Wednesday, February 13, 2008 | Reason : Evolution and Biology | print version

Earliest bats did not 'see' with sound

by New Scientist

Thanks to James Dowse for the link.

http://www.newscientist.com/channel/life/dn13315-earliest-bats-did-not-see-with-sound.html?feedId=online-news_rss20

Earliest bats did not 'see' with sound
Colin Barras

The earliest fossil bat yet found suggests that the species' trademark echolocation had yet to evolve.

Nancy Simmons of the American Museum of Natural History, New York, and her team found the fossil in the 52-million-year-old Green River Formation in Wyoming. The species, Onychonycteris finneyi, had a strong ribcage and long finger bones, suggesting that it could fly, and its teeth were similar to those of modern insect-eating bats. But it lacked the special ear-bone modifications needed for echolocation - the ability to use reflected sound to find and identify objects while flying - and probably flew "deaf" (Nature, DOI: 10.1038/nature06549).

"Without echolocation, Onychonycteris would probably not have been good at catching insects in flight," says Simmons, though it might have used vision or smell to help find insect prey. Like some modern bats, it might also have used "passive audition", such as listening out for sounds that insects make when they crash into vegetation.

But it was not long before echolocating bats replaced O. finneyi. Fossils of another bat, Icaronycteris index, found in the same rock, have skull bones consistent with echolocation.

Add to del.icio.us Posted: Wednesday, February 13, 2008 | Permalink

Comments 1 - 20 of 20 |

Reload Comments | Back to Top | Page Numbers

1. Comment #126423 by Backslidden on February 13, 2008 at 8:23 am

God is still trying to test our faith, duh

Other Comments by Backslidden

2. Comment #126428 by Quetzalcoatl on February 13, 2008 at 8:31 am

Interesting. Exactly what you'd expect if bats evolved from an earlier mammal that did not use echo location. Another gap filled.

Other Comments by Quetzalcoatl

3. Comment #126455 by alfonso on February 13, 2008 at 9:28 am

Well, echolocation must have been such a decisive advantage that no doubt it quickly prevailed.

In the land of the blind, the one-eyed is king!!

Other Comments by alfonso

4. Comment #126470 by DNAtheist on February 13, 2008 at 10:00 am

Quetzalcoatl wrote:

Another gap filled.

And two more created. Sigh.

Other Comments by DNAtheist

5. Comment #126475 by annabanana on February 13, 2008 at 10:21 am

In the land of the blind, the one-eyed is king!

Don't you mean one-eared? ;-)

Other Comments by annabanana

6. Comment #126483 by Peacebeuponme on February 13, 2008 at 10:41 am

And two more created. Sigh.

Unfortunately while dumb creationists do not understand evolution, there will be an infinite amount of these 'gaps'.

Other Comments by Peacebeuponme

7. Comment #126496 by bluebird on February 13, 2008 at 11:16 am

Very interesting discovery!! Here's a photo: http://www.au.news.yahoo.com/080213/15/15tt905/1267571074.html

Bats are so cool! Fortunately, bats are now more accepted by the public as the amazing, beneficial creatures that they are.
We thrill at the sight of bats flitting about during summer nights, amiably competing with Nighthawks for delectables.

http://www.batconservation.org/

Other Comments by bluebird

8. Comment #126512 by arogop on February 13, 2008 at 11:40 am

How many of these fossils have been found? Could this have been just a one time mutation that did not pan out?

Other Comments by arogop

9. Comment #126515 by Epinephrine on February 13, 2008 at 11:48 am

Given that fruit bats (megachiroptera) as a rule don't have echolocation either, I'm not that surprised. The exceptions are stunning - the fact that some microchiroptera are most closely related to megachiroptera, rather than other microchirpotera suggests that echolocation evolved more than once, as does the exception of a type of megachiropter that uses echolocation in caves.

Tree of life:bats
Bat genetic analysis
Egyptian fruit bat

The other possibility is that an ancestor of both mega and micro bats had echolocation, and various classes of megabats lost it (but not the Egyptian fruit bat, nor the rhinolophoids), or that it was lost and subsequently re-emerged. Given that echolocation evolved independently in various animals (cetaceans, some shrews, bats) it's not impossible that it could have arisen separately in the microbats.

Other Comments by Epinephrine

10. Comment #126523 by tybowen on February 13, 2008 at 12:28 pm

How many of these fossils have been found? Could this have been just a one time mutation that did not pan out?

Of course it could be a fossilization of a one time event, but as fossilization is so rare the odds of this one mutation in a single individual being fossilized are astronomical. Its immensely more likely that this individual is a representative of a species, which improves that odds of fossilization by many fold.

Other Comments by tybowen

11. Comment #126544 by Quetzalcoatl on February 13, 2008 at 1:56 pm

It makes you wonder, though. We know so much, but given how rare fossilisation is, who knows how many entire species we might never know about?

DNAtheist-

you cynic :-) (Although I actually did think that when I was typing it).

Other Comments by Quetzalcoatl

12. Comment #126546 by Goldy on February 13, 2008 at 2:05 pm

Flap, flap, flap...D'Oh! Flap, flap, flap...D'Oh!
The true origins of echo-location ;-)

Other Comments by Goldy

13. Comment #126552 by Quetzalcoatl on February 13, 2008 at 2:26 pm

I wasn't aware that early bats sounded like Homer Simpson! See, the things you learn on this site. :-)

Other Comments by Quetzalcoatl

14. Comment #126589 by Epinephrine on February 13, 2008 at 3:53 pm

Yup, the d'oh! sounds like a click now, because they say it so much faster. The beauty of evolution :D

Other Comments by Epinephrine

15. Comment #126655 by Goldy on February 13, 2008 at 7:19 pm

Donot creationists often cite t lack of any "missing links" as proof evolution isnot t way species come to be?

Yep. Mind you, they are never satisfied when given an intermediate - they then ask for the intermediate between that intermediate and the original :-)
Surely the first word you typed should have read "donut"...hmmmm, sweet sugar coated donut...drool!

Other Comments by Goldy

16. Comment #126672 by njwong on February 13, 2008 at 10:39 pm

Comment #126496 by bluebird on February 13, 2008 at 11:16 am

Bats are so cool! Fortunately, bats are now more accepted by the public as the amazing, beneficial creatures that they are.

Unfortunately, the Pteropid fruit bat was found to be responsible for the Nipah virus, which killed 106 people in Malaysia and Singapore back in 1999:

http://en.wikipedia.org/wiki/Nipah_virus#Emergence_2

There is a 20 minute documentary on YouTube about the Nipah virus and its devastating effects in Malaysia (entire towns were abandoned - 1 million pigs were culled - a 700 million dollar industry was completely decimated). Please note that the video contains horrific images of pigs being culled by shooting:

http://youtube.com/watch?v=1Y1id_KZ06w

Other Comments by njwong

17. Comment #126676 by alfonso on February 13, 2008 at 11:24 pm

In the land of the blind, the one-eyed is king!

Don't you mean one-eared? ;-)

No I didn't I am not that smart, but your way is a much better one, thanks ;)

Other Comments by alfonso

18. Comment #126686 by jo5ef on February 14, 2008 at 12:34 am

Thanks Epinephrine for the interesting link though i'm bound to say that im a little dissappointed that megabats didnt turn out to be even bigger.
Echolocation is a great example of how even evolution can even create new senses. I'm curious as to how many there are as well as the 5 (or so) we know and love.

Other Comments by jo5ef

19. Comment #126740 by Azven on February 14, 2008 at 5:05 am

I believe that Douglas Adams had his character Dirk Gently give 10 for himself (ie, for humans). I have counted 11 in myself, but given that there's no real difference between smell and taste I could be argued down to 10.

Other Comments by Azven

20. Comment #128035 by MaxD on February 15, 2008 at 10:29 pm

The evolution of flight and echolocation in the bats is a fascinating chapter in evolutionary history, that raises all sorts of questions (why isn't the sky abuzz with flying mammals? And why do the mammals that do take to the air tend to be nocturnal?) It seems like many of these questions are largely worked out but they are an excellent example of the way the ecology of a system supplies selective pressures on organisms, while at the same time providing excellent examples of the limitations on the process. That is species aren't free to evolve willy-nilly. Anyway, I think bats are just a keen example of evolutionary processes.

Other Comments by MaxD