Catholic News Service
VATICAN CITY — Evolutionary science is still grappling with understanding how the human species, with its unique capacities for language, culture, abstract reasoning and spirituality, may have emerged from a pre-ape ancestor.
While the Catechism of the Catholic Church teaches that God, “in a plan of sheer goodness freely created man to make him share in his own blessed life,” the church still considers the scientific investigation of the origins of humanity to be a valuable contribution to human knowledge.
A counselor specializing in biofeedback therapy poses next to an illustration of the human brain in his office in Litchfield Park, Ariz., in 2012. The Pontifical Academy of Sciences is in dialogue with world-renowned scientific experts about the physical and cultural changes that occurred during mankindâs evolution, including the development of the human brain. (CNS photo/ Nancy Phelan Wiechec)
In its continuing dialogue with world-renowned scientific experts, the Pontifical Academy of Sciences brought together evolutionary biologists, paleoanthropologists, archaeologists, neuroscientists, theologians and philosophers to discuss the major physical and cultural changes that occurred during mankind’s evolution.
The working group on “The Emergence of the Human Being” met April 19-21 to discuss topics such as the mastery and use of fire, the beginning of burial and funeral rites and the emergence of language, culture and conscience.
Bishop Marcelo Sanchez Sorondo, the science academy’s chancellor, told the group that scientific truths are part of divine truth and “can help philosophy and theology understand ever more fully the status and future of the human person.”
Science investigates the external world and how it works, while religion is concerned with “the internal world of the self, which belongs to the spirit present in his being and to his relationship with God,” the bishop said.
As such, theology and philosophy “must not engage in a losing battle to establish the facts of nature that constitute the very scope of science,” he said.
“Philosophy and theology should ask themselves how they can find a meeting point with and become enriched by the naturalist viewpoint of science, starting from the assumption that the human being is already a speaking, questioning being,” he added.
How that speaking, questioning being emerged from a 5 million-year-long lineage of other primates is still a matter of much debate.
Along that evolutionary path, no species turned out to be more unlike its ancestors than the human species, said Ian Tattersall, a British-American paleontologist and former curator of the anthropology division of the American Museum of Natural History in New York City.
What’s so unusual is humans ended up with such “special and unique properties” even though they followed the same evolutionary mechanisms of genetic variation, adaptation and natural selection as all other species, he said.
That radical transformation “I think was due to culture,” he said, which changed the way early humans responded to their environment.
But how that transformation came about is still a mystery, Tattersall said.
“It’s absolutely mind-boggling: How do you go from a nonlinguistic and non-symbolic creature to a symbolic and linguistic successor?” he said.
Wolf Singer, a neurophysiologist and founding director of the Frankfurt Institute for Advanced Studies and co-director of the Brain Imaging Center in Frankfurt, Germany, said, “The neurons are the same in our (human) cerebral cortexes as they are in the mollusk.”
Groups of neurons — called modules — in the brain cortex also didn’t experience any structural changes during evolution, so “a piece of cortex from a cat is exactly the same as a piece of cortex from a human being,” he said.
But the human brain radically diverged from other species in that it experienced a rapid and dramatic increase in volume; in evolution, “more of the same makes all the difference,” Singer said.
Simple animal brains have “a fairly short path” to follow from sensory perception to processing the information to reacting to that external stimulus, he said.
However, in the bigger, more complex human brain, there is an increase in areas that “digest the output of already existing areas” of the brain.
Neurons no longer take a direct path from sensing to responding or “talking to the environment,” but they mull things over in the cerebral cortex, “talking” to other neurons and engaging in highly dynamic and large scale interactions, he said.
Singer said it’s precisely this “very autistic, self-referential system” of neurons computing each other’s output in numerous stages that allows for increasingly abstract representation, “imagery, imagination, extrapolation and model-making” and ultimately a sense of self and consciousness.
“While we know a lot about the nuts and bolts of the system,” like how neurons work and pass signals to one another, these high-level human brain functions like reasoning, long-term memory and assigning meaning are enormously complex and “resist explanation,” he said.
Brain research has implications for topics that normally concerned only philosophy, such as free will, the boundaries of mind and body, and the nature of consciousness, he said.
“All of these are questions that neurobiologists can’t avoid anymore and there are heated debates with our fellow philosophers,” he said.
Bishop Sanchez said the evolutionary laws of heredity and genetic mutation pose no conflict to the Catholic faith and offer a biological explanation for the development of species on earth.
However, he said, the beginning of the universe, “the transition from nothing to being,” is not a mutation; God is the first cause of creation and being.
“In this first transcendent origin of the human being we should in fact admit the direct participation of God,” which also occurs with each conception of human life, he said.
Human beings are not just biological creatures, but spiritual, too, whose “incorruptible soul,” he said, “requires a creative act of God.”
Msgr. Fiorenzo Facchini, who is an anthropologist and paleontologist, said evolution could have ended at the pre-human stage, but thanks to God’s will, humans emerged with the capacity for self-reflection and knowing the transcendent.
Msgr. Facchini has said that rather than picturing it as humans descending from the apes, humans ascended or rose up from the animal kingdom to a higher level, thanks to the hand of God.