L12 current debates of inclusive fitness Flashcards
What is meant by “Darwinian fitness” in non‐social models?
The number of surviving offspring an individual produces, assumed to be maximized by natural selection.
Why is the idea that organisms always maximize fitness controversial?
Critics point out that actual gene‐frequency dynamics can deviate from simple optimization, so fitness‐maximization may not universally hold.
How can non‐social fitness‐maximization be viewed in the context of inclusive fitness?
As a special case where indirect (kin) effects are negligible—using the same selection gradients and game‐theory math but without relatedness terms.
What is a major gap in fitness‐maximization theory?
There’s no single mathematical model that is both biologically realistic and analytically tractable.
Summarize Moran’s (1964) counterexample to fitness maximization.
Moran demonstrated simple population‐genetic scenarios where gene‐frequency changes don’t align with greater individual reproductive success.
How do real populations complicate the maximization assumption?
Conditional behaviors, variable dispersal, overlapping generations, and spatial complexity create dynamics that may violate simple ‘maximize fitness’ rules.
Why do different researchers sometimes disagree about fitness models?
They use divergent terms and metrics, leading to mismatched assumptions and confusion.
What is neighbour‐modulated fitness (NMF)?
A ‘recipient‐perspective’ measure that tallies how an individual’s actions affect both its own fitness and that of its neighbors.
What is inclusive fitness (IF)?
An actor‐focused measure that partitions direct fitness plus weighted indirect fitness effects on relatives.
What key difference separates IF from NMF?
IF explicitly accounts for genetic relatedness and distinguishes actor vs. recipient effects; NMF simply sums local effects without that partitioning.
When can IF and NMF give identical predictions?
In symmetric or simplified models where relatedness structure and local competition balance out.
Why is calculating IF hard in spatially and generationally complex populations?
Overlapping generations, clustering, conditional dispersal, and age structure make it difficult to track kin interactions and fitness components.
What does “dynamic sufficiency” require in an evolutionary model?
Tracking not only allele frequencies but full genotype distributions over time.
What empirical challenges hinder testing of inclusive fitness?
Inferring relatedness, gene architecture, and selective contexts in the field is indirect and imprecise.
Why do theoretical debates about IF continue?
Disagreements over formalism and partial misunderstandings keep the literature unsettled.
What are the key contributions of Lehmann & Rousset (2020)?
They integrated an explicit genetic model with game theory under weak selection to show individuals maximize inclusive fitness.
How do Lehmann & Rousset maintain dynamic sufficiency in their model?
By tracking full genotype distributions over time, not just allele frequencies.
What does the “rigid demographic structure” assumption entail?
Each group or class has a fixed size and composition, simplifying analysis of social trait evolution.
What is meant by “weak selection” in their model?
Genetic changes are small enough that linear approximations around equilibrium are valid.
Why is “limited biological realism” an assumption in Lehmann & Rousset’s work?
They assume symmetrical interactions and uniform dispersal to keep the model mathematically tractable.
What outcome and significance did their work achieve?
It provided a concrete bridge between population genetics and game theory, supporting inclusive fitness maximization.
What common criticism is made of Lehmann & Rousset’s model?
It omits many real‐world complexities, limiting its generality.
What is the context for Levin & Grafen’s practical advice?
Behavioral ecologists and evolutionary biologists seeking to apply inclusive fitness without mastering its full mathematical depth.
What guidance do Levin & Grafen offer on models and assumptions?
They recommend verifying or approximating key assumptions before applying inclusive fitness logic.
