3 Scientific Research Methods

Human understanding on the concepts ‘big history’ and ‘deep time’ are always changing and developing because of the introduction and contributions of different scientific research methods. Some methods hold high historical significance due to the catalysing effect it may cause, and others may put forth a notion that fills a gap in our knowledge. One such scientific research method was the invention and application of radiometric dating. This was a monumental device in understanding the origins of our planet, specifically the dating of our solar system. Another such contribution was the Stanley Miller and Harold Urey (Miller and Urey) experiment. This provided the scientific community with convincing evidence relating to how life on Earth first started. Lastly, Charles Darwin’s Theory of Evolution was one of the most historically significant contributions towards human understanding regarding the nature of life on Earth. All these discoveries and methods have contributed to our knowledge of deep time, and have helped shape the scientific consensus regarding key ‘thresholds’ in big history.

Radiometric dating was a scientific technique discovered in 1905. It was then further utilised by astronomers to help understand the age of the solar system and Earth in the 1950’s.[1] Basically, this practice is used to accurately date materials such as rocks, fossils and minerals that contain radioactive isotopes by observing their known fixed radioactive rates of decay.[2] It works because this decay process is regular and statistically measurable. For example, when the radioactive parent uranium-238 (with a half-life of 4.5billion years) decays it passes through steps until it becomes the stable non-radioactive ‘daughter’ product lead-206.[3] This technique has been able to prove that the Earth is at least 4.5 billion years old, and that most objects in the solar system were formed at about this time as well.[4] Radiometric dating as a primary source of evidence has high value regarding its historical significance. Firstly, from its findings, it was able to further challenge previously held assumptions. For example, the Bible’s record of creation said that the age of the world was about 6,000 years old. This research method not only proves this assertion incorrect but also changes the view of the general society, whose belief in the Church’s teachings were difficult to undermine. This would also help to open the field of deep time and big history as scientists and historians could probe for deeper understandings, following up from results found through radiometric dating. Secondly, because it could provide reliable numerical dating of the past, it was central to the (second) “Chronometric Revolution”.[5] This relates to the science of measuring time. Such a deeper understanding on the age of the Earth and the universe is a relatively new phenomenon, in the scope of deep time. These important clues concerning the age of the solar system’s deep past will help to spur on further query into this field.[6] For example, scientists are using the same methodology to accurately date more recent history, such as humanity’s past.[7] One way this is achieved is by geologists using the radiometric dating of Carbon-14, which has a half-life of 5,730 years.[8] Furthermore, this ability to measure deep time so accurately helped to confirm theories that had unanswered questions or missing data such as gaps in the fossil records.[9] For example, knowing the age of the planet was fundamental to evolutionary theorist Charles Darwin’s adapted works. This was because his theory of evolution required the Earth to be more than 100 million years old, which few geologists believed at the time.[10] It allowed people to make concrete statements rather than just inferences using logic. However, on the other hand by the 1950’s, radiometric dating was primarily to do with accuracy because many already believed the Earth was very old. This technique merely further confirmed their suspicions. Thus it could be regarded as only a minor advancement in knowledge by some people. Overall, radiometric dating is a historically significant tool that has helped our understanding of deep time.

The Miller and Urey experiment in 1952/1953 provided vital evidence to support a theory on the formation of life on Earth.[11] By contributing to knowledge on how life on Earth first started, it proves to be historically significant and stimulating for this aspect of deep time. Harold Urey and Stanley Miller created this simple experiment to test Alexander Oparin and JBS Haldane’s theory that Charles Darwin’s evolutionary theories not only applied to the evolution of life but also to the inception of it.[12] They viewed complex but non-living chemicals as also being able to evolve, with only the stable copies better suited to its environment multiplying more (known as ‘chemical evolution’).[13] This experiment was a test to see if conditions for simple organic molecules, that could possibly develop and consequently lead to life, could appear in the early atmosphere (an atmosphere with little oxygen).[14] In essence, they simulated the early atmosphere in a closed model containing mainly methane, water and ammonia, and simulating lighting through shots of electric currents.[15] After seven days, their model produced a substance that contained several of the most important amino acids necessary for life.[16] This was a significant discovery because it helped to confirm that the creation of many of the basic chemical building blocks of life may have been possible on the early Earth, long before the Cambrian era (600 million years ago).[17] It therefore gave clues as to how life on Earth was formed, an important facet of deep time. Before the Miller and Urey experiment, Oparin and Haldane’s theory was merely plausible.[18] It was one of several theories that attempted to explain the beginning of life (for example that life was brought to Earth from meteoritic impacts).[19] This test was historically significant because it backed the theory up, thus furthering and enhancing the scientific understanding of this issue. It also provided further information regarding the ‘goldilocks’ conditions necessary for the birth of life. However, there were some downfalls that also partially diminished its significance. Firstly, there still remained many steps between the development of the molecules found, and the creation of life.[20] Furthermore, the makeup of the atmosphere in the experiment may not have been correct, in that in reality there probably was more ammonia and methane and less carbon dioxide and nitrogen.[21] Compared to the overall impact the Miller and Urey experiment had, these weaknesses however are dwarfed by its contributions.

Charles Darwin’s Theory of Evolution was an idea with high historical significance. Since its introduction and numerous developments, it has become vital to the understanding of the way species evolve. Essentially, Darwin’s theory (as modified in the 20th century) held that those individuals that had genetic advantages that made them slightly better adapted to their environment, are slightly more likely to survive into adulthood and produce healthy offspring, so they are more likely to pass on their genes to future generations.[22] The sum of individuals that do not possess the advantageous gene will produce fewer healthy offspring until the lineage shrinks or dies out.[23] For example, in the Arctic, a white bear would have a genetic advantage that would increase its chance of survival (by camouflaging with the ice) more than a black or brown bear.[24] We now know that evolution is driven by small variations and mutations that occur when DNA copies itself.[25] It makes on average one error for every billion bits of genetic information.[26] The Theory of Evolution thus contributes to our understanding of deep time because it argues that it is by small changes over vast periods of time that evolution of life occurs. It is also important because it has been adopted and widely accepted by the scientific community. Before this theory, people primarily believed in the Church and the Bible’s creationist teachings, that creatures were made perfect by the hand of God.[27] Despite early denial and scepticism, as technology advanced, Darwin’s theory was gradually established. This logic also challenged society and the church as it in a way deprived God of any reason of existence.[28] It was also historically significant because it helped to explain the origin of humans.[29] By an analysis of the genus’s between man and ape, we can see where our ancient heritage lies and how evolution has moulded the present day homo sapien.[30] Furthermore, it is useful as this theory is never ending, because environments are always changing and so species are always adapting.[31] This Natural Selection however is not always perfect and does not explain everything. For example, human technology may interfere with the ‘natural’ processes of the Theory of Evolution as people manipulate and innovate ways to control the biological makeup of living organisms. Likewise, the inability to naturally evolve from cancer is still under investigation.[32] Additionally, although natural selection makes creatures more fit for their environment, there are trade-offs to this as well.[33] For example, in humans, hernias are an evolutionary consequence of habitual bipedalism.[34] Overall, Darwin’s Theory of Evolution is a highly significant concept that has brought new understandings to deep time regarding the phenomenon of life.

These three scientific research methods each contribute uniquely to human understanding of deep time. Radiometric dating generated a new understanding on how old the Earth and the solar system is. Such a reliable and accurate technique thus proves historically valuable. The Miller and Urey experiment expanded upon theories on how life on Earth began. As this topic is of such historical significance, this scientific research method was historically important. Lastly, Charles Darwin’s Theory of Evolution was monumental to understanding the adaption and increasing complexity of life on Earth. Its principles served as a foundation for further investigation. Altogether humanity’s understanding of deep time and big history have been aided by these three methods.

Bibliography:

Adams, Justin. “Origins of humans: The Palaeolithic Era”. Monash University, Clayton. 14 Aug 2017. Lecture.

Burd, Martin. “Origins and Evolution of Life on Earth”. Monash University, Clayton. Aug 2017. Lecture.

Christian, David, et al, “The Fourth Threshold: The Emergence of the Sun, the Solar System and the Earth”, in Big History: Between Nothing and Everything New York, NY: McGraw Hill Education, 2014, pp. 33-53

Christian, David. “Origins of Life and the Theory of Evolution” in Maps of time: an introduction to Big History. Univ of California Press, 2004, pp. 79-105.

‘Chronometric revolution’ at https://www.khanacademy.org/science/biology/history-of-life-on-earth/radiometric-dating/v/chronometric-revolution, accessed at 15 August 2017.

Wood, Bernard, and Brian G. Richmond. “Human Evolution: Taxonomy and Paleobiology.” Journal of Anatomy 197, no. 1 (2000): pp 19-25, 50-1.

Stringer, Chris and Julia Galway-Witham, “On the Origin of the Species”, Nature 546, no. 7657 (2017), pp 212-3.

Zimmer, Carl. “Evolved for cancer?” Scientific American 18, 2008, pp. 14-21.


[1] Christian, David, et al, “The Fourth Threshold: The Emergence of the Sun, the eaSystem and the Earth”, in Big History: Between Nothing and Everything New York, NY: McGraw Hill Education, 2014, pp. 36.

[2] ibid

[3] Christian, D. pp. 36-37

[4] Christian, D. pp. 37

[5] Christian, D. pp. 37

[6] ‘Chronometric revolution’ at https://www.khanacademy.org/science/biology/history-of-life-on-earth/radiometric-dating/v/chronometric-revolution, accessed at 15 August 2017.

[7] Christian, D. pp. 37

[8] Ibid

[9] Stringer, Chris and Julia Galway-Witham, “On the Origin of the Species”, Nature 546, no. 7657 (2017), pp 212-3.

[10] Christian, David. “Origins of Life and the Theory of Evolution” in Maps of time: an introduction to Big History. Univ of California Press, 2004, pp. 90

[11] Christian, D. pp. 95

[12] Christian, D. pp. 94

[13] Christian, D. pp. 94-95

[14] Burd, Martin. “Origins and Evolution of Life on Earth”. Monash University, Clayton. Aug 2017. Lecture.

[15] Christian, D. pp. 95

[16] Burd, Martin. “Origins and Evolution of Life on Earth”. Monash University, Clayton. Aug 2017. Lecture.

[17] Christian, D. pp. 95

[18] Christian, D. pp. 94

[19] Christian, D. pp. 97

[20] ibid

[21] ibid

[22] Christian, D. pp. 104

[23] Christian, D. pp. 83

[24] Adams, Justin. “Origins of humans: The Palaeolithic Era”. Monash University, Clayton. 14 Aug 2017. Lecture.

[25] Christian, D. pp. 92

[26] Ibid

[27] Christian, D. pp. 88

[28] Christian, D. pp. 89

[29] Adams, J. Lecture.

[30] Wood, Bernard, and Brian G. Richmond. “Human Evolution: Taxonomy and Paleobiology.” Journal of Anatomy 197, no. 1 (2000): pp 19-25, 50-1.

[31] Christian, D. pp. 84

[32] Zimmer, Carl. “Evolved for cancer?” Scientific American 18, 2008, pp. 14-21

[33] Adams, J. Lecture.

[34] Adams, J. Lecture.