next monday review next wednesday (feb 14) exam i announcements
TRANSCRIPT
Next Monday Review
Next Wednesday (Feb 14) Exam I
Announcements
Recognition Systems:
1. What are they (types of recognition)?2. How do they work?3. Optimal Threshold Models
The Major Transitions
Maynard Smith & Szathmáry 1995
1. Replicating molecules ---> Molecules in protocells
2. Independent replicators ---> Chromosomes
3. RNA as gene and enzyme ---> DNA genes, protein enzymes
4. Bacteria (prokaryotes) ---> Eukaryotes (organelles)
5. Asexual clones ---> Sexual populations
6. Single-celled organisms ---> Multicellularity
7. Solitary individuals ---> Eusocial colonies
8. Primate societies ---> Human societies (language)
The Major Transitions
Maynard Smith & Szathmáry 1995
1. Replicating molecules ---> Molecules in protocells
2. Independent replicators ---> Chromosomes
3. RNA as gene and enzyme ---> DNA genes, protein enzymes
4. Bacteria (prokaryotes) ---> Eukaryotes (organelles)
5. Asexual clones ---> Sexual populations
6. Single-celled organisms ---> Multicellularity
7. Solitary individuals ---> Eusocial colonies
8. Primate societies ---> Human societies (language)
Recognition Systems
Self / Non selfKin Recognition
MateIndividualSpecies
Prey/Predators
Recognition Systems
Self / Non selfKin Recognition
MateIndividualSpecies
Prey/Predators
Recognition vs. Discrimination
Recognition Systems
Allorecognition systems
Self / Non self auto immune systems (MHC)self incompatibility (plants)sex determining locus (hymenoptera)
Genetic basis, highly variable (many alleles - most alleles known for almost any gene).
Recognition Systems
Intraspecific recognition
Kin Recognition formation of social groupscooperation / altruismmating behavior
Distinguish others based upon their degree of genetic relatedness.
Can be learned or innate. Self-referent or phenotype matching.
Recognition Systems
Intraspecific recognition
Kin Recognition formation of social groupscooperation / altruismmating behavior
Recognition Systems
Intraspecific recognition
Mate Recognition finding mates (right species) mate choice (right individual)
Individual Recognition pair bonds neighbors/territoriality
Species Recognition conspecific attractionterritorialitymate choice
“The grossest blunder in sexual preference, which we
can conceive of an animal making, would be to mate
with a species different from its own […]”
Ronald A. Fisher (1958)
Recognition Systems
Interspecific recognition
Species Recognition predator avoidanceprey capture (foraging)host / parasite association
naïve prey responding to cues of introduced predators
learned response innate response
New Zealand Robin and mustellids
Maloney & McLean 1995
Rana aurorabullfrogs and crayfish
Pearl et al. 2003
Conspecific Recognition and Social Development in
Brown-headed Cowbirds (Molothrus ater)
“[…] Brown-headed Cowbird behaviour is strongly influenced by learning, just as in other species. The Cowbird’s trick is to delay learning until it has become independent and has followed a genetic predisposition to seek company with its own kind. This means that […] it avoids the problems encountered by Lorenz’s geese and the cross-fostered Zebra Finches
Davies (2000)
“Brood parasites seem to know just who they are at an early age. Brown-headed Cowbirds join flocks of their own kind after they gain independence from their foster parents. This species recognition is most likely under genetic control and is a necessary precondition of brood parasitism.”
Ortega (1998)
Conspecific recognition in parasitic cowbirds
Recognition Systems
Other types of recognition
Abiotic conditions habitat choicenest site selectionprecipitation / temperature
Recognition Systems
Other types of recognition
Abiotic conditions habitat choicenest site selectionprecipitation / temperature
Lesser Prairie-Chicken
Components of recognition systems:
Evaluator (receiver, discriminator, actor):Individual whose behavior is modified by a signal.
Signaler (target, cue-bearer, recipient):Individual creating a signal to illicit a response.
(usually different individuals except in self recognition)
Components of recognition systems:
Label - a signal, cue, or stimulus that is perceived by the evaluator.
(can include chemical odors, cell surface proteins, songs, color patterns, stereotypic displays)
Template - what the evaluator uses to compare the signal.(can be genetically “hard wired” or acquired during development through learning or imprinting)
Referent - basis for a template when not genetically based
Components of recognition systems:
Decision rules - Different types of recognition systems may employ different matching rules.
Exact match for acceptance - foreign label rejectionPartial match is sufficient - shared label acceptance
Behavior can very depending on degree of match.
evaluatortemplate signal
signaler
Components of recognition systems:
1. Production - the nature and development of labels (cues) in signalers.
2. Perception - the sensory detection of labels by evaluators followed by a comparison of labels to a template. (includes the ontogeny of templates)
3. Action - modification of behavior in response to an assessment of the signaler’s label relative to the evaluator’s template.
Nest mate recognition in social insects
Label
Template A E
A E
Label
Template ABCD EF
A E
AB
AB
Nest mate recognition in social insects
Diet (C)Nest material (D)
Signal = cuticular hydrocarbons:acquired from genes, diet and nest
Label
Template ABCD EF
A E
AB
AB
Nest mate recognition in social insects
Diet (C)Nest material (D)
Signal = cuticular hydrocarbons:acquired from genes, diet and nest
Referent
Foreign label rejection
Label
Template ABCD AB
C B
AB
CD
“reject”“accept”
1
2
3
4
0.6 0.7 0.8 0.9 1.0
Y = 8.227 - 7.044 * X; R2 = 0.58
Correlation of hydrocarbon profiles between nests
Ave
rage
agg
ress
ion
s cor
e
Optimal Threshold Model
adapted from Reeve 1989, Starks 2003
Optimal Threshold Model
adapted from Reeve 1989, Starks 2003
signals you want to accept
signals you wantto reject
acceptance errors rejection errors
TAccept Reject
Dissimilarity between template and cues
Fre
quen
cy
Ideally, there would be no overlap between signals you want to accept or reject.
Dissimilarity between template and cues
Fre
quen
cy
However, the distribution and variation of signals (cues) can be constrained by selection or the environment.
TAccept Reject
Dissimilarity between template and cues
Fre
quen
cy
Moreover, the threshold of response may also be constrained by ability to distinguish among signals, or can evolve rapidly in response to selection.
TAccept Reject
Dissimilarity between template and cues
Fre
quen
cy
Moreover, the threshold of response may also be constrained by ability to distinguish among signals, or can evolve rapidly in response to selection.
TAccept Reject
Threshold shifts to the left (more stringent) to reduce acceptance errors if they are too costly.
Dissimilarity between template and cues
Fre
quen
cy
Moreover, the threshold of response may also be constrained by ability to distinguish among signals, or can evolve rapidly in response to selection.
Threshold shifts to the right (less stringent) to reduce rejection errors if they are too costly.
TAccept Reject
TAccept Reject
0 1Dissimilarity Score
Flexible Threshold Model(change in acceptance threshold)
Fre
quen
cy
Rejected Non-Nestmate
Accepted Non-Nestmate
Accepted Nestmate
TAccept Reject
Decrease in Genetic Diversity
Fixed Threshold Model(change in labels)
Rejected Non-Nestmate
Accepted Non-Nestmate
Accepted Nestmate
Fre
quen
cy
Dissimilarity score0 1
Mate Kin
Possible overlap of recognition cues/perceptual filters:
SpeciesIndividual
Species
Mate
Kin
Individual
Recognition: Production Perception Actioncue brain response
Mate Kin
Possible overlap of recognition cues/perceptual filters:
SpeciesIndividual
Species
Mate
Kin
Individual
Recognition: Production Perception Actioncue brain response