• Question: how long did it take for dinosaurs to evolve to what we know they were like and is their a chance that dinosaurs will evolve back to what they were like millions of years ago?

    Asked by to Shaylon on 26 Jun 2014. This question was also asked by .
    • Photo: Shaylon Stolk

      Shaylon Stolk answered on 26 Jun 2014:

      True dinosaurs first appear in the fossil record 225 million years ago. That’s about the same time as bivalve shellfish (such as cockles and scallops), conifer trees (like pines and spruce), the first ray-finned fish (like cod) and the first mammals. These dinosaurs were part of a group called sauropodomorphs. They had long tails, long necks, and small heads, and were plant eaters.

      Their ancestors were a group of reptiles called rhynchosaurs. These weren’t true dinosaurs, but shared a lot of traits with dinosaurs. Like the first true dinosaurs, they ate plants. It’s about 15 million years between when these dinosaur and mammal ancestors first appeared and when true dinosaurs appeared.

      The current descendants of dinosaurs are modern birds. The modern bird that’s closest to ancestral birds is the hoatzin. It lives in South America. Unlike most birds, it eats tree leaves. It’s also born with claws on its wings just like some winged dinosaurs did! Here’s a baby one using its claws to climb:

      In an evolutionary sense, modern birds have done very well. They are a very diverse group of species and have populated every continent. They also survived the major extinction events (meteor strikes and huge volcanic eruptions) that killed the other dinosaur species. So given how advantageous it is to be a bird, it’s unlikely that any early dinosaur traits will re-emerge naturally.

      That said, birds still do carry a lot of their dino genes– they just don’t ‘express’ them. (Expressing a gene means that an organism actually uses that gene to make a trait). For example, chickens still have the gene for making teeth!
      http://www.scientificamerican.com/article/mutant-chicken-grows-alli/
      http://science.kqed.org/quest/2011/09/12/turning-chickens-into-dinosaurs/
      So some genetic engineering could partially revert birds back to their ancestral dinosaur state, although they wouldn’t be fully developed dinosaurs.

Comments