Flashcards in Test 3 Deck (237)
How would you assess the importance of density-dependent processes in bighorn sheep?
A. look at correlations between sheep populations and rainfall
B. look at correlations between reproduction/mortality and rainfall
C. look at correlation between reproduction/mortality and sheep population size
Look at correlations between reproduction/mortality and sheep population size
Stable populations fluctuate within relatively ___ limits
Population stability is achieved by the sum of both
density-independent and density-dependent regulatory factors
T or F? The population may be stable but not necessarily at equilibrium
Equilibrium implies regulation via
T or F? Density-dependent control always results in stability
What is a metapopulation?
a group of populations in a landscape composed of habitat of varying quality and linked by migration
The metapopulation is comparatively ___ because it's composed of a set of populations that fluctuate independently
Life history comprises:
1. the pattern of development and growth
2. life span
3. the timing and quantity of reproduction
Selection's perfect organism would
-be mature at birth
-continuously produce lots of high-quality offspring
The amount of energy that is available to an organism over the course of its life is
Finite energy drives the importance of trade-offs in the evolution of organismal life histories
principle of allocation
Life span (i.e. senescence) is influenced by an organism's ability to keep itself going at the expense of
decreases in potential reproduction
What are the trade-offs of reproduction?
-when is sexual maturation optimal?
-what is the optimal number of offspring to have?
-what is the optimal parental investment for each offspring?
Life history traits are optimized by
natural selection to maximize parental fitness
Adaptive life history strategy evolves as
the life history traits evolve in response to ecological conditions
Life history traits do not evolve in isolation and are linked via
energy trade-offs (principle of allocation)
Investment in each life history trait has a
benefit and a cost to the organism
For each life stage, there is an optimal
investment into a certain life history trait
Investment beyond the optimum investment into a certain life history trait,
reduces fitness by limiting energy available for other important functions
What is teleology?
the idea that purpose exists in evolution in the same sense that it does for human intention
T or F? Evolution has no pre-designed or intentional goal
T or F? "Strategy" implies a conscious choice by the organism
Optimal life history does not mean the best possible, it means
the best of those existing in a certain population under certain environmental conditions
-life history strategy only needs to be "good enough"
T or F? Trade-offs mean that it is the overall strategy rather than a single life history trait that determines fitness
The components of the life history strategy evolve as
an integrated unit
Reproductive vale (Vx) of an organism is
the expected reproductive contribution of an individual of age x to the next generation
-changes over the course of the life span
-is closely tied to fitness
the probability of an individual of age-class x surviving to a given future age-class