“I was chasing this gazelle, see, when there was this pain in my butt and these two weird things started poking me… I couldn’t move or anything and when I could I had this stupid heavy thing around my neck…”). Such is anthromorphosizing the animals a bit, but the point is the same; we should strive for objectivity and admit when it is not possible or may be compromised.