May 22, 2017 | David F. Coppedge

Living Birds Recapitulate Their Hopping Dino Ancestors

Can a hopping parrot tell you what life used to be like as a dinosaur?

Sam Wong thinks so. At New Scientist, he titles his article, “Hopping miniature parrots suggest how birds first got airborne.” That sounds like a testable hypothesis. Let’s all hop like the birdies hop, and see if we evolve wings. Wong easily wins Stupid Evolution Quote of the Week for his opening just-so story:

You have to jump before you can fly. A species of tiny parrot saves energy by hopping from branch to branch when foraging – a skill that may have helped bird ancestors to first get off the ground.

 

These small birds hop between branches up to 30 times a minute, gaining propulsion from their legs and adding a few wingbeats to extend their range.

 

A new study shows they do this in ways that minimise energy requirements, and suggests bird-like dinosaurs might have benefited from the technique too.

Surely there must be some experimental evidence for this, if it is in New Scientist instead of New Mythmaker. And there is. Wong cites work by Diana Chin at Stanford who measured the forces on the legs and wings of young parrots as they hopped and flapped from perch to perch over various distances. To save energy, she noticed, they only use their wings when they have to. In good scientific fashion, Chin thinks of applications to robotics from her work.

But what does this have to do with evolution?

For clues, let’s examine the paper in Scientific Advances to see if Chin and her colleage David Lentink connect the dots. Does she identify beneficial mutations that were acted upon by natural selection? Do the two also do this for insects, bats and pterosaurs, to see if similar hopping initiated powered flight?

Birds frequently hop and fly between tree branches to forage. To determine the mechanical energy trade-offs of their bimodal locomotion, we rewarded four Pacific parrotlets with a seed for flying voluntarily between instrumented perches inside a new aerodynamic force platform. By integrating direct measurements of both leg and wing forces with kinematics in a bimodal long jump and flight model, we discovered that parrotlets direct their leg impulse to minimize the mechanical energy needed to forage over different distances and inclinations. The bimodal locomotion model further shows how even a small lift contribution from a single proto-wingbeat would have significantly lengthened the long jump of foraging arboreal dinosaurs. These avian bimodal locomotion strategies can also help robots traverse cluttered environments more effectively.

That’s basically the same Stupid Evolution Quote of the Week dressed up in Jargonwocky. In the paper, the perhapsimaybecouldness index rises when Chin and Lentink visualize ancient dinosaurs trying to fly:

  • This visually guided feeding behavior in cluttered habitats not only is critical to the energetics of many extant birds but also was likely used by avian precursors….
  • Understanding the biomechanics of perch-to-perch foraging flights can therefore help mechanistically underpin how protobirds could have honed their foraging flight skills, and fill critical gaps in our understanding of the energetics of extant arboreal birds.
  • …by investing more energy into locomotion, these proto-fliers could have expanded their foraging volumes in trees and gained critical advantages over competitors.
  • Regardless of how flapping flight evolved, extending long jumps with proto-wingbeats to increase foraging gain provides a self-reinforcing, gradual path through which protobirds could have honed their flight skills.

If birds “honed their flight skills” by use and disuse, that’s a Lamarckian just-so story instead of a Darwinian just-so story. Both explanations have one thing in common: they are just-so stories.

This peer-reviewed scientific paper, published by the AAAS and gushed on by Sam Wong, shows that evolutionists have learned nothing since Ken Dial’s old Partridge Family story (see 12/22/03). In fact, Ken Dial’s original 2003 paper appears in the references, along with his 2011 update (6/26/11).

Illustra Media: FlightFor relief from the stupidity of Darwinian storytelling, watch the Illustra Media film Flight: The Genius of Birds. See also Jonathan Wells’ updated book on the icons of evolution, Zombie Science, which includes new information on Archaeopteryx and feathered dinosaurs.

 

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Comments

  • alfan says:

    It’s a very sad tale, actually, because every avian “hopeful” that misses a branch perishes, thus “trunk”ating the evolutionary tree.

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