How can hammerheads smell blood a full kilometer away?

Here's a report about research into the mechanism of the hammerhead shark's incredible sense of smell.

It is said that hammerheads can smell a drop of blood up to one kilometer away. How the hell is that possible? I'm not surprised if the sharks can detect really, really small amounts of certain molecules. Rather, I am surprised that any blood molecules appear up to a kilometer away. Obviously, I understand that can happen, but the way it is told, it sounds like you drop the blood in the water, and next thing you know the sharks can smell it, and that seems impossible. Can two hammerheads located two kilometers apart both smell blood right in between them? Does the blood really diffuse that far, and that fast? How fast? Is this diffusion isotropic?

Very strange.

Polygamy leads to crime, so outlaw it

Where do we get our morals from? That's a contentious question asked and tried answered somewhere on the web I bet almost every day. Personally, I think much of our moral compass is instinctive - the ubiquitous sentiment that killing and stealing are bad have roots in the benefits of evolved altruism. However, we clearly also change our morals on timescales that are much shorter than those that evolution happens on. For example, slavery used to be acceptable, but now it's immoral (except in Mali).

Homosexuality is considered immoral by some (assholes), and as acceptable as heterosexuality to others (like me). But then, if we'll allow same-sex marriage (which we should), then who are we to say that three consenting adults should not be able to marry? Or more? One woman with four husbands, or one man with 80 wives? Why not? Does it feel wrong to you? Admittedly, it does to me. But then, can we ignore that same-sex marriage feels bad to other people? It's a problem, quite frankly.

But today I have seen the light, you could say. There are, apparently, and not entirely to my surprise, scientific reasons why polygamy is a really, really bad idea.

According to Joseph Henrich, professor of anthropology, polygamy is bad for society because it leads to crime:

• Polygamy pretty much always really means polygyny (one man with more than one wife).
• Polygyny results many men not being able to find a wife.
• Unmarried males commit more crimes than married men.

In India and China, where male-biased sex selection has resulted in more men than women, researchers found "bachelor bands that compete ferociously and engage in aggressive, violent and anti-social activities."

In India, the state of Kerala's murder rate is half that of Uttar Pradesh. The reason? Kerala's male-to-female ratio is 97:100; Uttar Pradesh's is 112:100.

Another social harm that Henrich says is consistent regardless of whether researchers use data from 19th-century Mormon communities or contemporary African societies is that children from polygynous families have considerably lower survival rates. It seems polygynous men, rather than investing in their offspring, use their money to add wives.

Henrich also thinks that monogamy is at the root of even democracy and equality.

He argues that as the idea of monogamy spread through Europe during the 15th century, king and peasant alike had the same rules and the idea of equality gained a foothold -- at least among men.

It's a great example of science informing us about morality. Of course, science can't tell us what is good and what is bad, but couple scientific understanding with our desires, then these two together can tell us if something is morally acceptable or not. Is it okay to catch fish with a hook? If it's not overly painful to the fish, then we might say it is okay. If science at one point informs us that every fish caught that way undergoes excruciating torment, then it will likely change a lot of people's minds about fishing, I'd like to think. We want a peaceful, crimeless society, and if polygamy leads to more crime, then that supports the feeling that it's morally wrong.

Never mind that the Canadian constitution might prohibit prohibiting polygamy, I say. When we have good reasons to do something that is unconstitutional, then we'll just have to change the constitution.

Via Epiphenom.

Phytoplankton are disappearing, so we're all going to suffocate

Phytoplankton is responsible for about half of the total amount of oxygen produced by all plant life. That would make a 1% yearly reduction of phytoplankton a really negative outcome of global warming, don't you think?

We observe declines [of phytoplankton] in eight out of ten ocean regions, and estimate a global rate of decline of ~1% of the global median per year. Our analyses further reveal interannual to decadal phytoplankton fluctuations superimposed on long-term trends. These fluctuations are strongly correlated with basin-scale climate indices, whereas long-term declining trends are related to increasing sea surface temperatures. We conclude that global phytoplankton concentration has declined over the past century;

I can just picture how the majority of the world's mammals will suffocate in the next one hundred or two hundred years, and how only a fraction of all humans will survive by artificially produced oxygen.


Oceanic regions use to estimate phytoplankton abundance.


Rates of phytoplankton biomass change, measured by total chlorophyll pigment concentration (‘Chl’).

And as if a reduction in atmospheric oxygen wasn't bad enough all on its own (I do so think it is), that's of course not the only effect the drop in plankton abundance will have:

These results provide a larger context for recently observed declines in remotely sensed Chl, and are consistent with the hypothesis that increasing ocean warming is contributing to a restructuring of marine ecosystems, with implications for biogeochemical cycling, fishery yields and ocean circulation.

Are we doomed yet?

Reference:
Boyce, D., Lewis, M., & Worm, B. (2010). Global phytoplankton decline over the past century Nature, 466 (7306), 591-596 DOI: 10.1038/nature09268

The scare of genetically engineered crops

People are so scared of science, man. I think a huge part of the population even in well-educated countries don't trust the scientists very much.

Ingo Potrykus is chairman of the Golden Rice Humanitarian Board, and writes in Nature about the trouble getting golden rice out to the people who really need it: Regulation must be revolutionized.

The potential benefits of genetically engineered crops is huge. Take golden rice, which has just two genes added that adds vitamin A to the rice. The benefits to malnourished children is huge.

Within the normal diet of rice-dependent poor populations, it could provide sufficient vitamin A to reduce substantially the 6,000 deaths a day due to vitamin A deficiency, and to save the sight of several hundred thousand people per year.

So why is it not on the market and the fields yet? Because regulation is extremely tough.

For example, we lost more than two years for the permission to test golden rice in the field and more than four years in collecting data for a regulatory dossier that would satisfy any national biosafety authority.

But why, you might ask? It's not like some new drug that you're going to take and which you don't know if they have side effects, etc. Or is it? Judging by politicians, it is. And that's just inane. But worse, releasing the crop could have saved so many people's lives.

The crop was stalled for more than ten years by the working conditions and requirements demanded by regulations (see 'From bench to belly'). For example, we lost more than two years for the permission to test golden rice in the field and more than four years in collecting data for a regulatory dossier that would satisfy any national biosafety authority. I therefore hold the regulation of genetic engineering responsible for the death and blindness of thousands of children and young mothers.

There is essentially no difference in genetically engineering a crop to do what you want (e.g., making vitamin), from what nature does on it's own. It's just directed with a specific goal in mind, rather than occurring by chance.

Meanwhile, a new plant created by traditional breeding methods — which also modify the genome — requires no safety data, only the demonstration that it performs at least as well as others. It is a quick and cheap process. This imbalance allows non-scientific opponents of genetic engineering to raise unfounded concerns, which a nervous public cannot properly evaluate, especially in Europe.

The stupidity of people demanding the tough regulations angers me. Genetically engineering crops does not make them more harmful than any other crop engineered by breeding. If anything, it makes it safer, because we at least know what changes are made to the genomes. What is it that these people are afraid of? That crazy scientists with fake German accents will masterplan the crops to wipe out all others? That these crops will somehow be more prone to pests? That the engineered genes will jump into other crops and thus spread their dangerous vitamin A-making capabilities?

Goddammit!

¡Buenos dias, Catalonia!

Today, Catalonia has banned bullfighting. Culture, tradition, and great fun at the expense of the pain and death of sentient beings have lost to compassion in a narrow 68-67 parliamentary vote.

¡Buenos dias!

Bat skull evolution

I'm giving my PhD defense tomorrow, July 28th, so no time to blog. Here's a cool video of bat skulls evolving to specialize to different diets.

Evolution of cranial morphology in phyllostomid bats in relation to feeding habits.

Secularism leads to peace, or...?

Image Source

It's the eternal questions of correlation and causality. Is my home country of Denmark so prosperous and peaceful because it is secular, or is it secular because it is prosperous and peaceful. Or, is some third factor the responsible for both secularism and peace? Or, is the correlation coincidental?

Because correlation it is. Compared to most other countries, Denmark is rich and benevolent, and the same goes for the rest of Scandinavia. As has been shown a number of times before, the more secular countries are, the richer they are, with some exceptions, like the US and Kuwait. → → →

Phil Zuckerman: In secular countries the core values of human right are being more successfully implemented than in religious countries.



Here's what Tom Rees concludes, blogging about his own paper, Is Personal Insecurity a Cause of Cross-National Differences in the Intensity of Religious Belief?

Nations have choices over how to look after the people at the bottom of the social pile. Those nations that choose to make this a priority, which inevitably involves shifting money and resource from the rich to the poor, lower the overall levels of stress. And when you remove the stress caused by their social situation, people tend to lose interest in religion.

In other words, Tom suggests that removing stress makes a secular nation, and giving from the rich to the poor, you remove stress.

On a personal note, I can vouch for the stress that having no money brings, but not that it leads to religion. But then again, I have a whole internet chuck full of people helping remind me that religion is not the answer. If only they could also send money.

Requirements for becoming a professor in ecology and evolution

Oh boy! If you're thinking about landing a tenure track job or similar in ecology or evolutionary biology, here's a kicker for you.

A study of 181 recently hired faculty members shows that to be competitive in ecology and evolutionary biology, the requirements are stiff as hell.

The authors report numbers at the time of hire for the survey respondents in four categories:

• age at time of hire (mean = 33.54 years)
• years as postdoctoral scholar (mean = 2.92)
• total number of publications (mean = 11.75)
• total number of grants received (mean = 4.20)

I am one of those who will be seeking faculty jobs in the future, and these data do scare me. I am a good way over the mean age at time of hire already (and am only just about to finish my PhD), but that really doesn't bother me at all. Rather, my suspicion is that the age distribution is an effect of those who end up in faculty jobs are mostly people who know what they want early on, and pursue that from the beginning. I didn't, but now I do pursue it, and I think that's all that matters.

What scares me is also not so much the number of publications (except that the data suggest that one first-author publication in a journal with impact factor greater than 10 is required), and not at all that the average number of years as a postdoc is about three at the time of hire, but rather that the number of grants received is 4.2. But, looking at carefully at the data, it turns out that this breaks down to about 2.20 grants of less than US$10 thousand, 1.20 between $10k and $100k, and 0.75 over $100k. That's still tough, especially in these financially hard times, but at least one can get about half of those grants as travel grants and other awards of any value. But, it is an eye-opener for me, how much the grant-issue means. I shall keep it in mind.

Reference:
Marshall, J., Buttars, P., Callahan, T., Dennehy, J., Harris, D., Lunt, B., Mika, M., & Shupe, R. (2009). Letter to the Editors Israel Journal of Ecology and Evolution, 55 (4), 381-392 DOI: 10.1560/IJEE.55.4.381

Some more junk DNA shown to have function

Here's another study that's going to get creationist arms in the air. It shows a function for some "junk DNA" - DNA that does not serve any function for the developing organisms - namely in coding for micropeptides (very short proteins), which have now been shown to have a regulatory function in Drosophila. The first lines of the abstract reads

A substantial proportion of eukaryotic transcripts are considered to be noncoding RNAs because they contain only short open reading frames (sORFs). Recent findings suggest, however, that some sORFs encode small bioactive peptides. Here, we show that peptides of 11 to 32 amino acids encoded by the polished rice (pri) sORF gene control epidermal differentiation in Drosophila by modifying the transcription factor Shavenbaby (Svb). [Emphasis added.]

It's actually quite interesting, the finding that very short proteins have a regulatory effect on gene expression, much the same way that very short RNA molecules do (microRNA). But it doesn't mean that all DNA has a function. Just some more than what we previously thought. Some.

Of course, the researchers have not shown that all DNA has a function, which is nevertheless how this is going to be presented, tacitly. For example:

But according to David Stern, a Princeton professor in the Department of Ecology and Evolutionary Biology, scientists increasingly believe "junk DNA" is crucial for turning the information encoded in genes into useful products.

*Multisigh*

For those who think that no DNA is without function, please consider The Onion Test.

The onion test is a simple reality check for anyone who thinks they have come up with a universal function for non-coding DNA. Whatever your proposed function, ask yourself this question: Can I explain why an onion needs about five times more non-coding DNA for this function than a human?

An inordinate fondness for beetles, and also for very large and redundant genomes, perhaps?

Reference:
Kondo, T., Plaza, S., Zanet, J., Benrabah, E., Valenti, P., Hashimoto, Y., Kobayashi, S., Payre, F., & Kageyama, Y. (2010). Small Peptides Switch the Transcriptional Activity of Shavenbaby During Drosophila Embryogenesis Science, 329 (5989), 336-339 DOI: 10.1126/science.1188158

---

Update 7/19:

This table shows the genome sizes for 30 species of onions. They all have huge genomes (from Evolution of genome size across some cultivated Allium species, A. Ricroch, R. Yockteng, S.C. Brown, and S. Nadot, Genome 48: 511–520, 2005).


Click for larger image.

Say you're wrong

Let me start by sharing just how much of an opinionated bastard I am. I was conceived out of wedlock, so I am truly a bastard. I treasure that fact on a weekly basis. But other than that, I am not really much of a bastard. I'm a nice enough guy, and if you think not being a scoundrel disqualifies me, pass along. As for opinionated, I was once called that because once no one could decide where to go for lunch, and that quickly drove me nuts and I plainly said where I felt like going.

But I really wasn't one. I am not arrogant, dogmatic, nor bigoted. Okay, maybe a little arrogant, because I do think this world if chuck full of very stupid people, and I just said it. The far biggest majority of people are definitely among the 90 percent dumbest, or something. But, crucially, not dogmatic or bigoted, because those terms imply an unwillingness to listen to the evidence to the contrary, and that the biggest sin of all, in my opinionated opinion.

I don't have the data, I readily admit it, but I believe - undogmatically - that a whole lot of what is wrong with this human world, is that humans are supremely reluctant, even fearful, of admitting that they are wrong. Like the stereotypical Italian, who'd sooner give you the wrong direction rather than admitting not knowing the right one, humans will go to great lengths to save face. Whole nations build foreign policies on that fear, risking sanction and war to save face. Also on a personal level can it lead to much discomfort, for example when you end up in Firenze when you were going to Parma. And perhaps to the person saving face, too? The thing is, I wouldn't know, because I have honestly not really ever tried it, I think. If anyone who knows me can tell me a time that I did, I'd dedicate a blog-post in your honor (don't care much for honor either, though), or not, if that's preferred. Because I'd like to know when I'm wrong.

Which brings me to the point I wanted to make: do everything you possibly can to realize when you're wrong. And when you are, say it out loud, even if in private, so that you may acknowledge yourself that you were wrong, but now know better. In science, admitting when you're wrong is absolutely crucial, and can bring quite a lot of joy, since the pursuit of knowledge is only aided by realizing you were wrong (and the scientists who can't admit to themselves that they were wrong are the real losers - unless they happen to always be right, but I've never heard of no apple-box). But outside of science it is also a really good idea. Again, the benefits to everyone around the person admitting their mistake should be obvious, but I think (prove me wrong) that it is generally unhealthy going around being wrong. Not only may you lose out in tangible ways, but I suspect (pmw) that people who can't admit to themselves when they're wrong suffers emotionally, because deep down they probably know, at least part of the time, that they chuck full of bs. Unless they're one of the 90 percent that I mentioned earlier, in which case they may never know any better. This post was not for them.

So, say you're wrong at least once a day. Don't mock yourself, 'cause being wrong is a respectable business. Just be honest, and remember being wrong can happen to anyone. Does happen to everyone. Being wrong is the path to being right, which is great, too. Makes for better pies, which no one can object to. And I really wanted to go to Parma.

Hans Rosling wins again

Not only is Hans Rosling one of the very best speakers on TED, he has also, appropriately just changed my mind.

He has just convinced me that up until right now I have been wrong about the effect of increased medical care in the poorest countries. I had been telling myself that the effect of improved healthcare, leading to lowered child mortality rates, would only work to increase the rate of world population growth even more. But in this talk he makes it clear, I think, that the effect of lowering child mortality in the poorest nations is actually to decrease the rate of growth, because - never mind what the actual mechanism is - clearly the data shows that once child mortality decreases, what always follows is that the average number of children people have drops, too.

See for yourself.

The role of the west is to become the foundation of the modern world. Nothing more, nothing less. But it's a very important role. Do it well and get used to it.

Opinionated bastard™

Now also blogging at Opinionated Bastards.

Obnoxious reviewers, obnoxious author

I am working on improving a manuscript that I just got back from review. Here's a few nuggets with my replies (no, they won't be sent as is to the reviewers):

the impact on what? This sentence reflects much of the paper. It is difficult to see what we are talking about in the first place.

Are you serious? It says right there in the preceding sentence that we are talking about adaptation!

Sentence wrong. Drift is irrelevant to the fact that a mutation is deleterious.

Review wrong. We aren't talking about drift, but random death.

Epistasis is not defined per mutation

Yes, we define it per mutation. You're welcome.

This is wild speculation

Or just speculation. Heed it.

I should say that the reviewers did make several reasonable points as well. It wasn't all "I'm too lazy to read your ms carefully, and you didn't cite my 1947 paper, so I hate you" kind of comments.

Job discrimination

As occasional readers here may have noticed, I'm looking for a job. A postdoc kind. Here's a line from an advertisement I've just seen (for a job I am not interested in, I should add):

all suitably qualified candidates will be considered but preference will be given to Chilean and Falkland Island citizens.

Oh really?! So, nepotism is openly advertised, then. In America, faulted as this nation is for so many things, at least the usual disclaimer reads

equal employment opportunity without discrimination or harassment on the basis of race, color, creed, religion, national origin, alienage or citizenship status, age, sex, sexual orientation, gender identity or expression, marital or domestic/civil partnership status, disability, veteran status, genetic information, or any other basis protected by law. [Emphasis added.]

Hail that!

Via Brian Golding's EvolDir.

FucM gene deletion makes mice lesbian

Whatever else you might think about the study and how the Korean authors presented their results of a gene knock-out experiment in mice, you gotta love the fat that the gene is called FucM (encodes an ezyme called fucose mutarotase).

Whole story on Neurophilosophy.

Creation science validates evolution, too

Just a super-quick note about an interesting paper in the newest edition of Journal of Theoretical Biology: "Using creation science to demonstrate evolution: application of a creationist method for visualizing gaps in the fossil record to a phylogenetic study of coelurosaurian dinosaurs", by Phil Senter.

At first that sounds like something got though that shouldn't have, doesn't it? Well, not to worry, the editor's career is safe. Rather than demonstrating the capability of creation science (101), it applies a method used by some creationists to fossil data, and ends up demonstrating that non-avian dinosaurs and early birds and genetically related.

Abstract:

It is important to demonstrate evolutionary principles in such a way that they cannot be countered by creation science. One such way is to use creation science itself to demonstrate evolutionary principles. Some creation scientists use classic multidimensional scaling (CMDS) to quantify and visualize morphological gaps or continuity between taxa, accepting gaps as evidence of independent creation and accepting continuity as evidence of genetic relatedness. Here, I apply CMDS to a phylogenetic analysis of coelurosaurian dinosaurs and show that it reveals morphological continuity between Archaeopteryx, other early birds, and a wide range of nonavian coelurosaurs. Creation scientists who use CMDS must therefore accept that these animals are genetically related. Other uses of CMDS for evolutionary biologists include the identification of taxa with much missing evolutionary history and the tracing of the progressive filling of morphological gaps in the fossil record through successive years of discovery.

Somehow I imagine that "creation scientists who use CMDS" was already a very small group, and that it's bound to get even smaller now, assuming that they ever read this paper (which is a big assumption).

Reference:
SENTER, P. (2010). Using creation science to demonstrate evolution: application of a creationist method for visualizing gaps in the fossil record to a phylogenetic study of coelurosaurian dinosaurs Journal of Evolutionary Biology DOI: 10.1111/j.1420-9101.2010.02039.x

What's so great about modeling?

Not my kind of model, really.

Warning! For those who thought this was about fashion: it ain't.

I have a model of speciation that I have been working with for a while now, and I think it's good. And it's a model™. With this model I think we can learn something real about nature, and I would even go as far as saying that it's a better model in some respects than previous models. It includes certain aspects of the problem that simpler models didn't take into account, and it is simpler than some other models that are great, too, but they're sometimes so complex that it isn't easy to discern what goes on inside them. In fact, this model originated in an attempt to mathematically describe what goes on in Avida, which is an artificial life model used to study evolution.

Why do we make models of things? Why do some scientists spend time making and analyzing mathematical and numerical models of systems and processes in nature? Can't they just use the natural systems and look at the processes out in nature? After all, if we're trying to learn something about nature, that seems to most direct route, rather than building a model on paper or on a computer and work with that instead.

I am interested in evolutionary processes, such as they take place in nature. That means, for starters, that the models I build have to contain elements similar to those found in nature. As an example, inheritance has to be done in a way that resembles how real living organisms inherit genotypic information from their parents (or parent, in case of asexual organisms). That means I can't go around having little critters in a computer inherit what their parents learned in their lives, because that's not the way genetic material is inherited out in nature (Lamarck thought so, but we now know better). But one could argue that if we build a really, really good model, then it wouldn't be different from the thing we're modeling, and then we might as well just study that thing directly in nature. So the model has to be somewhere in between - simpler than reality, but still realistic. And the advantage of making such a model is that

• we can do controlled experiments to study isolated processes
• we can repeat the exact same processes as many times as we want

We only have one sun, one biosphere, one mexican gulf with crude oil pumping out at the rate in excess of 5,600 cubic meters per day, and one species of California Red-Legged Frog (Rana draytonii), and we can't afford to tamper with them, even if we are able. With numerical models we can, and processes that in nature take a very long time can be modeled on much shorter time-scales, provided the models are simple enough (sometimes they get so detailed that they take longer than the real thing). Additionally, we can hold parts of the model constant, so that we can study other variables in separation. For example, the evolution of a population can be studied without the interference of other populations and environmental effects - which is usually impossible an/or unethical with living organisms.

But more to the point, modeling is how we understand things. Theories, such as the one about evolution, can be viewed as a model. The whole obnoxious, sidetracked debate with creationists about the theory of evolution being a just a theory, and have not yet been proven and elevated to a law, and all that crap is really quite misplaced. If we instead introduced the notion of a model, and that models cannot ever be proven, in part because they are just models, and models are never 100% accurate, or they would be identical to the system that it attempts to describe, then I think perhaps some people (other than committed creationists, of course) would get it, and realize that the evolution is just a theory argument is vacuous.

In April I gave a talk at this great Early Career Scientists Symposium at University of Michigan. Spot Wally seven times (not counting reflections)! Rich Lenski have the plenary presentation on aspects of his lab's long-term evolution experiment with E. coli, and because I am occasionally asked and frequently think about the issue of choice of numerical models to study evolution, and whether we can expect to learn anything about organic evolution from them, I asked Rich how he feels taking discoveries about evolutionary processes in E. coli and inferring how evolution proceeds in other organisms. The problem is that E. coli, like any particular numerical model, could be highly specific (as in, evolution being "just one damn thing after another"), and lessons learned from it not necessarily transferable to other organisms. It's not that I don't think it's a good idea to study E. coli, or any other particular organism, but that the people who do need to be careful about their conclusions about evolution in general in the same way as people using numerical models must. Unicellular, asexual microbes may not be the best model of how evolution proceeds in mammals, for example. Rich's answer was that he agreed, and that... (shit, I can't remember the rest now - so much for jokes without punchlines).

And to make the missing-punchline punchline even worse, I have to admit that I was going to write a fair bit more about the model I am working on, but truth be told I really can't make myself do it. See, I am working on finishing the manuscript that will be submitted to some journal, and I don't have the energy to also blog about it. I promise to blog about my own paper once it's out in some form, of course, though that might take a very long time. Sorry.

Comments redux

I have never been able to get the widget highlighting recent comments to work, which is a damn shame.

Three posts from the past that I keep getting comments to:

Perry S. Marshall's idiotic Random Mutation Generator
I must not say 'idiotic'. I may not call a moron 'moron'. Doing so only reveals how empty my arguments are.

Lisle's ultimate proof of creation proves nothing about creation
I am asked to say where the law of logic comes from, if not from God.

Islamic crud stones innocent girl in Somalia
Very old post, and ranks high on Google. It's never going to stop with this one.

And lastly, the recent blogging-meme about getting readers to say hello: Who the hell are you?

If you don’t understand evolutionary biology...

Donald Prothero* joins the long list of people who have read and reviewed What Darwin Got Wrong by Jerry Fodor and Massimo Piatelli-Palmarini: If you don’t understand evolutionary biology, don’t write a book about it!

Here's the gist of Prothero's criticism:

Yet FPP take the Gould/Lewontin critique too far, and make the absurd claim that because some features are possibly constrained and not fine-tuned by natural selection, we cannot assume that natural selection works anywhere. What about all those studies that demonstrate tight correlations of cause and effect between a feature and the selective response that occurs when nature intervenes? According to FPP, these are not conclusive enough. Therefore, whenever we have a large data set that shows a strong correlation between say, obesity and heart disease, or increases in carbon dioxide and global warming, we cannot even begin to suggest that there might be a causal connection. If this is the angle that FPP are pushing, then they have a dispute with almost all of science, not just evolutionary biology. [Emphasis added.]

I can only second that. The inference that we cannot assume that NS works anywhere is absurd, because i) it is very, VERY well understood theoretically, and ii) as Prothero points out, there are many studies that show "that have done careful work with controls and minimizing the variables that conclusively show natural selection to be the only reasonable explanation for the results".

* More on Donald Prothero and his great book, Evolution: What the Fossils Say and Why it Matters, here, and on debating creationists here.

Who the hell are you?

Ed Yong's meme about getting readers to say something about themselves is spreading. Now it's here. Also on The Loom and Evolving Thoughts.

I thought it might be fair to share then some statistics on Pleiotropy, before I ask you to share something about yourself.

In the last three months Pleiotropy has had 8,395 visits, 10,579 pageviews, 1.26 pages viewed per visit, and on average visitors spent 45 seconds here (not a Poisson distribution - few people spend many minutes, while 85% of all visits are by people who are here for the first time, and most of those come via Google, and stay a couple of seconds of average). I get significantly more visitors when I blog about peer-reviewed research and post it to Research Blogging, which is not often lately, because I am working on the last of my PhD thesis. I have earned a total of $29.12 with Google ads since I signed up in April 2009.

As of today, the ten most visited posts (with total pageviews) are:

1. Paul Zachary Myers 11,853
2. Sex among siblings 3,504
3. Islamic crud stones innocent girl in Somalia 3,167
4. Wealthy men's women have more orgasms 1,638
5. The male beard as proof of God 1,179
6. Homosexuality is not a choice 1,178
7. Carnival of Evolution 16 - the [find modest synonym for outstanding] edition 1,049
8. Orangutans to replace chimpanzees as our closest relative? 981
9. Why is cannibalism taboo? 886
10. Darwin was wrong about the human appendix being vestigial 857

(PZ linked to the post I wrote about him.)

With a little luck, I expect three or four people sharing something about themselves in the comments here. Say what you want, but I'd especially like to hear i) what you do for a living, ii) why you read what I write, iii) how you first found this site, and iv) if you know of an available postdoc position in theoretical/computational evolutionary biology starting next month.

Thanks in advance.

25th edition of Carnival of Evolution

The 25th edition of Carnival of Evolution is ready at Hannah Waters' blog, Culturing Science. Thanks to Hannah for a great edition.

Spread the word!

A sample:

As we know, the process of evolution takes an incredibly long time. How do evolutionary biologists study the process of natural selection just in their lifetimes? Two posts this month feature experimental methods to test traditional theories of natural selection.

I'm not sure I know this myself. There's good of evidence that some processes can be very fast (e.g. my favorite Croatian lizards described by Herrel et al., 2008). Yes, some things take millions of years, like the morphological change from terrestrial ungulates to whales, but many other events can be observed in our lifetimes. Another example is Drosophila speciation.

Multicellular origin at 2.1 billion years ago

New fossils found in Gabon might push back the origin of multicellular life. By about 200 million years.

Here we report the discovery of centimetre-sized structures from the 2.1-Gyr-old black shales of the Palaeoproterozoic Francevillian B Formation in Gabon, which we interpret as highly organized and spatially discrete populations of colonial organisms.

Macrofossils in colony form from the FB2 level. Scale bars, 1.0 cm.

The authors deduce that these long structures (up to 12 cm) aren't just colonies of bacteria, but must have had cell-to cell signalling and coordinated-growth behaviour.

Although we cannot determine the precise nature and affinities of the 2.1-Gyr macroorganisms from the Francevillian B Formation of Gabon, we interpret these fossils as ancient representatives of multicellular life, which expanded so rapidly 1.5 Gyr later.

I'm not at all educated to have an opinion here... They look convincing enough like fossils, but if experts were to tell me that these structures could have been formed by non-organic processes, I'd have to believe them. On the other hand, while this is definitely a story that is deservedly on the cover of Nature, moving the origin of metazoans multicellular life back 200 million years isn't something that is going to shake up a lot of people who aren't just working in that narrow field already.


Evidence of early life, and the chemical state of the atmosphere and oceans, from News & Views article in Nature by Donoghue ∓ Antcliffe, Early life: Origins of multicellularity. The Gabon fossils would push back the first occurrence of metazoans multicellularity 200 million years (red bar), but, interestingly, close to the oldest certain bacterial fossils.





Four different specimens in four different views. a, Original specimen. b, Volume rendering in semi-transparency. c, Transverse (axial) two-dimensional section. d, Longitudinal section running close to the estimated central part of the specimen. Scale bars, 5 mm.

Reference:
Albani, A., Bengtson, S., Canfield, D., Bekker, A., Macchiarelli, R., Mazurier, A., Hammarlund, E., Boulvais, P., Dupuy, J., Fontaine, C., Fürsich, F., Gauthier-Lafaye, F., Janvier, P., Javaux, E., Ossa, F., Pierson-Wickmann, A., Riboulleau, A., Sardini, P., Vachard, D., Whitehouse, M., & Meunier, A. (2010). Large colonial organisms with coordinated growth in oxygenated environments 2.1 Gyr ago Nature, 466 (7302), 100-104 DOI: 10.1038/nature09166

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Update 7/8:
I have changed all instances of 'metazoan' with 'multicellular', also in the title. My mistake. Thanks to Psi Wavefunction for pointing that out.