Researchers think they understand how some dinosaurs grew so large. NPR’s Eyder Peralta talks with Michael D’Emic, paleontologist at Adelphi University.
D’EMIC: There’s tradeoffs. So evolving to grow faster than your ancestors means that you can possibly outcompete other species in your environment for resources. So maybe you can reach taller trees or get to environments that smaller species can’t get to. And you can also then outpace the growth of predators in your environment. So you’re not small for as long, and so maybe you’re not potential dinner for as long in your life. The disadvantage is that it takes a lot of energy. And so if lean times come, like a drought, there’s not that much food around, then you would be more prone to extinction.
PERALTA: Can we talk about living animals? Do we see that kind of variety in how fast or slow large species grow in animals that are living now?
D’EMIC: Absolutely. Yeah, we see a whole range of growth rates and patterns in animals today. The tricky thing is that the sample of animals that we have today, those are just the animals that happen to be with us, right? I call them animals that happen to not be extinct. So it’s not a true evolutionary sample. To get a sense of how evolution proceeds, you need to sample fossils in the past. There’s a famous quote – nothing in biology makes sense except in light of evolution. We can get led astray by just looking at animals today.
