Mendelian Genetics and Social Evolution (Part 2 of 3)

Part 1 of 3 of this article: www.chennaicounselorsglobal.org/interdisciplinary-approach-to-understanding-human-behaviour

How does Evolutionary Biology and Genetics connect in the aspect of Human behaviour?

Gregor Mendel who proposed the Mendelian Genetics that explains concept of genetic inheritance, because of which we understand the concept of dominant trait and recessive trait and their generational transference modality that explains the differences in inheritable traits & temperament in individuals, that Darwin could not understand or explain.

Gregor Mendel studied inheritance in pea plant. He repeated his experiments many times with various pairs of dichotomous pea plant traits and gave us the concept of dominant and recessive traits, phenotype and genotype traits and alleles. The research study of Drosophila melanogaster (or the fruit fly) by Thomas H. Morgan et. al. is a powerful model organism widely used in biological research that has made significant contributions to the greater scientific community over the last century, because of their striking genetic similarities to humans and other mammals1. The use of Drosophila as a model organism for neuroscience and developmental biology led to discoveries that provided a lasting impact, thanks to its short-life cycle, low maintenance costs, conserved biology, and powerful genetic toolbox².

When I ventured into Human Resource Management (HRM) in a workplace context, I was exposed to concepts organizational behaviour and group dynamics. Thanks to my Amazon Kindle recommendation, I read the e-book Sociology – A Graphic Guide by John Nagle & Piero. To my surprise, I found Darwin and his work on evolution, being mentioned in this book. Hebert Spencer (1820 – 1903) who worked on the concept of Social Evolution, adapted Darwin’s theory to explain structural differentiation (how apparently “simple societies became increasingly complex) and functional adaptation (how societies adjust to change and complex forms of social organisation)³.

In the field of Biology, evolution by natural selection is a widely accepted concept even today as the new areas of genetics and biochemistry only reinforced Darwin’s conclusion4. Recent research in genetics, epigenetics, neuroscience largely relies on the Mendelian Genetics and Darwin’s Evolution Theory.

There was one more time, I was reminded of Darwin and Mendel. This time, it was when I was reading about theories of motivation, specifically instinct theory of motivation, which is rooted in Darwin’s theory of natural selection & fitness, which forms the basis of survival of any species. It explains the drive to act in a certain way by linking them to biological roots that aid in our survival. The Moro reflex, rooting reflex, and sucking reflex in newborns, migration of birds for change of weather are all example behaviours of instinct theory of motivation in action in different species.

How do psychological theories and the other disciplines of biology and sociology complement each other in understanding human behaviour? Look forward to the last part of the three-part series.

References

1. www.jove.com/v/5082/drosophila-melanogaster-fruit-fly-as-a-model-organism#:~:text=Drosophila%20research%20can%20also%20have,culminating%20in%20decreased%20locomotor%20ability
2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4783153/
3. Nagle, John & Piero (2016). Sociology – A Graphic Guide (pg. 41). Icon Books Ltd, London.
4. Pinel, John.P.J. (2003). Biopsychology (fifth edition). Chapter 2 - Evolution, Genetics, and Experience: Thinking about the Biology of Behaviour (pg. 23 – 49). Pearson Education, Inc., USA.
5. https://www.cdc.gov/genomics/disease/epigenetics.htm#:~:text=Epigenetics%20is%20the%20study%20of,body% 20reads%20a%20DNA%20sequence.

Glossary

1. Dominant Traits: In genetics it is a trait that will appear in the offspring even if one of the parents contribute it.
2. Recessive Traits: In genetics it is a trait that will appear in the offspring even if one of the parents contribute it.
3. Genotype: The genetic makeup of an organism
4. Phenotype: the observable physical properties of an organism; these include the organism's appearance, development, and behaviour.
5. Epigenetics is the study of how your behaviours and environment can cause changes that affect the way your genes work. Unlike genetic changes, epigenetic changes are reversible and do not change your DNA sequence, but they can change how your body reads a DNA sequence⁵.

Aarthi Prabhakaran
AM314