Abstract
The domestic dog (Canis familiaris) is the species of greatest morphological diversity among mammals. Seventy-four Labrador Retriever dogs- 27 males and 47 females – were used in this experiment. Thirty quantitative biometric characteristics, related to morphology were measured. The objective of this study was to evaluate the morphometric traits of the Labrador Retriever breed to establish descriptive biometric attributes that may show sexual dimorphism through principal component analysis (PCA) and discriminant analysis (DA). The PCA was processed using all the variables and performing a pre-selection of the most correlated variables. The DA was performed for the 30 variables and also for the five most correlated variables with the first component (CP1), in order to classify new individuals. The PCA was able to identify sexual dimorphism in size, with both the 30 original variables as with the pre- selected variables, the latter optimized the reduction to two principal components. The DA was able to discriminate the two populations, both for 30 variables as for the five variables most correlated with the CP1. The functions with five variables can be used to classify other purebred dogs for sex, with an error of about 6.75%.
Highlights
Sexual dimorphism can be considered a key evolutionary trait that can lead to important biological discoveries (AJAYI et al 2012)
The objective of this study was to evaluate the morphometric traits of the Labrador Retriever breed to establish descriptive biometric attributes that may show sexual dimorphism through principal component analysis (PCA) and discriminant analysis (DA)
Sexual dimorphism in mammals can occur in several ways, including anatomical and physiological characteristics that can serve for different purposes in the genesis, development and raising offspring
Summary
Sexual dimorphism can be considered a key evolutionary trait that can lead to important biological discoveries (AJAYI et al 2012). Secondary sexual characteristics are attributes that facilitate mate choice, even if this feature is of little benefit or no apparent addition to its survival. These distinctions tend to be more pronounced in polygamous, with day habits and living in an open habitat (MCPHERSON; CHENOWETH, 2012) species. These features are considered as physical or behavioral attributes genetically transmitted to offspring. According to Polák e Frynta (2010), the artificial breeding during domestication implies pressures of different types of selection that occurs under natural conditions, and it has different consequences on the body size. The geographical isolation and selection for various tasks such as herding, guarding, hunting, and company have created specialized subtypes within the species
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
