Constructional morphology within the head of hammerhead sharks (sphyrnidae)

2015 ◽  
Vol 276 (5) ◽  
pp. 526-539 ◽  
Author(s):  
Kyle R. Mara ◽  
Philip J. Motta ◽  
Andrew P. Martin ◽  
Robert E. Hueter
2017 ◽  
Author(s):  
Johnny Waters ◽  
◽  
Bonnie K. Nguyen ◽  
Lyndsie Elizabeth White

2005 ◽  
Vol 148 (5) ◽  
pp. 1143-1155 ◽  
Author(s):  
J. M. Quattro ◽  
D. S. Stoner ◽  
W. B. Driggers ◽  
C. A. Anderson ◽  
K. A. Priede ◽  
...  

2019 ◽  
Vol 15 (4) ◽  
pp. 20190004 ◽  
Author(s):  
Amanda M. Barker ◽  
Douglas H. Adams ◽  
William B. Driggers ◽  
Bryan S. Frazier ◽  
David S. Portnoy

Hybridization between closely related species has been documented across a wide range of taxa but has not been well studied in elasmobranchs. Hammerhead sharks have drawn global conservation concern because they experience some of the highest mortality rates among sharks when interacting with fisheries. Here we report on the detection of hybrids between the globally distributed scalloped hammerhead ( Sphyrna lewini ) and recently described Carolina hammerhead ( S. gilberti ) which are only known from the western Atlantic Ocean. Using a genomics approach, 10 first-generation hybrids and 15–17 backcrosses were detected from 554 individuals. The identification of backcrosses demonstrates hybrids are viable, and all backcrosses but one involved a scalloped hammerhead. All hybrids but one possessed Carolina hammerhead mtDNA, indicating sex-biased gene flow between species. Repeated hybridization and backcrossing with scalloped hammerheads could lead to the loss of endemic Carolina hammerheads.


2013 ◽  
Vol 6 (1) ◽  
pp. 21-42 ◽  
Author(s):  
Jörg Meibauer

German adjectival and nominal compounds like ratten+scharf (‘rat sharp’) sau+schlecht, (‘sow bad’) Hammer+auftritt (‘hammer performance’), Arsch+gesicht (‘arse face’) contain meliorative or pejorative elements as part of their structure. The left-hand evaluative members of these compounds are usually considered as so-called semi-prefixes. Contrary to recent approaches within constructional morphology ( Booij 2009 , 2010 ), I will argue that these elements are still lexemes, but that they have undergone metaphorical extension. Evidence stems from the consideration of right-hand members like Kommunisten+schwein (‘communist pig’), which have never been considered as semi-suffixes in a similar way. The metaphorical meaning of these heads and non-heads is systematically connected with expressive meaning. It will be shown that the criteria for expressive meaning proposed by Potts (2007) by and large apply. Furthermore, I will argue against a possible analysis in terms of conventional implicature, as proposed by Williamson (2009 , 2010 ) with respect to the meanings of ethnical slur terms like spic.


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Mark Royer ◽  
Kelsey Maloney ◽  
Carl Meyer ◽  
Edward Cardona ◽  
Nicholas Payne ◽  
...  

1985 ◽  
Vol 13 ◽  
pp. 88-101 ◽  
Author(s):  
Adolf Seilacher

This part of our course builds on the assumption that evolutionary change, although being stochastic in principle, is channeled by external and internal constraints to such a degree that it becomes quasi-predictable – or at least understandable. On this basis it makes sense to use the old methods of comparative morphology in the new framework of constructional morphology (Seilacher, 1970) in order to recognize patterns and to interpret them as trends and evolutionary pathways. For such an approach, bivalves are particularly suited:1. they deviate little from a common design (for instance they never lost their shell).2. their preservable hard parts adequately reflect the developmental biography of each individual.3. their shell form expresses the compromise between developmental constraints and functional paradigm with little interference from soft part anatomy, physiology and biotic interactions.4. they are diversified enough to provide many examples of parallel adaptations for model testing, particularly if we include the fossil record.


Sign in / Sign up

Export Citation Format

Share Document