The sex with the reduced sex chromosome dies earlier: a comparison across the tree of life | Biology Letters
The sex with the reduced sex chromosome dies earlier: a comparison across the tree of life. Female homogametic species live 20.9% longer and male homogametic species live 7.1% longer. #longevity
Fascinating new study finds that, across species, the sex with different sex chromosomes (e.g., male mammals [XY] and female birds [ZW]) tends to die younger, consistent with the unguarded-X hypothesis.
This new article sheds light on sex differences in lifespan by analysing 229 species. The heterogametic sex has, on average, a shorter lifespan than its homogametic counterpart across a range of taxa. The homogametic sex lives, on average, 17.6% longer.
When males are the heterogametic sex, they die 20.9% earlier than their female counterparts, but when females are the heterogametic sex, they die only 7.1% earlier than their male counterparts
Xirocostas et al. 2020
The claim: The homogametic sex, on average, lives longer than the heterogametic sex. Sadly, the variation is huge, there are too many exceptions , and the visuals indicate that the claim, while statistically significant, maybe biologically insignificant.
Matching sex chromosomes the secret to a long life? Females in species where they have identical sex chromosomes live 20.9% longer than males & males with matching sex chromosomes have a 7.1% life span
Heather E Heying
From the original research, which looked at more clades than just mammals and birds:
New paper from Roy. Soc. shows that if you have like sex chromosomes (XX females in mammals), you live longer than if you have unlike sex chromosomes (XY males). This also holds in species like birds where MALES have matching sex chromosomes. A mystery.
: Fascinating new study finds that, across species, the sex with different sex chromosomes (e.g., male mammals [XY] and female birds [ZW]) tends to die younger, consistent with the unguarded-X hypothesis.