Do older parents allow faster development of offspring? This is what seems to show a study carried out in worms. Offspring also tend to reproduce more and faster.
- The worms observed measure on average 1 mm, and live underground.
- The researchers observed the lifespan of the worms, their rate of reproduction but also the size of their eggs and their offspring in adulthood.
Having children late is often badly perceived, because late pregnancies present more risks: gestational diabetes, hypertension, miscarriage, etc. At the same time, fertility decreases with age. But researchers from the University of East Anglia show that late parenthood could have benefits. Their work has been published in Proceedings of the Royal Society B Biological Sciences.
A comparison between different species
“Reduced lifespan in offspring of older parents has been observed in many species, including humans“, reminds the director of this study, Laura Travers. Several factors related to late parenthood can be harmful for the offspring. “For example, older parents may have poorer quality eggs or sperm, or be less able to care for their offspring.” Conversely, in some animal species, older parents give birth to more robust young, because they have “more resources to invest” and are “more experienced in life, which allows them to take better care of their offspring“.
A research carried out on verses!
To learn more about the impact of the age of the parents on the offspring, the scientists chose to observe worms, of the species Caenorhabditis elegant. “They have no bones, heart or circulatory system. But they are a classic model organism for studying aging and reproductive processes in biology, as they share many genes and molecular pathways with humans, says the researcher. They are also very useful because they have a short lifespan of about three weeks, so we can study them over several generations in a short time. To do a similar study in humans would take more than a century!” The observation of these invertebrates has shown that older worms produce larger eggs, which will develop more quickly and give larger adults, but which will also reproduce earlier. Their lifespan was not affected by the age of their “parents”. “We believe that older parents are able to invest more nutrients in each egg, resulting in offspring that reach sexual maturity faster and produce more offspring over their lifetime.”, adds the scientist. Other studies would be necessary to test this theory in humans, even if it will take longer to realize them!
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