Questions about birds – Letters – Castanet.net


As bats are one of the animals most associated with Halloween, it was timely that CBC Radio (Kelowna) (recently) interviewed Canadian evolutionary biologist Dan Riskin, a bat expert, science journalist and author.
Riskin has written a new picture book for young kids titled Fiona the Fruit Bat, illustrated by Rachel Qiuqi. This engaging book combines the science of bat echolocation with the idea of overcoming the fear of new experiences.
A few questions come to mind:
• How does evolution explain the origin of bats from a supposed non-winged ancestor, gradually developing fully functional wings?
• Is there any fossil evidence for their transitional forms? The earliest bat skeletons in the fossil record are 100 per cent bat!
• How did lingual and laryngeal echolocation in bats originate?
The same question applies to non-winged ancestors of pterosaurs, gradually developing fully functional wings, with their long bony fourth finger. Is there any fossil evidence for their transitional forms?
In a July 21, 2021 ScienceDaily article states: "Researchers detail the most ancient bat fossil ever discovered in Asia.”
"Bats show up in the fossil record out of the blue about 55-ish million years ago — and they're already scattered on different parts of the globe,” writes Matthew Jones. a doctoral student at the KU Biodiversity Institute and Department of Ecology and Evolutionary Biology).
"By the time we get their earliest known full skeletons, they look modern, they can fly, and most of them are able to echolocate. But we don't really know anything about this transitional period from non-bats to bats. We don't even really know what their closest living relatives are among mammals. It's a really big evolutionary mystery where bats came from and how they evolved and became so specialized."
I watched the highly entertaining Nature episode on PBS Nov. 2, Woodpeckers: The Hole Story, which included amazing close-up cinematography.
In it, narrator Paul Giamatti says "Banging your head into a tree has always seemed reckless, but woodpeckers suffer no brain damage. His head and bill can act like a hammer because his brain is small enough to sustain repeated shocks without injury."
Later, he adds: "We know that woodpeckers come from an ancient lineage that separated from other birds some 24 million years ago, and they are different in so many ways."
Really.
Woodpecker traits include a tough bill that never gets dull, a thick skull with shock-absorbing tissues, super-strong neck muscles, and long tongue (up to 10 centimetres in the Northern Flicker species). The tongue is so long it wraps around the woodpecker's skull to protect its brain while hitting a tree or other hard surface.
If human tongues were the same proportion, they would be about 60 cm long. These traits depend on one another for any of them to have functional value.
How did banging its head into trees increase the woodpecker ancestor's likelihood for survival?
How did random genetic mutations and natural selection produce the coordinated set of structural and behavioural adaptations necessary for woodpecker evolution?
Natural selection can only act on those biologic properties that already exist.
On YouTube, watch the 1994 debate, Darwinism: Science or Naturalistic Philosophy? between Phillip E. Johnson, a UC Berkeley law professor and William B. Provine, a historian of science and of evolutionary biology and population genetics at Cornell University).
David Buckna, Kelowna
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