What do the following organisms have in common with regard to ageing, mortality and fertility rates?
- Japanese women in 2009
- Swedish females born in 1881
- Female killer whales living between 1973 – 1987
- All of the Bali mynah birds both male and female in zoos around the world
- Trinidadian guppies
- Human hunter-gatherers from Paraguay
- Southern fulmar (birds living in Antarctica)
- Water fleas (Note: I have fond memories of counting Daphnia from an ichthyology class)
- African lions from the Serengeti
- Yellow baboons in Kenya
- Rotifers – a microscopic animal
- Roe deer from France
- Red deer from the island of Rum in the UK
- Nematode worms
- Female human lice (400 of them!)
- Chimpanzees from various African countries
- Fruit flies
- Chamois – an antelope with goat characteristics from Europe
- Mediterranean fruit fly
- Alpine swift
- Soay sheep from the U.K.
- Mute swans
- Field voles from China
- Scots pine (It’s about time we had a plant!)
- Brenda’s yellow cryptantha (a plant in Utah)
- Freshwater crocodile from Australia
- Yellow-bellied marmot
- Hypericum cumulicola (a plant)
- sparrowhawk
- Agave
I give up. It will take me forever list all forty three species that were used. A team of scientists used a fantastic selection of organisms from around the world to study ageing and you can find the complete list here.
Erin Brodwin from Business Insider produced an excellent summary of their research and related topics:
These charts will radically change how you think about aging
Here are few things I found interesting in the paper:
The researchers noticed some unexpected results. For example, there is a steep rise in mortality in the modern day Japanese women studied when compared with other human groups that lived earlier.
They also found that the mortality rate declines in some species such as the desert tortoise. I have a vested interest in this as my wife and I have two red-footed tortoises.
Other species such as net leaf oak trees experience a constant mortality rate.
The researchers estimated that hydra living in the lab could possibly live for 1,400 years if the conditions were right. Wow! I wish they would have included Tardigrades in the study.
I’m not going to discuss the fertility section of the research but feel free to browse the entire paper.
One interesting point they made was that organisms that continue growing throughout life seem not to age as much. For an organism like a tortoise or a tree, the mortality seems to be constant if environmental conditions are right.
Why is all of this important or interesting?
Maybe studies like this will help scientists uncover the mechanisms of ageing. If they succeed then perhaps all of us can have good health until we shuffle off this mortal coil peacefully of old age and not suffer from preventable diseases.
It is fascinating research. Why do some species experience ageing, increases in mortality and decreases in fertility while other do the opposite?
The authors finish their paper with a wise caution. Humans are animals and we are in no special position with regard to other organisms when we look at mortality and fertility. There is a tremendous amount that can be learned from the wealth of living organisms that share the planet with us.
Click the link below to read the original research paper:
Diversity of ageing across the tree of life