The new lab rats

This article won second prize in the New Scientist Prize for Science Writing

Lab rats... or lab lizards?

Bridget Murphy investigates how reproduction in reptiles may help us better understand the evolutionary history of cancer as well as identify new targets for treatment.


It all starts with a single cell, a cell genetically different from the rest in the body. This cell doesn’t have an identity yet and has the potential to develop into any cell type in the body. The single cell divides, repeatedly and rapidly, to form a growing clump of cells. The body’s immune system does not recognise or attempt to destroy the alien cells, which are very effective at “hiding” themselves from the host’s immune system. With the body powerless to halt their rapid growth, the cells continue to grow, unchecked, and begin to tap into the blood supply of the host. The invading cells have now secured the oxygen and nutrients they need to continue to invade and parasitise the body…

This foreboding description sounds like the birth of a cancerous tumour, spreading uncontrollably through the body. But actually, it also perfectly describes the first stages of embryogenesis, when a fertilised egg divides to form a ball of cells that implants into the wall of the uterus at the beginning of its development.

The similarities between a growing cancer and a developing embryo have long been recognised. In fact, the commonalities are so striking that some scientists think that embryos and cancers share an evolutionary connection. To understand this concept, we need to delve hundreds of millions of years back into our evolutionary past, to a time when the ancestors of modern-day mammals laid eggs instead of giving birth to live young.

Embryos and cancerous tumours grow in similar ways. Photo: Nadav Pezaro

Scientists think that our egg-laying ancient ancestors might have been less susceptible to cancer than modern humans because they laid eggs (Medical Hypotheses, vol 66, p 888). This is because as the ability to give birth to live young evolved in our ancestors, a series of gene systems also evolved. Among other things, these gene systems helped to prevent immune rejection of an embryo during pregnancy. They also allowed embryos to produce blood vessels in their placenta, helping to shuttle oxygen and nutrients between the mother and her baby.

Giving birth to live young instead of laying eggs has definite advantages for an animal, but, unfortunately, evolutionary advantages come with side effects. Scientists think that these same gene systems that developed during the evolution of live birth are also the systems that result in cancer cells being so successful at growing and spreading throughout the body. In other words, live-bearing animals (including humans) can’t have their cake and eat it too.

It is sobering to think that cancer, a disease that always seems to be one step ahead of the treatments we develop, may be woven inextricably into our evolutionary history. But researchers hope that this evolutionary connection will allow them to better understand cancer’s arsenal and will help identify new ‘chinks in the armour’ that they can exploit to treat the disease.

But how do you study evolution once it’s already happened? Live birth evolved in the ancestors of rats and mice, the animals usually used in research, about 103 million years ago (Science, vol 294, p 2348). Surprisingly, it’s probably not mammals that will provide the answers about what happens during the evolution of live birth, but lizards and snakes.

More than 20% of snakes and lizards give birth to live young, and live birth has evolved more than one hundred times in the reptile family tree. In fact, scientists have recently discovered an Australian lizard that is right in the middle of this evolutionary process.

The lizard in question is three-toed skink (Saiphos equalis). Living most of its life underground, the three-toed skink is approximately 10 cm long and has tiny legs, each with three toes, helping it slither snake-like through narrow tunnels in the soil. It has a bullet-shaped head, allowing easy burrowing, and its small eyes are ultra-sensitive to light.

The three toed skink (Saiphos equalis) gives birth to live young. Photo: Nadav Pezaro

Scientists think that the three-toed skink is at an “intermediate stage” of the evolutionary process (Journal of Morphology, DOI: 10.1002/jmor.10877). Its egg-laying relatives lay eggs with a thick shell that make take months to hatch, while its live-bearing relatives give birth to fully-developed babies surrounded by a placenta instead of an eggshell. The three-toed skink is somewhere in the middle, laying eggs with very thin translucent eggshells that can hatch in less than 24 hours.

Just as transitional forms in the fossil record can help retrace steps in the evolutionary process, the three-toed skink could tell us more about what happens during the evolution of live birth. New research suggests that this lizard may also harbour secrets about the important evolutionary connection between embryos and cancer.

A rare gene, called VEGF 111, was found expressed in the placenta of the three-toed skink, where it promotes the growth of blood vessels (Journal of Experimental Zoology, vol 314B, p 148). The only other place that medical scientists had seen this gene before was in precancerous human cells grown in the laboratory (Journal of Cell Biology, vol 179, p 1261). It seems that VEGF 111 is a gene that is important for placental growth and maybe also for the evolution of live birth in the three-toed skink, but it is possibly also involved in the transformation of healthy human cells to cancerous ones.

VEGF 111 may be another example of a genetic system that first evolved to allow embryos to grow successfully in utero, but has since been hijacked by cancer cells to improve their own growth. It is information like this that can identify the ‘chinks in the armour’ that cancer researchers are looking for, providing potential targets for future drugs and therapies. The new lab rats in cancer research may, in fact, be lab lizards, if scientists continue to investigate the disease from this novel perspective.

Q & A fuels climate change hysteria

Television is such a powerful medium for stimulating discussion about current topics of debate. A good televised debate among members of a panel has the incredible potential to inform and engage the public about important issues and decisions that we face as a community.

Previously I might have agreed that the ABC’s Q & A program promoted these types of constructive debates, but last night was a disgrace.

Last night’s one hour episode (transcript here) sped through a number of controversial topics, including the canonisation of Mary MacKillop, the prosecution of Australian commandos in Afghanistan, bias in the Australian media and, lastly, the family favourite, climate change policy and carbon taxes.
Q & A seemed to take great pleasure in seating Tim Flannery, a scientist and a prominent climate change activist, next to fellow scientist but passionate climate change denier, Jennifer Marohasy. The two visibly squirmed in their chairs for 45 minutes in anticipation of the big face-off between them, so that the audience was positively baying for blood by the time discussion of climate change finally started.

This is not the appropriate forum for a “balanced” debate (whatever that means anyway) about climate change. In fact, Q & A last night served to actively promote and encourage the hysteria and fervour that clouds any notion of reason surrounding this topic.

Climate science, and all science for that matter, is founded on evidence-based research and hypothesis testing. It is based on real data, numbers and statistics that are meticulously and thoroughly presented in well-respected peer-reviewed publications. A “balanced” view, as the media so often piously claims to strive for, requires thorough review of this peer-reviewed scientific literature. A “balanced” view does not come from 10 minutes of two people from opposite sides talking over the top of each other, reeling off numbers and percentages to support their argument. Quoting facts and figures in this scenario becomes hear say rather than hard evidence. How can people be expected to develop informed opinions if neither side is given the opportunity to provide any substance and evidence for their argument? How can someone possibly effectively demonstrate the credibility of their evidence in such a highly emotionally-charged forum?


A debate such as this does not empower people to develop informed opinions and is far more destructive than constructive. At a time when we need society to start forming some sort of consensus for making policy decisions on this issue, the Q and A debate will serve only to further polarise public opinion rather than encouraging any common ground. The media needs to start accepting responsibility for the chaos that they continue to create.

Lamentably, debates about climate science are no longer based on careful review of available evidence, or even any sense of reason or logic, but are “won” by those who can yell the loudest. I don’t endorse the behaviour of the representatives of either side of the debate last night, even though I do agree with the opinions of one and not the other. Both Marohasy and Flannery showed gross disrespect for each other and for the subject they were attempting to discuss, and this was largely the result of their desperation to cover too much ground in such a short time slot. Both scientists became visibly flustered, interrupted each other and unnecessarily raised their voices to express completely futile arguments on both sides.

Whatever your opinion on climate change, decisions made about climate policy have serious ramifications for everyone and do not deserve to be trivialised in emotionally-charged debates such as this. What Q & A staged last night was no better than a melodramatic conflict better suited to a reality TV show. The debacle produced no clear result, rather just two frustrated, flustered and, dare I say, embarrassed scientists. The real victim of last night’s fiasco was neither Marohasy nor Flannery, only our prospects of rational and constructive debate about how to tackle climate change.

Happy birthday, love from “Me, no me first” et al.

Buying a birthday present for a friend isn’t a difficult task in theory, but it does become more complicated as more and more people contribute. What starts off as a generous gesture can become an awkward and, in extreme cases, nasty situation as the number of names on the card grows. Especially when you have to get one of those huge novelty-sized cards!

All gift givers are not created equal, and there are always a few people who put in more effort, time and money on the present than others. There are also many different steps involved in group gift-giving. First of all, someone has to come up with the original idea to give the present, and then it needs to be decided what the present should be. The gift needs to be found, paid for and wrapped up. Someone needs to organise and write on the card and finally, someone needs to hand over the gift to the birthday person. Then there is almost certainly one person who has forgotten their friend’s birthday who, having been involved in no part of the gift-giving process, asks to put their name on the card at the last minute.

It is important to be acknowledged on the card if you have contributed in a significant way in the gift-giving process. But how worthy does this contribution need to be to be recognised on the card? Usually the person who organises the gift writes their name first on the list of gift-givers on the card, and the recipient can tell who to thank most. But what if someone else contributed more money or prepared an elaborate hand-made card especially for the occasion? What position in the list of names do they deserve to occupy?

Most of you would agree that this is a rather trivial and petty argument and you might ask what a post about group birthday presents is doing in a science blog like this. But the scenario of giving a group birthday present is perhaps the most appropriate analogy to describe the issue of authorship on science research papers. And authorship is certainly not a trivial issue.

As I discussed in my previous post, it is no easy task to climb (or sometimes simply hold onto) the slippery sides of the pyramid scheme of science academia. Peer-reviewed research papers are the internationally-recognised currency of science research. A scientist’s chances of landing a job, successfully applying for grant funding or achieving the respect of their peers all depends largely on the number of research papers they have authored.


Quantifying a researcher’s excellence is not simply a case of counting the number of articles they have authored, since not all articles are created equal. A single-authored papers is often considered more valuable fodder for a curriculum vitae that one with multiple authors. The order of names in the author list on multi-author articles is also paramount – being first author suggests ownership and leadership of the research project, while the last author is usually the head of the laboratory or research group and may have supplied the funds for the project. Other positions in the author list are less esteemed, reserved for people who played more minor parts in the project, but they nevertheless serve as a feather in the cap of any scientist’s CV.

Potential employers and funding bodies also consider the reputation of the journal in which the article is published, and how many times other researchers around the world have cited the article in subsequent publications. Both the quality of the journal and the number of citations are good indicators of the timeliness and excellence of the research. Such is the need to measure the research output of scientists that there are several indices that attempt to reduce a scientist’s worth to a single number for ease of comparison.

The pressure on scientists to be authors on more and more articles creates tension and politics and can lead to soured relationships between colleagues. It is not unusual for arguments to arise about author list order or about whether someone’s contribution is sufficient to merit authorship or simply an acknowledgement at the end of the article. Unfortunately, inexperienced researchers and students can be exploited and may not receive the recognition they deserve if other co-authors or supervisors abuse their positions of trust.

Navigating the sticky issue of authorship requires sensible and honest discussion before the project starts, and a certain amount of tact and diplomacy never goes astray. This should avoid the problem of last-minute, unexpected or unreasonable requests for authorship, because the consequences of authorship in science are definitely more significant than whether or not you get due credit for the bath soaps and scented candles you gave your mate for their birthday.

Comic from www.phdcomics.com

Science academia: Cutting edge or cut-throat?

A career in science academia is an attractive one. An academic career offers perks that just aren’t available in other lines of work. Research scientists enjoy a job with flexible hours, a high degree of autonomy, the chance to travel, and the luxury of choosing a research topic that is intellectually stimulating and challenging. Academia seduces many with its alluring mix of research and teaching, as well as the opportunity to make new discoveries and win respect from the international scientific community.

No doubt this is part of the reason why there are more people than ever studying for PhDs. A PhD is a huge commitment – 3 to 4 years in Australia, and 5 to 6 years in the U.S – and presumably a large proportion of students begin studying for a PhD with an academic career in mind. But are students sufficiently informed about the realities of academia before they begin such a huge undertaking? What is involved in climbing the academic ladder, and how many people fall off the ladder along the way?

Actually, the academic ladder is more like a pyramid; There are many more PhD graduates than there are post-doctoral positions, and many more post-docs than permanent tenured positions as lecturers. Job security for aspiring academics is precarious until they get a permanent position, and many people fall (or leap for dear life!) off the pyramid in their quest for greater job certainty. Competition for academic jobs is fierce in a world where your curriculum vitae boasts about the number of publications you have, what journal they are in, and the amount of grant money you have won.


But is such cutthroat competition really conducive to good research? Or are we compromising the quality of our science by placing researchers under such high levels of job stress? Such a highly competitive environment is certainly not a pre-requisite for good research, as the likes of Darwin and Einstein slowly (in Darwin’s case, this took decades) but carefully developed their revolutionary theories under the patronage of wealthy members of society.

Inevitably for some, the long hours and job stress of a modern academic career begin to take their toll on a researcher’s personal life. Frequently switching jobs (and often countries) often makes it difficult to sustain personal relationships. Those ‘significant others’ that do come along for the ride usually make large sacrifices for their partner’s academic career. Aspiring academics without sufficient financial support in tough times, either from family or partners, can also fall by the wayside. Carola Vinuesa, awarded the Science Minister’s prize for Life Scientist of the Year in 2008, recently wrote in Cosmos Magazine (August 2010) that prior to winning the prize she was struggling to manage her lab while also raising a toddler and baby at home. She said that the prize meant she could afford some domestic help, which saved her career. She wrote to thank one of her mentors in Britain, who replied bluntly that he “always suspected that every woman scientist needs a wife”.


I wonder how many students would still begin studying for a PhD if they knew that this was the case? Often by the time a PhD student works this out for themselves, many feel they come too far to turn back. So why then aren’t students warned about this before they start? [citation needed] speculates that PhD students are often collateral damage in the highly-competitive world of modern-day science research, just a means to an end for the supervising academic to increase the research output and increase their success when applying for their own grants. This is certainly not the case for my own PhD supervisors, but frankly it seems to be the case for one or two academics that I know of.

Or is it simply the case that there are too many people doing PhDs out there, competing for too few jobs? I think it is important for students to understand that an academic career is not the only option after a PhD, and that choosing to opt out of academia is not something to be ashamed of. In order to graduate, PhD students must be highly self-motivated, show initiative, have superb organisational skills and, as my fellow PhD students will agree, be able to take constructive (and often not-so-constructive) criticism on board. These characteristics are highly sought-after in other careers that afford employees better work-life balance than academia.

So if you feel like academia is your true calling, go for it, but be aware of what hurdles you face along the way. If you do choose to do a PhD and then realise that academia isn’t for you, walk away with your head held high and find a career that satisfies you. Remember that your PhD was by no means a waste of time, but is an achievement that you should be proud of.



All comics are from www.phdcomics.com

Justifying experimentation

Bridget Murphy puts the science back into the debate about animal research.

“You ask about my opinion on vivisection. I quite agree that it is justifiable for real investigations on physiology; but not for mere damnable and detestable curiosity. It is a subject which makes me sick with horror, so I will not say another word about it, else I shall not sleep tonight.” – Charles Darwin, 1871.

Sobering words from a man, whose intimate knowledge of anatomy from animal dissections allowed him to compile enough evidence for his revolutionary theory of evolution.

In response to “Feathers, fur and faculties” in the Week 6 edition of Honi Soit, scientists are not the crazed characters depicted in films, “playing god” with their research on animals. I know of no researcher who feels comfortable or “normal” about killing or experimenting on animals. The issue is a highly sensitive and moral one, but the benefit of both historical and modern animal research to society is undeniable. For this reason, scientists strive to develop and use alternatives to animals in their research as much as possible.

But scientists are also fully aware that our society would be very different without animal research. Our basic knowledge of biology, as well as most of modern medicine, is thanks to pioneering discoveries made in animal research. For example, it was animal research that allowed Louis Pasteur to discover that diseases were not caused by imbalances of the organs but external micro-organisms. Only by isolating and culturing these microbes from the gut of chickens with cholera, and then reintroducing these microbes back into healthy chickens, did Pasteur prove that the culprits were not evil spirits, not the flying spaghetti monster, but pesky microbes.

Armed with this new knowledge, British surgeon Joseph Lister began insisting that other surgeons wash their hands in between patients. He also started sterilising his instruments, sutures and wound dressings with carbolic acid.

The result was a drastic reduction in the number of deaths from septicaemia in his hospital ward, and the concept of antiseptic technique was born. Animal research has also indisputably established causes and vaccines for many diseases, aided the development of antibacterial and antibiotic drugs and helped researchers develop the techniques used in modern-day organ transplants.

But just because animal research played an important part in these developments, does it mean that they were an essential part? Would these discoveries have been made eventually by other means? The alternative methods that activists say could have been used, such as cell culture, would never have been developed without the basic descriptive knowledge that scientists gained from animal studies.

It is fantastic that the availability and validity of alternative methods continues to improve and that they are increasingly being substituted for animals. But there are still no viable alternatives to animals in many avenues of research. For this reason, animal research for which there is sufficient justification but no viable alternatives must continue.

The argument that animal research should be stopped because of animal rights is the safe but soft stance to take on this highly complex issue. Physiologist and physician, Dr. Walter B. Cannon, described the conundrum beautifully in 1896 by quoting Theodore Roosevelt: “Common sense without conscience may lead to crime, but conscience without common sense may lead to folly, which is the handmaiden of crime.” All of us need to acknowledge that we are indebted to animals used in research, but we also need to support rather than slander scientists in their pursuits to improve animal welfare.

This article was published in the University of Sydney newspaper Honi Soit 14/9/10

Semantics of scientific theory

Scientific theory too often becomes a matter of debate and opinion in the public arena when there is no debate to be had. The two most obvious examples of this are the evolution-creation debate and arguments about climate science. Much of this debate arises not because of deficiencies in the science, but because of confusion in the terminologies used, particularly differences in the type of language used by scientists and the general public to describe the scientific method.

Colloquially, and to most people, a theory refers to a prediction or an idea. In science, a theory is not just an idea that people float out into the scientific literature, but is actually the best available explanation, well-supported by the evidence, that correctly accounts for all elements of a given phenomenon. Evidence that contradicts a current scientific theory invalidates the theory in its current form, and it must be rejected or revised to incorporate the new evidence.

So why are scientific theories – the best available explanations based on the evidence – demoted to mere opinions in public forums? Much of the basis of the argument against the theory of evolution, for example, is that “it is just a theory, not a fact”. This argument highlights how language and expression can distort the meaning of science and the debate quickly becomes one about semantics. As Massimo Pigliucci elegantly explains, “evolution is both a theory and fact” (emphasis from the original); it is fact because the fossil record demonstrates that present-day life forms are very different from those that lived millions of years ago (1). Detectable changes in life forms also occur over shorter time scales, in organisms with short generation times such as bacteria, for example, allowing us to observe evolution in action. The mechanisms that biologists have proposed to explain these changes over time form the theory of evolution (1). The amount of evidence contradicting creationism means that it does not qualify as a theory in the scientific sense of the word. But creationists have, and will continue to, exploit the confusion about this term to lend weight to “their side of the story”.

This brings me to my next point. The noble aim of (hopefully all) journalists is to report stories objectively and without bias. Unfortunately, because scientific theory is too often misrepresented as only one side of a debate, news reporters present both sides of the story as a matter of fairness. But do both sides deserve the equal treatment they usually receive?

Before scientific discoveries even reach the news desk, they are scrutinized by other scientists. Only if these scientists agree that the methods of the investigation are sufficiently rigorous can the discovery be published in a scientific journal and then covered in the media. If there was any room for debate about the issue, then the study would have been deemed inconclusive and the discovery would not be published. So why give “both sides of the story” – one supported by the science and the other just an opinion – equal and undue attention in news pieces? When scientific conclusions are presented as just one side of the debate, then rigorous science becomes worth no more than opinion, and all because the journalist wanted to seem fair. The general public must then choose which “opinion” they agree with, without the benefit of knowing the true weight of evidence that supports or contradicts each option. This is why there may be no controversy about issues such as climate change and the theory of evolution in the scientific community, but public opinion is often split close to 50-50.

Unfortunately this means that people can no longer publicly acknowledge a scientific conclusion. Instead this becomes their opinion, or more cringeworthy, their belief. Emotive language used to convey what was originally a completely objective and tested conclusion rapidly demotes the “opinion” to “propaganda”, and much of this transformation comes down to the use (or misuse) of the word “believe”. A quick google search reveals that countless people “believe in evolution”, and our current prime minister Julia Gillard has repeatedly emphasized her belief in climate change. The word “believe” carries with it distinct religious connotations of having faith in an idea (namely a god or a creation story) for which there isn’t necessarily any evidence. Religions require faith in order to accept their teachings and creation stories, but people’s belief in a scientific theory misrepresents science as an alternative faith, quite the opposite of science and its philosophy.

The use of the word “believe” in discussions about the theory of evolution and the validity of climate science adds an uncomfortable religious fervour to these debates. I suggest that it is this religious-like fervour from climate change advocates that has resulted in such skepticism of climate science. While reviewing a book from climate change sceptic Bjørn Lomborg, The Skeptical Environmentalist (2), Andrew Greely commented in the Chicago Sun-Times that environmentalists have “helped create a new religion whose devotees are compelled to accept false prophecy as unquestionable truth” (3). While reviewing the same book, Jonathan Adler in the National Review refers to the green orthodoxy of environmentalists. Religious analogies paint scientists and, in this case, environmentalists, as people pushing hidden agendas. This produces a level of distrust in ill-informed members of the public that is sometimes sufficient to sway their opinion away from the “side” that is rational, logical and supported by rigorous science. All this from a lack of understanding of the language used to describe science and the scientific method.

Science and its philosophies are some of the most important tools we have for gaining new knowledge as a society. But our failure to communicate this science to non-scientists effectively allows often influential individuals to remain irrational and ignorant about important issues and persuade others accordingly. Confusing terms need to be explained to the general public in ways they can understand, or be substituted with non-ambiguous ones. The media must also be ethical in their news reports and place the correct emphasis on the side of the story supported by the facts. And please, for God’s sake, don’t believe in science!

(1) Massimo Pigliucci, Nonsense on stilts: How to tell science from bunk (University of Chicago Press, 2010), 163.
(2) Bjørn Lomborg, The skeptical environmentalist (Cambridge University Press, 2001).
(3) Andrew Greeley, “Doomsday phophecies lack merit,” Chicago Sun-times, 9 December 2001.
(4) Jonathan Adler, “Dissendent from Denmark,” National Review, 8 April 2002.

The proof of climate change

Where is the proof that climate change is real and that humans are at fault? Climate sceptics love to pounce on the fact that scientists cannot prove that humans are the cause of climate change. Tony Abbott has said previously that climate science is “absolute crap”. More recently he has clarified that he meant to say the science of climate change is not yet “settled”. These comments presumably refer to climate scientists’ inability to prove that the climate is warming and that humans are contributing to it.

The concept of “proof” in science relates to the way in which scientists form and test hypotheses. But, as discussed by Massimo Pigliucci in his book Nonsense on Stilts, the way scientists go about testing these hypotheses depends on the complexity of the system they are trying to explain.

For example, a chemist in the laboratory may be trying to determine whether some compound “A” causes a particular reaction “B” to occur. To test this hypothesis, the chemist would probably set up an experiment to test whether reaction B occurred in the presence of A, and compare this with what happened in the absence of A. The chemist can follow this particular line of inquiry because they have the ability to manipulate and control most or all of the different factors that could affect the outcome of the lab experiment. An experiment is highly repeatable in controlled conditions, meaning that if the experiment is repeated over and over, the same results can be obtained consistently. Thus, predicting the behaviour of a system becomes very accurate when most of the variables are accounted for.

But imagine now that the chemist now has to perform their experiment out of the lab. The temperature and light intensity now fluctuates, and a little dust or dirt gets into the reaction. A little of compound A blows away in the wind before the chemist can add it to the reaction. Reaction B does not occur. The frustrated chemist repeats the process and this time reaction B does occur. Another repeat of the experiment produces a negative result. Once a system moves outside the lab and into the real world where some variables cannot be controlled, the system becomes less predictable.

Now consider an atmospheric scientist, who, like the chemist, wants to know whether compound A causes reaction B to occur in the atmosphere. In this situation, the atmospheric scientist cannot perform an experiment to change the concentration of compound A in the air - that would be impractical and irresponsible. Instead, the atmospheric scientist has observed that the concentration of compound A has increased in the atmosphere over the last few decades. Furthermore, the rate of reaction B has also increased during the same time period. Is the atmospheric scientist able to confirm or refute their hypothesis that compound A causes reaction B to occur in the atmosphere? Given that an experiment in the atmosphere is not feasible, is the current evidence sufficient to support the hypothesis? Or is the question just unanswerable? Is the science just “crap”?

Not all streams of science are able to test hypotheses by conducting a controlled experiment. While the outcome of a controlled experiment is highly repeatable, the results of the experiment have limited relevance in the real world, where conditions are impossible to standardise. On the other hand, it is difficult to conclusively demonstrate cause-and-effect relationships in natural systems because there are so often multiple factors that determine the outcome. Streams of science such as ecology and climate science often rely on making observations to identify trends and links between potential causes and effects. But scientists in these fields must report these results using sufficiently cautious language, using phrases such as “the evidence suggests…” and “our results may mean…”

Pigliucci argues that this does not make the science “crap” but instead reflects the limitations that scientists face in answering questions about complex systems. Unless we have a spare planet earth that we could observe, subject to exactly the same conditions as our own, except devoid of human life, proving in a scientific sense that climate change is human-induced is an impossible task and a foolish endeavour.

Scientists studying these complex systems are stuck between a rock and a hard place when it comes to communicating their work. The philosophy of science is such that definite conclusions are made only when hypotheses are tested in controlled experiments. The strict peer-review process, in which published science research is scrutinised by other experts in the field (I’ve discussed this in a previous post), effectively discourages scientists from making outlandish, unfounded claims. In contrast, those in business and politics want to see strong definitive results from science research, particularly when deciding whether to make a monetary investment in a discovery or when making government policies based on the results of a study.

But in some situations, as is the case with climate science and climate change, another aspect needs to be taken into account. With the climate data we have and the trends we have identified, we need to weigh up whether the price of inaction outweighs our need for a controlled experiment to prove our hypothesis. With this in mind, and considering that a controlled experiment to test the hypotheses is not feasible, I think we need accept that we are as close to proof as we are going to get, and we to act now.