cooperative selection
DESCRIPTION
This paper analyzes the dynamics of a new selection scheme based on altruistic cooperation between individuals. The scheme, which we refer to as cooperative selection, extends from tournament selection and imposes a stringent restriction on the mating chances of an individual during its lifespan: winning a tournament entails a depreciation of its fitness value. We show that altruism minimizes the loss of genetic diversity while increasing the selection frequency of the fittest individuals. An additional contribution of this paper is the formulation of a new combinatorial problem for maximizing the similarity of proteins based on their secondary structure. We conduct experiments on this problem in order to validate cooperative selection. The new selection scheme outperforms tournament selection for any setting of the parameters and is the best trade-off, maximizing genetic diversity and minimizing computational efforts.TRANSCRIPT
Cooperative Selection: Improving Tournament Selection via Altruism
J.L.J. Laredo, S. Nielsen, G. Danoy,
P. Bouvry, C.M. Fernandes
University of Luxembourg, University of Lisbon
Scope
Cooperative Selection is an altruistic improvement of Tournament Selection…
…but, what´s wrong with Tournament Selection?
What is cool?
What is wrong ?
(Poli05) points outthe not-sampling and
the not-selection issues
What is wrong ?
Not-sampling
Population at generation xn individuals
What is wrong ?
Not-sampling
Population at generation xSampling 1
n individuals
Selection 1
What is wrong ?
Not-sampling
Population at generation xSampling 1
n individuals
Sampling 2
Selection 1
Selection 2Breeding
What is wrong ?
Not-sampling
Population at generation x
Population at generation x+1
Sampling 1
n individuals
Sampling 2
Selection 1
Selection 2Breeding
What is wrong ?
Not-sampling
Population at generation x
Population at generation x+1
Sampling 1
n individuals
Sampling 2
Selection 1
Selection 2Breeding
n x
n
What is wrong ?
Not-sampling
Population at generation x
Population at generation x+1
Sampling 1
n individuals
Sampling 2
Selection 1
Selection 2Breeding
n x
n
Was sampled at all?
What is wrong ?
Not-sampling
Was sampled at all?
The answer is:might be not!
Good news: (Poli05) proposes a solution to the not-sampling issue
What is wrong ?
Not-selection
Population at generation x
Population at generation x+1
Sampling 1
n individuals
Sampling 2
Selection 1
Selection 2Breeding
Population at generation x
Population at generation x+1
Sampling 1
n individuals
Sampling 2
Selection 1
Selection 2Breeding
n x
n
What is wrong ?
Not-selection
Population at generation x
Population at generation x+1
Sampling 1
n individuals
Sampling 2
Selection 1
Selection 2Breeding
Population at generation x
Population at generation x+1
Sampling 1
n individuals
Sampling 2
Selection 1
Selection 2Breeding
n x
n
Were they ever selected?
What is wrong ?
Not-selection
Were they ever selected?
The answer is also:might be not!
So far… there are no good news
Cooperative Selection
2 24 4 56 64 45 34 2 24 4 56 64 45 34
Tournament Selection Cooperative Selection
A B C D E F G A B C D E F G
2 24 4 56 64 45 34 2 24 4 56 64 45 34
Sampling Sampling
1st mate
Cooperative Selection
Tournament Selection Cooperative Selection
A B C D E F G A B C D E F G
2 24 4 56 64 45 34 2 24 4 56 64 45 34
64 64
Selection Selection
1st mate
Cooperative Selection
Tournament Selection Cooperative Selection
E E
A B C D E F G A B C D E F G
2 24 4 56 64 45 34 2 24 4 56 64 45 34
24+56
2=40
Selection Altruism
1st mate
Cooperative Selection
Tournament Selection Cooperative Selection
64 64
E E
A B C D E F G A B C D E F G
2 24 4 56 64 45 34 2 24 4 56 40 45 34
24+56
2=40
Selection Altruism
1st mate
Cooperative Selection
Tournament Selection Cooperative Selection
64 40
E E
A B C D E F G A B C D E F G
2 24 4 56 64 45 34 2 24 4 56 40 45 34
2nd mate
Cooperative Selection
Tournament Selection Cooperative Selection
Sampling Sampling
A B C D E F G A B C D E F G
64 40
E E
2 24 4 56 64 45 34 2 24 4 56 40 45 34
45
Selection Selection
2nd mate
64
Cooperative Selection
Tournament Selection Cooperative Selection
A B C D E F G A B C D E F G
64 40
E EE F
2 24 4 56 64 45 34 2 24 4 56 40 45 34
2nd mate
4+40
2=22
Cooperative Selection
Tournament Selection Cooperative Selection
45
Selection Altruism
64
A B C D E F G A B C D E F G
64 40
E EE F
2 24 4 56 64 45 34 2 24 4 56 40 22 34
2nd mate
4+40
2=22
Cooperative Selection
Tournament Selection Cooperative Selection
22
Selection Altruism
64
A B C D E F G A B C D E F G
64 40
E EE F
2 24 4 56 64 45 34 2 24 4 56 40 22 34
Cooperative Selection
Tournament Selection Cooperative Selection
22
Breeding
6464 40
E EE FBreeding
2 24 4 56 64 45 34 2 24 4 56 40 22 34
Cooperative Selection
Tournament Selection Cooperative Selection
22
Breeding
6464 40
E EE FBreeding
Cooperative Selection
2 24 4 56 64 45 34 2 24 4 56 40 22 34
Tournament Selection Cooperative Selection
22
Breeding
6464 40
E EE FBreeding
Cooperative Selection
2 24 4 56 64 45 34 2 24 4 56 40 22 34
Tournament Selection Cooperative Selection
22
Breeding
6464 40
E EE FBreeding
Thanks for your attention