Top 10 changes happened to humans in past 100k years| How did we evolve?| Human Evolution

TOP 10 CHANGES THAT HAPPENED TO HUMANS IN THE PAST 100K YEARS

Perspective is a wonderful thing. Sometimes you can only truly appreciate something by making all the random thing comparisons with slightly altered parameters, for example of location, age, or time.
Today we have satellite images that let us see how the Earth’s surface changes from year to year. But what about our case, Yeah the answer is always within us because we are the ones who are carrying the DNAs of our ancestors in our blood. We have undergone numerous changes since our species first evolved. Some changes were universal whereas others were more regional in effect. Regional populations have also evolved different physical and genetic characteristics in response to varying climates and lifestyles.

One year ago in his speech at the Oxford University Union, the legendary Stephen Hawking proclaimed that humanity can only survive for another 1,000 year

Well before that happens, let’s find out how evolution has caught up with us in the past 1000 years and above 

1.  Body Appearance

                        Our ancestors were like longer, stronger and larger boned a 100,000 years ago. The decrease has been gradual but has been the most noticeable in the last 10,000 years. However, there has been some slight reversal to this trend in the last few centuries as the average height has started to increase.

What about now- We are generally much shorter, lighter and smalled boned than our ancestors. Popular answers for why that happened comes down to 

the genetic interactions, environment, and lifestyle practices of different diets and technology.

 

    2. Height variations

                             10,000 years ago there happened a dramatic reduction in the size of humans. Many scientists think that this reduction was influenced by global climatic change and the adoption of agriculture. Agricultural communities suffered from malnutrition as a result of failed crops and a more restricted diet. Furthermore, a close association with domestic livestock introduced new diseases into human populations.

     100,000 ago - 5ft 4 inches  , Present - 5 ft 9 inches

       3.Smaller brains

                              

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 centimeters less than when our species first appeared.

100,000 years ago: average brain size: 1500cc                                      Today: average brain size: 1350c

     

 

   4.Smaller teeth and jaws

                          The trend toward smaller jaws and teeth that were 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. lol, so we are gonna miss some 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. However, 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.

      5.Developing physical diversity: All one species but looking different

Humans today show an enormous diversity in appearance, however, this diversity was not apparent in early Homo sapiens. Early members of our species lived in Africa and had evolved physical characteristics that were similar to each other to survive in that climate. When humans started to spread to different parts of the world about 100,000 years ago, they encountered a variety of different climatic conditions and evolved new physical adaptations more suitable to those new climates.

Recent DNA studies (since 2007) confirm that genetic traits have changed or adapted to new environments during this time. In fact, the rate of change of DNA, and thus the rate of evolution, has accelerated in the last 40,000 years.  Still, areas of the human genome seem to be undergoing selection for things such as disease and skin color.

Physical characteristics such as skin and eye color, hair type, and color and body shape are determined by genetics, but can also be influenced by the environment. Over long periods, the environment will act on the genes to develop particular characteristics within a population.

 

   6.Body build

                           Short, stocky builds are typical of humans living in cold climates. The reduced surface area compared to weight allows more body heat to be retained. A thin, long-limbed build is typical of humans in hot regions. The larger skin surface compared to weight allows for body heat to be lost more easily. It clearly explains the way our body tends to adapt to our survival.

    7.Skin color

                             A range of skin colors evolved at different times, in different populations, as humans spread across the globe. Lighter skin allows the penetration of the sun’s UV rays. These rays help the body to synthesize vitamin D. Darker skin protects the body from absorbing too many UV rays. This can cause cancer or destroy important vitamins and minerals,                                                    

        Human skin tone varies as a global gradient, with the darkest populations around the equator and the lightest ones near the poles. Put simply, the dark complexion is advantageous in sunnier places, whereas fair skin fairs better in regions with less sun.

That may seem obvious, considering the suffering that ensues when pale folks visit the beach. But actually, humanity’s color gradient probably has little to do with sunburn or even skin cancer. 

Instead, the complexion has been shaped by conflicting demands from two essential vitamins: folate and vitamin D. Folate is destroyed by the sun’s ultraviolet (UV) radiation. Whereas the skin kickstarts the production of vitamin D after being exposed to those same rays.

            8.Noses

                        People living in hot, humid climates tend to have broad, flat noses that allow inhaled air to be moistened and the moisture in exhaled air to be retained.          -People living in hot, dry climates typically have narrowed, projecting noses. This type of nose reduces the amount of water that is lost from the lungs during breathing. 
                                                                          -People living in cold, dry climates generally have smaller, longer and narrower noses. This type of nose moistens and warms the incoming air.

9.Hair

                   - Tight, curly hair keeps the hair off the neck and exposes more areas of the scalp than straight hair. This helps with cooling and evaporation of sweat.   
                                                                                                      -Straight hair is common in people living in colder climates as it keeps the neck and heads warm. Straight hair also allows cold moisture to run off the scalp more easily.

10.Face shape

                            - Humans also have adapted to extreme cold by retaining layers of fat on their faces for additional warmth.                                        -Populations in northern Asia and the Arctic tend to have broad, flat faces as these reduce the effects of frostbite.

2 more of those interesting changes :)

           11. Mouth shape:                                                                       

                                  Thick lips have a larger surface area to help evaporate moisture and cool the body. The larger surface also allows cooling by moistening the lips.

12. Eyes:                                                                                                   

         The epicanthic (skin fold of the upper eyelid) fold common among Northern and Eastern Asian populations is an adaptation for protecting the eye from the hard-driving snow typical in these regions, and also to reduce snow glare.                                                                                                 -Blue eyes are better adapted for vision in regions where there is reduced light, as they let in more light than darker colored eyes.

So that was the 10 Changes that happened to humans over past years
Comment down your thoughts below