Ancient Greek thinkers, for example, distinguished two forms of life. First, zoe, which is the simple fact of life common to all living things, which shows signs of biological, physical and material life. Everything is said to be “alive”, because it has “life” and exhibits movements that indicate biological, physical and material life, as distinguished from everything that is “dead” or “lifeless”. Second, bios, which is a decent form of life, which is also called “good life” (good life), namely life that is loaded with values, beliefs, ideologies and meanings. ” (Scientific Oration of Prof. Yasraf Amir Piliang, p. 5)
The quote from Prof. Yasraf’s scientific oration above inspires me to make a writing about what is interpreted as life and humans in the eyes of Biology. It is true that the definition of ‘life’ has been one of the fundamental questions since the time of the ancient Greek thinkers, even until the era of modern biological science today. Answers are given from various perspectives, some of which are considered unacceptable by others. Biology is now arguably the main discipline that scientifically monopolizes the explanation of life. On the other hand, trying to answer what a human being is is an even more complicated challenge. Religion, science and philosophy all have different conceptions of what a human being is and what distinguishes them from other living beings.
Presumably, it is difficult to reflect and distance ourselves from something that we cannot escape. Nonetheless, in this paper, I try to see how Biology contributes to the long debate about life and humanity. This paper is organized into three parts. In the first, I review some of the views on life in the era before biological science provided (almost) affirmative explanations. In the second part, I discuss the organization of life, a conception that can bridge the definitions of life and humanity. The final section provides a review of who is human in the eyes of biology. While this paper attempts to accommodate a variety of viewpoints, the main paradigm used in biology remains materialism and Darwinian evolution, where life and human beings are seen in terms of their physical construction and evolutive development. This is hopefully not limiting in taking the discussion into the broader realm of metaphysics.
An overview of life before science
What distinguishes rocks, water and fire from plants, animals and humans? This question has haunted humans perhaps since the dawn of civilization. The animist viewpoint, which is still relevant in many cultures around the world, does not necessarily mean the worship of humans to the objects around us. More deeply, this viewpoint sees that within every object in nature there is a ‘soul’ that also enters the human body. Humans are a small part of the flow of that ‘soul’. Like a river that flows from a spring in the mountains and empties into the sea, energy flows from something big (mountains, rivers, oceans) to every form of matter on earth. For the Maori people in New Zealand, for example, mountains and rivers are part of life that shape human identity. The word for ‘ancestor’ in Maori is ‘tupuna’, which in its root is not ‘ancestor’, but ‘the larger part from which this self originates’. The view that the earth is considered to be one big life in which humans are a small part of is encapsulated in the Gaia theory (I won’t go into this in depth, but will touch on it a little in the discussion of the organization of life).
In ancient Greek philosophy, one of the thinkers who attempted to integrate inanimate elements with life was Empedocles, who argued that all life in the world is composed of four basic elements: fire, water, earth and air. Different life forms are specific combinations of these four elements, and the change from one life form to another is practically a rearrangement of them. This also underlies another theory of life called spontaneous generation, in which life can arise from inanimate matter as long as the combination of the basic elements is suitable for it. Worms, therefore, arise spontaneously from the combination of water and soil, with a slight mixture of fire and air. What is also interesting about this view is that fire is considered matter, just like water, earth and air. This underlies an outdated theory that tells of flogiston, an element in the air that ‘animates’ living things and burns others. Breathing creatures are seen to take in and take out flogiston from the air, and death means the release of most flogiston into the air. The combustion process also causes the loss of flogiston – air that can no longer be burned is said to be depleted of the element. A similar theory is also examined in vitalism, which sees that in every living thing there is a ‘life force’ (elan vital) that organizes its life processes in a way that is completely different from inanimate objects.
These theories are also based on the view that there is something non-material (the soul) that animates living things and distinguishes them from inanimate objects. Aristotle, for example, saw that everything in the world consists of form (soul) and matter (body). The soul cannot exist without the body, but it is also the soul that gives the body its form and character. In this case, the soul appears in different forms. Plants are the simplest form of life, where the soul causes the plant to grow, develop and decay, even though the soul does not make it move. Animals, on the other hand, have souls that allow them to move and have sensations. Aristotle later argued that man has the highest soul, which not only gives him the ability to grow, develop, move and feel, but also to think and be conscious.
While these views on life flourished in ancient Greece and formed the basis for the development of philosophy and science in the following centuries, it was during the development of science in the 17th-19th centuries that these views were challenged by science itself. Francesco Redi (1668) and Louis Pasteur (1859), for example, refuted the theory of spontaneous emergence through their experiments on meat covered in a dish and the disinfection process. It was previously believed that maggots emerged spontaneously from rotting meat. With the findings of Redi and Pasteur, this spontaneous emergence theory was disproved, and also established the basis for better medical treatment. Lavoisier, furthermore, refuted the flogiston theory through his experiments with oxygen in combustion and oxidation. Beyond this, perhaps the underlying argument for these refutations stems from Rene Descartes’ materialist view, which saw living things as nothing more than a combination of tiny components (later known as cells) working in harmony like the gears and screws that make up a watch. How then does science, and in this case biological science, view life and the organization of life?
Life and the organization of life
Life is not only explained by the discipline of biology. Various other disciplines also have their own perspectives on life. In physics, for example, life is seen as a thermodynamic system built on certain molecular structures, which are capable of reproduction. In chemistry, a living cell is a semi-closed chemical system capable of self-organization. Life can also be seen as a system with negative entropy, as proposed by Erwin Schrödinger. In the review of his book, What is Life?, Schrödinger brings up the second law of thermodynamics which requires that closed systems tend towards disorder, or entropy. This is paradoxical in biological systems that have low entropy. Schrödinger argues that this can be explained because living systems (and the biosphere) are not closed systems, and therefore the high order in these living and earth systems is compensated by disorder in the wider system. I will stop here and leave the elaboration to those more competent in the field.
I, on the other hand, would like to draw this back to the realm of Biology, not only because this discipline specifically talks about living things, but also because its explanation of life and the organization of life can be considered quite profound. To begin with, Biology starts with a consensus on the characteristics of living things. In Campbell’s (2008) basic biology book, for example, it is explained that a living thing must have all or most of the following characteristics:
- Being in order/organization
- Growth and development
- Uses energy
- Respond to the environment
- Have homeostasis mechanisms
- Make evolutionary adaptations
The most important characteristics of living things are order and organization. Living things in biology are called organisms (from the Greek word organon which means device), which is a structure that together is able to grow and reproduce. Organisms are composed of organ systems, which are composed of organs, which are composed of tissues, which are composed of cells. The cell, in this case, is the smallest unit of life capable, as a unit, of growth and reproduction. Superorganisms, on the other hand, are defined as the unity of individual organisms that work together and ‘grow’ as if they were organisms. Given this definition, it is interesting to consider the two perspectives on organisms, as offered by Chunglin Kwa when discussing complexity. The first views the individual as an indivisible whole in which the components cannot stand alone. The individual is seen as a system. The second perspective sees the individual as a collection of cells working together (and the ecosystem as interconnected individuals), as a complementary table companion. The individual, in this case, is seen as a network. These two views, though seemingly contradictory, go together in the discipline of biology.
One thing all living things have in common at the molecular level is what is called DNA. Living things build their body structure from proteins, both directly as structural proteins and enzymatic proteins that form non-protein structures in the body (such as bones). Each protein is a combination of various amino acids, which are imprinted by a specific gene code sequence in the DNA. This DNA also codes for proteins that can aid the replication of the DNA itself, and therefore fundamentally underlies the ability of living things to reproduce. No living thing escapes this mode of organization. Even viruses, which are said to be transitional between inanimate and living things, have their own DNA (or RNA) sequences, although they can only replicate when their DNA is inserted into the cells and DNA of other living things.
All of the above characteristics of living things lead to their ability to make evolutionary adaptations. In my last post in a forum, I explained that Biology cannot be separated from the Darwinian evolutionary paradigm. This paradigm also shapes the view of what constitutes a living being. An organism cannot be separated from its ‘lineage’, which develops through a long process of adaptation and evolution. Today’s smart machines or computers may be capable of adaptation, but evolutionary adaptation only occurs in living things that are on an evolutionary path. Within the evolutionary paradigm, no living thing emerges spontaneously – all the way back to single-cell living things that emerged from complex combinations of molecules in the so-called ‘primordial soup’. The theory of abiogenesis seeks to answer what environmental conditions enabled the transition from inorganic molecules to organic ones, and from organic molecules to cells.
Evolutionary adaptation explains how today’s complex living things started out as much simpler living things. Single cells were originally thought to be symbiotic with each other; single cells capable of converting solar energy into chemicals, or cells capable of splitting one chemical energy into another, were originally thought to be separate organisms. These organisms entered the cell body of the larger organism and evolutively became part of the larger organism – they became cell organelles. A primitive form of obligate mutualism symbiosis between several living things can be seen in crustose lichens, which are a combination of algae and fungi. As individuals become more complex, as in animals and humans, there is no other way our brains can digest these organisms other than from a systems point of view – that animals and humans are a single entity with a central regulatory center. Only when a doctor dissects a patient is the individual viewed as a collection of interconnected organs.
Although the development of science has invalidated many views on how life came to be, it is still unable to fully answer what life is. Science in this case is unable to penetrate the realm of metaphysics, even though the foundations within the biological paradigm attempt to negate the singular purpose and noble form of life. The Darwinian evolutionary paradigm sees that there is no soul and no progression towards perfection among the various levels of living beings. Humans are no better than animals, and animals are no better than plants, although the organization of life may be more complex. This approach refutes the assertion that form (soul) determines the purpose of matter (body). For example, polar bears do not have white hair to camouflage in the snow, or butterflies have spheres on their wings to scare off predators. Instead, these animals are able to camouflage as a form of behavioral adaptation to their morphological conditions and the environment they live in. The story of the two differently colored moths in the city of London that evolved surrounded by soot is the simplest form of evolutionary adaptation of living things – in reality, evolutionary adaptation is much more complex and takes much longer.
Viewed with this paradigm, the direction of my writing may become clearer in addressing the quote from Prof. Yasraf’s scientific oration above. It is undeniable that humans have an advantage over animals in terms of their ability to think, be conscious and express themselves. What else has caused him to be able to dominate this earth to the point where the extinction of thousands of species of living beings and the future of life on earth are determined by human hands? The critical point for me is not to dispute this fact, but to see whether the wonder of man lies in his fundamental difference from other living beings, as Prof. Yasraf suggests – or whether humans just happen to have a morphology that can be used in adapting to their environment and building new realities on it.
Life and humans
Biologically, humans are no different from other living things, especially animals. Humans cannot be separated from all the characteristics of living things mentioned above (zoe in Prof. Yasraf’s writing). Human physiology is similar to that of mammals – we have mammary glands, grow hair and reproduce viviparously. Physiologically too, humans are very ordinary creatures. Our running ability is far below many other mammals such as deer, horses or lions, but neither are we as slow as lorises and tortoises. Our hearing ability is within a limited range, as are our senses of smell and sight. The size of the human body is not large enough, but also not too small to be easily preyed upon. Human hair is much thinner than that of a bear or cat, so humans are less tolerant of cold conditions than other animals. Evolutively, compared to many other mammals, humans are a very weak organism. Their physical capabilities are very limited, although they are still able to prey on other animals so they are not at the bottom of the food web. This is interesting to see because the ‘ultimate product’ of evolution, if that is what we are, does not come from the strongest and most dominant, largest or fastest organisms.
Despite the sameness and ordinariness of humans, it must be recognized that humans also have uniqueness that allows us to be able to do things that other animals cannot physically do. Humans and the primate family have a thumb that is positioned opposite the other fingers (opposable thumb). This physical condition allows primates to grip and use tools more freely than other animals. Many studies have shown how chimpanzees are able to use twigs to pick up ants or stones to crack hard seeds. Furthermore, humans have hands that are relatively shorter than their legs and a posture that allows them to walk on two legs. This also allows humans to use their hands more freely for other purposes. Another thing that is unique to humans is the structure of their vocal cords and tongue, which allows them to produce various forms of sound. Our voice is certainly not as beautiful as birds, but humans are able to produce various combinations of phonemes and morphemes that form the basis of language. Unlike birds and some other mammals, the ability of the human voice is not limited to one sex, so communication that is more basic than just mating behavior can be formed. This combination of physical conditions is at least partly responsible for the development of tool culture and language use, both of which are unique to humans. But why haven’t apes, who also use tools or language, developed as far as we have?
Much has been written in the realm of biology and biological anthropology that the most important advantage of humans is in their brain size, relative to their body. From fossil evidence, it is known that ‘early humans’ such as Australopithecus and Pithecanthropus walked on two legs first before evolutively showing differences in brain size. Richard Dawkins, a biologist best known for his book The Selfish Genes, argues that these conditions gradually allowed early humans’ brains to expand. It is now known that humans have the highest brain-body ratio (encephalization quotient). However, some animals such as mole rats also have high ratios, even though they do not exhibit high intelligence. Some scientists then proposed that differences in intelligence are not only measured by this ratio, but also by the differentiation within the brain, the number of neurons present and the speed of connections between these neurons. In this regard, the human brain is still superior to all others.
The greater complexity of the human brain leads to the greater differences between humans and animals. Jonathan Marks, a biological anthropologist, for example, argues that the fundamental difference between humans and apes lies in the ability to think abstractly. Animals are capable of material mental powers, i.e. those that require the presence of materials in their manifestation. Forms of material mental powers include sensation, perception, appetite and imagination. These capacities are useful in responding to particulars, such as food, predators and obstacles. Humans, on the other hand, have the ability to abstract universals, which do not require a material presence to manifest. Animals can think about hunger and pain (something material), but they cannot think about concepts such as injustice and suffering (something immaterial). This difference, Marks sees as qualitative.
The human brain, with its combination of vocal cords and tongue, is also capable of producing endless words through the combination of phonemes and morphemes. Mark van Oostendorp, a linguist, describes how humans can produce combinations of sounds that are distinctly different from other sounds (sounds that have no meaning), and then give meaning to these sounds. These meanings were attached to objects around him (rocks, water, birds), but also to concepts developed in his mind. A series of new words can be combined indefinitely into an idea, and the idea is transmitted to other groups of people or younger generations culturally. This also clearly distinguishes the development of language and ideas in humans and other animals.
There are at least two conclusions that can be drawn from this paper. The first is that humans are living beings, just like any other living organism (zoe). The characteristics of living beings are inherent in humans just as they are in plants and animals. This has never been disputed even by philosophers since ancient times. What may be different within the framework of modern biology is that as living beings, humans are, in evolution, interconnected with other organisms. The similarities and differences of humans are closely related to their kinship with other living things. These differences are not distinctive, but continuous, or quantitative. Humans differ a lot from plants or insects, and share more in common with mammals and, moreover, with primates.
The second conclusion is related to these differences and similarities. Humans are not superior to other animals in many specific features, such as agility, speed, strength, sense of smell, hearing and vision. Just as the cheetah, with its ergonomic physical structure, has a superior capacity for agility, humans have a physical structure that makes them superior in intelligence, namely the structure of their brain. Human intelligence enables humans to survive in their environment, just as agility enables cheetahs to survive. From this paper, what separates humans from animals is ultimately something that seems completely unrelated to the capacity to survive. The ability to think abstractly has no direct link to material things. Awareness of the concept of justice does not help humans to survive against predators or make humans able to scoop up natural resources for consumption. However, it is rather this awareness of immaterial concepts that makes us human – this, and the ability to communicate this to other humans in complex language, and with it concepts become even more complex.
Prof. Yasraf asserts that what distinguishes humans from animals is the “good life” (bios). However, human abstraction can lead to good or bad values, which more or less justify and amplify our animal drives. Altruism, compassion and communal bonds exist in animals as much as in humans. But immaterial abstraction takes these values to a more universal realm. Similarly, competition and predation can be amplified through human universal abstraction. In this sense, there is nothing bad and low about animals. But the ability of humans to take animal values to a higher plane, whether they are bad or good, and amplify them in the wider society through language, I think is what separates humans from animals.
“Science no more says that I am an ape because my ancestors were, than it says that I am a slave because my ancestors were. The statement that you are your ancestors articulates a bio-political fact, not a biological fact.” – Jonathan Marks, 2015