Figures
What is the horizontal axis in Figure 1?
Describes parent types that put a certain fraction of available energy into each offspring.
What does k represent in Equation 3?
A parameter for group of parents with the same fitness (Wp = k)
Who are the authors of this paper?
Christopher C. Smith and Stephen D. Fretwell
What is one critical assumption of the paper?
1) Optimum energy investment per offspring is the same across all offspring within a clutch
2) At any given point in an organism’s life history, there is a fixed and finite amount of energy available for reproduction
3) Inverse relationship between the size of each offspring and the number of offspring produced (trade off between offspring size and number)
K-selected animals have more offspring than r-selected animals. True or false.
False
In Figure 1, how are more successful parent types represented?
They are represented by a diagonal line with a steeper slope which indicates better reproductive success.
What does Ny = Ip/Iy represent biologically?
If a parent has a fixed total energy, investing more energy in each offspring means fewer offspring produced.
In most cases, fitness will be measured by...
relative survival
Known for their rapid reproduction and minimal parental care, these TWO K-selected species all start with the letter 'B'
Bison, Black bear..
What is K-selction?
The strategy where the number of offspring is low, high parental investment, and reach reproductive maturity later.
What does the curved line represent in Figure 2?
Represents the relationship between parental effort and the fitness of individual offspring.
What assumption was made in the parental fitness equation?
The production of offspring in the present does not affect the future fitness of the parents.
Although the model can be applied for all organisms, this model is especially useful for understanding the reproductive strategies of...
Species that have large clutch sizes and provide no parental care.
Known for their rapid reproduction and minimal parental care, these THREE R-selected species all start with the letter 'R'
Rabbit, Rat,
Would salmon be considered r-selected or k-selected species? Explain your decision.
Salmon are r-selected species because they produce large numbers of offspring that are left to fend for themselves in the wild.
What is the optimal parental type?
The point where the adaptive function with the highest slope intersects the curve (Figure 2).
What parameter was not included in the model?
The amount of time spent gaining energy to invest in having offspring.
How do we get a fractional clutch size of 1.5?
This happens when the energy available for reproduction is divided by the optimum energy per offspring.
In life-history evolution, this term refers to the age and size at which an organism first reproduces, balancing the benefits of early reproduction against the advantages of growing larger.
What is the age at maturity or optimal reproductive timing?
What is kin selection?
The process where offspring from early clutches help care for offspring from later clutches.
In Figure 2, why is the curve convex?
There's a limit to how much an offspring's fitness can improve, no matter how much the parents invest.
Where would we find the optimum phenotype?
At the point where the adaptive function (straight line) intersects the offspring's fitness curve (fitness set).
From the model, what would lead to a large increase in offspring fitness?
If the clutch size is small enough, a decrease in the number of offspring will lead to an increase in offspring fitness (Wy).
This term refers to organisms that reproduce only once before dying, maximizing energy into a single reproductive effort.
What is semelparity?
What concept from Levins' 1968 model is used to describe the set of alternative parental phenotypes that all have the same fitness?
The adaptive function, a line where all points represent parent phenotypes with the same fitness.