Until a few years ago, the scientific community defended the belief that wild animals died before they grew old , mainly due to the action of predators or the presence of parasites. However, the elements opposed to them in a hostile habitat or ecosystem fail to fully anticipate the passage of time. It wasn’t until 2011 that aging and senescence was first demonstrated in nature.
The first animals to be monitored for their aging pattern were the blue-footed boobies ( Sula nebouxii ).
These birds are especially long-lived and inhabit the Pacific coasts between Mexico, the Galapagos Islands and Peru. The results obtained show that the germ line , the DNA that gives continuity to the following generations, can be damaged with age . Just like the offspring of men over 50 years of age are at greater risk of genetic diseases, the same is true of these birds. The DNA of older birds is damaged and can make their offspring more prone to disease or mutations .
For blue-footed boobies, it is precisely the color of their limbs that makes the difference . The coloration of the legs undergoes aging and is an indicator of oxidative damage in the sperm , so older males tend to have duller colors, while middle-aged males have a less deteriorated germ line and more colorful legs . According to the study, females choose males based on the color of their legs and are less attracted to older subjects, with more subdued colored legs.
Before this study, the general belief was that senescence, the natural problems or deterioration of the body associated with the passage of time and age, only manifested in humans and domestic animals because we have a life expectancy much higher than what that would correspond to us in a natural way; we live longer than it would touch us . However, the discoveries made by Alberto Velando as the main research leader show that senescence exists in nature and that it affects the ability of wild animals to live and reproduce .
The research results opened a new field of perspectives on what lies behind sexual cues and served as a first indication of the importance of sexual selection in purging genetic mutations .
