The inheritance: from parents to children
The program will visit the International Bird Fair of Valls, where there are exposed hundreds of different breeds of pigeons. We will understand how breeders obtained these huge diversity. We will also understand what is genetic recombination, the laws of inheritance and mutations. And finally we will see how all this knowledge is integrated to reconstruct the tree of humanity.
Inheritance is what our parents give us: money, property, debts… and all our biological traits. The set of all these characters is a unique and unrepeatable individual, and the information to “build” him is inherited from an ovule and sperm united in fertilization. Surprisingly, a person does not produce two sperm or two ovules equal throughout his life. During the formation of sex cells, chromosomes get paired and exchange information in a process called “genetic recombination”. This blend of information is a key to explain why inheritance is so variable. There is, however, a few exceptions to this rule: the Y chromosome, which is inherited virtually without recombination from the father, and mitochondrial DNA, which is inherited maternally full. Studying mutations lead to develop a family tree for humanity of tens of thousands of years. The results show that all modern humans proceed from a common ancestor appeared in Africa about 100,000 years ago. Our history is marked by a succession of migrations from which were progressively replacing the five continents and went differentiating into current peoples.