10 human body mutations after their existence on the Earth

10. Eyes color

The eyes certainly are windows to the soul, and if you know anything about eyes or windows, you are aware that they come in many different tints and colors. Most commonly, you see brown, blue, or hazel eyes when you look at the people around you, but some people, whether it be luck or a medical condition, wind up with a really cool and rare eye color. What are the rarest eye colors and how do they happen? Originally, we all had brown eyes. But a genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a ‘switch,’ which literally ‘turned off’ the ability to produce brown eyes. It is believed that the human race started out having brown eyes and due to genetic mutations, other colors came about. Perhaps this is why brown is the most common (but no less beautiful). So many people who have perfect vision choose to wear contact lenses just to have a rare eye color so if you made the cut, consider yourself lucky!

---

9. Human height

On average, we’re taller than our predecessors’ thanks to better nutrition and health, over the past century adult height has changed substantially and unevenly in the world’s countries. People from central and southern Europe, as well as East Asia, grew taller in the last 100 years. Meanwhile there was little gain in height for people from sub-Saharan African and South Asian nations. A few countries experienced decreases in their average adult height after years of gain. Researchers found that Dutch men, at 182.5 centimetres (about 6 feet), and Latvian women, at 170 centimetres (5 feet 7 inches), are the tallest in the world. Men from Timor-Leste, at 160 centimeters (5 feet 3 inches), and Guatemalan women, at 149 centimeters (4 feet 11 inches), are considered the shortest.

---

8. Bones are stronger now

We’re definitely heavier than we’ve ever been — about two-thirds of adults are now overweight or obese — but our bones aren’t as strong as those of our forebears. In fact, they’re not even as strong as the bones of our closest living relatives, the chimps. What caused this thinning of modern man’s skeleton? We could blame our shift from hunter-gatherer lifestyles to a more sedentary way of life, and the ensuing change in our diet. Or we could place the blame on modernization, pointing the finger at buggies, cars, planes, trains and other technological advances for keeping us off our feet and less mobile. Using bone samples from 1,842 people collected from all over Europe from the Paleolithic period (11,000 to 33,000 years ago) to the 20^th century, they found that the biggest shift in bone strength came with the move from a hunter-gatherer way of living to an agricultural one. The move to more settled and permanent living arrangements had a dramatic effect on changes in the human skeleton. Since that time, the bones of Homo sapiens have remained relatively similar.

---

7. Smaller teeth and jaws

The trend toward smaller jaws and teeth that was seen in our ancestors has continued in our own species. In fact, some people today do not have enough space in their jaws to fit their 3rd molars or wisdom teeth. Overall, these changes have occurred in proportion with a decrease in body size. However, over the last 10,000 years dietary changes and technology have played a major role. A decrease in size has occurred in the jaws and teeth of Homo sapiens over the last 30,000 years. Nevertheless, there has been a very slight reversal in this trend in the last century as teeth have increased in size. This is partly related to the introduction of fluoride, which thickens dental enamel, so making teeth a little larger.

[postads]

---

6. Smaller Brains than our ancestors

For the last two million years there has been a trend toward a bigger brain that has affected many species in our family tree. This trend has seen a reversal in our own species and our brains are now the smallest they have been at any time in the past 100,000 years. Most of this decrease occurred in the last 6,000 years. In part, this is related to a decrease in body size that also occurred during this period, however, other factors are probably also involved.Our brains now average about 100-150 cubic centimetres less than when our species first appeared.

• 100,000 years ago: average brain size: 1500cc
• 12,000 years ago: average brain size: 1450cc
• Today: average brain size: 1350cc

---

5. Earlier puberty

In many countries, children mature earlier these days. The age of menarche in the United States fell about 0.3 years per decade from the mid-1800s (when girls had their first menstrual period, on average, at age 17) until the 1960s, which also suggested better nutrition, health and economic conditions often play roles in lowering the age of menarche. Today the average age of menarche in U.S. girls is about 12.8 to 12.9 years, according to Bogin. The onset of puberty, however, is defined as the time when a girl’s breasts start to develop. In the United States, it is 9.7 years for white girls, 8.8 years for black girls, 9.3 years for Hispanic girls and 9.7 years for Asian girls. Studies have also pointed to a link between obesity and early puberty, as girls with higher body mass indexes (BMIs) are generally more likely to reach puberty at younger ages.

---

4. Sperm Count

The total male sperm count has decreased by about half since the 1950s, according to a large study that came out in the early ’90s, which showed sperm counts had decreased from 113 million sperm per mL to 66 million sperm per mL over the course of 52 years. Though that study was critiqued, an analysis from a decade later reached similar conclusions, and the World Health Organization even lowered the numbers for what’s considered a “normal” sperm count in 2010, from 20 million per mL to 15 million sperm per mL. Steroids and cocaine may make for a crazy night out, but they’re terrible for sperm. Cocaine use, in particular, is surprisingly prevalent and closely associated with both low sperm counts and poor sperm motility. Laptops are also a sperm killer — not because of radiation but because of heat. Testicles are outside the body in order to keep sperm slightly cooler than your body temperature.

---

3. Two Legs, Long Arms; Moving Around in Diverse Habitats

By about 4 million years ago, the genus Australopithecus had evolved a skeletal form that enabled adjustment to changes in moisture and vegetation. The best current example of adaptability in Australopithecus is apparent in the skeleton known as Lucy, which represents Au. afarensis. Lucy’s 3.18-million-year-old skeleton has a humanlike hip bone and knee joints coupled with long apelike arms, longer grasping fingers than in humans, and flexible feet for walking or climbing. This combination of features, which appears to have characterized Australopithecus for nearly 2 million years and possibly older hominins, afforded an ability to move around in diverse habitats by changing the degree of reliance on terrestrial walking and arboreal climbing. This flexibility may also have characterized earlier hominins such as Ardipithecus ramidus.

---

2. Women in ancient times

Art from this era of ancient Egypt tells us that long, braided hair was an important aspect of female beauty. Braids framed a symmetrical face, and women wore thick black kohl around their eyes. Women are shown as slender, with high waists and slim shoulders. Chinese society has been patriarchal since ancient times, which as a result minimized women’s roles and rights in society. During the Han Dynasty period of Chinese history, feminine beauty meant delicate, slim bodies with a radiating inner glow. Women were expected to have pale skin, long black hair, red lips, white teeth, and a graceful walk with small feet. Small feet were an aspect of Chinese beauty that would continue for hundreds of years. Women in the 2000s have been bombarded with so many different requirements of attractiveness. Women should be skinny, but healthy; they should have large breasts and a large butt, but a flat stomach. To achieve all these, women have increasingly been turning to plastic surgery. Studies have shown that butt augmentation procedures, patients under the age of 30, and patients citing selfies as a reason for plastic surgery have all increased in recent years.

---

1.Body Hair disappeared

One of the most distinctive evolutionary changes as humans parted company from their fellow apes was their loss of body hair. But why and when human body hair disappeared, together with the matter of when people first started to wear clothes, are questions that have long lain beyond the reach of archaeology and palaeontology. We were naked for more than a million years before we started wearing clothes. Humans lost their body hair,  to free themselves of external parasites that infest fur – blood-sucking lice, fleas and ticks and the diseases they spread.

[postads]

---

Also Read: HEIGHT- KNOW HOW IT CHANGES AND AFFECTS YOUR LIFESTYLE?