January 28, 2005 | David F. Coppedge

Bat Theory Strikes Out

An international team of biologists set out to write the family history of bats, a story that is “largely unknown,” they admitted in Science.1  They didn’t have much to go on.  “The fossil record is impoverished,” their research confirmed, so they tried to piece together a phylogenetic story by combining all that is known about bats from molecular genetics, biogeography, and the fossil record.  First, some background about bats from Nancy B. Simmons, who analyzed the research in the same issue of Science.2  They really are quite a remarkable group of mammals:

Bats, the only mammals capable of powered flight, constitute more than 20% of living mammal species.  Unlike birds and other terrestrial vertebrates, most bats use echolocation—a biological form of sonar—to locate and track their prey.  Bats are found on every continent except Antarctica, and they exploit a wide variety of food sources including insects, small vertebrates, fruit, nectar, pollen, and even blood.  More than 110 bat species may coexist in some ecological communities, a number that far exceeds that of any other mammalian group.  Despite their prominent position among mammals, the evolutionary history of bats is largely unknown because of a limited fossil record and incomplete phylogenies [circular reasoning].   (Emphasis added in all quotes.)

It seems surprising that such a large and diverse group of mammals should be so under-represented by fossils.  The researchers estimate that 61% of the fossil history is missing.  Furthermore, “the evolutionary history of this order has been obscured by controversial phylogenetic hypotheses.”  There are large bats, small bats, Old World bats, New World bats, echolocating bats and non-echolocating bats.  Some theories propose that echolocation arose more than once: unlikely, says Simmons, “Because bat echolocation is a complex system involving specialization of the respiratory system, ear, and brain….”  Their tree requires either that it arose more than once, or some groups had it then lost it.
    The group of researchers came up with a family tree all right, but not without problems.  “Our molecular dates suggest that there are large gaps in the fossil record for most bat lineages,” they state.  More importantly, they exploded on the scene without apparent ancestors:

On average, the fossil record underestimates the origin of 58 bat lineages by 73% (Fig. 2).  The four major microbat lineages are missing on average 56 to 86% of fossil history, with the Gondwanan clade (noctilionoids) missing the most (Fig. 2).  Megabat lineages are missing a sum total of 98% of their fossil history (table S5).  The terminal and internal branches are missing on average 58 and 88% of fossil history, respectively (table S5).  With well over half of the Cenozoic history missing for microbat lineages and nearly all of the fossil history missing for megabat lineages, it is not surprising that Paleocene bat ancestors having transitional morphological adaptations for flight and echo-location have never been discovered.

So how does one put together a family tree with so little data?  The best one can.  Despite the phylogenetic tree drawn for publication, the above statement was the last paragraph in the paper!  Simmons says of this predicament, “The scope of this ‘big bang’ Eocene radiation is unprecedented in mammalian history.”

1Teeling et al., “A Molecular Phylogeny for Bats Illuminates Biogeography and the Fossil Record,” Science, Vol 307, Issue 5709, 580-584 , 28 January 2005, [DOI: 10.1126/science.1105113].
2Nancy B. Simmons, “An Eocene Big Bang for Bats,” Science, Vol 307, Issue 5709, 527-528 , 28 January 2005, [DOI: 10.1126/science.1108871].

For a case study on how to spin-doctor a bad situation, read the UC Riverside press release.  You’d expect lies from National Geographic, of course: “Scientists Fill Blanks on Bat Family Tree.”  They just don’t tell you what they filled it with: imagination.
    In debates with evolutionists, creationist Dr. Duane Gish, author of Evolution: The Fossils Say No, often taunted the opponent by showing a picture of the earliest known fossil bat, which was clearly 100% bat.  He would emphasize that there were no transitional forms between a mouse-sized mammal and a flying bat.  Dr. Gish has earned a grin for Science to say the same thing.
    Both papers suggest that bats appeared because new food sources arose.  Presumably, a wealth of new insects, fruits, flowers and small mammals was like a shopping mall without customers, so the customers “emerged” somehow to fill all the wonderful new ecological niches.  Maybe this is the “If you build it they will come” theory of evolution.  We think, rather, that if Charlie has been up to bat for 140 years and is still striking out, it’s time to retire.
    Bats are exceptional examples of incredible creatures that defy evolution.  Some of their technical feats are illustrated in the Moody Institute of Science classic Dust or Destiny, which shows them navigating through jail bars in total darkness by echo-location.  They can swoop up an insect in their wings during their agile, acrobatic flights, and detect texture, shape and movement with sonar.  Despite their scary appearance, bats are our allies, ridding the air of excess insects.  Bats are among four totally separate groups of animals capable of flight – reptiles (pterosaurs), insects, birds and mammals – each different, yet thoroughly capable from first appearance on earth, just as the Bible creation account says.

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Categories: Fossils, Mammals

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