Conservation inaction

A friend who runs a conservation organization in Papua New Guinea is visiting. She and I have been discussing whether, in the long run, there would be any meaningful change in long-term conservation outcomes if every western conservation organization in PNG were to up and leave. We are not convinced that there would be.

Sad.

Fishy

One of my students, DC, emailed me, very confused. I had asked her to compile data on sex-baised dispersal in primates, and she has been doing a huge amount of work, digging through the literature, and has found data for about 50 species. Then in April, a paper came out in a high profile journal which, among other variables, examines sex-based dispersal in primates. DC student found the paper, but couldn't find the data on sex-biased dispersal. There are lots of references, and lots of supplemental materials, but nothing to our cause. So DC emailed me, and I read the paper and the supplemental materials. I also could find no data and no sources on sex biased dispersal, even though there were graphs (with 70 unlabeled diamonds, circles and squares labeled as male biased dispersers, female biased dispersers or both sexes dispers equally) and analyses based on those data. "Must have been left out by accident," I thought, and looked up the author's website to see if the data were posted there. Nope.
So I emailed the author, asked for either the data table or the references on which it was based, and got an almost immediate reply. She stated that:

A. The data and sources had been cut out to save space. This is fishy, as the journal has no space limits on supplemental online materials, and many papers come out in this same journal with far more appendixes than this paper has.

B. It would be too much work to track down all the references and sources again. This is fishy, as the paper came out only this year, and it would be truly remarkable to lose track of one's data set and all of its sources so quickly and thoroughly.

C. If I wanted information on a particular species, she would be glad to see what she could find. This too is fishy, as it implies that she would have to go to the library looking for the data that her published paper is already based on.

I can't help but wonder if there ever were data and sources. I would like to think of some innocuous explanation, but have not done so yet. I told my student to take this as an example of what not to do.

Snake self defence

Iris and I were on our way up Blake St from the BART station to our house.
At the corner of Walnut St, I exclaimed, "Oh!"
"What! What!? What?" Iris responded.
"A garter snake!"
The sleek black ribbon, two feet long and no more than half an inch wide, with a bright yellow strip up its back, was frantically trying to wriggle out of the street and onto the curb. That corner has no curb-cut, and its movements were too disorganized to allow it to climb the 6-inch curb.
Three facts jumped to mind:
1. It was clearly overheated by being on the black pavement in the sun, and would cook to death or get run-over unless we rescued it.
2. Garter snakes are not poisonous, but can bite.
3. It probably came from El Cerrito Hillside Natural Area, 200m up the street.

So I handed my cane and groceries to Iris and grabbed the snake with both hands. But I had forgotten that the hotter a snake is, the faster it can move. Before I could get a finger on it, my thumb was bleeding from multiple tiny punctures. I grabbed the little snot anyway and held firmly, but without squeezing, on the back of its skull. Then it hit me with a garter-snake's last line of defense: musk. A garter snake's musk glands are in its vent (a.k.a. cloaca, a.k.a. butt) and can rapidly discharge a surprising quantity of a fluid that smells somewhere between a port-a-potty and old gym-socks.

With one hand bleeding and the other clamped on a snake and stinking, I looked up at Iris. She handed me my cane and retreated up the street.

Thamnophis elegans - Western Terrestrial Gartersnake

Catnip -> Olfaction -> Happy

My Friend Terry Johnson is a lecturer in Bioengeneering at UC Berkeley. He also writes the Ask a Biogeek column for io9.com. Now he is one of the judges for their Mad Science Contest: Build a Lifeform. And, in investigating my idea for an artificial organism, I came across this abstract:

Hart BL, Leedy MG.1985. Analysis of the catnip reaction: mediation by olfactory system, not vomeronasal organ. Behav Neural Biol. 44(1):38-46.

Pet owners and behavioral scientists alike are fascinated by unique behavioral reactions that cats show in the presence of catnip. These experiments explored the possibility that the catnip reaction might be triggered by chemosensory stimulation of the vomeronasal organ. In the chewing and mouthing of the catnip source, substances might be dissolved in saliva and transported to the vomeronasal organ. The rolling and rubbing during a catnip reaction might be a sexual response activated by the accessory olfactory system since the system projects to parts of the brain involved in mediation of sexual behavior. However, removal of the vomeronasal organ did not attenuate any of the behavioral reactions to catnip. Olfactory bulbectomy immediately eliminated catnip responding, revealing that the chemosensory stimulus evoking the catnip reaction is undoubtedly mediated through the main olfactory system. Catnip activates behavioral elements associated with several species-specific behaviors, including sniffing and chewing as associated with oral appetitive behavior, rolling and rubbing characteristic of female sexual behavior, batting the catnip source characteristic of play behavior, and a type of kicking associated with predatory behavior. These behavioral reactions occur randomly and intermittently.

The moral of the story seems to be that:
A. Cats respond to catnip through their olfaction, the type of smelling that humans do fairly well, rather than through the vomeronasal organ, the part of smelling that humans don't seem to do at all.
B. Catnip elicits from cats behaviors associated with almost every active things cats enjoy (eating, playing, sex and hunting). Catnip does not elicit the calming and resting behaviors such as self-grooming and napping that cats also enjoy. Catnip also does not elict behavior associated with things cats don't enjoy (fighting, danger, housechoirs).

Based on this, and my own observations, it seems likely that catnip is a quick-acting stimulant, extremely pleasant to the cat and absorbed through the olfactory epithelium.

Stefanie Schwartz, in her book "Psychoactive Herbs in Veterinary Medicine" list some other useful facts. Catnip response is not associated with any know histological or physiological effect, (meaning that while it certainly does something in the body, it is something subtle) catnip is not toxic even at relatively high doses, and the physiological and psychological effects are very different in cats than in humans. In humans, catnip is mild sedative, and smoked catnip is said to have similar psychtrophic effects to smoke marijiana. In cats, it is clearly a stimulant. In neither species does it have any known side effects.

Nepetalactone, the active ingredient, is also aparrently a powerful insect repellant, driving off both lice and cockroaches many times more powerfully than does DEET.

Better Solar Cells

It is amazing how when one does research into a technology, that technology can get better.

Science 11 July 2008:
Vol. 321. no. 5886, pp. 226 - 228

High-Efficiency Organic Solar Concentrators for Photovoltaics
Michael J. Currie, Jonathan K. Mapel, Timothy D. Heidel, Shalom Goffri, Marc A. Baldo

The cost of photovoltaic power can be reduced with organic solar concentrators. These are planar waveguides with a thin-film organic coating on the face and inorganic solar cells attached to the edges. Light is absorbed by the coating and reemitted into waveguide modes for collection by the solar cells. We report single- and tandem-waveguide organic solar concentrators with quantum efficiencies exceeding 50% and projected power conversion efficiencies as high as 6.8%. The exploitation of near-field energy transfer, solid-state solvation, and phosphorescence enables 10-fold increases in the power obtained from photovoltaic cells, without the need for solar tracking.

Sock of Science!

The Ozone Sock company employs my baby cousin David as National Sales Director, or some such title. He told me about their "My Socks are Your Socks Design Competition." Naturally I have been designing science themed socks.
Here is a sock I call, "Where's Pluto?"

The Velige People

One of the great pleasures of working with really talented undergraduates is that they know stuff I don't and make me learn stuff I would never otherwise have gotten to learn. Take NN. I met NN when I went to the Invertebrate Zoology class she was taking to ask if any of the students wanted to help me with my rotifer experiments. A couple of days later I got a resume from NN, and quickly realized that in addition to being a great assistant, she knows enormously more about aquatic invertebrates, and a bunch of other biological topics, than I do. A good start.

One of the topics she knows and I don't is biomechanics. She quickly developed an interest in rotifer fluid mechanics. So yesterday afternoon NN and I went up to the lab of Dr. Mimi Koehl, aquatic invertebrate biomechanician extraordinar and talked to her grad-student and my friend, Lindsay.

It turned out Lindsay and NN have a lot in common. They both are fascinated by aquatic invertebrates, biomechanics, fluids, and the interactions of these concepts. And they both know what a veliger is. In fact, they had quite a long discussion about veligers of different types, and how many of them have a range of similarities to rotifers. I, throughout this entire conversation, played the game of trying to take part in the discussion while also attempting to deduce what a veliger was.

I figured out this much: veligers are a subset of the larvae of aquatic invertebrates. They are motile plankton whose motive force and/or feeding is supplied by rings of compoud cilia, the same as one would find in a rotifer. They often grow up into forms that are not moved by cilia, like muscles and snails. When said quickly, veligers sounds a lot like villagers, which renders funny any conversation about what sorts of creatures eat veligers.

Today I looked up what a veliger actually is. I wasn't too far off the mark. A veliger is a young mollusk in a developmental stage provided with a velum, a membrane edged with clilia used for locomotion and feeding. Cilia are only a reasonable way to get around if one is small (a couple of millimeters at most) so once a veliger grows that big it generally moves on to other means of locomotion, losing its velum and thereby its veliger status. Veligers are found in the bivalves (clams, muscles etc) and the marine gastropods (snails and sea-slugs).

Lindsay says that several people have wanted to study how veligers use their cilia to feed and move, but that little progress has been made because of the difficulty of finding and keeping them. They die, they grow up, they don't reproduce quickly. So since I know how to provide a large number of the animals that most closely resemble veligers in their use of cilia, rotifers, and Nicole and Lindsay know about biomechanics and veligers and all that, it seems we have a good collaboration.

P.S. Here is a photo of a Fusitriton veliger that Lindsay sent me. I Photoshopped it to increase the contrast, to make the cilia more visible.

Plant Behavior

There is a scientific society dedicated to the study of almost anything. But until recently (2005) there was no society dedicated to the study of the behaviors of plants. Enter The Society of Plant Neurobiology. which states on its website:

"Plant Neurobiology describes a newly named, but also old and fascinating field in plant biology addressing the physiological basis of adaptive behavior in plants. Perhaps this field could be called "Sensory Biology in Plants" or something similar. However, these names don't quite cover topics like plant cytology and anatomy, adaptive plant behavior, signaling and communication in symbiosis and pathogenesis, or newly emerging topics like for instance plant immunity, plant memory and learning, plant-plant communication, as well as plant intelligence."

This is very convenient for me, as I am currently writing a paper on, among other things, taxonomic bias in definitions of the word 'behavior.' Having gotten input from member of the Animal Behavior Society and the International Society for Applied Ethology, I am thrilled to be able to get the viewpoints of botanists interested in behavior. I emailed the chair of their steering committee, asking her to forward a link to my "what is behavior?" survey to their membership. If she is sympathetic, this could be really cool.

I learned of the existence of SPNb through this article on NYTImes.com. Check out the video of the parasitic plant sniffing for prey and pouncing on the unsuspecting tomato vine.

Rotifer fluid mechanics

One of my best students, NN, has become fascinated with the ways in which rotifers use their cilia, and wants to do a senior honors thesis on the fluid mechanics of rotifer cilia. She is interested in issues of scaling, how they use their cilia in feeding and locomotion, and the differences in the cilia between males and females. Males use their cilia only for locomotion, while females use them for both locomotion and feeding, leading to some fascinating questions about the trade-offs females make to have their cilia serve these two very different, and very important roles.

I very much want to encourage her in this, but started by explaining to her that as an evolutionary demographer, I know squat, make that squat/2 about biomechanics. And of all the parts of biomechanics I don't understand, Low Reynolds Number Fluid Mechanics may just be the part I understand least. I understand it so little I don't even know what it means. The Reynolds number has something to do with the ratio of the size of the object to the viscosity of the fluid, or something like that. This helpful Wikipedia article describes it in terms I only vaguely understand. What I understand it to mean is that the smaller an organism or piece of an organisms is, the more viscous the fluid effectively is. A whale moving through water experiences an environment in which viscosity is much less important than a rotifer moving through the same, equally viscous water. The rotifer has a very low Reynolds number, and its cilia have even lower Reynolds numbers. The viscosity of the water they move is so high, it is like a human arm through tar. Or something like that.
But don't quote me on any of that because it is probably wrong.

So I told NN that I was glad to work with her on that, but she would need an adviser from a biomechanics lab, like that of Mimi Koehl. Luckily, one of my best friends in my department is one of Mimi's students, and is interested in ciliary feeding. And this morning we went to the grocery store together, and by the time the groceries were in the fridge, my friend had agreed to meet with my student and help her figure out how to frame and answer her question. My only claims on the project will be that I helped generate the questions, am brining the collaboration together, and am providing the study organisms. In other words, I may end up co-advising a senior thesis on a topic I know nothing about. Hopefully by the end I will at least know what a Reynold's number is.

Inching toward science

For as long as there have been science classes, creationists have wanted to teach creationism as science. And in many countries, including this one, they have often done so. In some countries, much more so than the US, they still do. But in the US they have suffered a long series of court defeats on the basis that creationism is religion, and not science, and therefore does not belong in science classes. And it often seems like a battle that can't really be won, because as soon as they lose one court battle they repackage and try again. But considering that history as outlined in this NYTimes article gives me a sense that while we will never convince them to give up entirely, in the long run they are gradually being forced to adopt positions with more and more resemblance to science.

At first, of course, they simply outlawed the teaching of evolution where they could. These laws didn't stand up in the courts, so they decided that creationism and evolution would be taught side by side. That didn't stand up either, so they came up with the bright idea of wrapping creationism in a thin film of scientific lingo and calling it 'creation science.' That didn't stand up to examination for very long either. Next they decided that rather than creationism painted science-color, they would have the nugget of creationism with many layers of scientific sounding text, language, calculations and books wrapped around it, and call it Intelligent Design Theory. No explicit mention of any particular intelligent designer, just a very selective use of scientific knowledge and concepts with the goal of concluding that evolution can't explain the universe, and therefore there must be a creator. Some of them even went so far as to acknowledge microevolution (the modification of existing forms) while still rejecting macroevolution (the accumulation of those modifications to the point that it seems to us to be a really different form). That, as you know, didn't stand up in court either. Partly their arguments made no sense, and partly there was plenty of documentation of the fact that they had started with a conclusion and worked backwards, making up results to support that conclusion, making up methods that would lead to those results and then trying to figure out what question they should pretend to have been trying to answer. In other words, they were demonstrably engaged not in science, but in fraud. But for all its repugnance, ID had the desirable property of getting the creationists to agree that they needed to make evidence based arguments, even if they then failed to do so. ID, exposed as the cynical lie that it is, is now dying from too much light. Thus always to imposters.

But creationists have too much faith in their own infallibility to give up and go home. So the Discovery Institute and its usual corral of quacks are designing a new and improved 'science curriculum' intended to highlight the 'strengths and weaknesses' of Darwinian evolutionary theory. I have absolutely no doubt that this is just the same spoiled sausage in a shiny new casing, but at least they have finally been forced to adopt a truly scientific casing. Examining the strengths and weaknesses of theories is what science is about. Now there are unscientific ways of going about it, and I have no doubt they will employ almost all of these, but the details of the curriculum can be challenged in court.

There are of course downsides to them having finally found a really scientific name to call their beliefs. They are adapting to the fact that their ideas are demonstrably not science by gradually phrasing them in a more and more scientific way. That may make it a little bit harder each time to prove that religion is still not science, and harder for the average person to understand exactly why it is not science. This time, instead of getting 'strengths and weaknesses' thrown out of the classroom entirely, we may have to fight item by item about what can be presented as a strength or a weakness, and how they can be presented.

But as long as we can continue to find judges willing to judge on the evidence (which I know is in some doubt), we will continue to win those fights. Religion really isn't science, and no matter how cleverly disguised will continue to not be science. We can explain the data without invoking non-scientific concepts like a benevolent omnipotent and omniscient creator, and they can't. So once the argument is on our turf, once they are arguing with us about what evidence and logic show, they can only lose. Not to say that it will be a sea-change. What we have accomplished to date is extremely incremental, and that will continue. But we are pushing them back, inch by inch, foot by foot, concept by concept. They will argue that the human eye is irreducibly complex, we will use data and logic to show that that is ignorant nonsense. The courts will be forced to rule in our favor. They will argue that the laws of thermodynamics make it impossible for order to arise from disorder. We will explain to the judges that this is true only in a closed system, with no input of order, and there will be a court ruling that says that their argument is not science. And on. And on. But as long as our country holds it together enough to continue having a judiciary that has to listen to evidence most of the time, and as long as the data and logic are all on our side, all they can do is stall, limit the rate at which they lose ground. And as that happens, they will be forced to incorporate more and more actual science into their arguments. Who knows, maybe some day they will be forced to admit to both microevolution and macroevolution, but continue arguing that their had to be a creator to get it all started. At that point, they will be in agreement with Darwin himself, who wrote in The Origin of Species, "There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator 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." This view is of course still not science, but if they can be driven back this far they will be rendered, in my view, mostly harmless.

Of listing and sex

Among many bird-watchers, there is an obsession with listing. Species one has seen anywhere, species one has seen in Ontario, species one has seen in Ontario in October, species one has seen through a particular window while sitting on the toilet and so on. I once had a colleague point his binoculars up at the sky for a few seconds, and say, "Awesome, I've never seen a Red-Throated Loon on the southward migration over Lake Eire before. Another tic for my list."
I keep a few place specific lists, "birds I've seen in the El Cerrito Hillside Natural Area," or, "birds of Mahopac, NY," and used to keep a life list (e.g. all the wild birds I've ever seen anywhere) but I've never really gotten into listing for listing's sake. Hard-core listers (commonly referred to as twitchers for their inability to hold still if someone suggests a bird they don't yet have on a particular list is nearby) are often far more interested in adding birds to lists than in actually looking at the birds, and will often travel long distances to find a bird, look at it for just long enough to confidently add it to their list, then begin the long journey home. Those of us who are not twitchers, but know people who are, enjoy the game of making up new types of lists and mentioning them to twitchers so that they will feel compelled to rush out and start building a bigger, longer more impressive list with more rare species. So, in that spirit, I have started to compile a copulation list, of all the bird species I have ever observed copulating. This list is necessarily incomplete, as I am only including those species which I know a particular time and place when I witnessed a copulation in the wild, but excluding all the other species that I forget where or when. This list was inspired by the activity of two house-sparrows this fine June morning.

In no particular order:
House Sparrow
California Condor
Turkey Vulture
Fairy Bluebird
Florida Scrub-Jay
Western Scrub-Jay
Steller's Jay
Common Raven
American Crow
Bald Eagle
House Finch
European Starling
Canada Goose
Mallard
Muskovi Duck
Great Egret
American Robin
Dark-Eyed Junco
California Towhee
Red-Tailed Hawk
Red-Shouldered Hawk
Willie Wagtail

Rotifer Photos

I have a couple of students working with me this summer on an ethogram of my rotifers. An ethogram is a list of behaviors exhibited by a species, with a description of each one. One of the students, Laura is particularly interested in invertebrate behavior, and the other, Harmony, wants to get experience in scientific illustration. Harmony will make the illustrations of that go with the descriptions of each behavior.

In order to help her with this, I am figuring out how to get good photos of the rotifers through a compound scope. Here are some of the prototypes:

A juvenile female rotifer feeding on bright green algal cells.

This very small female (on the right) dwarfs the normal sized male on the left. Male rotifers are tiny, fast and anatomically simple. He has no digestive system, a very rudimentary foot, and no defensive spines. The very dark area in the middle of the female is her trophi (aka teeth). The male has none. His penis is at the base (caudal end) of his foot, and he is attempting to inject sperm into the female.



This juvenile female has retracted her head and foot into her shell (lorica) in a defensive posture, because I poked her with my pipette.


This is a high magnification shot of a dried out male rotifer. The males never hold still and are very hard to get photographs of in life. I dried this male onto a microscope slide with a lamp. On the left you can see his shaggy 'mane' of cillia, which propel him through the water. The males are very small compared to their cillia, which may help to explain why they are so damn fast.

Three Birds, Two Cats and a primate

It was an awful lot of croaking for a Friday afternoon. I went out on the patio to investigate. The Ravens were in an uproar about something. My first thought was that one of their nestlings had fledged and was hiding in our yard. They were flying back and forth, low over the top of the apple tree, scolding and creaking and booming. I decided their fledgling must be in the top of the tree, and they must be trying to tell it that this was not a safe place. My eyes scanning the trees for a fledgling, I was impressed and intimidated to see these two birds, each the size of a large hawk, diving and screaming just over my head. And just as I was starting to think they might really be screaming directly at me, I heard something moving only a couple of yards from my feet. Looking down, I saw this:

A turkey right in our garden, and clearly the focus of the Ravens' ire. They were responding to it as they would any large animal (except humans and deer, which they seem to be used to ) getting too close to their nest tree: by screaming and scolding, "you better git the hell off our land if you know what's good fer ya!" The turkey had apparently responded by hunkering down by Betty's compost bin.


I pulled out my cell phone and started to take pictures. After a couple of minutes the ravens went off to scream at something else and the turkey and I were left to talk amongst ourselves. I went for my better camera, but finding the batteries dead, knocked on Betty's door and said, "Hi Betty, sorry to bother you, but there is a turkey in the backyard. You should bring your camera please."

It was a very tame turkey. I taking photos with my cellphone and Betty with her big digital SLR each stood about 10 feet from it. "People have been feeding it." I said as it watched us hopefully and I resisted the urge to feed it. It rooted around in the garden.

FeLion wandered out onto the patio and saw the turkey. Her response seemed perfectly split between, "That is the biggest bird I have ever seen, I'm gonna eat it." and "that is the bigest bird I have ever seen, I hope it doesn't try to eat me." She was frozen with indecision.


Betty's cat Sophie, on the other hand, was not at all reluctant to charge a bird twice her weight. She burst out of the bushes and sprinted toward the turkey, who turned tail and ran up the step to the very top of our yard.


When I caught up, the turkey was defending a position on top of the garden gate arch, and Sophie was attempting to storm the battlements.

Eventually she succeeded, and the Turkey took to the air, at which point the Ravens resumed their harrying. The turkey, pursued from above an below. stopped in a tangle of low Eucalyptus branches. Betty and I snapped a few more shots and then took the cats inside.

Garden of Science!

Most anyone in the Northern Hemisphere who has put out a bird feeder has had the problem of dealing with squirrels raiding their feeder, spilling the seed and chasing off the birds. There are a huge range of products designed to deter, exclude or punish the offending rodents, many of which work only marginally. I am currently using a product which is highly effective and nearly free: chili-pepper seed mixed into the bird seed. As any mammal who has bit into a chili-pepper knows, chilies make mammalian mucous membranes burn. What most mammals don't know is that to birds, the active compounds in chilies, capsaicin, does not cause pain to birds. In fact, to them is is an analgesic, meaning a pain killer. 

Wild chilies make their seeds and fruits to propagate themselves. But chili seeds eaten by mammals tend to be chewed up, and even if they are not, they don't germinate successfully after passing through our digestive systems, and even if they did, mammals don't tend to transport seeds as far as birds would. So it is well worth their while to produce a compound that dissuades mammalian seed predators and simultaneously encourages avian seed dispersers. Chili seeds pass though the guts of most seed eating birds perfectly primed to germinate, and get a ride far from their parent plant.

But in my bird feeder, the seeds are an enticement to the birds I want to attract, and a strong discouragement to the squirrels. And because it is whole seed, it won't wash away as chili powder would, and pouring whole seed it does not induce as much coughing. 

I bought a very cheep bag of over-ripe Thai chilies from my local grocery store, dried them in the sun and then banged them around in the food processor until all the seeds had come loose and settled to the bottom. I then mixed them with commercial bird seed before filling the feeder. The squirrel, to my knowledge, visited the feeder only once.

All quiet on the Hayward Fault

For the five years I have lived in the Bay Area, I have occasionally checked this map to see what recent earthquakes have happened round these parts. This is the least activity in a week I have seen. And there has been almost this little for some weeks now. The cluster of small quakes in the upper left corner is "The Geysers," an area of hydrothermal activity that always has many small quakes. On the San Andreas Fault and the Hayward Fault, the two main faults running through the Bay Area, there is not a single anything. No movement. This makes me very nervous. It makes me think that things have jammed. As long as there are many small earthquakes, my fabulously limited knowledge of seismography suggests that tension is being released. For the last several weeks there has been almost no release of tension on the faults around here. I consider it fairly likely we will have a significant earthquake pretty soon here. That said, I really don't know squat about earthquake prediction.

Art Show of Science!

This coming Friday at 5PM in VLSB is the Integrative Biology Art and Science Show. Food. Drink. Science inspired art.

All are invited.

A good time is guaranteed for most.

(Also, it is not too late to submit your own art to the show.)

Dying for Sex

One of the projects I am working on currently is an analysis, using data from primates, of what life history factors are correlated with sex-biased longevity. To put that plainly, I want to know why in some species the females live longer, in some the males live longer, and in some they live equally long. One of the dozens of hypotheses out there explaining why females live longer, in species where they do, is the 'risky male behavior' hypothesis' which says that males don't live as long because they take risks while out looking for sexual partners.

There has been limited support for this hypothesis, and most of the others, because so many hypotheses make the same predictions that one can rarely conclude that a particular factor is at play unless one ignores all the other possibilities (which seems to be the standard practice.)

This paper from Proc.Roy.Soc.B. takes an interesting new tack, looking not at whether males that are shorter lived than their mates are taking more risks, but rather at whether their short-livedness can be explained by increased mortality during the season of risk taking.

Here is the abstract:

Abstract

Male excess mortality is widespread among mammals and frequently interpreted as a cost of sexually selected traits that enhance male reproductive success. Sex differences in the propensity to engage in risky behaviours are often invoked to explain the sex gap in survival. Here, we aim to isolate and quantify the survival consequences of two potentially risky male behavioural strategies in a small sexually monomorphic primate, the grey mouse lemur Microcebus murinus: (i) most females hibernate during a large part of the austral winter, whereas most males remain active and (ii) during the brief annual mating season males roam widely in search of receptive females. Using a 10-year capture–mark–recapture dataset from a population of M. murinus in Kirindy Forest, western Madagascar, we statistically modelled sex-specific seasonal survival probabilities. Surprisingly, we did not find any evidence for direct survival benefits of hibernation—winter survival did not differ between males and females. By contrast, during the breeding season males survived less well than females (sex gap: 16%). Consistent with the ‘risky male behaviour’ hypothesis, the period for lowered male survival was restricted to the short mating season. Thus, sex differences in survival in a promiscuous mammal can be substantial even in the absence of sexual dimorphism.

Argument of Science!

Listening to NPR this morning, I heard two stories which did an excellent job of articulating two opposing point of view, both wrong, which taken together helped me articulate to myself how scientific knowledge is formed, and the difference between a denier and a skeptic.

The first story was about an extremely bright 15 year old who sat down to read the science on global warming, decided she didn't believe humans were causing the change, and then set up a hugely popular website 'debunking' the climate change 'hysteria' and attacking the scientists who support it. She objects not only to their conclusions, but to their dismissal of those who make the arguments she makes.

The second was about the Pope, and his visit to the US. One of the main goals of this tour, and this pope, is the War on Relativism. The pope argues that in this modern era, people believe that there is no objective truth, that every viewpoint is equally valid, and therefore anyone can believe anything they want. He argues that if there is no objective truth, we are all lost in a swamp of uncertainty, and life is not only meaningless but unpleasant.

So the 15 year old thinks that anyone who looks at the evidence and makes up her mind should be taken seriously, and the Pope thinks we need to have one objective truth arbitrated by the Church. To my way of thinking, they are both wrong.

Science (as a process and a culture) is neither a free for all where every view is equally valid, nor a dictatorship where those in high status can pontificate and the 15 year olds have to listen. Science is, in the words of Ernst Mayr, "one long argument," but it is a highly organized argument. There are only certain ways one is permitted to advance one's viewpoint. One can present data, but one cannot engage in personal attacks (although Mayr himself was well known for questioning the intelligence of those who disagreed with him). One can criticize, or tear to shreds, the logic used by other scientists, but one cannot simply refuse to listen. One can question the motives of others, but then still has to look at their arguments. If evidence is legitimate, one has the responsibility to be open to being won over. Personal attacks like 'quack', 'pseudo-scientist', 'corporate whore' and so on are to be reserved for those who grossly violate these rules. The only way this argument ever reaches an endpoint is if everyone on one side is either won over or dies of old age. Even then, if someone thinks they have found new evidence that the world is in fact flat, they can reopen the argument. Science does not deliver absolute, unquestionable truths.

But while you can argue anything you want, if your argument does not meet certain standards, it, and you, will be dismissed out of hand. Your statements must be logical, consistent with and based on data and must demonstrate knowledge of and meaningful response to what has been said and written before. If you want to argue that the world is flat, you'd better have a good explanation for all those data that seem to suggest a spherical Earth. And how a flat Earth came into being, and tides, and cosmology, and so on and so forth. There is a strong scientific consensus on the basic shape of the Earth (although there are bulges and deviations from sphericallity that still need to be better understood), because there is overwhelming evidence from a wide range of disciplines. The same can be said for the reality of evolution, the Holocaust, global warming, and a variety of other topics where the argument continues despite being settled in the minds of almost all scholars.

Those who oppose the consensus view on these issues generally point out that science is not "majority rule." As an example, the great majority of geologists long thought that plate tectonics was a ridiculous idea, and if the majority had ruled, we would have rejected what is now a foundational (possibly even bed-rock?) concept of geology, geography and evolution. It is therefore important to address this objection, because while true, it is a straw man. No reasonable scientist believes that truth can be arrived at through a popular vote of experts. That is not how the long argument works.

The relevant fact is not that the vast majority of informed scientists now accept plate-tectonics, but rather that we had that argument, and the plate-tectonics skeptics were unable to explain the data. Skeptics were converted, or gradually modified their views, or retired, and the number of supporters increased. The heroes in this story, from my perspective, are not those who believe because their teachers told them so, but those who were open minded enough to carefully change their minds.

We now accept plate-tectonics because the skeptics, being good scientists, had no choice but to look at the evidence presented, and there was eventually no logical way to cling to the view that continents are too big to move. "Eventually" being several decades.

So maybe several decades from now, we will have rejected evolutionary theory, decided that the Holocaust was just a historical ploy by the Jews for sympathy in their bid for an Israeli state, and realized that the global climate is just naturally cycling? Possible, but not likely, for several reasons.

First, plate-tectonics was a new idea that opposed everything humans had always assumed about our world. It was a hard idea to wrap a mind around. Creationism is not a new, radical and difficult to comprehend idea (my niece is dating a creationist who says he believes it because it is easier to understand than evolution, and his family believes it). Nor is a naturally controlled climate, or anti-Semitism. The idea of plate-tectonics overcame a distinct disadvantage these other ideas don't have.

Second, plate-tectonics took so long to gain acceptance partially because it took that long for technology to improve enough to produce convincing data. But during those decades, data gradually accrued. These other ideas have been around for decades, or millennia, and during that time the evidence has increasingly pointed against them.

Third, there was no lobby or faith pushing plate tectonics. No one stood to get rich or win political points by arguing that the crust of the earth moves and changes. Quite the opposite. The same cannot be said for Ahmadinejad, Bush and Exxon-Mobil.

Finally, and most importantly, there never was a body of data showing that the continents had always been in their current locations. That was the null hypothesis. We have enormous bodies of data supporting the reality of evolution, the Holocaust and anthropogenic climate change. Those who argued for plate-tectonics did not have to ignore or misinterpret a similar body of data presented by the other side. Scientific creationists (pseudo-scientists), scholarly anti-Semites (quacks) and professional global warming deniers (corporate whores) have to do exactly that. The only way to advance their views within the rules of the scientific process is to take all that data, and show us why it is fake or misunderstood. It is because they can't do this that they are disrespected. (Let me here be entirely clear that these insults are not intended to include either the pope or the teenager, both of who are honest non-scientists.)

The argument cannot be won, so there will always be Flat-Earthers, Static-Plate-ers, Creationists, and deniers of the Holocaust and Global Warming. And those people have the right to their points of view. And we have the responsibility to look at any new evidence they produce, if it really is new and it really is relevant evidence. We don't have to pay attention to people who, for the 5 millionth time, argue that the human eye is irreducibly complex and therefore there is a God. They violate the rules of the argument both by ignoring what has already been said, and by foregoing logic, and thereby forfeit their right to be taken seriously.

So, all of that said, how would I reply to the young woman who doesn't believe in human caused climate change, and to the Pope? To her I would say, "It is great that you are getting into science, and you absolutely have the right to come to your own conclusions. Based on your statements, I believe you have misunderstood much of what you read, and been mislead by those with a financial interest in misleading the public. I encourage you to learn more about the conceptual fields on which the science rests." To the Pope I would say, "The days when the Catholic Church was the unquestionable arbiter of truth for western civilization are long gone. At no point in the foreseeable future will the Church, or any other entity, resume that role. I respectfully suggest you accept this and guide the church into a new and more constructive role."

Muller's rachet be damed!

Mutation, and the ability to repair it, are incredibly important drivers of evolution on just about every level.

Last month's PNAS has two cool articles on bdelloid (pronounced DELL-oyd) rotifers and their ability to repair mutations, which demonstrate this extremely well. Bdelloids are the group of rotifers that reproduce only asexually, unlike the Monogonont rotifers I study, which alternate between sex and asex. Asex doesn't allow natural selection to remove deleterious mutations nearly as effectively as does sex (i.e. Muller's ratchet), so most species that go asexual quickly build up an enormous mutational load and die out after some hundreds or thousands of generations. But bdelloids have apparently been happily asexual for billions of generations. So how have they avoided Muller's ratchet? By not allowing it to turn in the first place, apparently. One doesn't need natural selection to remove mutations if one can repair them one's self.

Bdelloids apparently are degenerate tetraploids, meaning instead of two copies of each chromosome, at some point in their evolutionary past they had four, but those four then diverged somewhat into two pairs. Still, this means they have four copies, on separate chromosomes, of most of their genes. And it appears they can use these four copies as templates to repair each other. If one copy might have a mutation, check it against the other three, find the differences and correct them.

The utility of of this system in the short term (on the time scale that natural selection functions) is demonstrated by two other super-powers of bdelloids. First, they can dry out completely, at any life stage, and when rehydrated will repair all the damage to their chromosomes and resume life where they left it. Second, they can continue reproducing at radiation levels five times higher than what most anything else can stand, because every time the radiation damages their DNA, they just fix it. Bdelloids don't need to worry about cancer, apparently.

So with all these advantages, why haven't bdelloids taken over the world? Why doesn't everything do the bdelloid? Presumably because there are disadvantages in other contexts. Bdelloidism removes mutations so effectively, it seems unlikely very much macro-evolution could take place. After all, the repair mechanisms remove pretty much all mutations, and have no way of knowing if that particular mutation would have been advantageous. Once a bdelloid, always a bdelloid. Bdelloids might also be slow on the micro-evolution side of things. If selective pressures shift, having genetic variation is essential to any sort of adaptive response. Mutations are the ultimate source of genetic variation, so if they are all repaired out of existence, it may be hard to adapt. Finally, I would guess (not knowing the details of the repair mechanism) it is physiologically expensive to do all that checking and repairing all the time.

Now I find myself wondering about the demography of bdelloids. Hmmmm.

Non-scatological poo

Biologists not infrequently find ourselves speculating in a purely intellectual way about things that are otherwise not discussed in polite company. Take feces for example. The discussion of feces is so stigmatized as to have its very own adjective. Scatological humor is humor relating to poo. If one's conversation, thinking, humor or complexion is described as scatological, one is generally not flattered. But there are legitimate biological questions to ask about poo.

This afternoon, I was considering the question of why we evolved to have our anus placed such that feces, after leaving the rectum, have ample opportunity to contact the surrounding skin, which then need to be cleaned. And then I began trying to imagine other places a human's digestive tract couple potentially end, and what the advantages and disadvantages would be. What would it be like, for instance if our genitals were behind, rather than in front of, our anuses. And, taking a comparative approach, I thought about what I know about the anal anatomy of other species, and how they clean themselves, or avoid the need to do so. And all in a purely intellectual context, without the slightest feelings of revulsion, shame or titillation. Yet somehow, I knew that one is expected to keep that sort of speculation to one self. Unless one is a biologist. And even so, I probably won't bring it up to my neighbor on the train tomorrow.