Field of Science

On theory and hypothesis

This article in the Washington Post is very tough in creationism, which I can only agree with. For example:
Evolution could not have produced a single mother and father of all future humans, so there was no Adam and no Eve. No Adam and Eve: no fall. No fall: no need for redemption. No need for redemption: no need for a redeemer. No need for a redeemer: no need for the crucifixion or the resurrection, and no need to believe in that redeemer in order to gain eternal life. And not the slightest reason to believe in eternal life in the first place.
It's a great thing to read in such a prominent newspaper.

However, the author, Paula Kirby, also reiterates a characterization of 'theory' and 'hypothesis' that I vehemently disagree with:
In everyday English, 'theory' can mean something vague, a hunch, a guess. In scientific English, it is almost as far from that meaning as it's possible to get: in science, a theory is the best explanation for a set of facts. It carries real weight: in science, nothing can be called a 'theory' until it is very well established indeed. Science has its own term for what, in a non-scientific context, the rest of us might call a 'theory': the scientific term for a suggestion, a best guess, something that seems plausible but has not yet been shown to be reliably true, is 'hypothesis'. You will never, ever hear a scientist talk about 'the hypothesis of evolution', for the simple reason that evolution is long past that stage. Evolution is a theory in the scientific sense of the word - tested, researched, explored and supported by masses and masses of evidence. There may still be specific details that are not entirely agreed upon; but the fact of evolution itself is not disputed by any reputable scientist.
It's a common misunderstanding that those two words convey degrees of certainty in science. They do not. A theory need not be "very well established", and a hypothesis is not necessarily something that has "not yet been shown to be true".

Rather, in science, a theory specifies a cohesive explanation of a natural phenomenon. A theory is a model of how something works, and can produce several hypotheses that can be tested. For example, gravity is a theory of how masses attract each other and other related phenomena (and it is a fact that the phenomenon of gravity exists), and one hypothesis that comes from that theory is that that a hammer dropped above the surface of the moon will fall down to the surface. But again, neither theory nor hypothesis need to be true to be called theory and hypothesis. There are theories that have been shown to be wrong, and yet we still call them theories. The theory of the ether has been shown to be wrong, but it is still a theory. The theory of homeopathy has been shown time and again to be false, and yet we can still refer to it as a theory.

Similarly, a hypothesis need not be a tentative statement of fact. It is a hypothesis that a hammer will fall down to levitate over the moon, but even when that hypothesis has been tested, it is still a hypothesis. It is a disproven hypothesis, but nonetheless still a hypothesis. In everyday English, it does indeed connote uncertainty, but not so in science. For example, we can still refer to both the 'null hypothesis' and our pet hypothesis even when the evidence favors one of them over the other. It's a hypothesis that the hammer will levitate, and while it has been shown to be false, but it can still be termed a hypothesis.

At least, this is how I use the words, and I am a scientist (but see impostor syndrome).

Payback Charlesworth style

Ruse on the left, Charlesworth on the right.
A few days ago I told the story of an exchange between Michael Ruse and some member of the audience at ESEB 2011.

On the train from Tübingen to Stuttgart I sat next to Brian Charlesworth. We spoke about research and the conference, and also about Ruse's talk. I commented how amusing I found the above exchange, and Brian joyfully let on that it was he who had voiced his disagreement. Brian gave the final plenary talk at the conference, and with a smile on his face, he recalled how he in his talk had mentioned that Haldane has written so lucidly about evolution, and that perhaps that was why certain philosophers had trouble appreciating him, since lucidity is not the strength of philosophers in general. Har! Hear hear. Rumor has it that Ruse didn't find that comment all that amusing, but I'm not so sure.

Michael Ruse at ESEB 2011

I'm at ESEB 2011 in Tübingen (website, Twitter), and saw Michael Ruse give a talk today titled What, if anything, does a historian and philosopher has to say to real scientists?

At one point he showed these pictures of Fisher, Wright, and Haldane (left to right), and said that out of those there could be no doubt that it was Fisher and Wright who were the heavyweights. One person in the audience made a sound to disagree, which made Ruse look at the clock and say "in 9 minutes you'll get your chance - if you're a graduate student*. With a comment like that I rather suspect you are."

Major laughs.

As for the answer to his query, I rather fear the answer is "no." At least, he didn't explicitly say anything to the contrary.

* At ESEB 2011, graduate students can raise a page in the program with a green hand to indicate they are graduate students, which will give them priority in the discussion.

Can Michelle Bachmann embarrass herself more than this?

The answer is without a doubt that, yes she can. And I can't wait for the next bigger blooper. While wishing Elvis happy birthday on the day he died is hard for most people to top, I think Michele has got it in her.

How can anybody take her serious as a candidate after dissing Elvis so badly? Surely she could never take Tennessee now!? And the answer to that is that lest we forget, her backers are the craziest of the craziest in this nation of crazies: the Tea Party movement.

Scandinavians have bigger brains for better vision

ResearchBlogging.orgNo matter that this study proposes that people of the north have bigger brains than those at the equator merely to cope with lower levels of sunlight - it would still cause an uproar if the rather large group of people (including scientists) who regularly commit the moralistic fallacy should ever hear about it.
We demonstrate a significant positive relationship between absolute latitude and human orbital volume, an index of eyeball size. Owing to tight scaling between visual system components, this will translate into enlarged visual cortices at higher latitudes.
Bigger brains, and by usual (though not in this case) inference, higher intelligence ranks at least as high on the list of taboos as race does. Telling someone they are less intelligent is one of the worst things one can say about another. As a consequence, research into intelligence is under more scrutiny than most other disciplines, and freely voicing hypotheticals can get researchers fired.

In the world of bats, saying someone has substandard echolocation is not politically correct. Among snails, calling someone fast is frowned upon. Elephants are known to ostracize those claiming to have longer trunks that others. Because if a bat or snail or elephant is substandard in the prime measure of worth, then the fear is that they will be treated badly by those with better echolocation, speed, and trunks.

But luckily (eh?), the study does not suggest any difference in intelligence after all. Just that we Scandinavians have bigger brains because we need to be more sensitive to light, because there is less of it. Phew! Perhaps now we can even use this data to cancel out any differences in intelligence? After all, that there should be any systematic variation in intelligence among human populations is, unlike many other traits, just unthinkable!!!


Pearce, E., & Dunbar, R. (2011). Latitudinal variation in light levels drives human visual system size Biology Letters DOI: 10.1098/rsbl.2011.0570

Evolution meetings in August

Right now the BEACON congress is going on at Michigan State University (Twitter #beacon11). Participants from all five member institutions are here (UT Austin, U Washington, U Idaho, NC A&T, MSU). Program is here (PDF).

While the BEACON congress is a little for the initiated, the European Society for the Evolutionary Biology meeting in Tübingen later this month is not (Twitter #eseb11) . I'm giving a talk there on a paper on epistasis and pleiotropy that I blogged a little about earlier. Anyone else going to Tübingen?

I'll be missing the evolutionary modeling meeting in Groningen just before ESEB, which I'm pretty annoyed about. However, I will go to Denmark after ESEB on vacation, and it just so happens that there is another interesting conference there at that time, so I might drop by there a little: Setting Time Aright*. Gatecrashing is always fun.

* Gotta hate that title.

Is this job posting legal?

Brigham Young University is looking for a professor in plant biology (aka botany). I honestly wonder if this is legal:
Plant Biology - Brigham Young University

The Department of Biology seeks to fill a full time, continuing status position in plant biology. Qualified applicants with a PhD, postdoctoral experience, and expertise in evolutionary or organismal biology (including, but not limited to, modern applications such as molecular ecology, systematics, genomics, evolutionary development, and so forth) are encouraged to apply. The successful candidate is expected to maintain an externally funded research program involving both undergraduate and graduate students. Excellence in teaching is required; teaching responsibilities will include general biology, plant diversity, and a graduate course in the candidate's area of expertise. The department offers competitive start-up packages and reduced teaching loads for new faculty. Interested persons should complete a BYU faculty application form at and attach a current CV and statements of teaching and research interests. Questions can be directed to: Dr. Clint Whipple, Plant Biology Search Committee Chair, 401 WIDB, Department of Biology, BYU, Provo, UT 84602.

The review process will begin September 15th, 2011 for this position and continue until the position is filled. Additional department and college information is available at website: Brigham Young University, an equal opportunity employer, does not discriminate on the basis of race, color, gender, age, national origin, veteran status, or against qualified individuals with disabilities. All faculty are required to abide by the university's honor code and dress and grooming standards. Preference is given to qualified candidates who are members in good standing of the affiliated church, The Church of Jesus Christ of Latter-day Saints. Successful candidates are expected to support and contribute to the academic and religious missions of the university within the context of the principles and doctrine of the affiliated church.
Are they allowed to not include religion in the list of things they don't discriminate against? Are they allowed to give preferential treatment to Mormons?

Other fun stuff at BYU:
Dress and Grooming Standards

A clean and well-cared-for appearance should be maintained. Clothing is inappropriate when it is sleeveless, revealing, or form fitting. Shorts must be knee-length or longer. Hairstyles should be clean and neat, avoiding extreme styles or colors, and trimmed above the collar, leaving the ear uncovered. Sideburns should not extend below the earlobe or onto the cheek. If worn, moustaches should be neatly trimmed and may not extend beyond or below the corners of the mouth. Men are expected to be clean-shaven; beards are not acceptable. Earrings and other body piercing are not acceptable. Shoes should be worn in all public campus areas.

A clean and well-cared-for appearance should be maintained. Clothing is inappropriate when it is sleeveless, strapless, backless, or revealing; has slits above the knee; or is form fitting. Dresses, skirts, and shorts must be knee-length or longer. Hairstyles should be clean and neat, avoiding extremes in styles or colors. Excessive ear piercing (more than one per ear) and all other body piercing are not acceptable. Shoes should be worn in all public campus areas.
Clones, in other words.

Carnival of Evolution # 38 on Sandwalk

CoE #38 is now live on Sandwalk, and there's plenty of interesting stuff there. In fact there are so many posts that it would be overwhelming if Larry hadn't categorized the posts:

  • Classification (10 posts)
  • Fossils (3)
  • Evolution in Action (9)
  • Evolution of Behavior/Evolutionary Psychology (12)
  • Evo-Devo (3)
  • Evolutionary Theory (6)
  • Molecular Evolution/Genetics (7)
  • History of Evolutionary Biology (5)
  • Evolution vs Religion (3)
  • Evolutionary Humor (3)

And so, from the winning category, here is Zen Faulkes of NeuroDojo:
We know what Bruce Wayne picked as a “creature of the night”: a bat.

But why are bats so strongly nocturnal? Why don’t we see bats out flying around in the daytime (besides a few out on remote islands)? After all, most people can quickly think of one line of birds that is largely nocturnal.

If a bird had flown through Bruce Wayne’s window, we might have had a very different character in stately Wayne Manor.

Are we doomed?

#SciDoom New Statesman posed the question "Are we doomed?" to a bunch of prominent scientists, but we are all game.

Yes, of course we are. Let me count the ways.

I can think of at least seven "levels" at which we could be doomed, and out of those, three are certain but long term, while the rest are less certain but short term: universe, solar system, planet, life, humans, civilization, economy.

The first three are bound to cease to exist, and this is known with certainty. The universe will keep expanding and cooling until the temperature is the same everywhere (wiki). Fortunately this will take a little while. Sooner than that will be the end of out dear sun (5-10 billion years) and with it the Earth.

But life on Earth might be destroyed long before that. A nice gamma-ray burst or a cool meteor shower could annihilate all life on the planet. And much sooner than that we might see humans going extinct for a plethora of reasons. Civilization may cease to exist for a number of reasons, and our economic system may indeed be doomed, which is what I think many people concerns themselves with than any other of those seven levels.

Wearing my evolutionary biologist hat, I worry that we humans as a species are doomed much sooner that I'd like. As much as I can feel disgust in our many greedy ways, I also love so many of the things we do, and would be really sad if we all were to disappear. And yet, I think that is likely to happen. The evolutionary processes that I would credit with this would be bottlenecking, genetic drift, and natural selection. In that order.

For whatever reason, it is likely that the human population will be decimated some time in the future, perhaps even as soon as within the next hundred years. A cataclysmic event caused by global climate change, perhaps?

If anyone survives at all, I predict it will be in a number of smaller populations separated from each other geographically. These lucky few will thus pass through a genetic bottleneck, which will reduce both the effective population size and the genetic variation within each population. Such a surviving population will eventually bounce back and start growing again, and as it does, the genetic idiosyncrasies of each population will be retained, because the isolation of the surviving populations will make them unable to mate with each other and reduce the variation between the populations. Rather, the genetic variation between the different populations will be amplified, since each population is small. Small populations are more affected by genetic drift - the random sampling of genes (alleles, actually) - and so the population will evolve by drift through the generations. Eventually some populations will grow in size, and intra-population variation in fitness will start to matter again. This is because genetic drift is less effective in large populations, just as throwing ten thousand 7-sided dice will give you an average closer to 4 than using only ten dice will (incidentally, I just did that and got 3.9954 and 2.6000, thus proving my point and that evolution is true, no less). The population thus transitions from being at the mercy of genetic drift to being ruled by natural selection.

Natural selection has the same effect as drift, namely to decrease the variation within a population, while it will increase variation between populations. At least this is true if it holds true that the selection pressure isn't similar among the populations. If the environment is different for the different populations, then natural selection will push the populations to evolve differently. This will then result in a number of small, distinct populations evolving independently, each responding to the various selection pressures that the environment subjects them to. A small group of people in Hokkaido surviving a global cataclysmic event that also wipes out the amenities of civilization, will perhaps be selected for being short and stocky to keep warm, while the few survivors on New Guinea will go through rounds of selection (read: die-offs) due to diseases that they eventually will evolve resistance to. Et cetera.

Assuming that the environmental changes caused by the global cataclysmic event are severe enough that the separated populations won't be able to interact (i.e., have sex) for long enough, the different populations will continue to diverge from each other, and speciation will eventually occur. 6-7, say, million years hence, one of these populations will finally get the hang of it, and civilization will again rear its ugly head. The people of New New Guinea will have created technology and science, and because they are no less curious than their ancestral fools who caused the cataclysmic event in the first place, they will eventually figure out their own origins. Among other things they will find that they are closely related to another humanoid species native to Hokkaido - a species with a very different morphology form their own tall'n'handsome physique. Paleontologists will discover that their last common ancestor were a species of humanoid somewhat shorter than themselves, with smaller heads and no tail, not unlike the Hokkaido species.

With new techniques to decipher ancient DNA found at Antarctica, in addition to historical records unearthed in a bunker in the northern hemisphere, New New Guinean scientists eventually deduce that all living New New Guineans can trace their Y-chromosome back to one male from approximately 6.2833 millions years ago. This man had two offspring, both males, who happened to be separated from each other when the cataclysmic event devastated most of the human population of about 7 billion individuals. One of those was in Hokkaido, and the other was in New Guinea. He was, even without a tail, quite tall’n’handsome himself, and more than just quite proud of both his very successful sons.

This was a story of one way of human doom. Following a world-wide cataclysmic catastrophe, most of us will leave no descendants. A few of us will, and if fate will it, those descendants will split into two species (in this case via allopatric speciation). This may not sound much like doom, but humans in our present form will cease to exist, replaced by other species quite unlike our present selves. A beautiful doom, but doom for us nonetheless.

Did I answer the question "are we doomed?" I'm not sure I understood it in the first place, but this is what came out.