How Long on Earth? Life Spans of Animals, Humans, Insects, Plants, and Microorganisms: A Quiz Deck
Sample Card Text
Many marine mammals have enviably long life spans. What is the estimated maximum life span of the bowhead whale?
(a) 60 years
(b) 80 years
(c) 120 years
(d) more than 200 years
Answer (d) As far as we know today, the bowhead whale is the longest-living mammal. In 1981 indigenous Inupiat whale hunters on the north coast of Alaska discovered in a slaughtered bowhead an ivory harpoon tip estimated at between 130 and 200 years old. That led the scientific community to begin challenging the assumption that the bowhead’s life span was perhaps 100 years. In a 1999 study published in the Canadian Journal of Zoology, researchers examined the eyeballs of 48 bowheads that had been killed by hunters between 1978 and 1996. Analyzing the chemistry of protein layers in the eye lenses, the scientists estimated that four of the whales had been more than 100 years old when killed, and the oldest was estimated to have been 211. And since these whales had been killed and hadn’t died of old age, it became clear that the bowhead’s maximum life span might even be significantly longer than 211.