The study of aging in animals
Senescence is the study of aging. Our wild and distant relatives have a lot to teach us about aging, whether you look at an animal that lives for only 30 days like a bee, or an orca that lives more than a hundred years.
By studying these animal lives we can learn about the human journey.
Canadian filmmaker Ari A. Cohen has a wildlife documentary called Aging in the Wild, about growing older in the animal kingdom, and he talks about what we as humans can learn from animals about getting older.
Filmed over two year, the documentary touches on the themes of longevity, dominance, reproduction, wisdom and death.
“There are a lot of takeaways for us in this film about aging. One of those is the purpose of aging in some species. We all start somewhere and we all end up somewhere. It could be a few days or a few hundred years, this film displays that complexity. Life itself is spectacular, it’s something to cherish,” said Cohen.
In the animal kingdom age has its advantages, experience and size matter, especially if you are an elephant. Elephants are the longest lived land mammal on earth. One of the elephants in the documentary is a matriarch called Ella, she is 50 years old and pregnant again. The older you get doesn’t mean the weaker you get, for elephants, the older you get it means the wiser you become.
One of the researchers on the film, Lesley Evans Ogden said: “Matriarchs – the older female leaders – are really crucial to elephant societies, especially during hard times like drought, when it’s these wise old leaders that know where to find water and food. Without their expert knowledge and amazing memories, the younger elephants they lead would be in big trouble.”
“If parents and children have strong bonds early in life, they develop trust, like the young elephants that follow the older elephants trusting that they know where they are going and that they will protect them. Like humans, all that security, building all that comfort is passed on from generation to generation,” added Cohen.
Another of the animals featured in the film are whales. There is a grandmother orca of 103 that has a boyfriend in his 20s. She is as strong at 100 as she was at 20. We don’t see things like this very often in human societies, but orcas do have other similarities to humans. This grandmother orca exemplifies the idea to strive be your best self at any age that you are.
“As a documentary filmmaker, I have made many biographies about grandmothers that live in the arctic and many older people. I have always been really interested in the wisdom that comes with age. In doing this project I was looking also for that in wildlife,” said Cohen.
Female orcas can have babies until they are in their 40s, and then live another 60 years past their reproductive age. The female orcas are still vital to the pod as they have knowledge of feeding grounds etc. that they continue to teach for the rest of their lives. This pattern of imparting knowledge is something that we see in humans too.
“In the wild if you know where the food is and you know how to defend yourself it helps the other generations follow in your footsteps. The older animals are revered often by other animals,” explained Cohen.
For some species, the rate of aging depends on their social environment. Alpine marmots live in families. The whole family hibernates together for six months in the winter. This is one of the keys to their survival. All those bodies together generate heat, and staying warm through the winter equals survival.
Frequent hibernation, may be another factor to living longer lives. Bears like to live alone, and there is science that shows bears don’t lose memory when they hibernate. Humans don’t hibernate, but we do spend one-third of our lives sleeping, or we are supposed to.
Scientists have discovered that lack of sleep accelerates aging, because it prevents cells from properly restoring themselves. This in turn leads to forgetfulness.
“Marmots have what are called helpers to raise their young. The idea that we need help to raise our families, and help increases longevity makes sense. Less stress makes for a better life,” said Cohen.
Bees only live 30 days, and it would seem that there would be little in common with human aging. However, there is an experiment shown in the film where scientists looked to see if they could reverse aging and memory loss and teach older worker bees new tricks.
The bees didn’t live longer, but the bees were able to relearn behaviours from their youth. Scientists discovered that the social environment had an effect on the bees’ memories and their ability to learn. In understanding the science behind this, “researchers hope to gain insight into treating age related memory loss in humans too”.
“There is this idea, that as we get older, that we should be doing less. When I worked up in the arctic, the Inuit mothers and grandmothers, they were and packing up early in the morning getting their skidoos and their fishing rods ready and going out onto the ice. They weren’t running across the ice, but they weren’t afraid to go out onto the ice and they were not afraid to spend hours outside in the elements,” said Cohen. “Being close to nature is a great way to maintain vitality and remain connected.”
One thing that humans do is to take care of our elders, we feed them and look after them when they can no longer look after themselves. In the animal kingdom there is evidence that some species, like whales and elephants, also take care of their ailing members.
Healthy whales have been seen to hold up an ailing pod member in a group. Elephants have also been observed looking after sick or older members of the herd. They will slow down to allow them to keep up. If an elephant matriarch is dying, the herd will gather by her side and comfort her by touching her with their trunks. Elephants even remember their elders after they have died.
Evans Ogden said: “I think the key thing we can learn from animal aging is to respect our elders, and not be so fearful of getting old! In so many animal societies, like in elephants and orcas, it’s wise old leaders that are critical to the survival of families and communities. Their role in society is vital.”
Cohen also believes that we need to be open to what the animal world can teach us and how we can feel connected to all the species that live among us.
“We are just one among many species that are getting older. It’s something that we all have in common and that’s what makes it fascinating. There are so many ways to get there from beginning to end. We should look at animals through a different lense, so that we can learn more, and respect and appreciate life itself,” added Cohen.
The spectrum of aging is very diverse, and every species has its own trajectory, every species has its own rate and pace of aging and the concept of senescence, is as diverse as the number of different animals that live on our planet.