diff --git a/trunk/paradiseo-peo/src/peo.h b/trunk/paradiseo-peo/src/peo.h
index 8e708c3af..547abfd81 100644
--- a/trunk/paradiseo-peo/src/peo.h
+++ b/trunk/paradiseo-peo/src/peo.h
@@ -342,5 +342,7 @@
 /* Parallel PSO */
 #include "peoPSO.h"
 #include "peoEvalFuncPSO.h"
+#include "peoPSOSelect.h"
+#include "peoPSOReplacement.h"
 
 #endif
diff --git a/trunk/paradiseo-peo/src/peoPSOReplacement.h b/trunk/paradiseo-peo/src/peoPSOReplacement.h
new file mode 100644
index 000000000..eff1ac1b4
--- /dev/null
+++ b/trunk/paradiseo-peo/src/peoPSOReplacement.h
@@ -0,0 +1,77 @@
+/* <peoPSOReplacement.h>
+*
+*  (c) OPAC Team, October 2007
+*
+* Clive Canape
+* 
+* This software is governed by the CeCILL license under French law and
+* abiding by the rules of distribution of free software.  You can  use,
+* modify and/ or redistribute the software under the terms of the CeCILL
+* license as circulated by CEA, CNRS and INRIA at the following URL
+* "http://www.cecill.info".
+*
+* As a counterpart to the access to the source code and  rights to copy,
+* modify and redistribute granted by the license, users are provided only
+* with a limited warranty  and the software's author,  the holder of the
+* economic rights,  and the successive licensors  have only  limited liability.
+*
+* In this respect, the user's attention is drawn to the risks associated
+* with loading,  using,  modifying and/or developing or reproducing the
+* software by the user in light of its specific status of free software,
+* that may mean  that it is complicated to manipulate,  and  that  also
+* therefore means  that it is reserved for developers  and  experienced
+* professionals having in-depth computer knowledge. Users are therefore
+* encouraged to load and test the software's suitability as regards their
+* requirements in conditions enabling the security of their systems and/or
+* data to be ensured and,  more generally, to use and operate it in the
+* same conditions as regards security.
+* The fact that you are presently reading this means that you have had
+* knowledge of the CeCILL license and that you accept its terms.
+*
+* ParadisEO WebSite : http://paradiseo.gforge.inria.fr
+* Contact: paradiseo-help@lists.gforge.inria.fr 
+*   Contact: clive.canape@inria.fr
+*/
+
+#ifndef _peoPSOReplacement_h
+#define _peoPSOReplacement_h
+
+
+//-----------------------------------------------------------------------------
+#include <eoPop.h>
+#include <eoFunctor.h>
+#include <eoMerge.h>
+#include <eoReduce.h>
+#include <eoReplacement.h>
+#include <utils/eoHowMany.h>
+
+template <class POT>
+class peoPSOReplacement : public eoReplacement<POT>
+{
+    public:
+        peoPSOReplacement(){}
+
+        void operator()(eoPop<POT>& _dest, eoPop<POT>& _source)
+        {
+            unsigned ind=0;
+  			double best=_dest[0].best();
+  			for(unsigned j=1;j<_dest.size();j++)
+  				if(_dest[j].best() < best)
+  				{
+  					ind=j;
+  					best=_dest[j].best();
+  				}
+  			if(_dest[ind].best() < _source[0].best())
+  			{
+  				_dest[ind].fitness(_source[0].best());
+  				_dest[ind].best(_source[0].best());
+	 			for(unsigned j=0;j<_dest[ind].size();j++)
+	 			{
+	 				_dest[ind][j]=_source[0].bestPositions[j];
+	    			_dest[ind].bestPositions[j]=_source[0].bestPositions[j];
+	 			}
+  			}			
+        }
+};
+#endif
+
diff --git a/trunk/paradiseo-peo/src/peoPSOSelect.h b/trunk/paradiseo-peo/src/peoPSOSelect.h
new file mode 100644
index 000000000..1163f0415
--- /dev/null
+++ b/trunk/paradiseo-peo/src/peoPSOSelect.h
@@ -0,0 +1,63 @@
+/* <peoPSOSelect.h>
+*
+*  (c) OPAC Team, October 2007
+*
+* Clive Canape
+* 
+* This software is governed by the CeCILL license under French law and
+* abiding by the rules of distribution of free software.  You can  use,
+* modify and/ or redistribute the software under the terms of the CeCILL
+* license as circulated by CEA, CNRS and INRIA at the following URL
+* "http://www.cecill.info".
+*
+* As a counterpart to the access to the source code and  rights to copy,
+* modify and redistribute granted by the license, users are provided only
+* with a limited warranty  and the software's author,  the holder of the
+* economic rights,  and the successive licensors  have only  limited liability.
+*
+* In this respect, the user's attention is drawn to the risks associated
+* with loading,  using,  modifying and/or developing or reproducing the
+* software by the user in light of its specific status of free software,
+* that may mean  that it is complicated to manipulate,  and  that  also
+* therefore means  that it is reserved for developers  and  experienced
+* professionals having in-depth computer knowledge. Users are therefore
+* encouraged to load and test the software's suitability as regards their
+* requirements in conditions enabling the security of their systems and/or
+* data to be ensured and,  more generally, to use and operate it in the
+* same conditions as regards security.
+* The fact that you are presently reading this means that you have had
+* knowledge of the CeCILL license and that you accept its terms.
+*
+* ParadisEO WebSite : http://paradiseo.gforge.inria.fr
+* Contact: paradiseo-help@lists.gforge.inria.fr 
+*   Contact: clive.canape@inria.fr
+*/
+
+#ifndef peoPSOSelect_h
+#define peoPSOSelect_h
+
+#include <utils/eoRNG.h>
+#include <eoSelectOne.h>
+
+template <class EOT> class peoPSOSelect: public eoSelectOne<EOT>
+{
+ public:
+ 
+ typedef typename PO < EOT >::Fitness Fitness;
+
+  virtual const EOT& operator()(const eoPop<EOT>& _pop)
+  {
+  	unsigned ind=0;
+  	double best=_pop[0].best();
+  	for(unsigned i=1;i<_pop.size();i++)
+  		if(_pop[i].best() > best)
+  		{
+  			ind=i;
+  			best=_pop[i].best();
+  		}
+  	return _pop[ind];
+  }
+};
+
+#endif
+