A breakthrough study published on Friday in the journal Science uses life history theory to explain why tropical songbirds typically raise fewer chicks than temperate songbirds.
What’s life history theory?
Life history theory seeks to explain the ways in which natural selection works to determine a given organism’s anatomy and behaviors. Life history theory suggests that reproductive tendencies, or “life history strategies,” are part of a complex system of species traits, or “life history characteristics.” Parent organisms display reproductive strategies that essentially represent calculated trade-offs based on the anatomical, environmental, and ecological characteristics of their species. (For example, my parents strategized against having another kid because I was such a handful.)
We knew they were different, we …show more content…
Various explanations abound from Moreau’s initial discovery onward as to what exactly accounts for the variation, but none so far have held water with the scientific community for very long.
In this most recent study, evolutionary ecologist Thomas Martin documented life history characteristics of both tropical and temperate songbirds, focusing on closely related species across the latitudinal divide. His team determined that in comparison to the temperate birds, the tropical songbirds grow longer wings, they grow them more quickly, and they appropriate more resources per egg to their nesting offspring. Tropical songbirds also historically experience greater threats of nest predation than do temperate