Title: Humans are still evolving: 3 examples of recent adaptations
Headings: Humans are still evolving: 3 examples of recent adaptations
Humans are still evolving: 3 examples of recent adaptations
3. We are cooling down
2. Our genes are constantly changing
1. Our bones are becoming lighter

Content: The team analyzed medical records from the past 200 years, which included temperature measurements. They found that, averaged together, the records indicate that there has been a gradual decrease in body temperature of 0.05 degrees Fahrenheit every decade. Julie Parsonnet, the study’s senior author and professor of medicine at Stanford University, tells Inverse that this cooling trend is likely linked to a population-wide decline in inflammation, and improved standards of living. Many of the infectious diseases that were common in the 19th century would have caused chronic inflammation, which in turn burns calories and increases a person’s metabolic rate — upping their internal temperature, she says. Because people aren’t battling these diseases at the same rate anymore, that change would be reflected in body temperature, she theorizes. The average temperature of the human body has changed. Getty Images
Living comfortably indoors may also have profoundly impacted humans. Unlike our ancestors, “we don’t have to work terribly hard to be at physiologically neutral temperatures that don’t tax our metabolism," Parsonnet says. While healthier living likely drove this cooling trend, it’s unclear whether having a lower temperature necessarily also improves our health. The shift appears to mean that we need about 150 calories fewer per day to maintain our basic metabolic needs than we did in the past, she says.