Navigation Links
New fossil tells twisted tale of how flatfishes ended up with two eyes on one side of head
Date:7/9/2008

n 100 years. All previous studies of Amphistium mistakenly concluded that it had a symmetrical skull.

Examining the anatomy of Amphistium and Heteronectes with a diverse range of techniques (including CAT scanning and chemical preparation, which dissolves the rock surrounding the fossil skeleton), Friedman discovered that both represent primitive flatfishes with a somewhat asymmetrical skull. Nevertheless, in both cases the eyes remain on opposite sides of the head in adults. In other words, the fossils show incomplete asymmetry, displaying an intermediate condition between what is found in ordinary symmetrical fishes and extraordinary asymmetrical flatfishes.

This discovery rejects the notion that flatfishes must have arisen suddenly as "hopeful monsters" and documents two steps in the gradual assembly of one of the most bizarre body plans found among vertebrates. The position of Amphistium and Heteronectes within the fish evolutionary tree is confirmed by many aspects of their anatomy. Features unrelated to asymmetry link these fossils with flatfishes, but the specimens also show characters more primitive than those found in any living form.

Adding a further twist to the story, the right eye migrated in some specimens of Amphistium, while the left eye moved in other specimens. This is unlike most living species of flatfishes, where individuals are always right- or left-eyed. It also indicates that that mixed 'handedness' is primitive for flatfishes.

"There is a broad implication for the tempo and mode of evolution here," Friedman concluded. "Scientists had long assumed flatfishes must have arisen suddenly because they could not imagine the adaptive significance of intermediates, but this work delivers clear evidence that such intermediates did exist, and therefore, that flatfish asymmetry arose gradually."

The fossils described in Nature give clues to the lifestyle of th
'/>"/>

Contact: Greg Borzo
gborzo@fieldmuseum.org
312-665-7106
Field Museum
Source:Eurekalert

Page: 1 2 3 4

Related biology news :

1. Living fossils have long- and short-term memory
2. Ocean acidification -- another undesired side effect of fossil fuel-burning
3. A fossilized giant rhino bone questions the isolation of Anatolia, 25 million years ago
4. Scientists discover giant fossil frog from hell
5. Impacts of fossil fuels on fish and people
6. Oldest Australian crayfish fossils provide missing evolutionary link
7. 480-million-year-old fossil sheds light on 150-year-old paleontological mystery
8. Fossils excavated from Bahamian blue hole may give clues of early life
9. Rodent fossils allows to determine climate of the Iberian Peninsula 6 million years ago
10. 390-million-year-old scorpion fossil -- biggest bug known
11. Can plant-based ethanol save us from our fossil fuel addiction?
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/17/2014)... 15, 2014 Research and Markets ( http://www.researchandmarkets.com/research/s6qzt5/samsung_galaxy_s5 ... Galaxy S5 - Home Button Synaptics Fingerprint Sensor Technology ... http://photos.prnewswire.com/prnh/20130307/600769 Based on a ... introduces for the first time a fingerprint sensor in ...
(Date:12/17/2014)... Markets ( http://www.researchandmarkets.com/research/9zq33j/global_chemical ) has announced the ... report to their offering. ... in this market is the increasing demand for medical ... of patient data for quick and correct diagnosis during ...
(Date:12/11/2014)... and Markets , http://photos.prnewswire.com/prnh/20130307/600769 ... the addition of the "Biometrics Market in India ... One major trend emerging in this market is the ... more than one characteristic of an individual for verification ...
Breaking Biology News(10 mins):Samsung Galaxy S5 - Home Button Synaptics Fingerprint Sensor Technology Analysis 2Global Chemical Sensor Market 2015-2019: Key Vendors are Abbott Laboratories, Bayer, Hoffmann La-Roche, Johnson & Johnson, NGK Spark Plugs and Robert Bosch 2Biometrics Market in India 2015-2019: Key Vendors are 3M Cogent, NEC, Safran and Suprema 2
... decrease in yield and an increase in the concentration of ... with the results of previous studies which have shown a ... seeds in high ozone, these results (to be presented at ... on 29th June 2009) could signal a significant income loss ...
... serious demands for the organism, and this is true even ... the ancestors of present marine mammals initiated their return to ... new medium. Dr. Michael Berenbrink and his colleagues at Liverpool ... delivering oxygen to the muscles during locomotion, has been modified ...
... SALT LAKE CITY, June 29, ... use computers and may let amputees control bionic limbs. But existing devices ... Utah study shows that brain signals controlling arm movements can be detected ... it. ...
Cached Biology News:Natural-born divers and the molecular traces of evolution 2Reading the brain without poking it 2Reading the brain without poking it 3Reading the brain without poking it 4Reading the brain without poking it 5
(Date:1/22/2015)... 2015 Dr. Greg Leyer of UAS Labs ... Natural Supplements Pre-Conference seminar on probiotics in San Diego, CA. ... continuing education conference for health care professionals. This year’s pre-conference ... of probiotics in health. Dr. Leyer spoke about the emerging ...
(Date:1/22/2015)... (PRWEB) January 22, 2015 Selexis SA, ... mammalian Research Cell Banks (RCBs) used for drug discovery ... Cell Banks will include Next-Generation Sequencing (NGS) ... architecture de-risks biologic manufacturing by ensuring the integrity of ...
(Date:1/22/2015)... , Nueva Jersey , 22 de enero de ... Biomedical Research abre hoy su llamada a nominaciones para ... investigación científica ha hecho, o tiene el potencial para ... humana. Las nominaciones se aceptarán hasta el 15 de ...
(Date:1/22/2015)... , Jan. 22. 2015  Varian Medical Systems (NYSE: ... has been honored for its commitment to sustainability with inclusion ... Varian is the highest ranked healthcare equipment company among the ... during the World Economic Forum at Davos, Switzerland ...
Breaking Biology Technology:Selexis Generated Research Cell Banks Now Fully Sequenced Using Next-Generation Sequencing 2El Dr. Paul Janssen Award for Biomedical Research emite su llamada a los nominados para 2015 2El Dr. Paul Janssen Award for Biomedical Research emite su llamada a los nominados para 2015 3El Dr. Paul Janssen Award for Biomedical Research emite su llamada a los nominados para 2015 4Varian Honored Among World's 100 Most Sustainable Corporations 2
... 2011 Optimer Pharmaceuticals, Inc. (Nasdaq: OPTR ... financial results after the NASDAQ Global Market closes on ... that day at 5:00 p.m. Eastern Time (2:00 p.m. ... for the third quarter as well as provide a ...
... 2011 At the eighth annual Indiana Life Sciences ... the founder of Bloomington-based Cook Group and one of ... M. Watanabe Life Sciences Champion of the Year award.  ... a tribute to his friend and colleague. ...
... BOSTON, Oct. 26, 2011 13 leading industry speakers will ... Electronic Trial Master Files on November 14-15, 2011 in ... educational exploration of the major shift taking place in the ... Often called the heart of a clinical ...
Cached Biology Technology:Optimer Pharmaceuticals to Host Conference Call and Webcast to Discuss Third Quarter 2011 Financial Results 2BioCrossroads Awards Indiana Life Sciences Leaders 2BioCrossroads Awards Indiana Life Sciences Leaders 3BioCrossroads Awards Indiana Life Sciences Leaders 4
The AVR9-8 stream-select valve is a 9-port, 8-position valve for use with the BioLogic DuoFlow system. This valve is used for high-pressure stream selection....
... Versatile stain for staining RNA (bluish-purple), DNA (blue), proteins ... TLC ≥ 90 % Cation traces: Ca ≤ 10 ... Cr ≤ 5 mg/kg Cu ≤ 5 mg/kg Fe ... 5 mg/kg Mn ≤ 5 mg/kg Na ≤ 50 ...
... Biometras Tpersonal thermocycler provides maximum performance ... generation of Peltier elements, high heating and ... to short run times. With a maximum ... Tpersonal provides half the capacity of much ...
... One-Step Deparaffinization Solution is available ... is an easy-to-use reagent for dewaxing ... immunohistochemistry, in situ hybridization, or other ... paraffin removal consists of dipping the ...
Biology Products: