Bio325
Functional morphology of animals
• Professor Glenn Morris -- emeritus
• To arrange meetings or just ask questions contact via e-mail:
glenn.morris@utoronto.ca
• Office hour following Tues lecture
• ‘Office’ 2023B (Tuzo Research Wing).
Announcements
• Website: http://www.erin.utoronto.ca/~w3bio325/, can get there via
portal: old labs not removed until Thursday
• Lectures: Tues. & Thurs. 8 am 1140; selected topics posted on web
• Sources: J. experimental Biology et al., books on reserve; no text
• Labs: Tues, Wed., Thurs, Fri., 2-5 pm, 4068; Susan Dixon technician
• Lab outline: downloaded each week from website; bring to class.
• Dissecting: forceps as fine as possible, microscissors provided
• TAs: Colin Demill, Lisa Robertson, Michele Taffs, Raani Sarkar
•
Marking scheme
Midterm Test
Lab drawings &/or quizzes
Final Lab Practical
Final Exam
20% -- Feb. 17
10%
20%
50%
Course Theme
• This course is about the form of animal body parts and their behaviour:
we explain how structures work with mental models: mental constructs.
To decide how they work you often have to watch structures behaving.
Organ behaviour is what an organ does. Wing behaviour is what a wing
does.
• ‘What a structure does’ can be said simply, e.g., a wing is a structure that
flies or in a complicated way involving: models of lift, radial stop,
pleurosternal muscles, etc.
Evolutionary questions: function: adaptive consequence
• Why is an evolutionary question. Why has a structure evolved in a
particular form? Inherited variations in structure come to predominate in
a population because they allow the individual animals that have them to
live and reproduce more successfully than their competitors. Structural
features produced by selection in a certain context are said to be
adaptations. Function is adaptive consequence. Features that have not
been selected are said to be effects. Not every structure has been, or
continues, subject to selection; e.g., vestigial (degenerate) structure is not
being selected.
Terminology
• Naming parts: tentorium, femur, tibia, apodeme, muscular
hydrostat, coelom, haemocoel, gut
• Describing in words: basad, distad, promote, remote, adduct,
abduct, anterior, pronate, dorsal, extrinsic, sclerotized,
membranous, emarginate, strain energy storage, stridulation
• Drawing: visual study, filtering, photographic records
Imagine it otherwise
• Alternative form: in deciding how a structure functions (and
in arriving at hypotheses of adaptation) it is useful to imagine
a structure in a form other than the way it appears now. And
then to ask how it would work in this alternative form. Would
it be as effective and how would it promote survival in the
animal?
• Human pinnae
• Flatworm vs annelid as burrowers
• Fish or birds with pinnae.
• Broad fleas
• Polar bears without fur
Taxonomy
• You need knowledge of animal phyla: some species, but mostly
PHYLA. You should know the major phyla and their diagnostic
features – their body plans [e.g., Phylum Arthropoda: exoskeletal,
metameric (segmented) animals with tagmata, jointed appendages,
ventral nerve cord etc. You should know the major structural
differences between an arthropod and a vertebrate [e.g., Phylum
Chordata: subphylum Vertebrata: endoskeletal animals, notochord,
dorsal nerve cord, etc. Topics are diverse and beyond the theme the
course can appear incoherent, though there is a trend as lectures
proceed to go from locomotion (skeleton and muscle) toward
feeding and digestion, circulation, gas exchange, then excretion,
reproduction -- and finally nervous and sensory systems.
Comparison
• We underestimate the number of different species
• There are over 5000 described species of crickets; >7000 described
species of katydid
• Comparing stridulatory mechanisms among these taxa: great diversity;
there is no single mechanism for stridulation – no single katydid generator
– no single cricket generator
• Comparing gives insight into different adaptations; structural diversity
offers clues to function: e.g., inflated tegmina.
Tentorium
• Truss
• Resists tension and
compression
• Anchors head corners
Prognathous tentorium
Stridulation as structural adaptation
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Insect flight: tegmina, macropterous, brachypterous: change in function: evolution
working with what is already there.
Montealegre-Z F., Morris G.K., Mason A.C. 2006. Generation of extreme ultrasonics
in rainforest katydids. Journal of experimental Biology 209: 4923-4937.
Montealegre-Z F., Windmill J.F.C., Morris G.K., Robert D. 2009. Mechanical phase
shifters for coherent acoustic radiation in the stridulating wings of crickets: the
plectrum mechanism. Journal of experimental Biology 212: 257-269.
Original literature: Inside JEB