The Antleryzer: Automated Analysis of Antlers

1. The Antleryzer: Automated Analysis of Antlers

2. Problem Statement Given an antler, produce an automated analysis of its morphology, with an emphasis on symmetry. Formally speaking, the system is a mapping from a pair of antlers to the co-symmetry index (CSI), which is a real value in [-1,1], such that two antlers are most symmetric with CSI = 1.

3. Properties • Reproducibility • Objectiveness • Automation • Ease of use • Robustness • Configurability • Cooperation

4. Reproducibility • The system would always yield similar results for similar antlers, regardless of time, place, and operator

5. Objectiveness • The system would, ideally, portray the consensus of subjective grading by human observers, while normalizing the inter-observer discrepancies

6. Automation • The system would require minimal human intervention

7. Ease of use • Operating the system and viewing the results would require no previous knowledge

8. Robustness • The system would be parameter-free, in the sense that it would not require special parameter tuning for each antler

9. Configurability • The system would be easily configurable for use with other antlers and species, and allow selection of measurements and tweaking

10. Cooperation • The system would be free and allow contributions from the community. Its subroutines and data would be available under open-source license

11. Motivation • Determine whether symmetric antlers of Persian Fallow Deer give the buck an advantage in mating and dominance • The automation would replace manual measurements and allow a large-scale analysis - Applicable to other members of the Cervidae family?

12. Motivation • Examine synchronically pairs of antlers of individuals from the same year • Examine diachronically antlers of the same individual during his coming of age

13. Previous work • Malyon & Healy (1994) • E. Markusson & I. Folstad (1997) • R. J. Putman & M. S. Sullivan (2000) • L. Bartos,  G. Bubenik & E. Kuzmova (2012) • R. Rabinovich

14. Malyon & Healy (1994)

15. Malyon & Healy (1994)

16. E. Markusson & I. Folstad (1997) • Fluctuating asymmetry (FA) is defined as small random deviations from perfect bilateral symmetry, where the signed differences between the two sides are normally distributed with a mean value of zero. • FA is inability to complete identical bilateral symmetrical traits. Environmental stress (e.g., pollution, extreme temperatures) affect FA.

17. E. Markusson & I. Folstad (1997) • Large Symmetric Hypothesis (LSH)In ornamental characters large traits show low asymmetry. • Consistent with the handicap principle. • Sexually selected condition-dependent ornaments are often subjected to directional selection for size. Individuals with large ornaments are likely to develop lower asymmetry in ornaments than individuals with small ornaments

18. E. Markusson & I. Folstad (1997) • Visible vs Non-VisibleNegative relationship between size and asymmetry in the visual measures (i.e., length, number of tines) but not in the non-visual (i.e., weight ,volume). • symmetry in visual antler characteristics, as opposed to symmetry in non-visual characteristics, is subjected to directional selection • a visual signaler-receiver system is important in the evolution of the morphology of reindeer antlers.

19. R. J. Putman & M. S. Sullivan (2000) • no relationship between asymmetry in antler length and population density or body mass. • relationship between asymmetry anddeviation from maximum cohort body weight. • If it’s some index of competitive success or increasing environmental stress, asymmetry in antler length relates in some way to developmental stress

20. R. J. Putman & M. S. Sullivan (2000) • asymmetry in antler length declined with animal age, with antlers of 2 years or older showing greater symmetry. • a hypothesis: despite continued competition there is a changing balance of selection pressure as animals reach maturity • increased pressure from sexual selection produces more symmetrical ornaments

21. R. J. Putman & M. S. Sullivan (2000) • No consistent ‘bias’ of left-handedness or right-handedness, same number of animals with left antlers longer than right or right longer than left.

22. R. J. Putman & M. S. Sullivan (2000) • The significant drop in asymmetry is observed between yearlings and animals of two years of age, with no difference in asymmetry recorded between two year olds and older bucks. • BUT, males rarely become sexually active and competing for mates until they are fully mature at 4 or 5 years of age

23. R. J. Putman & M. S. Sullivan (2000) • This would perhaps suggest a lesser role of sexual selection and argue that the decline in asymmetry may be primarily due to a reduction in environmental stress over the period of antler development once animals have passed the critical yearling phase

24. Measurements • Angles • Distances Euclidean Geodesic • Perimeters • Volumes

25. Angles • Elevation • Azimuth

26. Euclidean Distance

27. Geodesic Distance

28. Perimeters

29. Volumes

30. GUI

31. Project Management WikiIssue TrackerCalendar

32. Project Management

33. Challenges • Automatic detection of the coronet

34. Challenges • Paucity of data

35. Challenges • Small tines

36. Q & A