Topic: Biology

Scientists used to think that genetics only played a small part in how long we live. But new research shows that our genes might be responsible for half of the variation in human lifespan.

For many years, scientists believed that genetics played only a modest role in determining how long we live. They thought that environmental factors and lifestyle choices were much more important. However, a new study from the Weizmann Institute of Science challenges this view.

The researchers analyzed data from three large twin studies from Sweden and Denmark. What's unique about these studies is that they included twins who were raised apart. This allowed them to separate genetic influences from environmental ones.

The team found that earlier estimates were skewed by something called extrinsic mortality. This includes deaths caused by accidents, infections, and other external factors. By using mathematical models and simulations of virtual twins, the researchers were able to filter out these outside influences and uncover a much stronger genetic signal than previously recognized.

This study's findings align with what we see in other complex human traits and animal studies. For example, the risk of dying from dementia shows a heritability of about 70% up to age 80 - far higher than that of cancer or heart disease.

These results could reshape how scientists think about aging and longevity. If genetics plays a larger role than assumed, it strengthens the case for searching for specific genes that influence lifespan.

Prof. Uri Alon's research is supported by several institutions, including the Sagol Institute for Longevity Research and the Knell Family Institute for Artificial Intelligence.

Why It Matters

This study matters because it could lead to a better understanding of how our genes affect our lifespan. This knowledge could be used to develop new treatments or therapies that help us live longer, healthier lives.

Key Facts

• The study found that genetics might account for roughly half of the variation in human lifespan.
• Previous estimates suggested that inherited factors explained about 20-25% of lifespan differences.
• The researchers used data from three large twin studies from Sweden and Denmark to reach their conclusion.
• The team created a new analytical approach using mathematical models and simulations of virtual twins to distinguish deaths caused by aging from those due to external factors.
• The study's findings align with what we see in other complex human traits and animal studies.

Key Terms

extrinsic mortality

deaths caused by accidents, infections, or environmental factors

Implications

This study matters because it could lead to a better understanding of how our genes affect our lifespan. This knowledge could be used to develop new treatments or therapies that help us live longer, healthier lives.