People grow taller, fatter and live longer than ever in stories. And all these changes have occurred over the last century, scientists say. However, it is not only a matter of evolution, since one a century is not enough for such changes.
Scientists believe that most of the transformations that occurred during such a period of time is the body’s response to changes conditions such as improved nutrition, health and hygiene. Here are the main changes that have occurred to people over the last century.
Human growth
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A recent study found that in developed countries people taller and the highest average height in the world – 1.85 cm observed in the Netherlands. Although the Americans were the tallest people in the world during the Second World War (1.77 cm), towards the end 20th century growth indicators have stalled.
And although in many countries average growth increased, it was not uniform. In some countries affected by disease, war and other problems, average growth declined from time to time.
Researchers believe that this suggests that negative factors such as hunger or epidemics affect next generations, and it takes about 5 generations to overcome these factors.
Recent studies have revealed a relationship between growth and quality of life, and tall people are perceived as more smart and influential.
People get fatter
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Since the 1970s, researchers have studied the growth dynamics of Mayan and their families living in Guatemala, Mexico and the USA. When maya moved to the USA, they became 11.4 cm higher than their peers in Guatemala and Mexico. However, their weight also increased, and they were more often obese.
The world also has a tendency to increase weight. So in 2013 29 percent of the world’s population was overweight or obesity.
The question of why people get fatter is a matter of scientific disputes. Some researchers believe that overeating is to blame. and lack of physical activity. But there is also a theory that Genetics play a role here, as well as viruses that are associated with obese. Contrary to popular belief, many studies found a link between being overweight and poverty.
Some researchers suggest that this trend associated with epigenetics or heritable changes that affect on how the body stores excess energy from food.
For example, if your mother and grandmother endured hard times, it is passed on to the next generation, and when good times, the body tries to store additional energy in the form fat.
Early puberty
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In many countries, children begin to mature earlier, especially girls. Many studies have shown that over the past half century the age when girls reach puberty has declined.
So a study in the United States showed that age menarche fell by 0.3 years in a decade since the mid-1800s, when the first menstruation occurred at 17, until the 1960s.
Studies also indicate that there is a connection between excessive fullness and early onset of puberty, and girls with a high body mass index reach puberty in more early age.
This can have negative health consequences, as studies have shown that early maturation is associated with development hypertension and diabetes at a later age.
There are social consequences. In some cultures, puberty is considered to be quite old for marriage, which means that it has fewer opportunities to continue education or career.
Human longevity and its negative consequences
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People now live longer than ever. According to who life expectancy worldwide has risen from 30 years in the 20th century up to 70 years in 2012. Experts predict that the global life expectancy of women born in 2030, grow up to 85 years.
The increase in life expectancy is associated with achievements in medicine, sanitation and access to clean water.
However, although these factors have reduced the mortality rate from infectious diseases, death rate from degenerative diseases such as Alzheimer’s disease, heart disease and cancer has grown.
In other words, people began to live longer, but die from others. diseases than in the past. Growth of autoimmune diseases such like multiple sclerosis and type 1 diabetes, some scientists associate with improved hygiene. That is, when the body exposed to too few microbes the immune system reacts too sharply even to the most harmless microbes.
Human Development in the Future
What awaits people in the future, given how quickly our world is changing technology?
There are some concerns that the future of evolution will be determined by genetic engineering. Bionic implants, nanotechnology and new drugs can extend life even further person.
Some scientists believe that we can achieve immortality with using technology in the next 30 years. Although it sounds like a scientific fiction, it’s clear that people are developing rapidly and technology have a big impact on this.
Time Life Mexico USA Maya Civilization Evolution
