Celebrate your skin colours

Hi,

This intriguing video explains why dark skinned people originate from equatorial countries such as Africa, India and South East Asia.

Melanin is a pigment molecule that give the dark colour to skin. It evolved by natural selection to cut out harmful UV radiation from the sun. It is a natural sunscreen.

However there has been much migration of light skinned people from low UV places to high UV places and vice versa. UVB light is important to make vitamin D in our skins. However, dark skinned people in the countries nearer to the poles are not getting enough of it and this will lead to serious health consequences such as bone and teeth problems, reduced immune system, mood and mental health problems.

Also dark skinned people who work at desk jobs should be aware of these health risks.

Light skinned people have less melanin and so they run the risk of skin cancer due to excessive UVB damaging their DNA. Lighter skin colour is a product of evolution by natural selection in a latitude that gets very little UVB light.






Cheers

Cell division, mitosis and meiosis, role of meiosis in sexual reproduction and natural selection in Galapagos Islands

Hi,

These two videos on the two types of cell divisions are superb. Watch and enjoy.








The function of sexual reproduction and the reason why organisms choose this form over asexual methods is explored in this video. Watch and be wowed.




Sexual reproduction, genetic variation and natural selection resulted in an explosion of phenotypes in the remote Galapagos Islands. More than 13 types of finches evolved to take advantage of the various niches available to them. This was recorded by Charles Darwin, the first scientist study these birds and the father of the theory of evolution.





Cheers