One scientist at the Calico laboratory, which deals with the mysteries of death and longevity, did not want to study the genes of roundworms and study the group of naked mole rats living in the laboratory. From the very beginning, he wanted to find an answer to a larger question: how important do genes play in determining life expectancy? The Wyerd magazine explains the results of this study.
In 2013, Google developer and co-founder Larry Page announced the creation of a new company, Alphabet, to tackle the mysteries of death and longevity. Since then, a longevity laboratory called Calico - short for California Life Company - has been trying to study the biology of aging in great detail in the hope of conquering death one day. The company, whose activities are shrouded in a veil of secrecy, has released very few details about what it is doing in its laboratory in Silicon Valley, but some hints still appeared. One of the first specialists invited to this company was the famous geneticist Cynthia Kenyon,a research scientist at the University of California at San Francisco who, 20 years ago, managed to double the lifespan of roundworms by changing just one "letter" in their DNA.
Starting at Calico, Kenyon brought in a PhD in bioinformatics from the University of California, San Francisco named Graham Ruby. He didn't want to study the genes of roundworms and study the group of naked mole rats living in the laboratory. From the outset, he wanted to find an answer to a broader question: how important do genes play in determining life expectancy? Other scientists before him have already tried to ask this question and have received conflicting results. Much more data had to be collected to clear things up. Therefore, Calico turned to the largest family history database in the world - the genealogy company Ancestry.
In 2015, the two companies signed a research collaboration agreement to investigate whether longevity is indeed a hereditary trait. Ruby spearheaded an assault on the giant Ensestri family tree forest. After examining the family histories of over 400 million people who have lived and died in Europe and America since 1800, he concluded that while longevity is indeed a family trait in some cases, a person's DNA has much less of an impact on how long they live. than previously thought. The Ruby study, published Tuesday November 6 in Genetics, is the first public release of the results of a joint project between the two companies, which ended in July and the details of which remain under wraps.
“The heritability of longevity among humans is probably less than 7%,” says Ruby. Earlier estimates of the extent to which genes determine the difference in life expectancy ranged from 15% to 30%. What did Ruby discover that his predecessors missed? How often people in love disprove the old adage about "opposites that attract."
It turns out that representatives of all generations are much more likely to choose partners with the same life expectancy than could be predicted, guided by the theory of chance. This phenomenon - "assortative mating" - may be based on genetics or some socio-cultural traits - or both at once. For example, you can choose a partner who also has curly hair, and if the characteristic of curly hair is somehow related to longevity, this will increase the chances that you will pass on the longevity predisposition to your children. The same is true for non-genetically determined traits such as income levels, education, and access to quality health care. People tend to choose partners with about the same income level and with the same education level,and high levels of both often lead to longer and healthier lives.
The first thoughts that the matter might not be in genetics and not in the general family environment came to Ruby's mind when he tried to analyze family members who are not related by consanguinity. He began by analyzing data from family trees, which included more than 400 million people. This data has been cleaned, de-identified and analyzed by genealogists and computer scientists at Ensestri. Drawing on the basic law of inheritance - an individual inherits half of its genes from its father and half from its mother - Ruby's team examined how closely the two people were related and how long they lived. They examined parent-child pairs, sister-brother pairs, cousins and second cousins, and so on. And here they did not manage to find anything particularly interesting.
But when Ruby began to analyze family members who are not related by blood, he found strange things. Logic tells you that you shouldn't have a lot of DNA similarities with your siblings' spouses - for example, your brother’s wife or your sister’s husband. But, as Ruby's analysis showed, people who were related through marriage of the next of kin showed a similar life expectancy with the same degree of probability as people who were related by consanguinity. “I was amazed,” Ruby said. "While no one has previously demonstrated the effects of assortative mating to this extent, it fits well with our knowledge of the structure of human communities."
Promotional video:
The results of this study could influence the course of many studies on longevity. Ruby said his research doesn’t deny the results of earlier studies and searches for genes associated with aging or the development of some diseases, but it proves that finding these genes will become increasingly difficult in the future. Finding them will require scientists to analyze huge amounts of data to achieve statistical reliability. But this should not be a problem for Calico, which through the partnership has access not only to family trees, but also to the de-identified DNA data of millions of Ensestri's genotyped clients.
Currently, another joint work of Calico and Ensestri is undergoing peer review. According to the Ensestri spokesman, according to the terms of their partnership agreement, their joint work should culminate in a report, which will reflect all their findings and conclusions. Calico has the right to continue working in any direction, based on this analysis, but so far the company has not announced anything about the results of their joint work.
While the main conclusion, most likely, is that people themselves determine their life expectancy to a greater extent than their genes. Circumstances shared by members of the same family - home and neighborhood, culture and cuisine, access to education and health care - have a much larger impact on which numbers will one day adorn their gravestone.
Perhaps that's why Ensestri's chief scientist, Catherine Ball, says their company has no plans to put lifespan tags on their products anytime soon. “Longevity now seems more like a consequence of the choices we make,” she says. She points to individual moments when life expectancy sharply decreased - for example, the First World War became such a moment for men, and then there were two more waves in the second half of the 20th century, when men and then women became addicted to cigarettes.
“Don't smoke, and don't go to war. Here are my tips,”she said. And, if possible, take the time to exercise. In Ball's diary, it is already noted that she is doing sports on Tuesday morning. This time, Ball admits, she won't cancel him at the last minute.
Megan Molteni
