Which organism has a survivorship curve similar to that of humans?

• A. Bacteria
• B. Elephants
• C. Birds
• D. Humans

Answer: (B)

Survivorship curves show how likely individuals are to survive as they age, reflecting a species’ life-history strategy. In a Type I pattern, most individuals live to old age, with relatively few deaths early on; this happens when there is high parental investment and few offspring, so organisms can devote energy to each young. Humans fit this pattern because, after long development and significant parental care, most survive into adulthood and risk of mortality increases mainly in old age.

Elephants follow a similar story: they have long lifespans and invest a lot in each calf, producing few offspring. As a result, many individuals reach adulthood, and mortality tends to rise later in life. Bacteria, by contrast, produce enormous numbers of offspring with little parental care, leading to high juvenile mortality (Type III). Birds often show a more constant risk of death across ages (Type II) or vary by species, not matching the human pattern as closely.

So, elephants are the organism whose survivorship curve most closely resembles that of humans.