What dictates the human lifespan? That is to say, why don’t humans live to be 150, 200 or more years old? Well, according to Microbiologists from the University of Birmingham in the UK, it might all have to do with the dinosaurs.
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00:00 [Music]
00:04 What dictates the human lifespan?
00:06 That is to say, why don't humans live to be 150, 200, or more years old?
00:10 Well, according to microbiologists with the University of Birmingham in the UK,
00:14 it might all have to do with the dinosaurs.
00:17 They're calling it a longevity bottleneck,
00:19 suggesting that when mammals were first coming onto the scene evolutionarily,
00:22 they needed to reproduce ASAP, as to not be eaten by dinosaurs.
00:26 Which the researchers posit could mean that our genes for longevity were cast aside
00:31 in exchange for quicker development and more numerous offspring.
00:34 With the researchers saying about it, quote,
00:36 "Some of the earliest mammals were forced to live towards the bottom of the food chain
00:40 and have likely spent 100 million years during the age of the dinosaurs
00:43 evolving to survive through rapid reproduction."
00:46 Saying that that very period of evolutionary pressure
00:49 likely has lingering effects on our aging even today.
00:52 They point to evidence of a lost enzyme in the eutherian mammal lineage,
00:55 one that repairs UV damage to cells.
00:58 That could have been lost when many mammals became nocturnal for safety.
01:01 They also point to prehistoric predators like alligators,
01:04 that can regrow teeth in perpetuity, unlike humans.
01:07 With the researchers adding that genetic information
01:10 would have been unnecessary for early mammals that were lucky to not end up as T-Rex food.
01:15 [music]