Man or Ape?

A scientific view holds that humans are just merely more intelligent apes and no different in their essential nature than any other species of animal.  Richard Dawkins points out that if it weren't for species extinction, we would not be able to identify a "dividing line" between humans and apes, or between any two species of animal for that matter.  That is to say, if every creature that had ever lived still walked the earth and never went extinct, there would be a complete continuum in the shape, form, and nature of every living thing, and the concept of separate "species" wouldn't even occur to us.  It's the gaps due to extinction that define where one species ends and another species begins.  

On the other hand, most religious views hold that humans are very different from the other animals.  Judeo-Christian traditions hold that humans and only humans have souls that are separate from their physical forms and that have an eternal life.  Buddhist cosmology holds that although all sentient beings share buddha-nature, humans occupy a separate realm of existence above the animal realm but below the realm of gods, and notes that escape from rebirth, that is nirvana, can only be achieved in the human realm.  

So, are we the same or are we different?  Do we only think we're different due to anthropocentric concepts, or are we indeed different due to the very fact that we can conceive of anthropocentric concepts?

George Gaylord Simpson (1902-1984) was perhaps the most influential paleontologist of the twentieth century, and a major participant in modern evolutionary synthesis.  He was an expert on extinct mammals and their intercontinental migrations, and anticipated such concepts as punctuated equilibrium.  Concerning the apparent difference between human nature and animal nature, in The Meaning of Evolution (1949), he wrote:

It is important to realize that man is an animal, but it is even more important to realize that the essence of his unique nature lies precisely in those  characteristics that are not shared with any other animal.  His place in nature and its supreme significance are not defined by his animality, but by his humanity.

Humans, it seems, are the only animal on this planet who's brains have evolved to the point where virtually all knowledge is from learning, and none is from instinct.  In The Anatomy of Human Destructiveness (1973), Erich Fromm sought to arrive at an understanding of human nature on the basis of two fundamental biological conditions that mark the emergence of man. One condition is "the ever-decreasing determination of behavior by instincts," and the other is the growth of the brain, "particularly of the neocortex." 

The process of ever-decreasing determination of behavior by instincts could be plotted on a continuum, at the zero end of which are the simplest forms of animal evolution, which have the highest degree of instinctive determination.  Everything they need to know to survive is hard-wired into their DNA, and no learning is necessary.  The degree of instinctive determination decreases with increasing evolutionary complexity, and reaches a certain level with mammals.  It decreases further in the development going up to the primates, and even here there is a significant gap between monkeys and apes.  In humans, Fromm holds, instinctive determination has reached its maximum decrease, and virtually all information necessary for survival must be learned, either by teaching or by figuring it out for ourselves.

The growth of the brain can also be plotted as a continuum.  The simplest animals with the least complex nervous structures and relatively small number of neurons are again at the zero end.  At the other end, we find humans, with our larger and more complex brain structure, especially a neocortex three times as large as even our hominid ancestors, and a truly fantastic number of interneuronal connecetions. 

To get an approximate idea of the number of potential neuronal connections in the human brain, consider that if a million neurons were each connected to only two other neurons in all possible configurations, the number of different patterns of inter-neuron connections would be 10 raised to the 2,783,000, and humans have not a million neurons, but between 19 and 23 billion neurons in the cerebral cortex.  For comparative purposes, the number of atoms in the observable universe is estimated to be about 10 to the 80.

Given all this, humans can be defined as the primate that emerged at the point of evolution where instinctive determination had reached a minimum, and development of the brain had reached a maximum.  "This combination of minimal instinctive determination and maximal brain development," Fromm notes, "has never occurred before in animal evolution and constitutes, biologically speaking, a completely new phenomenon."

So, to synthesize the scientific and the spiritual viewpoints, humans are indeed animals - apes with particularly large brains and a complex cerebral cortex, but animals that are unique on this planet not just due to anatomy, but to the loss of instinctive behavior and a self-consciousness that comes from each of us figuring everything out on our own.  This self-consciousness then makes us feel separate from other animals, from nature, from the Earth, and from each other, and leads, according to the Buddha, to suffering, and to Erich Fromm, to human destructiveness.