Longevity Quotient (LQ) is a simplified measure to enable normalized comparisons of various species' longevity. It shares some similarity with measures such as
Intelligence Quotient
An intelligence quotient (IQ) is a total score derived from a set of standardized tests or subtests designed to assess human intelligence. Originally, IQ was a score obtained by dividing a person's mental age score, obtained by administering ...
. It originated with
Steven N. Austad and
Kathleen E Fischer's 1991 paper on
mammalian aging.
The detailed description of LQ was originally defined as the ratio of Actual Lifespan divided by Predicted Lifespan obtained from the
Nonflying Eutherans (NFE) regression relating observed lifespan and body mass relationship. This followed the work of
John Prothero and
Klaus Jurgens who strictly looked to related longevity and body mass. Austad spells out that "Excluding bats and marsupials mean LQ is 1.0 by definition"
Aging and longevity researchers utilize LQ with additional metrics such as
maximum species life span (MLSP).
Rochelle Buffenstein considers MLSP as an important species aging characteristic that can vary over a factor of 40,000 throughout the animal kingdom, and is related species increase in body size. Buffenstein identifies the Longevity Quotient as the ratio of actual MLSP to that predicted by body mass.
Recent LQ based research identified some bats are relatively much long-lived.
Myotis brandtii
Brandt's bat or Brandt's myotis (''Myotis brandtii'') is a species of vesper bat in the family Vespertilionidae. It is native throughout most of Europe and parts of western Asia.
Taxonomy and etymology
The species was described in 1845 by Germ ...
is estimated to have an LQ of 8.
Common measures in Aging and Longevity research include Life-Span Variables
Mass, Maximum longevity, Predicted MLSP, Longevity quotient (Fisher Austad Formalism, Longevity quotient (Prothero Jugrens Formalism) and lifetime energy expenditure (LEE) (normalized using kilocaories/gram).
Theories of Longevity and LQ
Buffenstein describes the
evolutionary theory of aging as a nonadaptive result of the declining power of natural selection allowing harmful genetic mutations may prevail suggesting that species living underground would have long life spans. Using LQ measures it appears that only the social subterranean species have high LQs. Additional discussions of longevity and MLSP abound
Comparative LQ
See also
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Longevity
Longevity may refer to especially long-lived members of a population, whereas ''life expectancy'' is defined Statistics, statistically as the average number of years remaining at a given age. For example, a population's life expectancy at birth ...
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Siberian bat
The Siberian bat or Siberian whiskered myotis (''Myotis sibiricus'') is a species of vesper bat in the family Vespertilionidae. It is found throughout northeastern Asia, primarily in Siberia. It is known for its high life expectancy relative to ...
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Maximum life span
Maximum life span (or, for humans, maximum reported age at death) is a measure of the maximum amount of time one or more members of a population have been observed to survive between birth and death. The term can also denote an estimate of the maxi ...
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Rate-of-living theory
The rate of living theory postulates that the faster an organism's metabolism, the shorter its Longevity, lifespan. First proposed by Max Rubner in 1908, the theory was based on his observation that smaller animals had faster metabolisms and short ...
References
Further reading
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* {{cite journal , last1=Ruby , first1=J. Graham , last2=Smith , first2=Megan , last3=Buffenstein , first3=Rochelle , title=Five years later, with double the demographic data, naked mole-rat mortality rates continue to defy Gompertzian laws by not increasing with age , date=28 March 2023 , doi=10.1101/2023.03.27.534424 , s2cid=257837688
Longevity