Cannot Install RMySQL on MacOSX

I am trying to install RMySQL and it is giving the following error ? I have
looked at the previous messages and could not find a workable solution.

Any suggestions are greatly welcome

I have MacOS 10.4.6, R 2.3.1,  RMySQL_0.5-7.tar.gz, and MySQL 5.0

-------------------------------
trying URL 'http://www.imsv.unibe.ch/cran/src/contrib/RMySQL_0.5-7.tar.gz'
Content type 'application/x-gzip' length 142507 bytes
opened URL
==================================================
downloaded 139Kb

WARNING: ignoring environment value of R_HOME
* Installing *source* package 'RMySQL' ...
creating cache ./config.cache
checking how to run the C preprocessor... /lib/cpp
checking for compress in -lz... no
checking for getopt_long in -lc... no
checking for mysql_init in -lmysqlclient... no
checking for mysql.h... no
checking for mysql_init in -lmysqlclient... no
checking for mysql_init in -lmysqlclient...
The downloaded packages are in
    /private/tmp/RtmpMKx9nr/downloaded_packages
no
checking for mysql_init in -lmysqlclient... no
checking for mysql_init in -lmysqlclient... no
checking for mysql_init in -lmysqlclient... no

Configuration error:
   Could not locate the library "libz" required by MySQL.

INSTRUCTIONS:

   The "libz" library is required by the MySQL client library
   in order to compress/uncompress connections between clients
   and the MySQL engine.

   Make sure you have "libz" installed properly and/or included
   in your $LD_LIBRARY_PATH.  Perhaps it is not in any of the
   standard directories (e.g., /usr/lib/, /usr/local/lib)?

Aborting the installation of RMySQL.

** Removing 
'/Library/Frameworks/R.framework/Versions/2.3/Resources/library/RMySQL'
ERROR: configuration failed for package 'RMySQL'