Exam prep Flashcards
What are Tinbergen’s four questions?
- Ontogeny - how does X develop? (e.g. in Developmental Psych)
- Mechanism/Causation - how is X triggered? (e.g., neuroscience, learning)
- Phylogeny - evolutionary history (e.g. animal cognition)
- Adaptation/function - what is the survival value? (e.g. evolutionary psychology)
Define proximate explanations vs. ultimate explanations. Which is the focus of evo psych?
Proximate = How does X function?
Ultimate = Why did X evolve the way it did? (U is the focus of evo psych)
What is the dynamic question of proximate and of ultimate explanations? What does dynamic refer to?
Dynamic = past explains present
Proximate - ontogeny
Ultimate - phylogeny
What is the static question of proximate and of ultimate explanations? What does static refer to?
Static = explains current form
Proximate - mechanism
Ultimate - Function
Define artificial breeding, a.k.a. selective breeding
selection in which humans choose which organisms reproduce based on desired traits
Define Character
A structure or feature found in a group of organisms (e.g. the
vertebrate eye, a courtship display)
Define character state
An attribute or value of a character. For example the character “eye colour” may have the states “red” and “blue”, and a display may
be present or absent
Define comparative method
Comparing character states for multiple species or populations in order to understand relationships or trends among these
characters and how they have influenced patterns of evolution. Such correlations are often used to test adaptive hypotheses.
Define convergence
A type of homoplasy where two or more taxa independently evolve the same character state from different ancestral states. (E.g. eyes in humans and octopus.)
Define evolution via descent with modification
Change in genetic composition of
populations over successive generations, eventually leading to the formation of new species
define fit
Relationship between a character and a tree. The fit is obtained by
optimisation and is measured by the consistency index
define drift with ref to small and large populations
Changes in the frequency of genes in a population due to the fact that (in
the absence of selection, gene flow and mutation) one generation is a random sample of the previous generation.
The stochastic (random) nature of this process means that gene frequencies can fluctuate randomly. This process will be more pronounced in small populations, where stochasticity is higher.
Define gene flow
The movement of genes from one population to another via migration or dispersal.
define homology in its 2 different senses
- operational homology. can mean features of two taxa that a systematist considers are comparable (i.e. in some sense the “same”).
- Evolutionary homology refers to features that are similar due to inheritance from a common ancestor. can only be established after a tree is constructed. An homologous character should only originate once.
define homoplasy
Similarities between taxa that are not directly due to inheritance
from a common ancestor.
In other words character states that seem the same (operationally homologous) are not evolutionary homologues. Homoplasy includes reversal (taxa evolves a character state indistinguishable from one of its ancestors), convergence and parallelism
define length
The length of a tree is equal to the total number of character state
changes on that tree. The shortest tree is the most parsimonious.
define macro-evolution
Long-term process of descent with modification along phylogenies, reflecting the formation of species.
define micro-evolution
Short-term process of descent with modification reflecting change in gene frequencies through time within populations.
define monophyletic
A group of organisms is monophyletic if they have a common ancestor that is unique to them, i.e. all descendants of that ancestor must be included in the group.
Birds are monophyletic but reptiles are not.
define mutation
The introduction of variant alleles to a population via a change in the genetic material of the reproductive cells.
define Natural selection
The process in which organisms that are better adapted to their environment tend to survive and produce more offspring.
define optimisation
Process of fitting characters to a tree in the simplest, most parsimonious or most likely way. Under parsimony, characters have to be optimised before consistency indices can be calculated.
define parallelism
A type of homoplasy where two or more taxa independently evolve the same character state from the same ancestral state.
define parsimony
Principle of explaining observed data in the simplest, most economical way possible.
In phylogenetics, parsimony is sometimes used to choose (from the (2n-5)!! possible trees for n taxa) one or more trees to summarise the data.
Recently it has been superseded by likelihood and Bayesian methods.
define phylogeny
the actual pattern of descent, i.e. the historical relationship between organisms
define phylogenetic inertia
the tendency for descendants to be similar to their ancestor (and hence for similarity between closely related species).
define proximate explanations and give examples in terms of ontogeny, and mechanism
An explanation for a trait based on its immediate physical causation (“Mechanism” – e.g., the lens of the eye focuses light on the retina) and/or its development (Ontogeny – e.g. neurons need the stimulation of light to wire the eye to the brain).
define sexual selection
A form of natural selection in which some individuals reproduce more than others because they are better at attracting mates.
define ultimate explanations and give examples in terms of adaptation and phylogeny
An explanation for a trait in terms of the evolutionary forces that gave rise to it - Adaptation (e.g. the eye functions to find food and avoid danger) and Phylogeny (e.g. the vertebrate eye initially evolved with a blind spot and phylogenetic constraints prevent the evolution of a better solution).
define operational homology
features of two taxa that a
systematist considers are comparable (i.e. in some sense the “same”).
define evolutionary homology
features that are
similar due to inheritance from a common ancestor. Evolutionary homology can only be established after a tree is constructed. An homologous character should only originate once.
key tenets of Evolutionary Psychology
- massive modularity - mind consists of many evolved discrete modules
- adaptationism - modules are adaptations for fitness
- EEA adaptations designed to survive in Pleistocene hunter/gatherer enviro
- psychic unity - human nature = universal panhuman design
- evoked culture - differences across cultures produced by universal psychology responding to different circumstances
