diff --git a/eo/src/utils/eoHowMany.h b/eo/src/utils/eoHowMany.h
new file mode 100644
index 000000000..7776b6c2d
--- /dev/null
+++ b/eo/src/utils/eoHowMany.h
@@ -0,0 +1,78 @@
+// -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*-
+
+//-----------------------------------------------------------------------------
+// eoMerge.h
+//   Base class for choosing a number of guys to apply something from a popsize
+// (c) Marc Schoenauer, 2000
+/* 
+   This library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2 of the License, or (at your option) any later version.
+
+   This library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this library; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+   Contact: todos@geneura.ugr.es, http://geneura.ugr.es
+ */
+//-----------------------------------------------------------------------------
+
+#ifndef eoHowMany_h
+#define eoHowMany_h
+
+// to be used in selection / replacement procedures to indicate whether 
+// the argument (rate, a double) shoudl be treated as a rate (number=rate*popSize)
+// or as an absolute integer (number=rate regardless of popsize).
+// the default value shoudl ALWAYS be true (eo_as_a_rate).
+//
+// this construct is mandatory because in some cases you might not know the 
+// population size that will enter the replacement for instance - so you 
+// cannot simply have a pre-computed (double) rate of 1/popSize if you want 1 guy
+
+
+class eoHowMany
+{
+public:
+  eoHowMany(double  _rate, bool _interpret_as_rate = true):
+    rate(0), howmany(0)
+  {
+    if (_interpret_as_rate)
+      {
+	rate = _rate;
+      }
+    else
+      {
+	if (_rate<0)
+	  throw std::logic_error("Negative number in eoHowMany!");
+	howmany = (unsigned int)_rate;
+	if (howmany != _rate)
+	  cout << "Warning: Number was rounded in eoHowMany";
+      }
+  }
+
+  unsigned int operator()(unsigned int _size)
+  {
+    if (howmany == 0)
+      {
+	if (rate == 0.0)
+	  return 0;
+	else
+	  return (unsigned int) (rate * _size);
+      }
+    return howmany;
+  }
+  
+private :
+  double rate;
+  unsigned howmany;
+};
+
+
+
+#endif