Atmospheric Oxygen, Giant Paleozoic Insects and the Evolution of Aerial Locomotor Performance

This theory states that as exercise begins, rate of breathing increases rapidly, and in order for the air to be warmed and saturated with water as it is inhaled, water vapor from the respiratory epithelium must be contributed. This contribution leads to hyperosmolarity of the epithelium, which causes bronchoconstriction through a series of undetermined events. This can be supported by the fact that inhaling hyperosmolar saline at rest will cause bronchoconstriction.

Moreover, theropods were in fact large dinosaurs with “tiny arms, huge legs and a tail” (Lyndon, 2009). Two, the ground up evolution theory works against the facts of gravity and is thus a “highly improbable” explanation (Lyndon, 2009). Furthermore, the incline theory is unreliable because it works against logic (Lyndon, 2009). The Theropod’s legs remained small and did not evolved (Lyndon, 2009). “One would think that the legs of these creatures might evolve” to larger and “more muscular from running up ramps” (Lyndon, 2009). One might question why would they instead grow aerodynamic wings rather than larger lower body structure? Furthermore, evolution states theropods were able to achieve flight without an “intelligent brain among them”, yet it took human beings thousands of years to achieve such ability (Lyndon, 2009). These odds appear to be highly improbably (Lyndon, 2009). Lastly, in correlation with the evolution of insect flight during the Carboniferous Period, all the evidence regarding insect flight is that when they first appeared “they were skilled fliers” (Lyndon, 2009). The same is said of the evolution of bird flight; they were born skilled in the art of flight (Lyndon,

The author argues that the Pterosaurs were cold-blooded animals and they couldn't produce enough energy for flying by flapping. Conversely, the lecturer brings up the idea that the Pterosaur's body was covered by hair and this feature could efficiently isolate the heat in their body. This feature is common between warm-blood animals for saving energy. Therefore, these animals could have fast enough metabolic activity and efficient saving energy feature to produce and save energy for flight.

The chthonic hypothesis, as proposed by J. Lighton , suggests that the discontinuous gas exchange system used has evolved to accommodate insects that live in hypoxic conditions for the large majority of their lives. It is plausible that the respiratory system of insects is not the most efficient at CO2 diffusion under normocapnic conditions (21% O2 in the atmosphere). This system consists of external valve like openings, called spiracles, that channel oxygen into the body and allow CO2 to exit. From the spiracle, oxygen is sent through a series of progressively narrowing tracheae and tracheoles, and is diffused directly into the tissue and cells. This process relies mainly on passive diffusion and therefor internal and external gas pressures. Emekci et al examined the respiratory patterns of Tribolium castaneum in environments with atmospheric oxygen contents of 1%, 2%, 3%, 5%, 10%, and 15%. In adult specimens, CO2 output was high at 3-10% O2, with a respiratory quotient of 1.18 at 5%. This can be compared to the respiratory quotient of 0.88 observed at 21% O2. This research supports the theory that normocapnic conditions are not the optimal conditions for the respiratory system of insects to function under due to its designs that relies on environmental gas pressures and concentrations to facilitate

Altitude training is practised by endurance athletes who train for several weeks at high altitude, Over 2,500 metres above sea level, or at intermediate altitudes due to the shortage of suitable altitude training locations. Even at intermediate levels the air still contains approximately 20.9% oxygen, but partial pressure of oxygen is reduced (West J., et al, 1996)

The hypothesis was supported, if the exercise is more intense, then there will be more cell respiration because during exercise, ATP is used up more rapidly; at a resting state ATP is produced at a steady rate but when the body uses more energy than what is being produced, the cell needs to respire at a quicker rate to provide energy to the body. In a resting state, the average heart rate was 74 beats per minute, the average breathing rate was 9.5 breaths per minute, and the average carbon dioxide production times was 34.085 seconds. After a period of running, the average heart rate was 124 beats per minute, the average breathing rate was 24 breaths per minute, and the average carbon dioxide production times was 6.0875 seconds. The data shows

An albatross crosses thousands of kilometres of ocean during a single foraging trip. Once airborne the albatross does not flap its wings and expends almost no energy through muscle use. For many years scientists have wondered how the energy requirement for this foraging strategy is sustained. New work has now uncovered the albatrosses secrets of flying for free.

The measuring of flow-volume loops (FVL) in laboratory settings during exercise are becoming increasingly popular to identify the limiting mechanics of ventilation (Johnson, Beck, Zeballos & Weisman, 1999a). The collection of a maximum flow-volume loop (MFVL) through a forced maximal maneuver at rest allows researchers to compare a baseline value with tidal loops obtained during exercise (Johnson et al., 1999a). Dominelli and Sheel state that MFVL provides information on an individual’s capability to produce volume and flow with respect to their mechanical ceilings (2012). Placing the respective tidal loops associated with different exercise intensities within a resting MFVL shows the difference in volumes during exercise and rest. An MFLV maneuver would yield the largest loop; whereas, the resting tidal loop would be the smallest (Johnson, Weisman, Zeballos & Beck, 1999b). Additionally, tidal loops during exercise will fit somewhere between resting and maximal tidal loops; increasing in volume as intensity increases; however, the loops still remain small in comparison to the MFVL (Johnson et al. 1999b). This aforementioned trend observed in healthy individuals during increasingly intense exercise is related to the lack of constraints on ventilation (Johnson et al. 1999b). Major factors responsible for limiting ventilation at rest and during exercise are bronchodilation and bronchoconstriction; these in turn affect total lung capacity (TLC)--a key measure with

ions across the membrane of the mitochondria during oxidative phosphorylation. Muscle buffering capacity is also improved. One acute response to hypoxia is hyperventilation; this increased rate of respiration occurs to maintain the alveolar partial pressure of oxygen. Hyperventilation leads to increased removal of carbon dioxide through the lungs and a state of respiratory alkalosis. This state of respiratory alkalosis can lower the pH of the blood and result in additional bicarbonate being excreted by the kidneys. This is the mechanism by which we increase muscle buffering capacity. Something to note about muscle buffering capacity and the lactate threshold is that there is a phenomenon that is called the “lactate paradox.” The lactate paradox

A lasting respiratory system response to exercise includes numerous physiological variations. These adaptations eventually result in an increase in inclusive effectiveness of the respiratory system to collect, transfer and distribute oxygen to the working muscles. The long-term respiratory function is frequently measured with a VO2 max test that calculates your body’s ability for oxygen ingesting during maximal exercise. Through exercise and training, the effectiveness of the respiratory system and VO2 max improve. Jeremy Hoefs

When it comes down to essentials, VO2Max is the measure of aerobic fitness. This ability to consume oxygen is vital for the metabolic function of our body cells. The activity within our cells is dependent upon oxygen because the cell gathers its energy from adenosine triphosphate, ATP. Our most productive way to produce these large volumes of ATP are through aerobic metabolism via the oxidative pathway. This pathway echoes the capacity of the muscles’ mitochondria to synthesize ATP. Our maximal consumption of oxygen depends, not only upon our cells’ capability to extract and use oxygen, but also upon the ability of our cardiovascular and respiratory systems to transport this oxygen to our cells to be utilized.

Through the increased amount of oxygen and carbon dioxide transport, the respiratory rate is also

Original estimates for the Quetzalcoatlus, discovered in 1971, placed its wingspan at an astounding 12-14 meters. This was later changed to a more reasonable 9-10 meters long (Still nothing to be shameful of). These measurements, though not definitive, prove that the Azhdarchid group as a whole could not only be the largest flying animals of the Mesozoic era but of the entire history of our planet. Other giants like Arambourgiania or Hatzegopteryx grew to similar sizes, only demonstrating the immense size of the reptiles.

Dinosaurs were some of the largest, heaviest and fastest animals to walk the Earth. The longest dinosaur was either the

Many people underestimate how important oxygen actually is. They don’t realize that their entire survival relies on one element in more ways than one.