Here's a photo of some Howler Monkeys in New York City. I've met some of them. I'm not sure I want to meet the others ... just kidding. :-)
How many can you recognize? (Check here for their identities.)

That hyperbole has reverberated throughout the evolutionary biology community, putting Pigliucci and the 15 other participants at the forefront of a debate over whether ideas about evolution need updating. The mere mention of the "Altenberg 16," as Mazur dubbed the group, causes some evolutionary biologists to roll their eyes. It's a joke, says Jerry Coyne of the University of Chicago in Illinois. "I don't think there's anything that needs fixing." Mazur's attention, Pigliucci admits, "frankly caused me embarrassment."Jerry Coyne was wrong. There are some things that need fixing. Anyone who has read Stephen Jay Gould's The Structure of Evolutionary Theory should know that.
Well it seems our feedback to the University of Toronto about the upcoming Autism One conference has had an effect. As I noted earlier, Autism One is hosting a conference on autism in Toronto in October. The original brochure listed boldly that the conference was being presented with the Dalla Lana School of Public Health. Understandably concerned, I, along with many of you, contacted the university to register our concerns. Why would a school of public health support a program that touts dubious biomedical treatments for autism, and the ultimate quackery, homeopathy?I don't excuse the SickKids Foundation for their stupid attitude and support for this kind of quackery but the situation with respect to the University of Toronto is a bit different.
Well it turns out the school has acted – quickly and decisively. I’ve heard directly from the school, and have been assured that they were never an official supporter of the program. The brochure and website suggested that the school was actually co-hosting. The school has asked for its name to be removed – and the organizers have complied, as Orac noted earlier this week. The online version of the brochure no longer lists the school’s name.
But what about the SickKids Foundation? Well, this event has brought to light that the SickKids Foundation “takes a neutral stance on complementary and alternative health care” and seems satisfied to remain a sponsor of antivaccination pseudoscience. Their name is still on the brochure.
Which brings me to the topic of the post. Universities never have the funding that they think they need, and do whatever they can to bring in other types of revenue. So the Univeristy of Toronto has rented its space to AutismOne for the conference, and the brochure correctly notes that the address is the Medical Sciences Building on campus. Has a nice ring, doesn’t it? Despite the agenda clearly lacking both valid medicine or science, the conference has bought an air of legitimacy by locating itself on campus. It’s clearly a problem that needs to be addressed, as there’s stuff happening elsewhere on campus…
If a homeopathy manufacturer is providing sponsorship dollars for this symposium, the likelihood of the content being science-based is, well, probably homeopathic.There's no excuse for this. The Faculty of Pharmacy should be ashamed. All members of the University of Toronto community should be embarrassed. I know I am.
It pains me to point this out, as U of T is my pharmacy alma mater, and the school is filled with superb faculty, students, and researchers. So why is the Leslie Dan Faculty of Pharmacy willing to tarnish its good name by offering a continuing education program containing pseudoscience, sponsored by a company that makes homeopathy? Do they really need the money? Or have they run out of science-based topics to teach?
If this is the state of pharmacy continuing education, we should all be dismayed. Because when academic institutions that should know better are facilitating pseuodoscience like homeopathy, and accepting sponsorship from homeopathic manufacturers, what chance does pharmacy really have to be a science-based profession? And what does it mean for patient care, when pharmacists are learning how to use elaborate placebo systems to treat chronic pain?
HMB434H1I've spoken to the person who runs the Human Biology Program (Valorie Watt). She helped organize this course and she hired the lecturers. She doesn't see a problem.
Complementary and Alternative Medicine [20L, 4S]
Integrative health care is a phenomenon that is developing in health care systems in North America, China, India, and Vietnam, among others. It involves the coordination of multi-disciplinary and culturally-specific health services in the treatment of illness and disease, and an expanded concept of health, illness, and wellness.
[Photo Credit: Peter Macdiarmid/Getty: A kind of magic?]
The influence of this process on important evolutionary change, though, is probably minor, because it does not have the moulding power of natural selection. Natural selection remains the only process that can produce adaptation. Nevertheless, we'll see in chapter 5 that genetic drift may play some evolutionary role in small populations and probably accounts for some non-adaptive features of DNA.Okay, so it's not perfect, but at least he isn't confused about the difference between "evolutionary theory" and "Darwinism". Right?
Such random change in the frequency of genes over time is called genetic drift. It is a legitimate type of evolution, since it involves changes in the frequencies of alleles over time, but it doesn't arise from natural selection. One example of evolution by drift may be the unusual frequencies of blood types (as in the ABO system) in the Old Order Amish and Dunker religious communities in America. These are small, isolated, religious groups whose members intermarry—just the right circumstances for rapid evolution by genetic drift.1This sounds like a typical adaptationist speaking. As a general rule, adaptationists admit to random genetic drift but confine it to small populations. They also make sure you understand that drift can't cause adaptation. Finally they state their opinion that drift only affects neutral alleles.
Accidents of sampling can also happen when a population is founded by just a few immigrants, as occurs when individuals colonize an island or a new area. The almost complete absence of genes producing the B blood type in Native American populations, for example, may reflect the loss of this gene in a small population of humans that colonized North America from Asia around twelve thousand years ago.2
Both drift and natural selection produce genetic change that we recognize as evolution. But there's an important difference. Drift is a random process, while selection is the anti-thesis of randomness. Genetic drift can change the frequencies of alleles regardless of how useful they are to their carrier. Selection, on the other hand, always gets part of harmful alleles and raises the frequencies of beneficial ones.
As a purely random process, genetic drift can't cause the evolution of adaptations. It could never build a wing or an eye. That takes nonrandom natural selection. What drift can do is cause the evolution of features that are neither useful nor harmful to the organism.
At this point, some evolutionists will protest that we are caricaturing their view of adaptation. After all, do they not admit genetic drift, allometry, and a variety of reasons for non-adaptive evolution? They do, to be sure, but we make a different point. In natural history, all possible things happen sometimes; you generally do not support your favorite phenomenon by declaring rivals impossible in theory. Rather, you acknowledge the rival, but circumscribe its domain of action so narrowly that it cannot have any importance in the affairs of nature. Then you often congratulate yourself for being such an undogmatic and ecumenical chap. We maintain that alternatives to selection for best overall design have generally been relegated to unimportance by this mode of argument.This describes the views of many adaptationists but Jerry Coyne does not exactly fall into that mode of thinking—at least not when his attention is focused on the issue.
In fact, genetic drift is not only powerless to create adaptation, but can actually overpower natural selection. Especially in small populations, the sampling effect can be so large that it raises the frequency of harmful genes even though selection is working in the opposite direction. This is almost certainly why we see a high incidence of genetically based diseases in isolated human communities, including Gaucher's disease in northern Swedes, Tay-Sachs in the Cajuns of Louisiana, and in retinitis pigmentosa in the inhabitants in the inhabitants of the island of Tristan da Cunha.This is very important and Jerry Coyne is one of the few adaptationists who get it. Random genetic drift doesn't just work on neutral alleles. It can also lead to high levels of deleterious alleles. Even their eventual fixation.
Because certain variations in DNA or protein sequence may be, as Darwin puts it "neither useful nor injurious" (or "neutral" as we now call them), such variants are especially liable to evolution by drift. For example, some mutations in a gene don't affect the sequence of the protein that it produces, and so don't change the fitness of its carrier. The same goes for mutations in non-functioning pseudogenes—old wrecks of genes still kicking around in the genome. Any mutations in these genes have no effect on the organism, and therefore can evolve only by genetic drift.It's impressive that Coyne admits to the possibility that externally visible features could be neutral and could evolve by random genetic drift. However, he immediately qualifies the statement by pointing out that it's very difficult to prove whether a trait has absolutely no selective advantage. This is true, but adaptationists usually forget to mention two things about natural selection that weaken this argument. First, they forget to mention that it's often just as difficult to prove that a trait has a selective advantage. Second, traits with small advantages are most often lost before they are fixed. Natural selection is not random but neither is it as much of a sure thing as most people believe.
Many aspects of molecular evolution, then, such as certain changes in DNA sequence, may reflect drift rather than selection. It's also possible that many externally visible features of organisms could evolve via drift, especially if they don't affect reproduction. The diverse shapes of leaves of different tree species—like the differences between oaks and maple trees -- were once suggested to be "neutral" traits that evolved by genetic drift. But it's hard to prove that a trait has absolutely no selective advantage. Even a tiny advantage, so small as to be unmeasurable or unobservable by biologists in real time, can lead to important evolutionary changes over eons.
The relative importance of genetic drift versus selection in evolution remains a topic of hot debate among biologists.
1. This is technically correct. Individual alleles will be fixed much faster in small populations than in large populations ... if they are fixed. But this does not mean that random genetic drift only fixes genes in small populations.
2. The founder effect is an important feature of evolution by accident.
There are two ways that modern evolutionists approach the Cambrian explosion, or what has been called “Darwin’s dilemma”:Here's another option.
A. Some freely acknowledge that the Cambrian fossil evidence essentially shows the opposite of what was expected under neo-Darwinian evolution.
B. Others deal with the Cambrian explosion by sweeping its problems under the rug and trying to change the subject.
Thanks for asking for my reaction to Behe’s post on our recent paper in Nature. His interpretation of our work is incorrect. He confuses “contingent” or “unlikely” with “impossible.” He ignores the key role of genetic drift in evolution. And he erroneously concludes that because the probability is low that some specific biological form will evolve, it must be impossible for ANY form to evolve.
Behe contends that our findings support his argument that adaptations requiring more than one mutation cannot evolve by Darwinian processes. The many errors in Behe’s Edge of Evolution — the book in which he makes this argument — have been discussed in numerous publications.
In his posts about our paper, Behe’s first error is to ignore the fact that adaptive combinations of mutations can and do evolve by pathways involving neutral intermediates. Behe says that if it takes more than one mutation to produce even a crude version of the new protein function, then selection cannot drive acquisition of the adaptive combination.
[Photo Credit: Joe Thornton by Jack Liu Photographer]
[Image Credits:
Charlemange Empire map
Emperor Charlemagne]
Thousands of amateur genealogists have contributed to a huge database of family relationships, including genetic analyses. What does this teach us about human populations and evolution?
Genealogists have mathematically demonstrated how all Americans of European descent must be related to Charlemagne. In this regard, genealogists have established the exact lines of descent from Charlemagne for 14 U.S. Presidents. Two of these are President George W. Bush and his father President George H.W. Bush. Other Presidents whose descent from Charlemagne have been traced include: George Washington, Ulysses Grant, Franklin Roosevelt, Teddy Roosevelt, and Gerald Ford. To demonstrate how we are all related, the New England Historical Society has researched the genealogy of Barack Obama and determined that on his mother's side he is related to six other previous presidents: George W. Bush, George H. W. Bush, Lyndon Johnson, Harry Truman, Gerald Ford, and James Madison. Presumably, if Barack Obama's ancestry on his mother's side could be traced far enough back, he also would be shown to be descended from Charlemagne. Meanwhile, on his father's side, we are all related to President Barack Obama since anthropologists have determined that all modern humans are descended from a common African ancestor.
1. In my case it was my mother who did/does all the work. I just surfed the internet using her data.
2. The actual calculated value for my ancestors is 29 years per generation.
"for their discoveries concerning the function of single ion channels in cells"
Summary
Each living cell is surrounded by a membrane which separates the world within the cell from its exterior. In this membrane there are channels, through which the cell communicates with its surroundings. These channels consist of single molecules or complexes of molecules and have the ability to allow passage of charged atoms, that is ions. The regulation of ion channels influences the life of the cell and its functions under normal and pathological conditions. The Nobel Prize in Physiology or Medicine for 1991 is awarded for the discoveries of the function of ion channels. The two German cell physiologists Erwin Neher and Bert Sakmann have together developed a technique that allows the registration of the incredibly small electrical currents (amounting to a picoampere - 10-12A) that passes through a single ion channel. The technique is unique in that it records how a single channel molecule alters its shape and in that way controls the flow of current within a time frame of a few millionths of a second.
Neher and Sakmann conclusively established with their technique that ion channels do exist and how they function. They have demonstrated what happens during the opening or closure of an ion channel with a diameter corresponding to that of a single sodium or chloride ion. Several ion channels are regulated by a receptor localized to one part of the channel molecule which upon activation alters its shape. Neher and Sakmann have shown which parts of the molecule that constitute the "sensor" and the interior wall of the channel. They also showed how the channel regulates the passage of positively or negatively charged ions. This new knowledge and this new analytical tool has during the past ten years revolutionized modern biology, facilitated research, and contributed to the understanding of the cellular mechanisms underlying several diseases, including diabetes and cystic fibrosis.
What Happens Inside the Cell?
Inside the cell membrane there is a well-defined environment, in which many complex biochemical processes take place. The interior of the cell differs in important respects from its outside. For example the contents of positive sodium and potassium ions and negatively charged chloride ions are quite different. This leads to a difference in electrical potential over the cell membrane, amounting to 0.03 to 0.1 volts. This is usually referred to as the membrane potential.
The cell uses the membrane potential in several ways. By rapidly opening channels for sodium ions the membrane potential is altered radically within a thousandth of a second. Cells in the nervous system communicate with each other by means of such electrical signals of around a tenth of a volt that rapidly travel along the nerve processes. When they reach the point of contact between two cells - the synapse - they induce the release of a transmitter substance. This substance affects receptors on the target cell, often by opening ion channels. The membrane potential is hereby altered so that the cell is stimulated or inhibited. The nervous system consists of a series of networks each comprised of nerve cells connected by synapses with different functions. New memory traces in the brain are for example created by altering the number of available ion channels in the synapses of a given network.
All cells function in a similar way. In fact, life itself begins with a change in membrane potential. As the sperm merges with the egg cell at the instant of fertilization ion channels are activated. The resultant change in membrane potential prevents the access of other sperm cells. All cells - for instance nerve cells, gland cells, and blood cells - have a characteristic set of ion channels that enable them to carry out their specific functions. The ion channels consist of single molecules or complexes of molecules, that forms the wall of the channel - or pore - that traverses the cell membrane and connects the exterior to the interior of the cell (Figure 1B and 1D). The diameter of the pore is so small that it corresponds to that of a single ion (0.5-0.6 millionths of a millimetre). An immediate change in the shape of the molecule leads to either an opening or a closure of the ion channel. This can occur upon activation of the receptor part of the molecule (Figure 1D) by a specific signal molecule. Alternatively a specific part of the molecule that senses changes in membrane potential can open or close the ion channel.Figure 1. Registration of the flow of current through single ion channels using the recording technique of Neher and Sakmann. A schematically shows how a glass micropipette is brought in contact with the cell, and B, using a higher magnification, a part of the cell membrane, with ion channels, in close contact with the tip of the pipette. The interior of the pipette is connected to an electronic amplifier. C shows a channel in greater magnification with its receptor facing the exterior of the cell and its ion filter. D shows the current passing through the ion channel as it opens.
Neher and Sakmann Record the Electric Current Flowing Through a Single Ion Channel
It has long been known that there is a rapid ion exchange over the cell membrane, but Neher and Sakmann were the first to show that specific ion channels actually exist. To elucidate how an ion channel operates it is necessary to be able to record how the channel opens and closes. This appeared elusive since the ionic current through a single ion channel is extraordinarily small. In addition, the small ion channel molecules are embedded in the cell membrane. Neher and Sakmann succeeded in solving these difficulties. They developed a thin glass micropipette (a thousandths of a millimeter in diameter) as a recording electrode. When it is brought in contact with the cell membrane, it will form a tight seal with the periphery of the pipette orifice (Figure 1A, B). As a consequence the exchange of ions between the inside of the pipette and the outside can only occur through the ion channel in the membrane fragment (Figure 1B). When a single ion channel opens, ions will move through the channel as an electric current, since they are charged. Through a refinement of the electronic equipment and the experimental conditions they succeeded in measuring this "microscopical" current by laborious methodological developments during the seventies (Figure 1C).
How Does an Ion Channel Operate?
Ion channels are of different types. Some only permit the flow of positively charged sodium, potassium or calcium ions, others only negatively charged chloride ions. Neher and Sakmann discovered how this specificity is accomplished. One reason is the diameter of the ion channel, which is adapted to the diameter of a particular ion. In one class of ion channels, there are also two rings of positively or negatively charged amino acids. They form an ionic filter (see Figure 1D), which only permits ions with an opposite charge to pass through the filter. In particular Sakmann through a creative interaction with different molecular biologists elucidated how the different parts of the ion channel molecule(s) operate. Neher and Sakmann's scientific achievements have radically changed our views on the function of the cell and the contents of text books of cell biology. Their methods are now used by thousands of scientists all over the world.
The Study of Secretory Processes
Nerve cells, as well as hormone-producing cells and cells engaged in the host defence (like mast cells) secrete different agents. They are stored in vesicles enclosed by a membrane. When the cell is stimulated the vesicles move to the cell surface. The cell and vesicle membranes fuse and the agent is liberated. The mast cell secretes histamine and other agents that give rise to local inflammatory reactions. The cells of the adrenal medulla liberate the stress hormone adrenaline, and the beta cells in the pancreas insulin. Neher elucidated the secretory processes in these cell types through the development of a new technique which records the fusion of the vesicle(s) with the cell membrane. Neher realized that the electric properties of a cell would change if its surface area increased making it possible to record the actual secretory process. Through further developments of their sophisticated equipment the resolution finally permitted recording of each little vesicle fusing with the cell membrane.
Regulation of Ion Channel Function
Neher and Sakmann also used the electrode pipette to inject different agents into the cell, and they could thereby investigate the different steps in the secretory process within the cell itself (see above). In this way a number of cellular secretory mechanisms have been clarified such as the role of cyclic AMP (see Nobel Prize to Sutherland 1971) or calcium ions. For instance, we now have a better understanding of how the hormone levels in the blood are maintained at a certain level.
Also the basal mechanisms underlying the secretion of insulin have been identified. The level of blood glucose controls the level of glucose within the insulin-forming cell, which in turn regulates the level of the energy rich substance ATP. ATP acts directly on a particular type of ion channel which controls the electric membrane potential of the cell. The change of membrane potential then indirectly influences other ion channels, which permit calcium ions to pass into the cell. The calcium ions subsequently trigger the insulin secretion. In diabetes the insulin secretion is out of order. Certain drugs commonly used to stimulate insulin secretion in diabetes act directly on the ATP-controlled ion channels.
Many other diseases depend entirely, or partially, on a defect regulation of ion channels, and a number of drugs act directly on ion channels. Many pathological mechanisms have been clarified during the eighties through ion channel studies, for instance cystic fibrosis (cloride ion channels), epilepsy (sodium and potassium ion channels), several cardio-vascular diseases (calcium ion channels), and neuro-muscular disorders like Lambert-Eatons disease (calcium ion channels). With the help of the technique of Neher and Sakmann it is now possible to tailormake drugs, to achieve an optimal effect on particular ion channels of importance in a given disease. Drugs against anxiety act for instance on certain inhibitory ionic channels in the brain. Alcohol, nicotine and other poisons act on yet other sets of ion channels.
In summary, Neher and Sakmann's contributions have meant a revolution for the field of cell biology, for the understanding of different disease mechanisms, and opened a way to develop new and more specific drugs.
References
Alberts et al.: The Molecular Biology of the Cell. Garland Press, 1990, 2nd edition, pp. 156, 312-326, 1065-1084.
Grillner, S. I: N. Calder (ed.). Scientific Europe. Foundation Scientific Europe, 1990.
Grillner, S. & Hökfelt, T.: Svindlande snabb utveckling präglar neurovetenskapen. Läkartidningen 1990, 87, 2777-2786.
Rorsman, P. & Fredholm, B.B.: Jonkanaler - molekylär bakgrund till nervtransmission. Läkartidningen 1991, 88, 2868-2877.
The images of the Nobel Prize medals are registered trademarks of the Nobel Foundation (© The Nobel Foundation). They are used here, with permission, for educational purposes only.
Critical thinking—most faculty want students to be critical thinkers. Many students, however, are epistemological duelists, viewing the academic world in terms of true or false, right or wrong, credit or no credit. Instead of analyzing evidence that contradicts their erroneous conceptions, students often just passively receive knowledge from authorities—professors. To become active learners, students need professors to use methods that involve them in grasping the important concepts; but, only 10%-30% of professors use methods other than traditional lectures as their primary pedagogy.Do these sound like motherhood statements? If you answered "yes" then you aren't paying attention.
Whether or not students have taken courses in biology or evolution, they come to the science classroom with a variety of memories, knowledge, experience, and evolution conceptions. Often, some of those conceptions are different from scientific concepts. Students develop these conceptions from what they read in the popular press, find on the Web, and see on television and from their interactions with "nature," their peers, and their parents and other authority figures. Instructors at all levels have a complex task: to tap into what students know to assist them in building on their scientific knowledge, to help them replace their misconceptions with scientifically useful conceptions, and to help them construct meaning from their learning experiences.What this means is that students carry a lot of baggage into the university classroom. You're not going to change their conceptual understanding of evolution by just presenting the facts are you see them. You're also not going to be successful if you think that just giving them the right concepts—such as the importance of random genetic drift—is all it takes.
Helping students construct meaning from their learning experiences is a daunting task. Only the students can do it; instructors cannot "fill" them with knowledge. All instructors can do is to provide learning experiences that facilitates students' generating links between relevant information they already know and new information. From such a constructivist perspective, learning is a social process in which students make sense of experience in terms of what they already know. But how does the professor engineer lessons to help students link the new information with the old in useful, accurate, and appropriate ways? And what happens when the "old" information consists of one or more scientific misconceptions?
What many instructors know from their own classroom experience is that student misconceptions (also called native conceptions, alternate conceptions, intuitive use, prior conceptions, preconceptions, or undesired understandings) are not easily changed. What many people do not realize, however, is that the process of conceptual change takes a long time, perhaps years, depending on the concept, and appears to be an incremental process. In learning evolutionary concepts in particular, students appear to need an extended exposure to and interaction with these concepts for growth in their understanding to occur. Instructors, therefore, may think of the learning experiences they provide for students is only one stepping stone towards the goal of more complete under standing.
To facilitate a constructivist approach in the classroom, an instructor should provide situations in which students examine the adequacy of their prior conceptions, allowing them to argue about and test them. The contradictions students may face during this testing process can provide the opportunity for them to acquire more scientifically appropriate concepts.
[Image Credit: Project X]
[Image Credit: Brookhaven National Laboratory]
12% is a very big effect and would lead to rapid evolutionary change (on the order of thousands of years in the most simple population genetic model of a single locus of dominant effect).I posted a comment on his blog. I'm reproducing it here in order to get more feedback.
[Image Credit: "Rudyard Kipling’s illustration for The Elephant’s Child from Just So Stories (1902)." From Encyclopedia Britannica