Announcements
Next Monday Review
Next Wednesday (Feb 14) Exam I
Recognition Systems:
1. What are they (types of recognition)?
2. How do they work?
3. Optimal Threshold Models
The Major Transitions
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)
Maynard Smith & Szathmáry 1995
The Major Transitions
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)
Maynard Smith & Szathmáry 1995
Recognition Systems
Self / Non self
Kin Recognition
Mate
Individual
Species
Prey/Predators
Recognition Systems
Self / Non self
Kin Recognition
Mate
Individual
Species
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 groups
cooperation / altruism
mating 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 groups
cooperation / altruism
mating behavior
Recognition Systems
Intraspecific recognition
Mate Recognition finding mates (right species)
mate choice (right individual)
Individual Recognition pair bonds
neighbors/territoriality
Species Recognition
conspecific attraction
territoriality
mate 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 avoidance
prey capture (foraging)
host / parasite association
naïve prey responding to cues of introduced predators
learned response
innate response
New Zealand Robin
and mustellids
Rana aurora
bullfrogs and crayfish
Maloney & McLean
1995
Pearl et al. 2003
Conspecific Recognition
and Social Development in
Brown-headed Cowbirds (Molothrus ater)
Conspecific recognition in parasitic cowbirds
“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)
“[…] 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 crossfostered Zebra Finches
Davies (2000)
Recognition Systems
Other types of recognition
Abiotic conditions
habitat choice
nest site selection
precipitation / temperature
Recognition Systems
Other types of recognition
Abiotic conditions
habitat choice
nest site selection
precipitation / 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 rejection
Partial match is sufficient - shared label acceptance
Behavior can very depending on degree of match.
template
evaluator
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
Template
Label
A
A
E
E
Nest mate recognition in social insects
Diet (C)
A
Nest material (D)
B
A
B
Template
Label
Signal = cuticular hydrocarbons:
acquired from genes, diet and nest
ABCD
A
EF
E
Nest mate recognition in social insects
Referent
Diet (C)
A
Nest material (D)
B
A
B
Template
Label
Signal = cuticular hydrocarbons:
acquired from genes, diet and nest
ABCD
A
EF
E
Foreign label rejection
A
B
C
D
Template
Label
ABCD
C
“accept”
AB
B
“reject”
4
3
2
1
Y = 8.227 - 7.044 * X; R2 = 0.58
0.6
0.7
0.8
0.9
1.0
Correlation of hydrocarbon
profiles between nests
Optimal Threshold Model
adapted from Reeve 1989, Starks 2003
Optimal Threshold Model
signals you want to
accept
signals you want
to reject
acceptance errors
rejection errors
adapted from Reeve 1989, Starks 2003
Ideally, there would be no overlap between signals you
want to accept or reject.
T
Reject
Frequency
Accept
Dissimilarity between
template and cues
However, the distribution and variation of signals
(cues) can be constrained by selection or the
environment.
T
Reject
Frequency
Accept
Dissimilarity between
template and cues
Moreover, the threshold of response may also be
constrained by ability to distinguish among signals, or
can evolve rapidly in response to selection.
T
Reject
Frequency
Accept
Dissimilarity between
template and cues
Moreover, the threshold of response may also be
constrained by ability to distinguish among signals, or
can evolve rapidly in response to selection.
T
Reject
Frequency
Accept
Threshold shifts to the
left (more stringent) to
reduce acceptance errors
if they are too costly.
Dissimilarity between
template and cues
Moreover, the threshold of response may also be
constrained by ability to distinguish among signals, or
can evolve rapidly in response to selection.
T
Reject
Frequency
Accept
Threshold shifts to the
right (less stringent) to
reduce rejection errors if
they are too costly.
Dissimilarity between
template and cues
Rejected Non-Nestmate
Accepted Non-Nestmate
Accepted Nestmate
T
Accept
Reject
Frequency
Flexible Threshold Model
(change in acceptance threshold)
0
Dissimilarity Score
1
Rejected Non-Nestmate
Accepted Non-Nestmate
Accepted Nestmate
T
Frequency
Accept
Reject
Fixed Threshold Model
(change in labels)
Decrease in Genetic Diversity
0
Dissimilarity score
1
Recognition: Production
cue
Perception
Action
brain
response
Possible overlap of recognition cues/perceptual filters:
Individual
Kin
Species
Individual
Mate
Mate
Kin
Species
Recognition: Production
cue
Perception
Action
brain
response
Possible overlap of recognition cues/perceptual filters:
Species
Species
Mate
Individual
Kin
Mate
Kin
Individual