Haritha,Subject Matter Expert at Edumarz
Solution:Humans look different from each other in size, colour and appearance due to variations.Variations present in humans are responsible for the appearance of different traits.Genetically, all humans belong to a single species.
Studying fossils and determining DNA sequences is important for studying human evolution
Human skin colour is used as the most common way of identifying different human races
All humans belong to the same species
Study of the evolution of humans indicates the evolution of humans from African origin
Humans also contain the same number of chromosomes
All humans show similarities in their DNA sequences
Human skin colour
The pigment responsible for skin colour in humans is termed melanin.This pigment is present in the epidermis and is formed by the melanocytes.It is present in two forms: pheomelanin and eumelanin.In world population human skin colour is depends on the geographical region,presence of ultraviolet radiation etc.People who live close to the equator have dark skin to protect them from harmful ultraviolet radiation from the sun. People living at higher altitudes have light-colored skin.
source:https://unsplash.com/s/photos/human-skin-colour
Eumelanin
Eumelanin gives dark colour to the skin and appears in two forms: brown and black.
Pheomelanin
Pink coloration is provided by the pigment pheomelanin in areas such as the lips.