{"id":1975,"date":"2022-02-14T15:15:50","date_gmt":"2022-02-14T15:15:50","guid":{"rendered":"https:\/\/as.vanderbilt.edu\/biological-sciences\/?p=1975"},"modified":"2022-03-03T17:11:34","modified_gmt":"2022-03-03T17:11:34","slug":"vanderbilt-researcher-outlines-how-whales-sensory-systems-have-evolved-through-imaging-technology","status":"publish","type":"post","link":"https:\/\/as.vanderbilt.edu\/biological-sciences\/vanderbilt-researcher-outlines-how-whales-sensory-systems-have-evolved-through-imaging-technology\/","title":{"rendered":"Vanderbilt researcher outlines how whales\u2019 sensory systems have evolved through imaging technology"},"content":{"rendered":"
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Dec. 2, 2021, 9:00 AM<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n

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By Andy Flick, Evolutionary Studies Initiative scientific coordinator<\/i><\/p>\n

If you\u2019ve ever had an ear infection that made you dizzy or unbalanced, the infection likely was affecting your vestibular complex\u2014part of the intricate system of hard and soft tissues that make up the inner ear. Knowledge of this structure has been made possible through computed tomography scans\u2014imaging technology that continues to shape our understanding of evolution across species.<\/p>\n

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Rachel Racicot with beluga whale Juno at Mystic Aquarium in Connecticut (Darroch)<\/figcaption><\/figure>\n

In a review of a century of research on sensory systems of whales,\u00a0Rachel Racicot<\/a>, research assistant professor of biological sciences, describes advances in the field and key questions that remain. The article, \u201cEvolution of whale sensory ecology: Frontiers in nondestructive anatomical investigations<\/a>\u201d was published on Sept. 21 in the journal\u00a0The Anatomical Record<\/i>.<\/p>\n

\u201cAnatomy and morphology are areas of research where we are making huge discoveries, especially when we can include fossils to help inform our understanding of evolution, function and convergence that we wouldn\u2019t otherwise be aware of,\u201d said Racicot, also a faculty member of the\u00a0Evolutionary Studies Initiative<\/a>. \u201cThe evolution of sensory systems in whales (and other groups) can be studied using nondestructive CT scanning and other techniques.\u201d<\/p>\n

When animals die and become fossils, soft tissues, including those in the ear, break down, and bony areas become scattered with empty pockets where these soft tissues were once housed remain. By recreating these areas digitally, researchers can determine the frequencies animals could hear. One of the questions this technique addresses is whether echolocation evolved independently in different whale groups.<\/p>\n

According to Racicot\u2019s review, it is thought that the first completely marine whales used low-frequency communication, which could travel long distances. Later on, a group of whales evolved higher frequency communication and developed echolocation. In 2019,\u00a0she discovered<\/a>\u00a0that echolocation may have evolved twice and in separate groups of whales.<\/p>\n

Whales aren\u2019t the only animals whose ears are being examined with imaging techniques; researchers are also looking at dinosaurs, birds and other mammals. \u201cAnother cool study found that cochlear coiling has independently evolved at least twice: once in\u00a0monotremes\u00a0<\/i>(platypus) and another time in\u00a0therians<\/i>\u00a0(live-bearing mammals)\u2014something that we wouldn\u2019t have been able to detect without including fossils in the analysis,\u201d she explained.<\/p>\n

Racicot\u2019s review also acknowledges the open questions about how the whale sensory system has evolved, which are critical to our understanding of the overarching evolutionary trends in ocean-dwelling mammals that have proven difficult to access and study.<\/p>\n

This work is already informing and directing the research of Racicot and her trainees. Several undergraduates in her lab are reviewing a data-intensive sample of\u00a0ziphiid<\/em>\u00a0<\/i>(beaked whale) inner ears to understand their hearing sensitivities. \u201cWe can\u2019t directly measure their hearing ranges easily because they are deep sea diving animals, but there\u2019s a lot of interest because they tend to strand when naval sonar is used,\u201d Racicot said.<\/p>\n

\u201cMany of the big questions we\u2019ve answered using nondestructive imaging like CT scans in studying sensory evolution in whales have led to more questions\u2014which means there are so many more discoveries to be made!\u201d<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Dec. 2, 2021, 9:00 AM By Andy Flick, Evolutionary Studies Initiative scientific coordinator If you\u2019ve ever had an ear infection that made you dizzy or unbalanced, the infection likely was affecting your vestibular complex\u2014part of the intricate system of hard and soft tissues that make up the inner ear. Knowledge of this structure has been…<\/p>\n","protected":false},"author":11,"featured_media":1976,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[8],"acf":[],"jetpack_featured_media_url":"https:\/\/cdn.vanderbilt.edu\/vu-cas\/wp-content\/uploads\/sites\/5\/2022\/02\/22133604\/Rachel-Raciot-300.jpg","_links":{"self":[{"href":"https:\/\/as.vanderbilt.edu\/biological-sciences\/wp-json\/wp\/v2\/posts\/1975"}],"collection":[{"href":"https:\/\/as.vanderbilt.edu\/biological-sciences\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/as.vanderbilt.edu\/biological-sciences\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/as.vanderbilt.edu\/biological-sciences\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/as.vanderbilt.edu\/biological-sciences\/wp-json\/wp\/v2\/comments?post=1975"}],"version-history":[{"count":2,"href":"https:\/\/as.vanderbilt.edu\/biological-sciences\/wp-json\/wp\/v2\/posts\/1975\/revisions"}],"predecessor-version":[{"id":1978,"href":"https:\/\/as.vanderbilt.edu\/biological-sciences\/wp-json\/wp\/v2\/posts\/1975\/revisions\/1978"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/as.vanderbilt.edu\/biological-sciences\/wp-json\/wp\/v2\/media\/1976"}],"wp:attachment":[{"href":"https:\/\/as.vanderbilt.edu\/biological-sciences\/wp-json\/wp\/v2\/media?parent=1975"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/as.vanderbilt.edu\/biological-sciences\/wp-json\/wp\/v2\/categories?post=1975"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/as.vanderbilt.edu\/biological-sciences\/wp-json\/wp\/v2\/tags?post=1975"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}