A recent theory claims the 180-million-year age of the dinosaurs could have affected the human lifespan and aging process.
While mammals, including humans, change in appearance as they age, many reptiles and amphibians age without noticeable effects until their deaths.
A new theory, known as the 'longevity bottleneck hypothesis,' proposes that mammals faced strong selective pressure to evolve rapid reproduction when dinosaurs ruled the Earth.
Over 100 million years, this pressure likely caused the loss of genes which promote longevity, especially those crucial for DNA repair and body tissue rejuvenation, according to an article in the journal BioEssays.
“While humans are among the longest-living animals, there are many reptiles and other animals that have a much slower aging process and show minimal signs of senescence over their lives,” said study author Joao Pedro de Magalhaes, a biologist from the University of Birmingham.
The hypothesis offers insights into the evolutionary factors affecting mammalian aging over millennia, he added.
Evolution of Mammals and the Longevity Bottleneck Hypothesis.
© Photo : BioEssays by Joao Pedro de Magalhaes
Certain creatures exhibit exceptional powers of cell repair and tissue regeneration, traits perhaps not vital for ancient mammals that managed to escape predators like Tyrannosaurus rex.
Dr Magalhaes stressed that despite the large size and longevity of creatures like humans, elephants and whales, they still retain genetic imprints from the Mesozoic era. Interestingly, mammals, including humans, age faster than many reptilian species.
While the conclusions remain in the realm of theory theory, further studies could provide insights into the higher rate of cancer in mammals compared to other species, the biologist said.