Wilhelm Weinberg facts for kids

Wilhelm Weinberg (born in 1862, died in 1937) was a German doctor who became a very important geneticist. He was a specialist in helping women with pregnancy and childbirth (an obstetrician) and women's health (a gynecologist). He worked in Stuttgart. In 1908, he shared an idea that is now known as the Hardy–Weinberg law. Weinberg was also the first to explain something called ascertainment bias in genetics.

About Wilhelm Weinberg

Wilhelm Weinberg was born in Stuttgart, Germany. He studied medicine at universities in Tübingen and Munich. He became a doctor in 1886. In 1889, he went back to Stuttgart. There, he had a large medical practice helping women with their health and babies. He worked there until he retired a few years before he died in 1937. Much of his time was spent studying genetics. He especially looked at how the rules of inheritance work in large groups of people, called populations.

The Hardy–Weinberg Law

Weinberg came up with the idea of genetic balance on his own. This was separate from a British mathematician named G.H. Hardy. Weinberg shared his ideas in a talk on January 13, 1908. This was about six months before Hardy's work was published in English. Weinberg's talk was printed later that year.

For more than 35 years, people in English-speaking countries didn't know about Weinberg's important work. Later, a German geneticist named Curt Stern moved to the United States. He wrote a short paper in a science magazine called Science. He pointed out that Weinberg's explanation was both earlier and more complete than Hardy's.

Understanding Ascertainment Bias

Weinberg was a pioneer in studying twins. He created ways to study how traits (like eye color or height) vary. He wanted to figure out how much of this variation came from genes and how much came from the environment. While doing this, he realized that something called ascertainment bias was affecting his results. He then found ways to fix this problem.

Weinberg noticed that in studies of certain genetic diseases, the number of people with two identical genes (called homozygotes) was often higher than expected. He explained that this was because of ascertainment bias. For example, when studying albino children, he saw that some families with parents who carried the gene for albinism might not have an albino child by chance. He realized that many such families were not being counted in studies. He then showed how to correct the results to get the expected numbers.

He solved several confusing problems caused by ascertainment bias. For instance, he explained why parents, as a group, seem to have more children than their own children do. This is because children can only come from parents who were able to have children in the first place.

He also realized that ascertainment bias explained something called genetic anticipation. This is when a genetic disease seems to start earlier in life and be more severe in later generations. Weinberg understood that this happened because those later generations came from a selected group of earlier carriers who had successfully had children.

Weinberg also made other important contributions to the study of genetics using statistics. He was the first to estimate how often twins are born. He knew that identical twins are always the same sex. However, non-identical twins can be either the same sex or different sexes. Using this, Weinberg created a formula to estimate how many identical and non-identical twins there were. He also estimated that the chance of having twins itself was not strongly passed down through genes (its heritability was close to zero).

See also

In Spanish: Wilhelm Weinberg para niños