NOS as part of the Conceptual Ecology of Evolution Teaching and Learning among Greek Students and Science Teachers

The aim of this study was to investigate whether an epistemological adequacy (knowledge of the Nature of Science, NOS) contributes to a better understanding and the acceptance of the Theory of Evolution by Natural Selection (ThENS). It was performed in two parts with the help of two questionnaires: 1. with students of Education, with a minimum familiarity to ThENS and NOS, before and after the application of a general biology course, and 2. with 200 Science Education teachers of various specialties who teach or have taught biology-related subjects. The education students showed some moderate levels of proficiency regarding NOS that was improved statistically significantly, even after a limited teaching intervention. An interesting founding was that, while their understanding of the ThENS was not very much improved by the course, it was found a positive correlation between their NOS familiarity and acceptance of evolution. As for the Science teachers, besides the above queries, some other variables were additionally investigated: E.g. to what extent, a better Epistemological Adequacy (knowledge of the Nature of Science) can influence their understanding and acceptance of the ThENS, or whether this affiliation could have been affected by their college or university instruction. The results showed a positive correlation between their epistemological adequacy and the acceptance and understanding of ThENS.

About the Theory of Evolution by Natural Selection (ThENS) and its acceptance

Evolutionary theory is one of the most important and difficult concepts to understand or teach [1]. As an integrative theory in biology, it is involved in interpreting organism similarity, biological diversity, and other characteristics, while helping students realize the biological significance of various phenomena, such as reproduction, cell division, and biodiversity [2,3]. This is a modern universal principle that should be understood by students by providing scientific explanations [4].

Some parameters that have been implicated in the degradation of Theory of Evolution by Natural Selection (ThENS): restrictive measures in educational policy, resistance from various religious groups, school principals and community members, incomplete or non-existent teaching due to time constraints, insufficient coverage of the chapter in Textbooks and teachers' religious beliefs. Also included are the relatively low levels of acceptance and understanding of ThENS that often occur in teachers [5], as well as their misconceptions about NOS [6,7].

Evolution and biological literacy

Various scientific and educational organizations treat evolutionary theory as a central organizing principle of the biological sciences and have called for the teaching of evolution to be treated with as much value as its contribution to Biology [3,6,8]. Evolutionary theory is placed first in rank among the basic concepts of biological literacy for undergraduate students, because of its enormous contribution to the understanding of the natural world [9]. Mindell [10] argues that "the findings of evolutionary biology are deeply embedded in our culture, agriculture, medicine, public health, environmental health, natural resource management, human understanding, and even the practice of justice in the legal system."

Nature of Science-(NOS) as part of the conceptual ecology of evolution

According to Posners’ views on conceptual change [11], the change of major, organizing conceptions within the learner, can be represented with Kuhn’s model on scientific revolutions. The change experienced by the learner is understood to be holistic in which one conception is completely abandoned for use of another, more useful conception, as it is the case with the succession of Paradigms, through scientific revolutions. Posner’s theory of conceptual change has been strengthened by the inclusion of Toulmin’s idea of conceptual ecology [12]. Conceptual ecology includes fundamental organizing conceptions that serve as the changing conceptual environment in which conceptual change occurs, thus, the conceptual ecology controls and modifies this process [13].

More recent models of cognition, such as the Cognitive Reconstruction of Knowledge Model and the Cognitive–Affective Model of Conceptual Change [14], incorporate strong affective components, like motivation, efficacy beliefs, implication of self and intentions. According to the second model, acceptance can prohibit the possibility of true conceptual change. Southerland SA, et al. [15] believe that continued focus on the intersection of affective and cognitive factors is called for, as we begin to recognize that learning is not solely determined by the characteristics of the content in question or unconscious attributes of the learner (i.e., reasoning ability, background knowledge). Additionally, other researchers suggest that learning is not controlled solely by external factors (nature of content or instruction), but the learner plays a significant role in choosing to consider alternative points of view. This means that there are instances where the conceptual ecology of the learner must be taken into consideration before the teaching strategy is to be organized and applied [16].

Conceptual ecology of evolution

Conceptual Ecology (CE) of evolution, as described by Demastes SS, et al. [16] in addition to acceptance, also includes the following elements: 1. pre-existing perceptions related to evolution– understanding of evolutionary theory, 2. scientific orientation (the extent to which the apprentice organizes his/her life around scientific activities), 3. the view of the NOS, 4. the view of the biological world in terms of competition and causal relationships and not in aesthetic terms, and 5. the religious orientation. Meanwhile, we, in a previous our study, tried to find out if we can make any contribution towards the hypothesis that it is not only the religion, in general, that affects someone’s acceptance of the theory of evolution, but the type of religion and its qualitative characters, as well, something that it may be included among the factors that constitute someone’s conceptual ecology of the evolution theory [17-20]. In that study, we suggested, as well, that “withholding of beliefs” could be attributed to the views of several of the students about what the scientific community accepts about the theory of evolution, a belief that can be considered as a constituent of the Nature of Science (NOS). Knowing the NOS includes, among other things, the knowledge of how a theory is built up and the meaning of the term “Theory” in science. When someone is familiar with the NOS, she knows that a theory in science is a “...confirmed hypothesis that is accepted by the scientific community” [21].

Nature of Science (NOS)

The term NOS refers to the epistemology and sociology of science as a means of knowledge, as the values and beliefs inherent in the development and evolution of scientific knowledge [22,23]. Key aspects of NOS include various understandings of scientific knowledge. Scientific knowledge is considered temporary knowledge that is subject to change, supported, based on, and derived from empirical evidence collected through observation of the natural world. It includes interpretations derived in part from human creativity and imagination and is influenced by the social and cultural aspects of society [24-26]. NOS teaching is considered particularly useful for several reasons categorized into five dimensions [27,28]: the democratic, cultural, ethical, learning and procedural dimensions: understanding processes related to science and technology. In studies concerning NOS education, emphasis is placed on teaching its key aspects [2,24,29]. Knowledge of NOS is widely recognized as a fundamental learning pursuit of science teaching and is used as a term to describe a person's familiarity with the epistemology of Science [22,24,30]. One of the most important parameters of familiarity with NOS is related to the possibility of developing a conceptual understanding of the theories of Natural Sciences, since it can contribute to the formation of an appropriate framework that will give meaning to the conceptual background.

Aims of the study

The present study is an attempt to explain how adequate beliefs about NOS contribute to the understanding of the Theory of Evolution by Natural Selection (ThENS) and its acceptance. And to what degree does it affect the content knowledge of biology. Primarily, we investigate whether adequate views on the Nature of Science (NOS) held by students at the School of Education of the National and Kapodestrian University of Athens influence their understanding of the Theory of Evolution. At the same time, we examined the factor of acceptance of evolution and the extent to which it is likely to correlate with the factor of understanding the ThENS and whether epistemological adequacy affects its acceptance. We also examine whether there is a difference in the results after attending some lecture (s) on NOS and the ThENS.

The second part of the broader longitudinal research focuses on Secondary Education teachers from various specialties who are qualified to teach Biology subjects (i.e. Physicists, Biologists, Chemists, Geologists, etc.,). As part of this research, we have focused on the following questions: What is the level of knowledge of Greek Science teachers about the Nature of Science? 2. What is their level of knowledge and acceptance of the Theory of Evolution by Natural Selection and the degree of correlation between the two. 3. What conclusions can be drawn from the comparison with groups of students in the previous survey? 4. What are the conclusions from the comparison with studies conducted on groups of teachers abroad?

The study has been conducted in two stages

Phase-1: A questionnaire was distributed to 1st year students of the Faculty of Pre-School Education of the National and Kapodestrian University of Athens (F-PSEUA), before and after the release of a course on Biology, entitled “Teaching Biology with Evolution as their Unifying Theory”, which has been described previously, elsewhere [20]. The questionnaire (that is described in the next section), was answered by 69 students before the Semester course and the same 69 students, plus 2 ones after the end of the Semester, since two of the students, that gave blank sheets in the first place, they completed the questionnaire, at the end of the Semester. For its formation it was used in the first instance the questionnaires of Cho MH, et al. [31] to assess perceptions of NOS, then the one of Rutledge & Warden [7] for their understanding of Evolution, and finally the "MATE" (Measure of Acceptance of the Theory of Evolution) of Rutledge & Warden [7] to judge their acceptance of Evolution. The specific course among other things, it included a section dedicated to NOS: where we tried very briefly to explain the process of how a theory is constructed according to the Verification that is considered as the “received view about science and NOS” and persists to be the most widely applied methodology, even in contemporary scientific research, contrary to all the questioning and criticism that has received from time to time. In contrast to Verification, we very briefly, tried to outline briefly Poppers’ “Falsification” Theory, and to explain why according to this view, the ThENS is a scientific theory that although has too many opportunities to be falsified, it has never been refuted, and thus, it is considered as a very strong Scientific Theory [21].

Phase-2: The same questionnaire was distributed by e-mail to Science Teachers in various Secondary-Schools around Greece, and for the time being, we have received about 200 answered ones. The questionnaire is anonymous and consists of three sections: A. A section on Epistemological Beliefs, consisting of 29 5-Likerts’ scale questions, adapted from Cho MH, et al. [31]. (B) Some 13 questions false-correct, on the knowledge of the ThENS that were adapted from Rutledge & Warden, [7], and (C) 20 questions of five-point scale Likert’s A1-20 about the acceptance of the ThENS, adapted from Rutledge & Warden [7] and Athanasiou and Papadopoulou [18,19,29]. The questionnaire was edited with the SPSS statistics program SPSS v28.

Phase-1: In this phase for the analysis of the questionnaire data, descriptive statistical analysis, t Test for dependent samples, Pearson correlation and regression control were performed (Table 1). Before the teaching intervention, a relative understanding of NOS is observed by the students in the NOS questionnaire. As far as the questionnaire for understanding the ThENS is concerned, the students' knowledge is below the base, while in the questionnaire for the Acceptance of the ThENS, the students show a relative acceptance. In the second phase, there is also a relative understanding of students in the NOS questionnaire and even higher. The students' knowledge as shown by their answers to the questionnaire for the ThENS remains below the base, while in the part of the questionnaire for the Acceptance of Evolution there continues to be a relative acceptance that is higher compared to their answers before the teaching intervention. A correlation check was performed between the variables before and after the teaching intervention by calculating the Pearson's (r) correlation index. In the stage before the teaching intervention, the test showed that there is a statistically significant positive correlation between NOS and acceptance of evolution, and NOS with understanding of evolution. The variables of acceptance and understanding of evolution are not correlated. After the teaching intervention, a statistically significant positive correlation was recorded between NOS and acceptance of evolution and between acceptance and understanding of evolution.

The internal consistency of the questionnaires was assessed using the Cronbach's alpha index. The overall reliability of the questionnaire was quite high both before and after the instructional intervention. Before the instructional intervention, Cronbach's alpha was calculated as α = 0.73, and after the instructional intervention, it was α = 0.84. The Cronbach's alpha for the NOS questionnaire was estimated to be α = 0.64 in the first phase and α = 0.58 in the second phase (Table 2). Low reliability values of the questionnaire subscales have also been reported in the work of Cho MH, et al. [31], who developed it. Additionally, low reliability values have been found in other studies [2,18,32-34], hence these values are accepted (Table 3).

Phase-2: The processing of the first 200 questionnaires, in relation to the first 3 questions, showed that teachers show moderate levels of proficiency in their knowledge of the NOS (Table 4). Specifically, the level of knowledge among the participants varies across different specialties and is generally slightly above average. Regarding the acceptance of the Theory of Evolution by Natural Selection, the answers are significantly positive without much variation between specialties, but without keeping pace with a correspondingly significant percentage of knowledge about it. Regarding the correlation between the Nature of Science and the Theory of Evolution through Natural Selection, the results suggest a positive correlation, to varying degrees depending on the specialty and the degree of familiarity of teachers with the Nature of Science and the Theory of Evolution through Natural Selection from their 1st cycle university studies (Tables 6,7).

The internal consistency of the questionnaire administered to Science Teachers was evaluated using Cronbach’s alpha. The overall reliability of the questionnaire, as well as the reliability of its individual sections, was found to be quite high, indicating that the instrument is suitable for our research purposes (Table 5).

As has been mentioned previously, one main question that this work is examining is the probable correlation existing between knowledge of NOS of students and teachers and a better knowledge and acceptance of the ThENS. This issue is in question, as previous studies have shown that this is the case for the knowledge of NOS and some concepts of Physics, as it was previously shown by Stathopoulou and Vosniadou [34]. The Nature of Science (NOS) is a difficult issue to define as it is for students to learn. NOS involves a wide variety of topics related to the history, philosophy, and sociology of science. Many have claimed that no consensus exists among philosophers of science and science educators as to a precise definition or characterization of the nature of science. However, there is consensus on some aspects of NOS that are sort of generally accepted as constituents of it. Included here are the concepts that the scientific knowledge is: Tentative (subject to change); Empirically based (based on observations of the natural world); Subjective in the sense that science is a human endeavor, and investigations are conducted within the context of theoretical frameworks. Also, it is considered, to some extent, the product of inference, imagination, and creativity. Moreover, socially and culturally embedded (can be influenced by contextual factors outside of the scientific community); while it is advanced from a combination of observation and inferences [35].

As for the issue of the association between NOS and philosophical views, seeing as a subject of validation of the scientific knowledge as being an issue of specific importance for the teaching of Science, it is how a theory is created and accepted by the science community. It is very interesting the fact that the most generally accepted view about the process of how a theory is formatted is the one of Verification that has received the most criticism, as well. Namely the Verification principle as it was declared by the School of Vienna and the movement of Logical Positivism [21]. Nonetheless, it remains even today as the most used method of the research endeavor and is also the most typical method used within the Inquiry scheme in the modern Science classroom. At the opposite end stands Karl Popper’s theory of falsification which contends that scientific inquiry should aim not to verify hypotheses but to rigorously test and identify conditions under which they are falsified. According to Popper, for a theory to be considered scientific, it must be testable and conceivably provable false. Unlike verification, which focuses on confirming theoretical predictions, falsification emphasizes categorically trying to be disproving them. And the more they are not becoming disproved, the stronger they get. Moreover, according to Popper, the better a theory is when it has numerous opportunities to be disproved [36]. And this is the case with the ThENS. Although it has potentially so many opportunities to be falsified, none of them have been fulfilled. As the prominent biologist J.B.S. Haldane, humorously responded that the discovery of “Precambrian rabbits” or “fossil rabbits in the Precambrian” would shake his confidence in the theory of evolution. Thus, it is more and more consolidated and is becoming a rigid universal law accepted by all the scientific community.

The ideas described in the previous paragraph have been the content of a two-hours lecture within the 1st year biology course, that we are incorporating into the Chapter of Evolution that has been the foundation stone of the specific course (named, Teaching Biology with the ThENS as their Unifying Theory). And this is carried out within an effort to explain that “the theory of Evolution is not… just a theory…”, as many opponents declare [16]. Moreover, targets of the teaching endeavor have been the questions of “what a Theory in Science is”, “how it is constructed” and “how challenging an issue is the issue for a scientific Theory to become accepted by the Scientific community”. Concerning the first part of our study, that is related to first year students at the University of Athens, it seems that their attending the specific course contributed to fairly improving their views on NOS. As for their acceptance of the ThENS, there was progress that was recorded before and after the classes, although this progress remained relatively low. The latter is probably because the relevant courses (about NOS) were only two in number and in the form of plain lectures. In the case of understanding the ThENS, there is no change before and after the course. In fact, before and after the course, the level of knowledge of students about Evolution was valued below base. This may be due to the degree of difficulty of the questionnaire used [37,38], as it was originally constructed to address teachers of Biology [15]. Regarding the acceptance of Evolution, the variation in the acceptance of students after the course is statistically significant, so the relevant courses contributed to its improvement. However, the relatively low acceptance recorded before and after classes is consistent with Greece's low position on the global scale of acceptance of Evolution [4], which is related to the degradation of its teaching in the Curricula [39]. The results of this research are consistent both with papers in Greece using the same questionnaire [19,38], and with research abroad that support that levels of acceptance of Evolution can change with its teaching.

From the initial analyses of research concerning Phase-2, it seems that teachers of all specialties accept, in general, the Theory of Evolution through Natural Selection. However, there is a moderate understanding of the basic concepts that govern it [40]. This is probably because a significant percentage of them - close to 50%- did not study the ThENS during their university education, and their knowledge primarily comes from school textbooks, which they are required to use for teaching in classrooms. Regarding the level of acceptance, it seems to vary depending on the specialty, years of teaching experience, and whether they studied both the Nature of Science and the Theory of Evolution through Natural Selection during their undergraduate studies.

In the subsequent steps of the research, we will analyze the correlations that develop within each specialty and the extent to which the acceptance of ThENS depends on their epistemological adequacy. Moreover, the sample size is continuously expanding as the research on Science Teachers progresses. Additionally, we intend to link the findings of this research with similar previous studies conducted on senior students in the Sciences as well as with corresponding research on teachers from other countries.

1. Finley FN, StewartJ, Yarroch WL. Teachers’ perceptions of important and difficult science content. Science Education. 1982;66(4):531-538. doi: 10.1002/sce.3730660404.
2. Science for all Americans. American Association for the Advancement of Science. New York: Oxford University Press; 1990.
3. Teaching about evolution and the nature of science. National Academy of Sciences. Washington DC: National Academy Press; 1998.
4. Miller JD, Scott EC, Okamoto S. Science communication. Public acceptance of evolution. Science. 2006 Aug 11;313(5788):765-6. doi: 10.1126/science.1126746. Erratum in: Science. 2006 Sep 22;313(5794):1739. PMID: 16902112.
5. BouJaoude S, Asghar A, Wiles JR, Jaber L, Sarieddine D, Alters B. Biology professors’ and teachers’ positions regarding biological evolution and evolution education in a Middle Eastern society. International Journal of Science Education. 2011;33(7):979-1000. doi: 10.1080/09500693.2010.489124.
6. Rutherford FJ, Ahlgren A. Science for all Americans. New York: Oxford University Press; 1990.
7. Rutledge ML, Warden MA. Evolutionary theory, the nature of science and high school biology teachers: Critical relationships. American Biology Teacher. 2000;62:23-31. doi: 10.2307/4450822.
8. Position statement on teaching evolution. National Association of Biology Teachers. News & Views. 1995;6:4-5.
9. Vision and change in undergraduate biology education: A call to action. In: Brewer C, Smith D, editors. American Association for the Advancement of Science. 2011.
10. Mindell DP. The evolving world: Evolution in everyday life. Cambridge (MA): Harvard University Press; 2006. doi: 10.4159/9780674041080.
11. Posner GJ, Strike KA, Hewson PW, Gertzog WA. Accommodation of a scientific conception: Toward a theory of conceptual change. Science Education. 1982;66(2):211-227.   doi: 10.1002/sce.3730660207.
12. Toulmin S. Human understanding: An inquiry into the aims of science. Princeton, NJ: Princeton University Press; 1972.
13. Strike K, Posner GJ. A revisionist theory of conceptual change. In: Duschl RA, Hamilton RJ, editors. Philosophy of science, cognitive psychology, and educational theory and practice. New York, NY: State University of New York; 1992. p.147-176.
14. Gregoire M. Is It a challenge or a threat? A dual-process model of teachers' cognition and appraisal processes during conceptual change. Educational Psychology Review. 2003;15:147-179. doi: 10.1023/A:1023477131081.
15. Southerland SA, Sinatra GM, Matthews M. Belief, knowledge, and science education. Educational Psychology Review. 2001;13:325-351. doi: 10.1023/A:1011913813847.
16. Demastes-Southerland S, Good R, Peebles P. Students’ conceptual ecologies and the process of conceptual change in evolution. Science Education. 1995b;79(6):637-66. doi: 10.1002/sce.3730790605.
17. Athanasiou K, Katakos E, Papadopoulou P. Conceptual ecology of the evolution acceptance among Greek education students: what is the contribution of knowledge increase? Journal of Biological Education. 2012;46(4):234-241. doi: 10.1080/00219266.2012.716780.
18. Athanasiou K, Papadopoulou P. Evolution theory teaching and learning: What conclusions can we get from comparisons of teachers’ and students’ conceptual ecologies in Greece and Turkey? Eurasia Journal of Mathematics, Science & Technology Education. 2015;11(4):841-853.   doi: 10.12973/eurasia.2015.1443a.
19. Athanasiou K, Katakos E, Papadopoulou P. Acceptance of evolution as one of the factors making the conceptual ecology of the evolution theory of Greek secondary school teachers.  Evolution and Education Outreach. 2016;9:7. doi: 10.1186/s12052-016-0058-7.
20. Athanasiou K. Teaching evolution as the unifying theory of biology via a university course: Re-count of a praxis. Interdisciplinary Journal of Environmental and Science Education. 2022;18(4):e2275. doi: 10.21601/ijese/11976.
21. Losee J. A historical introduction to the philosophy of science. Oxford: Oxford University Press; 2001.
22. Lederman NG.  Students’ and teachers’ conceptions of the nature of science: A review of the research. J Res Sci Teach. 1992;29:331-59. Doi: 10.1002/tea.3660290404.
23. Lederman NG. Syntax of nature of science within inquiry and science instruction. In: Flick LB, Lederman NG, editors. Scientific inquiry and nature of science. Dordrecht: Kluwer Academic Publishers; 2004. p.301-317. doi: 10.1007/1-4020-2672-2_14.
24. Bell RL. Perusing Pandora’s box. In: Flick LB, Lederman NG, editors. Scientific inquiry and the nature of science (pp. 427-446). Dordrecht: Kluwer Academic Publishers; 2004. doi: 10.1007/978-1-4020-5814-1_19.
25. Abd-El-Khalick F, Lederman NG, Bell RL, Schwartz RS. Views of nature of science questionnaire (VNOS): Toward valid and meaningful assessment of learners’ conceptions of nature of science. In proceedings of the annual meeting of the association for the education of teachers of science. Costa Mesa, CA. 2001;1:18-21. doi: 10.1002/tea.10034.
26. Abd-El-Khalick F. Developing deeper understandings of nature of science: the impact of a philosophy of science course on preservice science teachers’ views and instructional planning. Int J Sci Educ. 2005;27(1):15-42. doi: 10.1080/09500690410001673810.
27. Apostolou A, Koulaidis Β, Kampourakis K. The nature of sciences, educational practices. Geitonas School, Child Services Publications. 2008.
28. Driver R, Leach J, Millar R, Scott P. Young people’s images of science. Open University Press; 1996. doi: 10.1080/03057268308559904.
29. Benchmarks for science literacy: A Project 2061 report. American Association for the Advancement of Science. New York: Oxford University Press; 1993.
30. Flick LB, Lederman NG. Scientific inquiry and nature of science: Implications for teaching, learning and teacher education. The Netherlands: Kluwer Academic Publishers. 2004. doi: 10.1007/978-1-4020-5814-1.
31. Cho MH, Lankford DM, Wescott DJ. Exploring the relationships among epistemological beliefs, nature of science, and conceptual change in the learning of evolutionary theory. Evolution and Education Outreach. 2011;4(2):313-22. doi: 10.1007/s12052-011-0324-7.
32. Alkyol G, Tekkaya C, Sungur S, Traynor A. Modeling the interrelationships among pre-service science teachers’ understanding and acceptance of evolution, their views on nature of science and self-efficacy beliefs regarding teaching evolution. J Sci Teacher Educ. 2012;23:937-957. doi: 10.1007/s10972-012-9296-x.
33. Kim SY, Nehm RH. A cross-cultural comparison of Korean and American science teachers’ views of evolution and the nature of science. International Journal of Science Education. 2011;33(2):197-227. doi: 10.1080/09500690903563819.
34. Stathopoulou C, Vosniadou S. Exploring the relationship between physics-related epistemological beliefs and physics understanding. Cont Educ Psychol. 2007;32:255-81. doi: 10.1016/j.cedpsych.2005.12.002.
35. Sumranwanich W, Yuenyong C. Graduate Students’ Concepts of Nature of Science (NOS) and Attitudes toward Teaching NOS. Procedia - Social and Behavioral Sciences. 2014;116:2443-2452. doi: 10.1016/j.sbspro.2014.01.589.
36. Popper K. Realism and the aim of science. London: Routledge; 1983.
37. Crouch DJM, Bodmer WF. Evolution by natural selection is a scientific law and not just a theory. Academia Biology. 2024;2. doi: 10.20935/AcadBiol6158.
38. Athanasiou K, Papadopoulou P. Conceptual Ecology of the evolution acceptance among Greek education students: Knowledge, religious practices and social influences. International Journal of Science Education. 2011;34 (6):903-24. doi: 10.1080/09500693.2011.586072.
39. Prinou L, Halkia L, Skordoulis C. What conceptions do Greek school students form about biological evolution? Evo Edu Outreach. 2008;1:312-7. doi: 10.1007/s12052-008-0051-x.
40. Le Page M. Evolution myths: Evolution can't be disproved. New Scientist; 2008.