Animal Physiology Exam 1

• Why is it important to study physiology in non-human animals? Include both a basic and an applied reason.

  • Basic: advantages of knowledge
  • Applied: to solve
• Which organ do fish use for osmoregulation, respiration, pH balance, and excretion?

  Gills
• Name at least two fish species from different taxonomic orders that generate electric fields. What is the difference between weakly and strongly electric fishes? Explain why this ability is adaptive.

  • Weak electric fishes: generate only weak electric field for communication and sensory detection (ex. mormyrids)
  • Strong electric fishes: stun prey (ex. Torpedo ray and electric eels)
  • This is adaptive because the body trunk should not participate in locomotion since axial flexion interferes with the ability to make electricity
• What is a conserved physiological structure or process, and what do they suggest about evolutionary relationships? Provide an example.

  • Conserved physiological structure ~ The presence of similar genes, portions of genes, or chromosome segments in different species, reflecting both the common origin of species and an important functional property of the conserved element.
• Name the specialized cells that create electricity and the cell type from which they derive. How is the electric organ an example of evolutionary convergence? Why is it also a performance tradeoff?

  • Electrocytes ~ battery-like cells that produce electricity, which evolved from myocytes in the ventral skeletal muscle of the body
  • Non contractile muscle cells, hence they cannot be used in swimming

  Ex. torpedo ray could only swim using its tail because they have an electric organ in the abdomen, thus cannot move its body to swim
• Define the following terms from evolutionary biology: convergence, homology, constraint.

  • Convergence ~ process where 2 distinct lineages evolve a similar characteristic independently
  • Homology ~ have the same evolutionary origin; characteristics present in multiple species due to shared evolutionary lineage

  Constraint ~ boxed in by genetic blueprint, which has given them predictable characteristics according to their taxa; selection must work with what it has for evolution
• Why can’t an animal be physiologically successful in every environment, since such a super-creature would have the highest fitness?

  Natural selection is a slow process and seeing as environments are constantly changing, evolution cannot keep up to create the ideal organism
• Define physiological plasticity. How does physiological plasticity differ fro

  • Physiological plasticity ~ the ability of an organism to adjust their physiology to different environments
  • Developmental plasticity/morphology is different as it is fixed after development, while physiological traits can fluctuate, adjust, and assimilate to changing conditions
• Describe the basic principle of homeostasis as it applies to living organisms. How does this process work? Do these animals achieve an equilibrium with their environment? Name at least 2 physical parameters that most animals monitor and regulate.

  • Homeostasis ~ maintaining a stable internal balance in a body’s system
  • Homeostasis works by using antagonistic pairings
  • Homeostasis requires vigilant monitoring of the body’s internal conditions → when sensors detect change a response is activated using NTs or hormones

  Ex. Glucose Homeostasis → insulin lowers blood sugar and glucagon increases it
• Regulated parameters:

  • Respiratory and circulatory systems to exchange gas and regulate blood pH
  • Metabolism using protein turnover and nutrient storage/breakdown
• How are the various levels of biological organization “nested”?

  • Emergent property ~ new parameters an entity gains when it becomes part of a bigger system
• What is an emergent property in relation to these levels?

  Biological Organization:

  1. Atoms
  2. Molecule (ex. myosin filament)
  3. Cell (ex. myocyte)
  4. Tissue (ex. smooth muscle)
  5. Organ (ex. stomach)
  6. System (ex. digestive system)
  7. Organism → phenotype
  8. Supra-organismal/Ecophysiological
• Define the following terms from evolutionary biology: convergence, homology, constraint.

  • Convergence ~ process where 2 distinct lineages evolve a similar characteristic independently
  • Homology ~ have the same evolutionary origin; characteristics present in multiple species due to shared evolutionary lineage

  Constraint ~ boxed in by genetic blueprint, which has given them predictable characteristics according to their taxa; selection must work with what it has for evolution
• Given the text: The nervous system consists of neurons, neuroglia, and extracellular fluid. Neurons are specialized cells that transmit information rapidly throughout the body via electrical signals called action potentials. They communicate with other neurons through synapses, small gaps between two neurons. Neuroglial cells support and protect neurons.
• Define physiological plasticity. How does physiological plasticity differ from developmental plasticity? How will environmental conditions affect a plastic trait compared to a canalized trait?

  • Physiological plasticity ~ the ability of an organism to adjust their physiology to different environments
  • Developmental plasticity/morphology is different as it is fixed after development, while physiological traits can fluctuate, adjust, and assimilate to changing conditions
• Describe the basic principle of homeostasis as it applies to living organisms. How does this process work? How does this process work? Do these animals achieve an equilibrium with their environment?

  • Homeostasis ~ maintaining a stable internal balance in a body’s system
  • Homeostasis works by using antagonistic pairings
  • Homeostasis requires vigilant monitoring of the body’s internal conditions → when sensors detect change a response is activated using NTs or hormones
• Name at least 2 physical parameters that most animals monitor and regulate

  Ex. Glucose Homeostasis → insulin lowers blood sugar and glucagon increases it

  Ex. Thermal Sensors → sensors tell the brain when we drift from our 37 C temp; if cold there’s vasoconstriction and shivering (brown fat for nonshivering animals), while if hot blood vessels dilate and we sweat

  • Regulated parameters: 
  • Respiratory and circulatory systems to exchange gas and regulate blood pH
  • Metabolism using protein turnover and nutrient storage/breakdown
• How are the various levels of biological organization “nested”? What is an emergent property in relation to these levels? Give an example.

  • Emergent property ~ new parameters an entity gains when it becomes part of a bigger system

  Ex. phenotypic adaptation of an organism compared to the vulnerable cells it is made up of

  Biological Organization:

  1. Atoms
  2. Molecule (ex. myosin filament)
  3. Cell (ex. myocyte)
  4. Tissue (ex. smooth muscle)
  5. Organ (ex. stomach)
  6. System (ex. digestive system)
  7. Organism → phenotype
  8. Supra-organismal/Ecophysiological
• Contrast genotype and phenotype. How is physiology related to each concept? How can natural selection act on a phenotype to give rise to a physiological adaptation?

  • Genotype ~ genetic
  • Phenotype ~ physical differences
  • When a phenotype that is better suited for an environment is produced, natural selection favors the adaptive trait and allows it to be passed on genetically as an adaptive trait
• How does ecological physiology differ from cell or organismal physiology in terms of the scope of what is measured by scientists?

  • Ecological physiology looks at the dynamic between physiological responses to/ effects on the environment
  • cell/organismal physiology looks at a small scale of the activities a single organism or cell performs
• Describe the relationship between physiological tolerances and species’ distribution.

  Seeing as an animal cannot survive outside of its physiological tolerance, the species is limited to the range and population density within a particular area
• Describe the relationship between physiological tolerances and species’ distribution.

  Seeing as an animal cannot survive outside of its physiological tolerance, the species is limited to the range and population density within a particular area
• Why can evolving physiological specializations be risky? How are anthropogenic impacts affecting specialists such as an alpine rodent or a pollinator

  • Physiological specializations are risky compared to generalized ones because the world and environment is constantly changing
  • Anthropogenic impacts, like climate change and habitat loss, impacts specialists because they are limited in the resources they are adapted to using and are not suited to quickly switch from one resource to another when theirs is depleted
• Name two aspects of an animal’s life history (or life cycle) that are linked to specific subdisciplines within physiology?

  Reproduction and development
• Why are phylogenetics integral to the study of comparative physiology? What does physiological divergence suggest about ecological adaptation?

  • hylogenetics are important because it allows us to reconstruct the past evolutionary history of a species or taxa to then compare to other species to find relationships and find adaptations that came to be to make survival better; multiple levels to compare
  • Physiological divergence makes suggestions on the cladogram (which is built on adaptations) as there is less physiological divergence/ more similarity between the nearest neighbors
• How do the Organismal and Comparative Systems approaches to physiology differ?

  • Organismal: has the species in the center to branch off into its evolutionary history, anatomy and physiology, and ecology and environmental change

  Comparative: has the integrated physiological system in the center to branch off into its form and function, phylogenetic diversity, and ecology and environmental change
• Explain how usage of the terms “evolution” and “design” differs when referring to biological systems versus human technology. Which of these is more contingent on past events?

  • Evolution in technology is able to start from scratch, while in biology natural selection must work with the same scraps are the previous design → is limited

  Designs in technology have a clear designer that has a vision on what they want and is progressive, while natural selection is constrained to a standing variation and works slowly overtime with no progressive goal
• Why might it be erroneous to perceive naturalness as inherently pure and good compared to the artificial? Why can it be dangerous to elevate natural ecological interactions and animal behavior as a model for morality or justification for socioeconomic policies?

  Animals act on their desires and what feel good to them, as well as the norms within their group rather than the possible results. Animals don’t just mate to produce offspring or because they have inherent feelings towards those they are mating with, but are doing that because of biological urges
• In pre-scientific times, someone suffering from epilepsy would have been easily thought to be under the power of demonic forces, since no neurobiological explanation yet existed. Name this logical fallacy.

  “God of Gaps” ~ supernatural explanations are not satisfactory as we understand more; shrinks daily
• How have the last several centuries of scientific inquiry changed what we ascribe to the spiritual domain? how might our attitudes change towards those afflicted by mental illnesses?

  The logical fallacy is believing that all things could be explained with the broad answer of a supernatural force, but in reality we may use scientific reasoning to explain and understand causes that were previously put into the box of supernatural and out of our control
• Given the second law of thermodynamics, how can biological complexity evolve from the simple?

  • Evolution can create complexity because natural selection is a gradual nonrandom force
• how can poorly-performing, rudimentary physiological processes evolve into highly efficient and specialized systems without cognitive awareness and long-term planning?

  • Adaptive evolution occurs from nonrandom accumulation of what traits work best, but it is not efficient as it takes a long time and a lot of energy.
  • Based on fitness that is relative to local condition
• Is this evolutionary force random? Are evolutionary-shaped designs necessarily the most cost effective and efficient solutions to physiological challenges?

  • There is no cognitive decision to evolving
  • Evolution can be cost effective as there are tradeoffs and possibilities that these evolutionary traits may be maladaptive later on. They are not the most efficient, but they do allow for opportunity for long term advantages
• What is a maladaptation and how does it arise? Give an example of how a formerly beneficial trait can become maladaptive, either naturally or as the result of anthropogenic modifications to the environment.

  • Evolutionary mismatch ~ evolved traits that were once advantageous but became maladaptive due to environmental changes
  • Maladaptation ~ when something is not providing adequate adjustment to the environment
  • Arises when formerly adaptive traits become useless because the environment has changed → scars/baggage of evolution
• How are animals constrained by the generations that came before - i.e., their ancestral lineage?

  Constrained as evolution and natural selection cannot develop backwards, but must use the already existing characters and pieces to adapt the species
• How does geneticist Theodosius Dobzhansky’s famous quote, “Nothing in biology makes sense except in the light of evolution” (the title of his 1973 essay) relate to peculiar or regressive traits observed in the bodies of animals? 

  Evolution explains what features came from what origin, which helps explain why some species adapted traits that appear maladaptive, but were actually constrained to the previous design
• Animals can be phylogenetically classified by the anatomy and embryology of their digestive system. Which animal taxa lack true alimentary canals? Of the animals that do have complete gastrointestinal tracts, which taxa first develop mouth openings in the gastrula stage? In contrast, which first develop an anus? Name these two categories.

  Protostomes first developed mouths while Deuterostomes first developed an anus.
• Why do cells secrete proteinaceous substances into an extracellular matrix? Name a common type of animal connective tissue and a protein that it is made of.

  Cells secrete proteinaceous substances into the extracellular matrix to allow movement throughout the ECM.   Muscle facia is made of the proteins collagen and elastin.
• List at least two evolutionarily-conserved features present in all/most animals.

  Myosin molecular motors, metabolic pathways, endocrine signaling (hormones), gas exchange, and other major physiological systems.
• Explain why cephalization was an important evolutionary innovation.

  Cephalization (having a head) was an important evolutionary adaptation as it allowed for more complex mouth structures for capturing and processing food.