actor -> recipient
four types of social interactions:
“The field of social evolution, of which Hamilton's rule has central importance, is broadly defined as being the study of the evolution of social behaviours, i.e. those that impact on the fitness of individuals other than the actor. Social behaviours can be categorized according to the fitness consequences they entail for the actor and recipient. A behaviour that increases the direct fitness of the actor is mutually beneficial if the recipient also benefits, and selfish if the recipient suffers a loss. A behaviour that reduces the fitness of the actor is altruistic if the recipient benefits, and spiteful if the recipient suffers a loss. This classification was first proposed by Hamilton in 1964.”(wikipedia, https://en.wikipedia.org/wiki/W._D._Hamilton)
Being an evolutionary theorist, Lynn Margulis criticized the traditionally accepted theory of evolution proposed by Charles Darwin; she introduced evolution as merely collaborative interaction rather than the struggle for existence. If the struggle for existence in Darwin's theory led to natural selection and survival of the fittest (Darwin, 1859), Margulis introduced a theory of symbiotic organisms wherein, through interaction and collaboration, prokaryotic organisms evolved into more complex eukaryotic cells (Sagan, 1966). In her article "On the Origin of Mitosing Cells,” the theory is introduced through the interaction of three ancient organelles: the mitochondria, the photosynthetic plastids, and the flagella, which, over the course of changing weather conditions in Earth's history, were impelled to mutate into one organism. This process was possible due to vapor and the escape of free hydrogen into the upper atmosphere, which led to the production of molecular oxygen. The increasing amount of oxygen, in turn, was consumed by other organisms that had to survive in the changing conditions: An aerobic prokaryotic mitochondrion was ingested into the cytoplasm of a heterotrophic anaerobe, while symbiotic cilium attached to other bacteria and formed a flagellum. Further evolution resulted in eukaryotic blue-green algae:
“During the course of the evolution of mitosis, photosynthetic plastids (themselves derived from prokaryotes) were symbiotically acquired by some of these protozoans to form the eukaryotic algae and the green plants” (Margulis, 1966:225).
The idea of evolutionary change via interacting organisms suggests that we humans are not humans because we “think,” but because we interact with other organisms and we evolve with other organisms.
The National Institutes of Health (NIH) carried out a project analyzing and sequencing the variety of DNA in the human body, coming to the conclusion that the ratio of human cells with other cells within the body is one to ten. The cells belonging to humans have one DNA strand and other organisms have the other. Those other organisms carrying different DNA are various fungi, bacteria, and protists that live on the skin, in the guts, or in the nose:
"Microbes inhabit just about every part of the human body, living on the skin, in the gut, and up the nose. Sometimes they cause sickness, but most of the time, microorganisms live in harmony with their human hosts, providing vital functions essential for human survival." (NIH, 2012)
To define the human microbiome, researchers analyzed 242 people by taking samples from different parts of body and analyzing them with DNA sequencing machines instead of by growing microorganisms in a medium under laboratory conditions; this way, they ended up with more accurate results. It follows that these more than 10,000 other microbial species occupying the human ecosystem must have a function that is more than just lurking around the body and consuming energy provided by digested food. Microorganisms break down proteins, lipids, and carbohydrates, making them ready to be absorbed by the human organism. They also produce vitamins and anti-inflammatories that regulate the immune system and keep the human body safe from diseases (NIH, 2012). In short, microorganisms have been collaborating with humans for survival over the course of the evolution.
Bruno Latour (1987). Reassembling the Social: An Introduction to Actor-Network-Theory. Introduction: File:latour-introduction-to-ant-theory.pdf
The idea of Actor Network Theory comes from a sociologic point of view, where Bruno Latour distinguishes the traditional meaning of social (=human, community focussed) adding to it other non-human "actors" like objects or activities like law, science, technology, etc.
Latour proposes two positions which distinguishes traditional sociology from the ANT perspective. The first one could be compared with Niklas Luhmann social systems and the other with Deleuzian rhizomatic systems.
“In the course of the book we will learn to distinguish the standard sociology of the social from a more radical subfamily which I will call critical sociology.7 This last branch will be defined by the following three traits: it doesn’t only limit itself to the social but replaces the object to be studied by another matter made of social relations; it claims that this substitution is unbearable for the social actors who need to live under the illusion that there is something ‘other’ than social there; and it considers that the actors’ objections to their social explanations offer the best proof that those explanations are right. To clarify, I will call the first approach ‘sociology of the social’ and the second ‘sociology of associations’ (I wish I could use ‘associology’). .. I may be forgiven for this roughness because there exist many excellent introductions for the sociology of the social but none, to my knowledge, for this small subfield of social theory8 that has been called—by the way, what is it to be called? Alas, the historical name is ‘actor-network-theory’, a name that is so awkward, so confusing, so meaningless that it deserves to be kept.”(Bruno Latour 2005:8-9)