The ducks of science

Living in the XXI century with our western culture and stage of technology, environmental and political issues, degree of education and concern about the future of humanity, we as human beings must have pretty clear in mind the principles, assumptions and precepts of science so we can make better decisions, take care of ourselves and the world we live in. The actual conditions where Brazil and other countries are in terms of basic and scientific education show us the great gap in understanding how science works and allow all the knowledge and technology that our world has formed.

First thing to know is that science doesn’t prove anything! We never achieve the truth. This is not pessimism, it is just to assume that we are beings that have understanding limitations (including sensorial and technology issues) towards the complexity of natural world. It is impossible to know about all variables and conditions that exists allowing patterns and process to be as they are. So what occurs is: if there are many strong evidences that support a hypothesis or a theory and nothing against, we say that this hypothesis or theory is well corroborated and the best available…and that is all!              

It is extremely important to notice which hypothesis is scientific and which is not. According to Karl Popper, a hypothesis must be falsifiable to be part of science. The more a theory states, the more opportunity there is to show that the world does not actually behave in the way it is. A good theory makes broad statements about the world, and as a consequence is highly falsifiable and resists every time it is tested. A vague theory is not falsifiable. If it does not make it clear exactly what it is claiming, then testing it can always be interpreted as consistent with the results of those tests. Hence the need to be clearly affirmative and precise.

It is only by excluding a set of logically possible propositions of observation that a law or theory is informative. Affirmations such as: (1) All points in a Euclidean circle are equidistant from the center or (2) I am very lucky person, tell us nothing  about the world. A law or scientific theory should give some information about how the world actually behaves, thus eliminating the ways in which it could possibly behave otherwise. The law “all planets move in ellipses around the Sun” is scientific because it states that planets actually move in ellipses and eliminate orbits that are square or oval. Just because the law makes decisive statements about planetary orbits, it has informative content and is falsifiable.

Observation is guided by theory and presupposes it. We only see what we already know. It is impossible to observe natural phenomena with nothing in mind and without all the knowledge that has already been taught to us. So we know theories and while making observations about the natural world, we question and raise hypotheses about it. However it is impossible to arrive at universal laws and theories assuming that theories can be established as true or probably true in the light of observational evidence. When somebody hypothetically says “In my life I only saw black ducks (because I only saw Daffy Duck cartoon in my whole life)”, we can’t deduce from this that “all ducks are black”. On the other hand, it is possible to make logical deductions starting from singular propositions of observation as premises, to arrive at the falsifiability of laws and universal theories. That is: you don’t confirm when your observation agree with the hypothesis or theory, you just don’t exclude until future observations and/or experiments fall into disagreement. So the premise “all ducks are black” is easily and actively refused with the encounter of ducks of other colors (Donald duck for example). So the acceptance of theory is always tentative, but rejection of theory can be decisive.  

So basically science begins with problems associated with explaining some aspects of the world or universe. Falsifiable hypotheses are proposed by scientists as solutions to the problem. The conjectured hypotheses are then criticized and tested. Some will be quickly deleted. Others may prove to be more successful. These should be subjected to further criticism and testing. When a hypothesis that has passed a wide range of rigorous tests successfully is eventually falsified, a new problem arises. This new problem calls for the invention of new hypotheses, followed by criticism and renewed testing. And so, the process continues indefinitely. science progresses by trial and error, by conjectures and refutations.

Bulletproof ideas

But life is not a bed of roses! We cannot forget that a scientific theory consists of a complex of universal statements rather than an isolated statement like “all ducks are black.” Very often a theory can be modified to “protect it” in case of a falsificationism threat. This “theory improvement” by adding new content and information can be very inefficient, even though it could be considered acceptable by “falsificationists” at a first sight. These later modifications  added to an existent theory are called ad hoc modifications – if it doesn’t have testable consequences. For example, considering a generalized theory where is said that “(all) water is good for health” and then, looking at a village where people drank the water getting sick and dying, we clearly can see that this premise is false. However, in attempting of “save” his work the researcher responsible for that theory rewrite the phrase saying that  “(all) water is good for health, except that water of that certain village”…well, this can’t be done. It’s a explicit example of an ad hoc modification, where we can see that this changed part of the theory can’t be tested separated of the original one. The consumption of water in the whole world by any human being becomes a test of the original theory as the tests of the modified theory are restricted to that village. Thus, the modified theory is less falsifiable than the original one and we don’t have to be a very careful falsificationist to see that. Of course in the real world this ad hoc modifications are way more complex, so we have to be careful with this additions to theories and be able to discern the valid ones

We must have in mind that the propositions of observation depend on theory and that they are fallible. So the problem is: falsifiability is based on the assumption that propositions of observation are perfectly safe. So if a theory or part of it collides with some proposition of observation, nothing in the logic of the situation requires that it should always be the theory to be rejected. An observation proposition can be rejected and the theory with which it is shocked to be retained. Consequently, direct, conclusive falsifications of theories are not achievable and not according to this is being part of the so-called naive falsificationism.

Historically it is possible to find observational propositions that were generally accepted at the time and were considered inconsistent with theories, which were not rejected. If so, classical scientific theories widely accepted today would never have been developed. Important concepts in the history of physics such as force and inertia did not arise as a result of careful observation and experimentation. Neither they arose through the falsification of audacious conjectures and continuous substitutions. Initial formulations of new theories, involving new conceptions incompletely formulated, were maintained with perseverance and developed in spite of apparent falsifications.

Literature:

CHALMERS, Alan F. O Que é Ciência Afinal? São Paulo: Brasiliense, 1995.

by Stephanie Sampronha and Bianca Cegolin

Using phylogenectics to enlight myth origins, cultural linking of peoples and human migration/colonization

Phylogenetics is a method of inference that evaluate observed heritable traits, such as DNA sequences or morphology of both present and past organisms. The method compares heritable traits in organisms of different species, and then by the use of algorithms, those traits can construct one or more hypothesis of evolutionary relationships. The result creates a phylogenetic tree – a diagrammatic hypothesis about the history of the evolutionary relationships of a group of organisms. Phylogeny shows the relationships between groups of organisms (taxa) generally expressed in shared traits among them.

The phylogenetic analysis is seen as a reconstruction of the organism’s evolutiorary history considering the actual model of biological evolution and the method itself. Thus – Would be possible to non-biological entities such as cultural elements: religion, pottery or architecture be evaluated by phylogenetic method?

In the article ‘A Cosmic Hunt in the Berber sky: a phylogenetic reconstruction of a Palaeolithic mythology’ the author Julien d’Huy tries to apply the method to mythological corpus. He uses mythems (elementar unchangeable units of an idea) as an equivalent to heritable traits. Mythems in mythology or religion can be as follows – ‘an animal turns into a star’ or ‘one person resurrect from the dead’. Those “traits” of a story can be compared to other tales to reconstruct a history of cultural evolutionary relationships. In the case of Julien, the mythology’s mythems are concerned into the ‘Cosmic Hunt’, which is a general cognate myth about some animal being pursued by hunters and eventually transformed into a constellation or part of it.

Let’s say that a mythem ‘X’ is part of a Siberian tale, and the concept of this mythem ‘X’ is found on both South and North America tales each one story with their our slight variations according to the addition of other mythems, in this cenario it’s possible to compare many of them from various stories and establish related groups.

Since two taxa are more closely related when they share a more recent common ancestor, Julien states that this similarity can be used to reconstruct cultural evolutionary histories and that there are some conclusive results in mythology. The author’s conclusion says that the phylogenetic approach on the handled myths allowed at least six corroborations. Most important ones refer that was possible to reconstruct the approximate first version of the myth. Corroborated the existence of mythological common root to Berbers and European hunter-gatherers. Document at least four migrations from Eurasia into America and suggest that there was reverse migration from Eurasia to Africa.

Figure above shows a phylogenetic tree of mythological versions of Cosmic Hunt spread through peoples and regions. Red: Asia. Gray: Greece. Yellow: Basque. Orange: Africa. Light blue: Artic. Magenta: American coast-plateau/Britsh Columbia. Pink: Northeastern America. Wood: American Great Basin/Great Southwest. Green: Guiana.

The use of phylogenetic method on cultural traits can help to trace relationships between different and distant peoples. Maybe this tool can be applied to revaluate or corroborate already existing theories of human migration and colonization, or even construct new explanations.

 

Literature:

D’Huy, Julien. A Cosmic Hunt in the Berber sky. A phylogenetic reconstruction of Palaeolithic mythology – Les Cahiers de l’AARS, 16, 93-106