Update on Nebraska

In my most recent blog I wrote about the possibility that the Board of Regents of the University of Nebraska might vote in a policy that would place severe restrictions on the range of embryonic stem cell research that could be conducted within the university. According to a news item published on November 25 by the American Association for the Advancement of Science, the board did not have sufficient votes to carry the policy forward:

“University of Nebraska Votes Against Changing Policies on Stem Cell Research. The University of Nebraska's Board of Regents voted against changing its existing policy governing research on embryonic stem cells, a move that will allow the university to continue research on stem cell lines in accordance with the new NIH guidelines. A resolution was proposed that would have restricted the campus policy to allow only research on the cell lines that were approved under the 2001 policy issued by former President Bush. The eight-member Board voted 4-4, and since a majority of votes is required to pass a resolution, the proposed change was defeated. AAAS issued a letter to the University's President and Board of Regents emphasizing its support for human embryonic stem cell research conducted with appropriate ethical guidelines.”

The Board's decision is, I suppose, something of a victory, but the closeness of the vote demonstrates how divided the Board was on the matter. I think of it as more of a reprieve than a victory. Those who would like to force their constructions of what is right and wrong on the rest of us will not give up on their efforts, not in Nebraska or elsewhere. The only defense for those who value intellectual freedom, and an open, pluralistic society in which to practice it, is to keep working on communicating their core values as vigorously as possible. If we want free choice within reasonable societally accepted boundaries, there is no real alternative to pushing back against extremism while engaging with others who may have differing viewpoints but seek a satisfying framework for making social policy.

Religion and Scientific Autonomy

When we determine whether we can trust someone, a prime consideration is whether that person is independent of external influences that might affect judgment or testimony. In a similar way, a core element in science’s claim to be a socially productive source of knowledge of the natural world is that it has autonomy . In science autonomy operates at different levels, from the freedom of the individual scientist to choose research goals and methods of pursuing them to the independence of the scientific establishment as a whole from interference from government or other powerful influence groups. This does not mean that there are no constraints on scientists. A host of laws and norms of good practice operate to prohibit certain kinds of research; for example, research with the potential for harming human subjects, or that would endanger anyone in the vicinity of a research facility. These are motivated by moral and ethical standards of the broadest kind, the same sorts of constraints that apply to people and organizations generally.

As I have explained in the book Imperfect Oracle, science frequently comes into conflict with other social sectors because it challenges older traditional understandings. These conflicts are nowhere more evident than in the United States, in science’s contentious encounters with conservative Christian groups. Here the issue that comes to the fore is whether certain kinds of research should be constrained because they are deemed contrary to the religious dogmas of a particular group of people. One of the hot topics over the past several years has been embryonic stem cell research. Christian conservatives, in concert with the Catholic Church, have campaigned against the use of embryonic stem cells, whatever the source from which they have been obtained, on the grounds that such cells literally constitute a human life, and their destruction would be a violation of God’s law.

The latest chapter in this seemingly endless saga is centered in Nebraska, where the extreme right-to-lifers have taken a new tack: get opponents of embryonic stem cell research elected to the University’s board of regents. A majority of such board members there could pass a ruling that restricts research on embryonic stem cells to the limited list approved years ago by President George W. Bush. The policies related to stem cell research were greatly liberalized by the Obama administration in Executive Order 13505. Thus the policy that may be put into place by the Board of Regents would move the University of Nebraska back to the dark ages of stem cell research. Actually, no embryos would be destroyed at the University of Nebraska in any case; cell lines that are, or would be, used were developed elsewhere and copied cells would be employed. That, however, still causes problems for those who advocate forbidding research with such materials.

The continuing controversy over the use of stem cells has led to formation of such organizations as The Nebraska Coalition for Ethical Research. These people claim not to be opposed to science, or even to stem cell research; they just want it done on their terms. They are free with their advice that scientists simply focus on adult stem cells. They point to recent work that has shown that adult stem cells can be reprogrammed so that they mimic the properties of embryonic stem cells. But what qualifications do these people have for advising scientists on how best to carry out their work? Reprogramming of adult stem cells is in its infancy, and there are many impediments to its general application. There is no assurance that it will ever constitute a substitute for work with embryonic stem cells. Even setting that aside, however, the point is that science cannot operate effectively when it is confined by an entity outside science on grounds that have nothing to do with the scientific merits of the work.

Science’s autonomy, its capacity to move in directions dictated by scientific considerations, is constrained in this and related instances because one particular social group frames the work in its own extra-scientific terms, and wants to hold the rest of society hostage to its judgments. The public seems dismayingly willing to tolerate such extremism. I hope, however, that it will become increasingly evident that most of us are the losers when the extremists win; things might then change. Society is not well-served by outmoded ways of thinking based on religious doctrines tailored by church authorities in other eras for their own dubious reasons. One does not have to become an atheist or agnostic to conclude that organized religion has, for the most part, become a bad thing for society. Like other addictions, however, it seems to be a hard habit to break.

Weather, Climate and Global Warming

In my most recent blog I made mention of the common fallacy of drawing conclusions about the reality of global climate change from observations of local weather. Climate change denialists like to bring up the cold, wet summer or an unusually heavy snowfall during winter as evidence against global warming. But, as I pointed out, weather and climate must be understood differently. Weather is highly changeable on a day-to-day basis. Climate can also vary, but it does so on much longer time scales. It is quite possible that in a given year some large scale measure of climate, such as hurricane intensity, or rainfall over a large area, will move in opposition to a longer scale trend. But for the most part, changes occurring over a period of time such as a year will tend to show behavior that follows the long term trends.

I was therefore pleased to see the piece in this Sunday’s New York Times by Andrew Revkin that deals with the trends in record high and low temperatures across the United States over recent time. The data illustrate nicely that while record highs and lows continue to occur, the number of record high temperatures is increasing year by year, whereas the number of record lows is decreasing. The video in the piece, by Gerald Meehl, provides a nice explanation of what is going on.

Changing minds about climate change

One scientific question that has relevance for every person on the planet is whether the global climate is changing in response to human activities. The major causative agents of the change, if indeed there is change, are the so-called greenhouse gases. Some of them, such as carbon dioxide, methane and nitrous oxide, are naturally occurring components of the atmosphere, but humans have caused their concentrations to increase greatly. Other greenhouse gases are substance that humans have learned to make and use for various purposes. These include the so-called chlorofluorocarbons and hydrofluorocarbons.

Not everyone is convinced that human activities are the driving force for some of the climate changes we have been seeing in recent years, or that the scientific models for climate reliably predict what may happen in the future if we continue to consume fossil fuels and add increasing amounts of other greenhouse gases such as methane to the atmosphere. In one sense this is not entirely surprising, because climate is not a well-defined entity, not easily described in terms of just a few critical measurements. Weather, something that happens at the local level, and climate, which extends over large regions and ultimately to the entire planet, are easily confused in many peoples’ minds. Although seasonal weather changes from one year to the next are not reliable indicators of climate change, they are frequently brought into discussions as though they were. Thus, a cold spring in the northwestern states of the United States are taken by many as evidence that global warming is not occurring. It seems that nearly everyone is an expert of some sort on climate. Political entertainers such as Glenn Beck and Rush Limbaugh, who have not a shred of expertise, don’t hesitate to declare that global warming is a massive hoax perpetrated by an establishment that wants to use it as a pretext for sinister incursions into private rights and freedoms.

This is a big topic, because if climate changes are occurring as a result of human activities to date, those changes will accelerate greatly over the next few decades as more and more greenhouse gases are pumped into the atmosphere. I need not rehearse here again, as I have in earlier blogs, the vast range of studies performed by scientists working in many different disciplines, and in a host of environments all over the planet, to attempt to learn about past climates and the changes occurring now in our own climate. Those studies have all gone into formation of the successive reports of the Intergovernmental Panel on Climate Change (IPCC), and the information collected there is continually updated as new evidence is produced. All of this scientific work, and the inferences drawn from it by the best minds working in all the areas of science related to climate change, have led to the conclusion that the climate is indeed changing as a result of human activities, and that the changes are accelerating. For example, the Greenland ice mass is decreasing; the latest evidence is that the loss is accelerating.

This past March, a group of about 2000 climate scientists gathered in Copenhagen to assess the current views on climate change. Because the group was not brought together under the auspices of the IPCC or any other single governmental agency, participating scientists were more free to offer frank appraisals and prescriptive statements. Many factors that bode ill for our prospects were either not considered in the IPCC report or were very conservatively estimated. For example, it is only now becoming evident that permafrost holds vast amounts of carbon that is becoming “unlocked” as the permafrost warms. The upshot is that the prospects look worse than the projections of the IPCC would lead one to expect.

The evidence for global warming and the role of human activities in the process, is at this point overwhelming. One way of putting this is that there is a strong consensus in the scientific community on these matters, of the same sort that exists with respect to many widely held bodies of evidence in chemistry, physics, genetics, and other branches of science. The National Academies of Science have produced a very nice video, America’s Climate Choices, that reveals the degree of consensus that obtains in the scientific world, and describes the organization of groups of experts that are being convened to assist the government in addressing the challenges that lie ahead. I urge you to watch this, to sense how deep and widely felt are the views of outstanding scientists and other citizens on this matter. Yet there are scientists, mostly without credentials in any of the relevant areas of science, and lacking acceptable scientific evidence that contravenes the current understanding, who continue to reject the consensual scientific position. Some seem to think it is a conspiracy of some kind, an attempt to somehow put something over on society. I can understand how some politicians, entertainers, entrenched interest groups such as those representing certain segments of the energy industry and the like, might find it convenient to resist the existing scientific evidence, but what is going on in the heads of deniers who have a supposedly scientific training? It must have to do with a deep-seated unease with the implications of greater governmental oversight as society comes to grip with the steps that must be be taken to reduce greenhouse gas emissions and at the same time begin to deal with mitigating global warming effects.

In a letter published in a recent issue of Chemical and Engineering News a writer reluctantly seems to agree that Earth’s climate is getting warmer, though he cites the low spring temperatures in the northeast as evidence that might contradict the global warming hypothesis (!). But he thinks that “blaming it (global warming) on human activities seems to be speculative.” What blows my mind is that this person can’t seem to imagine that the virtual army of scientists working on this problem would not have held this very question at the fore in all their work! What does that say about this person’s understanding of how science works? Apparently the means by which science establishes its epistemic authority, within the scientific community and outside it, is not clear to some scientists. We have a long way to go.

Evolution: theory or fact?

In writing Imperfect Oracle, which deals with how science exercises influence, or fails to do so, in contemporary society, I was struck many times by the challenges science faces in communicating its outlook. It is widely understood that communication is critical in determining science’s place in society. Much has been written on how scientists and the science establishment generally need to do better than they have done. The American Association for the Advancement of Science (AAAS) does a great deal at its annual meeting to present thoughtful commentary on important issues that affect society at large. This is but one venue, and it has limited reach into most peoples’ consciousness. One hopes that the program and others like it, such as the national meetings of the American Chemical Society, will be noticed and reported on by those who shape the content of internet, TV, cable and print media. Even when science content appears on these outlets, however, not much insight into how scientists actually learn about the world, or how their work leads to new scientific knowledge, goes with it.

As I show in the book, such insight is essential to establishing science’s authority when there is an inconsistency between what science has to say on some topic and what people hold as part of their core cultural understandings. An example came up this past weekend. Nicholas Wade has written a review of Richard Dawkins’s new book, The Greatest Show on Earth, in which he argues that Dawkins failed to appreciate the distinction between a theory and scientific fact in talking about the status of evolution. Those who wish to dismiss evolution as “just a theory” employ the notion of a theory as something supported by evidence but inescapably incomplete and always subject to refutation at some level. This view in varying degrees has dominated much of the philosophy of science for decades. Dawkins will have none of that; for him evolution is a “fact in the same sense as it is a fact that Paris is in the Northern Hemisphere.” Wade suggests a way of thinking about evolution that avoids Dawkins’s dogmatic stance, but in doing so he moves to an account that philosophers of science are likely to find wanting. Indeed, in the Letters section of the following week’s issue of the Review of Books, the philosopher of science Philip Kitcher wrote to defend Dawkins. He argues that evolution is a theory because it is a general systematic explanation, and because it accounts for such a vast amount of relevant experimental data “it may be accepted without debate.”
Perhaps, then evolution is a “fact” in the same sense as Paris’s location. But this rather facile response bothers me. The term “evolution” has meaning at many levels. There is the general theory grounded in Darwin’s original idea that organisms have evolved through time. Evolution in that sense can be traced in a paleontological record so extensive and self-consistent that, as Kitcher suggests, there is really no room for reasonable doubt. At the same time, evolution is a vital part of modern biology, and new insights relating to it are reported frequently. New technologies in biology have given rise to experiments that have required new interpretations of what “evolution” means in particular cases. Think, for example, of the contributions from molecular phylogenetics, which relates organisms in terms of the similarities in their DNAs. In other words, evolution is not a dead science, and in this sense it does not have the status of accepted fact. We need to be careful not to muddle our notions of what we mean by theory in a vain effort to make “evolution” impregnable to the objections of the congenitally unconvinced.

The truth is that arguments with creationists and others who fail to accept the claims of modern science will not be settled for the great audience of uncommitted nonscientists when one side or the other lands a telling blow. Daniel Dennett, in his letter preceding Kitcher’s in the Review of Books, wonders how the judge’s decision in the famous Dover, Pa. case of a few years ago can have failed to convince The Times that the intelligent design campaign is a hoax unworthy of any news space. He must be aware that within a week or so of the Dover decision the Discovery Institute had issued a book-length rebuttal. It is altogether like swatting flies; one of course should swat, but not really expect flies to disappear. The Times is a newspaper, not an arbiter of science wars. What is at issue here is how science can establish its epistemic and moral authority in society outside the scientific community. How can it bring people to the point of openly considering what science has to tell us about the world when its findings conflict with settled cultural biases and cognitive leanings? Science has not done well at engaging people in terms that have meaning for them. In his fine little book, The Culture of Education, Jerome Bruner wrote about what we need to do to equip people for participation in the full range of the culture in which they live. Science must learn how to be part of that challenging educational project in ways that it has not been in the past. As I have explained in Imperfect Oracle, it has a lot of difficult, uphill work to do.

Uncertain science

Sometimes it is impossible for science to produce certain knowledge about matters upon which we would dearly love to have definite answers. Consider the challenge that the Environmental Protection Agency faces in setting exposure limits in water supplies for substances known or strongly suspected of being carcinogenic . The concentrations of such substances in a water supply are typically very low, in the parts per million range. Still, such low levels could be harmful, at least to a fraction of people. We can’t get all of the carcinogen out of the water, but we could reduce its concentration at some cost. At what level of concentration would a particular carcinogen be expected to cause no more than a certain very low level of added cancer, and what would it cost to get to that level? Toxicologists can’t do useful experiments on test animals with the water as it is found, because at the low concentrations of pollutant, it would take a huge number of test animals to produce a statistically meaningful result. Instead, what is done is to use much higher concentrations of the pollutant in the laboratory, much greater than would ever occur in the natural situation, with a manageable populations of animals. Various concentrations of the carcinogen are used with groups of test animals, and the incidence of excess cancers is monitored after a period of using those levels. A graph is then constructed of excess cancers vs. the concentration used. We might then get the red data points, as shown in the figure above.

All the investigator sees of course are the red data points: they show that the more carcinogen, the more cancers. But what happens when we extrapolate backward, into the region of very low concentrations typical of natural water? The so-called linear dose-response assumption is that the data would fall along the straight line shown. But is it a good approximation to what happens at those low concentrations? Many scientists believe that the model is not a good one, and there are cases where it is known to be wrong. One could argue that the body has mechanisms for dealing with very low concentrations of carcinogens and that at some low level a carcinogen is not a threat at all. The actual response thus might be more like the curved line shown. This is called the threshold model.

To test the model on a specific case, George S. Bailey and colleagues at Oregon State University studied the effects of extremely low dosages of a known carcinogen, dibenzo[a,l]pyrene on more than 40,000 rainbow trout. With such a large population of fish, small excess cancer levels could be detected. These studies extended the studies of this compound to concentrations a thousand times lower than had been done before. The results showed that the linear dose response method greatly overestimates the cancer risk from this compound at these low concentration levels, by a factor of between 500 and 1,500. In other words, their data are consistent with the threshold model; their data would fall somewhere around the blue line in the graph (however, my drawing is just an approximation, not an accurate representation of the fish study). While this study applies for just this one substance and its effect on one species of fish it is important, because it shows that the linear dose-response model can greatly overestimate the dangers associated with very low concentrations of known carcinogens or other toxic substances. This study thus is significant for those in the EPA responsible for setting exposure limits.

Most people long for certainty in the affairs of their lives. They wish assurance that their jobs are secure for the foreseeable future, that their children are safe at school, that their spouse or significant other is faithful to agreements they have made. Yet we know that many aspects of life are uncertain. We’re unsure of the future of the housing market, of the impacts of climate change, of – well, of an awful lot of things! So we look for pillars of certainty, things that we know are true and will stay true regardless. The foundational documents of governance, such as the Constitution; religious dogma; fundamental scientific laws – all these promise certainty of a kind in particular domains of our concerns. Our reliance on these certainties is often so deep-seated that we instinctively react against evidence that they may not be as immutable as we have been led to believe.

This nearly universal need for certainty poses a continuing challenge for science in its attempts to inform the society outside the scientific community about how the world is. A great many ideas, theories and laws are very widely accepted in science and taken for all practical purposes to be true. Many of these form the basis of the technologies that undergird our modern life. If what science has to say about the operations of lasers were not true, how could they be effective in the multiple uses made of them, from removal of cataracts to reading the contents of CD’s and DVD’s? If very complex theories of combustion and turbulent gas flow were not very reliable descriptions of how airline jet fuel burns and propels a jet aircraft, how likely is it that jet aircraft would ever get off the ground? These examples and thousands of others like it promote the notion that science is a fountain of rigorously true statements and ideas. Yet a great deal that concerns scientists in the course of their everyday work , and that necessarily influences opinions they must deliver on matters consequential to the public good, is clouded by uncertainty. Just how much of a particular carcinogen can we have in our water supply before it constitutes a significant health risk? Scientists can attempt to narrow the range of uncertainty but there is no such thing as a single, true answer.

Scientific witness in the courtroom

This past June the U.S. Supreme court issued a decision with fascinating ramifications for the notion of scientific authority. They ruled that reports from crime laboratories may not be used at trial against a criminal defendant unless the analysts responsible for creating the data are present to give testimony and bear cross-examination. This decision is an interpretation of the Sixth Amendment, which provides in part that an accused has the right “to be confronted with the witnesses against him. “

The case brought before the court arose from the conviction of Luis E. Melendez-Dias on cocaine trafficking charges. Part of the evidence against him was a laboratory report stating that bags of white powder allegedly belonging to Melendez-Dias contained cocaine. The lab report was submitted by prosecutors with an analyst’s certificate, but no analyst appeared to give testimony.

Adam Liptak, reporting in the New York Times on the court decision, notes the unusual way in which the court divided on the 5-to-4 decision. With the majority were Justices Scalia, Thomas, Stevens, Souter and Ginsburg. Dissenting were Justice Kennedy who wrote vigorously for the dissenters; Roberts, Alito and Breyer. This was no ordinary cleavage along conservative/liberal lines! Scalia, writing for the majority, took the view that defendants had the same right to confront adverse expert testimony as they enjoy with respect to any other form of testimony. Kennedy, in dissent, pointed to the huge disruptions that might occur in court cases if every laboratory report needed to be brought to the court by a bona fide representative of the laboratory making the report; that is, a real analyst who could as needed provide expert background testimony. However, according to Jeffrey L. Fisher, a law professor at Stanford, who represented Mr. Melendez-Dias, about a third of states already follow procedures that comply with the new decision.

The court’s decision raises several questions that are of importance for science’s relationship with society. The first level at which to approach this is to ask whether there is a matter here at all of science’s epistemic, or expert, authority. Justice Scalia, in his majority opinion wrote that the Constitution would require allowing defendants to confront witnesses even if “all analysts always possessed the scientific acumen of Mme. Curie and the veracity of Mother Teresa.” In other words, even assuming that the crime lab results are of the highest scientific quality, and that the reporter is a person of impeccable moral standards, the Constitution requires that the defendant have the opportunity to confront the witness. But of course not all crime lab personnel are fully competent, free from making errors of various kinds, or always above suspicion of reporting results tilted toward the prosecution’s case. In these respects, cross examination of a witness reporting forensic results is of a kind with cross examination of any other witness. It really doesn’t go to the question of whether the scientific principles and applied technology that undergird the reported results are sound and relevant to the evidence being presented. Nor does it cover the question of whether the laboratory has obtained the results through full and competent observance of all the required protocols.

There is plenty of reason to be concerned regarding the quality and veracity of much forensic evidence. The National Academies of Science in February of this year issued a report on the state of forensic science in the US, and on what steps might be taken to strengthen it. Quoting from the report’s executive summary, “…in some cases, substantive information and testimony based on faulty forensic science analyses may have contributed to wrongful convictions of innocent people. This fact has demonstrated the potential danger of giving undue weight to evidence and testimony derived from imperfect testing and analysis. Moreover, imprecise or exaggerated expert testimony has sometimes contributed to the admission of erroneous or misleading evidence.” Defense counsel thus may have plenty of grounds for questioning the technical witness that brings forth the forensic evidence. It may be a good strategy to question the basic scientific assumptions underlying the methods employed. On the other hand, when the matter at hand is fairly simple, raising too many questions can be a poor strategy in that it merely serves to call attention to the results. In any event, the defense now possesses a power it had not previously had. Justice Kennedy and the other dissenting justices seem to be very concerned about cases where the analyst may not be available, or where over the passage of time the analyst may have retired, changed jobs and so forth. These are legitimate concerns, but they seem to me to pale in comparison with the prospect of defendants facing a written laboratory report without any means of cross examining the person or persons responsible for the analyses.

It is not always easy to keep the non-scientific world attuned to the notion that the doing of science, even at the level of often mundane analysis of forensic materials, is a human activity. Science is not really about objective truth in some abstract and disembodied sense. It is about kinds of truth found in the course of looking at aspects of the world with a certain kind of eye, with a certain ethic of disinterestedness. That sort of work is done by humans. Even given the best of intentions, errors may be committed, omissions may occur. When scientists report to the larger society on what they have done they should not be perceived as oracles, presenting something drafted by Gods. It is one of science’s shortcomings that is has not engaged the larger society as fully as it should, that science is not seen as the product of human endeavor. Yes, the social structure of science does go a long way toward weeding out errors and falsifications during the formation of new knowledge, but in the day-to-day applications of science, as in a forensic laboratory, human nature is at work. When someone’s future may hang on the outcome of courtroom deliberations, the human who has generated scientific evidence that bears on the case should be there to testify to it.