A reader forwarded this AP story about a new orangutan count for a relatively unexplored corner of Borneo:
JAKARTA, Indonesia (AP) — Conservationists have discovered a new population of orangutans in a remote, mountainous corner of Indonesia — perhaps as many as 2,000 — giving a rare boost to one of the world's most endangered great apes.
A team surveying forests nestled between jagged, limestone cliffs on the eastern edge of Borneo island counted 219 orangutan nests, indicating a "substantial" number of the animals, said Erik Meijaard, a senior ecologist at the U.S.-based The Nature Conservancy.
The area is around a fifth the size of Yellowstone National Park in the U.S., so 2000 orangutans sounds like a pretty high density.
This week's Nature has a news article by Emma Marris about bison conservation and genomics. I've been very interested in cattle and bison as an example of introgression in large mammals; in this case between two genera separated by over a million years of divergence. Possibly all, and certainly most of the bison left today have cattle genes in them. The article profiles geneticist James Derr, who sees these cattle genes as a conservation problem:
Wildlife managers have considered the genetic diversity of animals for some time, and animals in captivity have often been bred to preserve genetic diversity. But those were blunt approaches. Now, armed with genomic tools, researchers are starting to look at specific sequences in the genome, and are raising questions about what the fundamental unit of conservation should be. Most people see preserving wildlife as a matter of saving individuals; if all the individuals die out, the species becomes extinct. But that reasoning looks simplistic when considered at the genomic level. If the genes of a species change enough — through interbreeding, for example — that species will cease to exist even if individuals that look something like the original continue to thrive.
This issue is quite threatening to the entire idea of endangered species preservation. One argument for extending protection to multiple populations of species like chimpanzees is that you are preserving gene pools that have unique evolutionary histories. You can't just preserve one tiny corner of a species and expect to retain the genetic diversity that was present in the whole species' range.
But if your species' genetic diversity is already compromised by introgression, either from within the same species or from other more distant lineages, this argument is weakened. And if it's OK to preserve a fragment of diversity in an interbred population, then why not simply introgress the endangered species' genes into a more common, cosmopolitan relative. That is, why save the wolf, if you've already got lots of dogs with wolf genes in them? Why save the polar bear, when its genes will continue to exist in brown bears?
As the article notes, this question is really academic for most threatened species, whose population histories may not lend themselves to such promiscuous gene mixing. But bison are an interesting case nonetheless --
In 1905, then US President Theodore Roosevelt and William Hornaday, head of the New York Zoological Society (now known as the Wildlife Conservation Society), founded the American Bison Society, which collected bison and established herds in a few reserves in Montana, Oklahoma and South Dakota. A small herd, perhaps 30 in number, was still roaming Yellowstone National Park. According to Derr, all the bison in the United States today — there are now up to a million of them, mostly on private ranches — can probably be traced back to fewer than 200 bison.
Other scientists argue that the most important thing may not be unique genes, but instead unique cultural inheritance and status within ecological communities:
"There are more important things than genes," says Rurik List, an ecologist at the National Autonomous University of Mexico, who works with a herd that spans the US–Mexico border. These bison have some cattle genes, but they also have institutional memory. If List were to remove them and replace them with pure animals, would the bison still be able to find the water holes that the current herd knows so well? "They have been behaving like bison for 80 years," says List. "They have been fulfilling an ecological role."
So far all the genetic estimates of introgression are based on only 14 markers -- probably good enough as a test for the fraction of introgression dating back within the last 150 years, but it's not going to give any information about the dynamics or even the identity of genes that have moved into bison. Many more markers are going to be necessary in this and other cases of reintroductions and hybridization with domesticated varieties.
Marris E. 2009. Conservation: The genome of the American West. Nature 457:950-952. doi:10.1038/457950a
In today's mail, this question:
Stupid question that I wish you would address: Are the tissue samples left from recently extinct species such as the Auroch, passenger pigeon, moa, dodo etc etc of sufficient quality to use it to resurrect the species? I would much rather see an Auroch than a pet cat cloned. Of course a wooly mammoth or Neanderthal would be even more interesting but also more problematic.
It seems that those pursuing the idea of such resurrection are more interested in constructing artificial chromosomes. Once the technology is sufficient to do that, all you need is a genome sequence of the extinct organism and a suitable (closely related) host species to carry the pregnancy—of course with the attendant possible problems of immunocompatibility, etc.
So, the barrier now is not the amount of tissue or the availability of genomic data, both of which seem to be sufficient for any recently extinct organism.
I also mentioned the topic last month, after the NY Times carried an article about mammoth cloning. The idea raised there by George Church (which he thought would "alarm a minimal number of people" was constructing a Neandertal genome from a chimpanzee prototype. Is he imagining that people aren't ooked out by a Neandertal baby C-sectioned from a female chimpanzee?
OK, so I'm ooked out. Meanwhile, I think you're going to want to construct a diploid genome, not two identical ones, because there are going to be some recessive lethals in there. So it takes more knowledge of variation than a single genome, and ideally quite a bit more. That's a limit too.
Scientific American reports on a taxonomic auction by Purdue University:
Naming your kid after you is one thing. But imagine if an entire species were named for you.
This week, Purdue University is auctioning off the rights to name seven newly discovered bats and two turtles, the Associated Press is reporting. The winners — who will shell out a minimum of $250,000 for at least one of the bats, a Purdue spokesman told ScientificAmerican.com — can link their own name or that of a pal to the animal’s scientific name.
"Unlike naming a building or something like that, this is much more permanent. This will last as long as we have our society," John Bickham, who co-discovered the nine species, told the AP.
I don't think there's anything wrong in principle with selling the naming rights to your new species. Heck, I'd be happy to name a new species after a donor, if I had either. I don't even think there's anything wrong with consistently adopting a splitter's viewpoint on new species, keeping in mind that you have many donors and other people that you might honor with your work.
But it seems to me there is a truth-in-advertising problem here. Species names are not eternal. They are hypotheses. We re-evaluate the relations between living populations and fossil populations all the time. The scientific community ignores ("sinks") taxonomic names that they come to believe are synonymous with existing taxa. So there is an obvious question: what are you really paying for, if you bid on naming rights for a species?
Naturally, it will depend on the investigators. Are they credible? Do they have a good record in the practice of taxonomy?
In the end, you're taking a bet: A bet against future discoveries. A bet that today's knowledge is the best there will be, at least where taxonomy is concerned. A bet that today's fashion won't reverse itself -- where the fashion is to recognize lots and lots of species, which helps to promote conservation goals tied to Endangered Species status.
Well, I suppose we can say that the people who would splurge for more than $250,000 for a name don't really care if the name sticks. They probably want something else -- let's say, a story. That might include a motive to fund research on bats (in this case) or some other group of organisms, or just to fund conservation work generally. Or it might just be a line at a cocktail party -- hey, my wife has a species named after her. Or in the case of a recent taxon sale, good advertising for a casino.
But maybe the people who bid on species naming rights ought to be made aware that it is a bet. Not eternal glory, just a chance at it.
In that issue of Current Biology with the report about bonobo hunting, there is also a short correspondence describing the decline of chimpanzee populations in Côte d'Ivoire:
The pressing need to base conservation policy on up-to-date data is underlined by the situation in Côte d'Ivoire. For instance, Marahoué NP is listed as a priority site with an estimated population of 900 chimpanzees (information from the Woods Hole Research Center's website); however, our 2007 survey of 167.5 km of transects distributed throughout the park yielded a conservative population estimate of fewer than 50 individuals (unpublished data). Even in Taï NP, thought to represent one of the main refuges for chimpanzees within Côte d'Ivoire, our 2006–2007 survey along 362 km of transects revealed that only about 480 individuals survive, a tenth of the assumed population size (Campbell et al. 2008:R904).
The human population has increased by 50% since 1990, when the last attempt at a chimpanzee census was finished.
Campbell G, Kuehl H, Kouamé PN, Boesch C. 2008. Alarming decline of West African chimpanzees in Côte d'Ivoire. Curr Biol 18:R903-R904. doi:10.1016/j.cub.2008.08.015
This story describes research on the longevity and maturation of wild bears who have invaded urban habitat in Nevada:
It turns out that urban black bears are much heavier and more likely to die violent deaths than their wilder peers, the study found. Oh, and if female, they're more likely to get pregnant at a younger age.
The research is describing cities and suburbs as "population sinks" for bears. The idea is that the urban habitat is drawing in bears (to eat garbage) who would otherwise live in marginal wild areas. Since those marginal wild areas are themselves probably population sinks -- and the urban bears are reproducing younger -- it's not obvious that this is a net loss to the bears. But the behavioral and physiological consequences of the human diet -- fatter bears who reproduce younger -- and the interaction with the high death rate (from being hit by cars) is fascinating.
A grueling survey of vast tracts of forest and swamp in the northern Congo Republic has revealed the presence of more than 125,000 western lowland gorillas, a rare example of abundance in a world of rapidly vanishing primate populations.
The survey was conducted by the Wildlife Conservation Society and local researchers in largely unstudied terrain, including a swampy region nicknamed the “green abyss” by the first biologists to cross it. Dr. Steven E. Sanderson, the president of the society, marveled at the scope of what the survey revealed. “The message from our community is so often one of despair,” he said. “While we don’t want to relax our concern, it’s just great to discover that these animals are doing well.”
In last week's Science, Stanislas Dehaene and colleagues describe the relation of cultural invention to "universal intuition" about mathematical logic:
The mapping of numbers onto space is fundamental to measurement and to mathematics. Is this mapping a cultural invention or a universal intuition shared by all humans regardless of culture and education? We probed number-space mappings in the Mundurucu, an Amazonian indigene group with a reduced numerical lexicon and little or no formal education. At all ages, the Mundurucu mapped symbolic and nonsymbolic numbers onto a logarithmic scale, whereas Western adults used linear mapping with small or symbolic numbers and logarithmic mapping when numbers were presented nonsymbolically under conditions that discouraged counting. This indicates that the mapping of numbers onto space is a universal intuition and that this initial intuition of number is logarithmic. The concept of a linear number line appears to be a cultural invention that fails to develop in the absence of formal education (Dehaene et al. 2008:1217).
The idea is that children in Western societies have to learn that a number line is a linear representation; they begin by compressing the space devoted to large numbers:
When asked to point toward the correct location for a spoken number word onto a line segment labeled with 0 at left and 100 at right, even kindergarteners understand the task and behave nonrandomly, systematically placing smaller numbers at left and larger numbers at right. They do not distribute the numbers evenly, however, and instead devote more space to small numbers, imposing a compressed logarithmic mapping. For instance, they might place number 10 near the middle of the 0-to-100 segment. This compressive response fits nicely with animal and infant studies that demonstrate that numerical perception obeys Weber's law, a ubiquitous psychophysical law whereby increasingly larger quantities are represented with proportionally greater imprecision, compatible with a logarithmic internal representation with fixed noise (7, 20, 21). A shift from logarithmic to linear mapping occurs later in development, between first and fourth grade, depending on experience and the range of numbers tested (17-19).
They note that there's a problem testing these ideas in Western children, who are surrounded throughout their development by numbers -- in books, "elevators" and other places. Most of these numbers are small ones -- especially one through ten -- so they might naturally accentuate the ones they know.
They found when testing the Mundurucu that both adults and children tended to compress the high end of the number scale, even testing numbers between one and ten. This compression is logarithmic -- they accentuate contrasts between small numbers disproportionately. It makes sense logically -- we care more about detailed contrasts between small numbers than large numbers. They don't give an idea of which logarithm people are using; and in fact it may be different ones for different people. The important fact is the small number/large number contrast.
Dehaene and colleagues attribute this scaling to mapping at the neural level:
What are the sources of this universal logarithmic mapping? Research on the brain mechanisms of numerosity perception have revealed a compressed numerosity code, whereby individual neurons in the parietal and prefrontal cortex exhibit a Gaussian tuning curve on a logarithmic axis of number (27). As first noted by Gustav Fechner, such a constant imprecision on a logarithmic scale can explain Weber's law -- the fact that larger numbers require a proportional larger difference in order to remain equally discriminable. Indeed, a recent model suggests that the tuning properties of number neurons can account for many details of elementary mental arithmetic in humans and animals (21). In the final analysis, the logarithmic code may have been selected during evolution for its compactness: Like an engineer's slide rule, a log scale provides a compact neural representation of several orders of magnitude with fixed relative precision.
From that perspective, the Western conception of the number line appears as a very distinctive invention, capable of adjusting the logarithmic encoding to arrive at faster and more accurate mathematical conclusions about large numbers. The authors speculate that addition and subtraction (which display invariance between large and small numbers) and experience with measurement underlay the development of the linear concept in Western children.
Dehaene S, Izard V, Spelke E, Pica P. 2008. Log or linear? Distinct intuitions of the number scale in Western and Amazonian indigene cultures. Science 320:1217-1220. doi:10.1126/science.1156540
That's a quote from the International Union for Conservation of Nature, in this Elizabeth Rosenthal article. This spring has seen a backlash against biofuel generation based on its apparent impact on food prices. Among the most promising alternatives to starch or sugar-based ethanol production is cellulosic production from wild grasses or reeds.
The problem is that the perfect biofuel species -- one that grows easily in a variety of habitats, with little care, and possibly perennial so that it can be harvested year after year without repeated planting -- pretty much is the textbook definition of an invasive plant species.
The European Union is funding a project to introduce the "giant reed, a high-yielding, non-food plant into Europe Union agriculture," according to its proposal. The reed is environmentally friendly and a cost-effective crop, poised to become the "champion of biomass crops," the proposal says.
A proposed Florida biofuel plantation and plant, also using giant reed, has been greeted with enthusiasm by investors, its energy sold even before it is built.
But the project has been opposed by the Florida Native Plants Society and a number of scientists because of its proximity to the Everglades, where giant reed overgrowth could be dangerous, they said. The giant reed, previously used mostly in decorations and in making musical instruments -- is a fast-growing, thirsty species that has drained wetlands and clogged drainage systems in other places where it has been planted. It is also highly flammable and increases the risk of fires.
Well, burning the stuff certainly defeats the purpose. It seems to me that most of these drawbacks come from insisting on a monoculture, which -- if you have an efficient cellulose processing capacity -- I don't see why you care about. A real natural marsh or tallgrass ecosystem can't stand much mowing, but if you could tune a multispecies ecology for biofuel production, that would pose much less risk of invasive potential, and would be less trouble to look after. The tallgrass ecosystem was based on burning, anyway, so you should be able to maintain the soil while taking out hydrocarbons with minimal fertilizing.