Research Paper Concept Map
Abstract
Introduction
Methods
Discussion
Results
Backround
Unknown/Problem
Questions/Hypothesis/Rationale
Backround
Approach
Subjects
Materials
Design
Procedures
As exhibited by the illustration, a definitive, direct relationship can be observed between body mass and basal metabolic rate in birds. The upward trendline indicates that the data observed supports the initial hypothesis.
The pattern exhibited by the data points within the graph is roughly depictive of illustrations highlighting an inverse relationship between two subject variables, however, the relationship between mass-specific body mass and BMR follows allometric scaling whereby one variable changes in proportion to a power of another. Thus, the data obtained conflicts with- and does not fully support the initial hypothesis.
According to the data illustrated by the graph, a direct correlation does exist between body mass basal metabolic rate in mammals. Therefore the initial hypothesis is supported by the data obtained from the Quaardvark.
Results
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Approach
What is the relationship between mass-specific body mass and BMR in birds and mammals?
Basal metabolic rate (BMR) is the rate at which an organism expends energy while at rest, while mass-specific BMR is the BMR normalized to the organism's body mass, often expressed as energy expenditure per unit of body mass per unit of time.
Hypothesis
Methods
A direct relationship will be observed between mass in BMR in both mammals and birds while an inverse relationship will be observed between mass-specific body mass and BMR in both mammals and birds
Subject Organisms
Experiment Type
Analysis of pre-established actual data
Mammals
Birds
A direct correlation between mass and BMR exists within both mammals and birds
An inverse correlation between mass-specific body mass and BMR exists in both birds and mammals
A direct correlation exists between placental mammals and litter size
Hook
The dynamics of body mass and basal metabolic rate (BMR) unveil the compelling interplay between energy expenditure and physiological size across diverse organisms
Basal metabolic rate (BMR) represents the minimum amount of energy expended by an organism at rest to maintain essential physiological functions such as respiration, circulation, and cellular maintenance (Painter, 2005). It serves as a fundamental indicator of an organism's metabolic activity and is influenced by various factors including age, sex, body composition, and environmental conditions. BMR plays a crucial role in energy allocation strategies, influencing an organism's ability to survive and reproduce in its environment.
Mass-specific basal metabolic rate (mass-specific BMR) normalizes BMR to an organism's body mass, providing a standardized measure of metabolic intensity. This metric is particularly useful for comparing metabolic rates across different species, as it accounts for the influence of body size on metabolic demands. Mass-specific BMR reflects the energy requirements per unit of body mass, highlighting the metabolic efficiencies or adaptations that organisms have evolved to optimize their energy use. Understanding the relationship between body mass and mass-specific BMR is essential for elucidating the physiological and ecological implications of metabolic strategies in various organisms.
What is the relationship between BMR and litter size within placental mammals?
Purpose
Investigate the relationship between BMR, mass, and litter sizes within birds and mammals
What is the relationship between litter size and BMR in placental mammals?
What is the relationship between BMR and mass in mammals and birds?
A direct relationship exists between BMR and mass in mammals and birds?
An inverse relationship exists between mass-specific body mass and BMR in birds and mammals
A direct relationship exists between litter size and BMR in placental mammals
As the body mass of mammals increases, so does their metabolic rate (Kleiber's Law)
Mass-specific metabolic rate tend to decrease with increasing body size, as larger animals have lower mass-specific metabolic rates due to scaling in energy expenditure
Species with larger litter sizes often invest more energy into reproduction, including gestation, lactation, and parental care (Sadowska et al., 2013). This increased reproductive effort may lead to a reduction in available energy for other metabolic processes, resulting in lower basal metabolic rates.
Statistical analysis and comparison of variable data obtained from Quaardvark.
Variables
Independent
Dependent
Number of offspring (litter size)
Mass-specific bodymass
BMR
Average Mass
Birds
Mammals (placental)
Mammals
Quaardvark statstical data website was used to obtain appropriate data for comparison
Microsoft excel was utilized to graph and compare statistical data
To determine the relationships between the subject variables, complementary data was extracted from the Quaardvark site onto a Microsoft Excel sheet. To eliminate discrepancies in the final results, organisms which strongly deviate from the mean were eliminated from the data set. The remaining statistical data regarding each relationship and corresponding variable were graphed and the resulting data was compared to confirm or deny the initial hypotheses
Figures
The average mass-specific BMR of birds is higher than the average mass-specific BMR of mammals
The average body mass of mammals is higher than the average body mass of birds
An inverse relationship is observed between mass-specific body mass and BMR in both birds and mammals
An increase in average mass is correlated to an increase in BMR within both mammals and birds
The average BMR of mammals is higher than the average BMR of birds
A direct correlation exists between litter size and BMR within placental mammals
Average mass (g) vs. BMR (Watts); Mammals
Average mass (g) vs. BMR (Watts); Birds
Mass-specific BMR (g/Watts) vs. Average Mass (g); (Mammals)
Mass-specific BMR (g/Watts) vs. Average Mass (g); (Birds)
Number of Offspring vs. BMR (Watts)
Average Mass of birds vs. mammals
Average BMR of birds vs. mammals
Mass-specific BMR birds vs. mammals
Similarly to mammals, the relationship between mass-specific body mass and BMR in birds is depicted by the graphed data as an inverse correlation, however, because BMR and mass-specific body mass are allometrically scaled, this relationship cannot be concluded as definitive for all presented cases. The data obtained therefore does not fully support the initial hypothesis.
The data obtained from the Quaardvark illustrates that a weak direct correlation may be observed between litter sizes and basal metabolic rates. Interestingly, most strong deviants on the x-axis belong to species which average a single offspring per lifetime. The initial hypothesis is partially supported by the data obtained.
As initially hypothesized, the small average size of bird species relative to mammals indicated that they will likely possess a lower average body mass. In addition, one may arrive at such conclusion by noting the importance of flight for the survival of most bird species, and how such ability is impacted by an increase in body mass.
The data disproves the validity of the initial hypothesis which stated that birds will possess a greater basal metabolic rate. The observed differences are likely facilitated by multiple variables, however, the strategy utilized to obtained energy by each group likely has the greatest impact. Mammals, especially those with larger body sizes, may have a higher overall metabolic rate due to their higher energy requirements for activities such as foraging, running, and maintaining larger body sizes.
The data exhibited illustrates that birds, on average, possess a higher mass-specific BMR than mammals; such findings align with pre-established literature (Daan et al., 1990). The initial hypothesis accurately concludes the relationship observed between the two subject variables and is therefore supported by the obtained data.
Literature Cited
Daan S, Masman D, Groenewold A. 1990. Avian basal metabolic rates: Their association with Body Composition and energy expenditure in nature. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 259.
Painter PR. 2005. Allometric scaling of the maximum metabolic rate of mammals: Oxygen transport from the lungs to the heart is a limiting step. Theoretical Biology and Medical Modelling 2.
Sadowska J, Gębczyński AK, Konarzewski M. 2013. Basal metabolic rate is positively correlated with parental investment in laboratory mice. Proceedings of the Royal Society B: Biological Sciences 280:20122576.