Human Evolution Evident In Small Quebec Town

Scientists have argued for decades that human evolution has stopped. Advances in technology, sanitation, medicine, and community standards have all but negated natural selection. The sick and infirm are living just as long, in many cases, as the perpetually healthy. Food, water, and shelter are more accessible than ever before. Fortunately for Darwin, a group of geneticists from the University of Quebec have uncovered evidence of biological evolution in humans within the last two hundreds years; a relative blink in evolutionary science, and within our contemporary frame of reference.

In the small French-Canadian town of Ile aux Coudres in the Gulf of St. Lawrence, UQ geneticist Emmanuel Milot and his colleagues found a pattern of rapid genetic changes among women. From documents kept by the town’s catholic church, researchers found that between 1800 and 1940 women gave birth at steadily earlier ages. The average age of first-time mothers, an indicator of fertility, dropped from 26 to 22. According to Milot, cultural and environmental factors don’t fit in explaining this drop in age of maternity, leaving only biological evolution. “Our study supports the idea that humans are still evolving,” Milot toled Wired.com, “It also demonstrates that microevolution is detectable over just a few generations.”

The idea that human biology could be changing in an evolutionary sense within a few generations has received skeptical attention with previous claims by other scientists. Decades ago the assertion that the ever increasing average height of modern people was due to some kind of rapid evolutionary progression was easily dismissed. We’re taller because we eat better and with more nutrition our bodies grow larger, faster. The truth is that many of the biological pressures of natural selection are largely absent in the developed world. Milot’s finding challenge that idea that a species even needs those pressures to evolve…that it may simply be part of an organisms natural progression.

However, Harvey Harpending, a geneticist with the University of Utah, says that genetic changes are often dismissed as environmental changes, with imperial data being correlated to circumstances around the studied population. “Here and elsewhere we are discovering that changes are due to genetic changes,” Harpending says, “not changes in the environment.” He also acknowledged that he is inclined to believe the claims of Milot’s study since they are “empirically derived within the genetics community.”

Although culture and environmental factors may attest for some of the deviation in Milot’s study, as the town’s women gave birth progressively earlier, Milot points out that even culture can effect natural selection. “Culture shapes the selection pressures acting on the age at first birth and the reproductive history of women in this population,” he said. “The cultural context was favoring the selection of some genes.”