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Evidence in biology
[edit | edit source]In science in general, evidence is key to backing up all the scientific theories that surround us and try to make sense of all the phenomenons happening everywhere, all the time. But as these theories are only suggested by researchers, they need to be tested to collect evidence. The more evidence collected, by the more different people, the better. [1]
Scientific evidence is used in three main different ways. It can be a link -strongest link being a “cause/consequence” link, allowing for instance to predict the behaviour of a similar event-, a difference -data used as evidence that something isn’t the same as something else (different characteristics/reactions/etc.)- or a change -establishes something’s change within time.[2]
With these results and these different uses of evidence/data, one can solidify a scientific theory or, on the contrary prove it is wrong, generating what is called a paradigm change.
Darwinism
[edit | edit source]One major example of a paradigm change in the history of biology is the Darwinian paradigm. Darwin’s evolutionary theory justifies the diversity of life by the process of natural selection. At the time, it caused a real disruption in the way people saw evolution, therefore impacting their way of thinking about the evolution of humans which was very controversial as opposed to the Bible's explanation of the apparition of humans, thus perceived by some as “an attack of traditional values”. [3] Charles Darwin presented his theory in 1859 in On the origin of species.To back up his theory he used multiple different experimentations and observations - such as the notorious finches of the Galapagos islands possessing a large variety of shapes and sizes of beaks, accomplishing multiple functions that Darwin saw as a proof of the effect of natural selection on these different species according to the island they were one and its environment, requiring different beak qualities[4]-all these observations forming solid scientific evidence to back up his evolutionary theory; a theory adopted in most parts of the world today.
The Origin of Life
[edit | edit source]Stanley Miller’s experiment in 1953 was also an important event in the history of biology's paradigm changes, as it offered a new explanation of the origin of life on earth (based on scientific evidence), triggering the growth of research in this field.[5] “Life” is not easy to define. Christopher Chyba and Carol Cleland (two astrobiologists) even said in the Origins of Life and Evolution of the Biosphere that trying to define it would be a mistake, as the knowledge about life is too small to impose an actual definition on it. [6] A list of common characteristics of life on Earth can however, still be established; life’s essence is chemical, information is transmitted from one generation to the next by molecules, life exploits thermodynamic disequilibrium, biomolecules interact with water, and living systems have emerged as the result of random variations and natural selection. [7]
In 1953, Stanley Miller’s experiment concluded that the environment most likely to have hosted the development of life was a “primordial soup”.[8] Since then however, more evidence collected in different experiments have suggested that life wasn’t developed in such an environment but rather in black smokers or, more recently, alkaline vents. The need for more evidence is therefore always needed in this scientific domain, always backing up certain theories or proving that others are wrong, contributing to the ever-evolution of the theories of the origin of life, which is aplicable for all biological domains in general.
- ↑ Science relies on evidence [Internet]. Undsci.berkeley.edu. 2020. Available from: https://undsci.berkeley.edu/article/whatisscience_06
- ↑ Gott R, Duggan S. Understanding and Using Scientific Evidence. 2003.
- ↑ Almeida A. Darwin who?. Science. 2014;345(6194):260-260.
- ↑ Voss J. Darwin's Pictures: Views of Evolutionary Theory, 1837-1874. Yale University Press; 2010.
- ↑ Bada J. ChemInform Abstract: New Insights into Prebiotic Chemistry from Stanley Miller′s Spark Discharge Experiments. ChemInform. 2013..
- ↑ NASA - Life's Working Definition: Does It Work? [Internet]. Nasa.gov. 2020 [cited 23 October 2020]. Available from: https://www.nasa.gov/vision/universe/starsgalaxies/life%27s_working_definition.html
- ↑ NASA Astrobiology [Internet]. Astrobiology.nasa.gov. 2020 [cited 23 October 2020]. Available from: https://astrobiology.nasa.gov/research/life-detection/about/
- ↑ Bada J. ChemInform Abstract: New Insights into Prebiotic Chemistry from Stanley Miller′s Spark Discharge Experiments. ChemInform. 2013;44(23):no-no.