variations and distribution in body part sizes around the world


  Variation and distribution in body parts around the world
Distribution of body size

  1. Europeans possess the largest average body size. It is in Europe where Bergman’s rule is majorly vividly applied. The largest Europeans are from the far north, and the people farther south of Europe are smaller.
  2. Africans have both the world’s tallest and the world’s smallest people. The Nuer, Masai, Watusi, and related peoples of East Central Africa are the world’s tallest and among the world’s largest. The Pygmies of congo-West Central Africa and the Khoisan of Southern Africa are among the world’s smallest.

  3. Asians and Native Americans normally fall in the middle ranges. Just a few populations could be taken as large e.g- the Samoans.

Body weight

The majority of the variation in body weight of humans can be classified into linear build and lateral build.

The extreme linear build is found in the earlier mentioned tall peoples of East Central Africa. These people are very tall and slender. The chests, shoulders, and hips are extremely narrow – the narrowest in the world for their height. Their limbs are very long, particularly the legs.

On the other hand, the highly lateral build is found in a few Asian and

Native Americans cultures-the Eskimos, Japanese, Samoans, Apache, and many South American Indians exhibit lateral build. A few Caucasoid groups as well exhibit lateral build, particularly the peoples of northern Europe.

Laterally built people have the tendency to develop long and broad trunks, with wider chests, shoulders and hips. The widest hips of all can be seen among Europeans. Their limb bones tend to be short and the legs make less of a contribution to overall height.

Hair

A lot of things about hair are variable.

  1. Hair Color:

Generally, dark hair goes with dark skin and light hair goes with light skin.

You can possess dark hair with light skin, but it is rare to possess light hair with dark skin. People can as well different color of hair on different parts of their body.

Blond hair has little melanin and black hair and in reality very dark

Brown has a lot of melanin. Skin melanins are always brown while hair melanin can be either brown or red. Generally, brown melanin is stronger in color than red melanin and can cover it.

The distribution of hair color is almost completely a European feature, with the majority of the rest of the world’s people possessing dark brown hair.

The farther north in Europe the more likely the hair is to be blond. The farther west in Europe you go; the greater the tendency of the hair to be red.

  1. Hair curvature

The degree of curvature of the hair can be divided into 3 categories: straight, wavy, and curly. The shape of the hair follicle determines the curvature of the hair. Round follicles give rise to straight hair, oval follicles give rise to wavy hair, and disk-shaped follicles give rise to curly hair.

Straight hair is seen all over the majority of world population, including the Americas, Asia, and parts of Europe. Europe has the greatest hair variation in hair curvature. It ranges from straight to very wavy. The Middle East and North Africa have a lot of wavy and a few curly heads.

Subsaharan Africans range from curly to very curly. The curliest hair is found in the Khoisans whose hair is often so tightly curled that it is called peppercorn hair because it looks like pepper corns placed on their heads.

  1. Hair length:

A lot of people are amazed that there is as well genetic variation in hair length. Just like in other mammals, every one of us has a particular hair length outside which the hair plainly won’t grow. Hair length is longest in people who have round follicles, for the fact that round follicles appear to hold the hair better.

Eyes:

Eye color and type show another remarkable range of variation. The colored part of the eye-the iris surrounds the pupil of the eye and possesses muscles which dilate and contract the pupil. The iris has a lot of layers; two among the layers contain melanin. All eye melanin is brown.

The variation in eye color is as a result of the pigmentation of the exterior layer of the iris. The iris may or may not be pigmented.

View also
PHYSIOLOGICAL VARIATIONS

EXAMPLES OF CONTINUOUS AND
DISCONTINUOUS VARIATIONS

Ears:

Ears are very different in size, size of the ear lobe, protrusion, and whether the ear lobe is free or attached.

The African type of ear is a relatively small, non-protruding ear with small free lobes. The American and Indian type is the other extreme in average size and protrusion, and Asians typically have the maximum frequency of attached ear lobes. Europeans are the most variable and have ears that span the whole range of human variation.

Lips:

Possessing different types of lips is exceptionally a human characteristic. Every human being has lips, which differ basically in the extent to which they are rolled up to expose the pink membranous portion.

This observable fact is known as lip eversion. Everted lips appear to have a slight capacity to cool the body due to the fact that capillaries run very close to the surface of the lips, and the slight moistness of the lips assists to cool the body through evaporation.

The majority of everted lips are found on the faces of some Africans and the least everted lips on the faces of some Europeans.

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