WHAT COLOR ARE YOU?

[Music] [Applause] [Music] [Applause] [Music] so [Music] [Applause] [Music] [Applause] [Music] [Applause] [Music] people look different from one another do animals one of the ways in which we all differ is color come on [Music] hey look at that imagine a world in which everything were the same color [Music] rather dull isn't it but color is part of our world just as there are thousands of shades of birds so there are thousands of shades of people [Music] scientists usually divide people into three main groups based largely on skin color the negro or black race the or yellow race [Music] and the caucasian or white race [Music] actually the labels black white and yellow are exaggerations a member of the yellow race isn't really yellow any more than a member of the black race is really black and white is not really the color of a white boy [Music] yeah let's go [Applause] [Music] [Applause] although people may look very different everyone's skin color is made of the same few ingredients the chief one is a brown pigment we look different because of the amount of pigment we each have in our skin eyes and hair [Applause] how much money you got imagine that these pennies are particles of brown skin pigment if you have a few of them and they are far apart your skin will be of a light color if you have more your skin will look somewhat darker and if you have many particles of pigment arranged closely together your skin will look almost solidly brown i've been all pennies although our skin may not look alike we're all really colored from the same material uh what determines the color you are skin color is inherited when a baby is conceived he receives 23 chromosomes from each parent the chromosomes which determine a person's physical traits are made up of thousands of tiny chemical structures called genes the genes largely determine what we will look like including the color of eyes and hair some genes also determine skin color the darkest negroes have the most active brown pigment genes the lightest whites have genes which produce the least brown pigment when parents are of different colors the children's skin generally tends to be somewhere in between and since most parents are not exactly the same color children of all shades are constantly being created basically in the way our bodies are constructed we are all the same though superficially we may look quite different [Applause] [Laughter] compare an african oryx and a zebra they not only look different they are different they belong to different species and cannot mate even a dromedary and a bacterian camel though they look very similar can never be more to each other than neighbors in a zoo [Music] take a walrus and a seal they swim in the same water yet they are so basically different from each other that they cannot produce offspring but almost any pair of human beings anywhere in the world no matter how varied their color and appearance can produce children for we are all members of the same species regardless of where we live and what we look like we have all descended from a common ancestor if we all have the same ancestor you may wonder why we don't all look alike today [Applause] part of the answer may be seen here at the zoo [Music] hey where's brian i don't know i just saw him come on we better he is [Music] [Applause] what happened to you i saw this white wolf white wolf i thought it was too gray yeah well the zookeeper saw me looking at him and told me this was a rare breed at first there were just a few but now there are a lot of them the white wolf is the result of a mutation a change in heredity occasionally a change occurs in a gene causing a new trait to appear in this case a white wolf was born to gray wolf parents the silver fox is another mutation he turned up one day among a family of red foxes just a chance mutation but sometimes changes that occur by chance turn out to serve a useful purpose take the bottlenose dolphin for instance scientists believe that a long time ago dolphins probably lived on land they are warm-blooded air-breathing mammals their intelligence is surpassed only by that of man [Applause] today however they live only in water and look a great deal like fish through chance mutations dolphins must have developed flippers where their front legs used to be and a powerful tail better suited to getting around in water than hind legs unlike fish who have scales dolphins have skin which through millions of years has adapted to the water so in the case of dolphins chance mutations served a practical purpose and were retained [Music] [Applause] [Music] in the case of people scientists tell us mutations must also have occurred over a long period of time the result was different races so based on all available evidence here is the way many scientists see the development of races the first recognizable men developed somewhere in africa between one and two million years ago since man lived in the tropics he was quite probably dark-skinned and dark-haired the coloring that would have given him the most natural advantages it is from man very much like this that we are all descended from africa man's increasing population spread throughout asia and europe in time mutations occurred and where advantageous they were retained probably a chance mutation produced the first light-skinned man in the north such coloring was an advantage allowing the weak sun to penetrate his skin more easily to produce needed vitamin d therefore the white race became centered generally in the north in africa on the other hand dark skin gave natural protection against the burning sun here the negro race became concentrated meanwhile in eastern asia the people developed perhaps the change in skin color from brown to yellow was a random mutation other racial changes however proved an advantage in the colder climates such as well padded cheeks and stockier bodies to conserve body heat long ago a land bridge existed between asia and the americas the early mongoloids crossed it and spread over the continents of the western hemisphere this explains how the eskimos the north american and the south american indians belong to the race so from a common ancestor in africa over a long period of time all the human races developed if people gradually changed once they found themselves in a new climate you may wonder if they are not still changing today why for instance hasn't the american negro skin turned lighter now that he is in a colder place than africa for one thing past changes took thousands of years and there hasn't been enough time for major new changes to be noticed but also as man has learned to control his environment he himself has had no need to change a million years ago if you could not tolerate the weather you might die today you can put on a raincoat go inside start a heater or an air conditioner scientists reason that races will probably continue to be of different colors for a very long time scientists also know that these differences are only skin deep the brains muscles and bones of all races are pretty much the same people may look different but all over the world we share a common ancestor a common physical makeup common human [Music] experiences [Music] huh [Music] you