echolocation
neurophilosophy | May 25, 2011WE all know that bats and dolphins use echolocation to navigate, by producing high frequency bursts of clicks and interpreting the sound waves that bounce off objects in their surroundings. Less well known is that humans can also learn to echolocate. With enough training, people can use this ability to do extraordinary things. Teenager Ben Underwood, who died of cancer in 2009, was one of a small number of blind people to master it. As the clip below shows, he could use echolocation not only to navigate and avoid obstacles, but also to identify objects, rollerskate and even play video games…
jhalper | July 14, 2010Bats may be using an innate understanding of physics to track their prey in the dark. Institute neurobiologists trained Egyptian fruit bats to fly to food in a dark lab. They found that in some situations the bats sweep their sonar to either side, catching their "prey" on the beam's slope, while at other times they point their beams head-on. Some physical calculations showed that the changes in intensity near the slope help in getting a fix on the target's direction - a very efficient strategy for localizing targets - while the direct beam is preferable for discerning a hard-to-identify…
razib | January 25, 2010In Bats and Whales, Convergence in Echolocation Ability Runs Deep:
..."However, it is generally assumed that most of these so-called convergent traits have arisen by different genes or different mutations. Our study shows that a complex trait -- echolocation -- has in fact evolved by identical genetic changes in bats and dolphins."
A hearing gene known as prestin in both bats and dolphins (a toothed whale) has picked up many of the same mutations over time, the studies show. As a result, if you draw a phylogenetic tree of bats, whales, and a few other mammals based on similarities in the…
edyong | January 25, 2010
Millions of years before humans invented sonar, bats and toothed whales had mastered the biological version of the same trick - echolocation. By timing the echoes of their calls, one group effortlessly flies through the darkest of skies and the other swims through the murkiest of waters. It's amazing enough that two such different groups of mammals should have evolved the same trick but that similarity isn't just skin deep.
The echolocation abilities of bats and whales, though different in their details, rely on the same changes to the same gene - Prestin. These changes have produced such…
neurophilosophy | July 17, 2009BATS use sonar, or echolocation, to navigate complex environments, and also to forage and then accurately pinpoint the flying insects on which they prey. Insects in turn have evolved various counter-measures to evade capture. Some species have ears which are in tune to the echolocation signals, while others are capable of performing complex evasive flight maneuvers in response to the clicks produced by attacking bats.
Tiger moths have evolved the ability to produce ultrasonic clicks in response to attacking bats. However, the function of these clicks was unclear, although decades of research…
zooillogix | February 15, 2008For years debate has raged amongst bat researchers as to whether or not bats were really just "flying rodents..." World of Darkness at the Bronx Zoo when he heard a mother tell her young children this totally incorrect animal fact. As bats were his favorite animal, he became angry and marched up to the mother and informed her that she was totally wrong, told her to "read the signs if she didn't know the facts" and then filled her in on a few million years of evolutionary history
Does this limestone make me look fat?
Anecdotal stories about Benny's long lost intellectually-promising…