People often ask me: how can one explain the existence of altruism if evolution works by survival of the fittest? Doesn’t “survival of the fittest” mean that every individual must be working for their own personal success? If this question has troubled you too, you have come to the right place.
Biologists explain that the Theory of Evolution (TOE) is the cornerstone idea upon which all of modern biology depends. How so? All life on Earth share important characteristics. All life forms have the same chemical constituents and these are generally not found in inanimate objects. All living things are based on the same basic structure, the cell. The cells of all plants have the same basic structure as do the cells of all animals. Animals share a similar macro-scale structure as do plants. All these would be simply a jumble of information “bits” with no connection, no way to explain their existence without the TOE. However, with the TOE we can also understand why fossils exist but their living examples do not, why viruses often become less lethal as the pandemics they cause evolve, why antibiotics tend to lose their effectiveness over time, and so much more.
The TOE is thus the organizing principle of all of our knowledge about biology. All facts can and must be fitted into the TOE and if some facts are later discovered that cannot then we will need to reconsider, or update, the TOE. This is one of the great implications of the TOE, but it is not the one that causes difficulty for most people.
A second major implication of the TOE is that it is possible, or even likely, that life on Earth arose only a single time. We know of no reason why all life on Earth consists of the same left handed (a technical term in chemistry) 20 amino acids even though many more exist or can be made. There is no apparent reason why all life on earth uses one molecule (DNA) to store information and pass it on to future generations. (Some viruses use a similar molecule, RNA, for information but not all scientists consider viruses to be living.) The fact that the same chemistry is shared by all life on Earth suggests that all life that exists on Earth today has descended from a single initial progenitor. Does this bother you? It certainly does not conform to the biblical interpretation that each species was independently created but not all religious scholars are troubled by this concept .
I will soon get to a third major implication of the TOE, one that does cause angst for many people, but first an important aside.
According to the TOE all life forms have “morphed” over eons from earlier forms. I chose to describe the fact that the forms of present-day plants and animals are different than their ancestral forms as “morphed” in order to make an important point. Most often, you will find the word used to describe this process as “descended”. This makes perfect sense because we speak of ourselves as having “descended” from our ancestors. Unfortunately, the word descended also connotes the idea that the precedents were better (an idea well-enshrined in some aspects of Jewish thought) and the later examples less perfect. From an evolutionary point of view this concept is completely wrong, even if we take the opposite view and posit that modern examples are more developed, more perfect, more highly advanced. From the point of view of evolution, a species that is well-adapted to it’s circumstances, is “perfected” or nearly so, if it is successful in procreation and its population stable or increasing. Thus all species that have stable or increasing populations are well-adapted and perfectly evolved for their present circumstances. (I am ignoring here the fact that as nature is not static neither are the sates of evolution of species.) Thus, ants, worms, bacteria, and people, are equally evolved.
In his famous essay entitled “What is it like to be a bat” (The Philosophical Review, 1974) Thomas Nagel argued that we can never really know the answer to the question he posed. We are human and must see the world through the experience of being human. We can discover that bats understand their world partly through the use of echolocation but, because we don’t have this ability, we can never know what it’s like to have it. Anthropocentrism, or the feeling that people are the center of the universe is inherent because that is who we are. Thus, when we compare a bee dance to Alvin Ailey, a whale song to Mozart, or gorilla communications to French literature we find it hard to accept that animals are as highly evolved as people. We value thought and believe we function on insight, learning, and logic, while “lower” forms of life (which, not coincidentally, include all other forms of life) function at a “lower” level, on base instinct.
Furthermore, in our (Western) origin stories we have accepted the concept that we, as well as all other species, were made as we are by a superior being or force. The concept that people and the other great apes all “descended” from a no-longer extant common ancestor runs counter to this story and creates great discomfort (dissonance). However, nature is not anthropocentric and therefore neither is the TOE. Nature, life, and evolution existed long before there were humans or even our last common ancestor with the great apes, and they will continue long after humans cease to exist, unless we manage to make the Earth uninhabitable to all.
The natural world is the playground on which evolution takes place. The changing circumstances in which a species exists exerts a “force” called selection (more on this in the future) which determines which adaptations are favored or disfavored. In turn, this assures that the future of a species is likely to be different from it’s past. Animals evolve because 1) they are selected for reproductive success, and 2) because their circumstances change over time, the result of fluctuations in their environment and the ongoing changes (evolution) of other species with which they are in competition. Evolution is not static, but at any moment in time all species that are succeeding are highly evolved for their particular circumstances and, in the perspective of nature and evolution, none are “higher” beings than others though they might have different capabilities. One last point on this aside. Darwin himself recognized that mate selection has a powerful effect on evolution and can explain why certain structures are selected for and enhanced over time. In an important article entitled The Origin and Function of ‘Bizarre’ Structures: Antler Size and Skull Size in the ‘Irish Elk,’ Megaloceros giganteus (Evolution, 1974) the evolutionary biologist Stephen J Gould explored this further and showed that evolution can select for adaptations that ultimately become less adaptive in a changed world. The giant antlers of the Irish Elk may have made it a more attractive mate but, once the environment changed, may have led to its extinction. Similarly, the adaptations that we so value in humans, our great cognitive ability, or, more likely, our great predisposition to adhere to our group, may seem like the pinnacle of evolution now, but may conceivably lead to our own demise in the future.
Ok, back to the third great (and troubling) implication of the TOE. The theory explains how we have developed from earlier extant life forms through the slow accumulation of changes. It explains how we got to be us. As the organizing principle of biology, there is no other mechanism accounting for us and how we look, how we function, how we behave. Furthermore, nothing about us (or almost nothing) was “invented” denovo when modern humans first arrived on the scene. That means that everything about us, our emotions, our feelings (see Mama’s Last Cry by Frans de Waal for an explanation of how these are different) our way of thinking and behaving, has antecedents in the species that came before us and therefore was inherited by all of the descendants of those forebears.
Our brains did not evolve to make dance, or music, or literature per se. It evolved as a means of procreative success. It is not a computer onto which our parents load their personal software program. We are not born as a Tabula Rasa, a blank slate. Nature has an important part to play in how we think and how we behave. This fact, that genetics plays an important role in our personalities, is born out in numerous studies. To understand ourselves we must look not only to the “nurture” part of the equation, but equally, or perhaps even more so, to the “nature” part. The implication is that everything about us, even that part that can be influenced by our upbringing and by other environmental influences, is the product of evolution. The best parts of our nature, as well as the darkest corners, are all the legacy of our evolutionary past.
I will go out on a limb here and say that this principle should inform the way we think about (and treat) other species. For many decades the field of animal behavior was dominated by the ideas of B.F. Skinner (inventor of the Skinner Box) and his intellectual adherents and descendants. Animals were thought to be mostly automatons and scientists were proscribed from attributing any ability to animals that could not be proved to exist. Emotions and pain are difficult to prove experimentally (only reactions that “look like” emotions and pain can be observed and behaviorist proscribe scientists from calling these behaviors after the emotions they resemble) so scientists had to assume that animals did not have these, or any other emotions. Behaviorists received public disapprobation if they suggested that animals had these capabilities. As you now understand, this approach may appear to be scientific but runs afoul of the implications of the TOE. If we feel fear, and if we feel love, then it is likely that animals, at least those that are closer to us on the evolutionary tree, most likely have some form of these emotions too. It is true that this does not constitute proof but equally, the existence of a form of our capabilities in animals should not be denied without proof. Do our dogs love us? When viewed through this lens the starting position ought to be yes, they experience some form of affection because this emotion was invented for evolutionary purposes (rearing of offspring by mammals is a good guess), not for the employment of human writers, poets, and singers.
At the start of this post I suggested that if you want an explanation of how altruism may have arisen from survival of the fittest you have come to the right place. A detailed explanation will have to wait for a future blog post. For now, you will have to settle for this: evolutionary selection is more complicated than it seems and most certainly is not just “every individual for itself”. Darwin himself understood this; in On The Origin Of Species (1859) he wrote “I use the term “struggle for Existence” in a large and metaphorical sense including dependence of one being on another”. Our ancestors would not have survived and procreated successfully had they lived alone. Instead, they lived in groups and the success of every individual depended on their success within the group. Altruism can be thought of as both “paying it forward”, and also as signaling to the other members of the group that you are a good and trustworthy member that who deserves trust, help when needed, and the best mates.
The main point today is that yes, the TOE can account for altruism. If it can’t, then the TOE is flawed.