EXHIBIT A JOINT FILING AGREEMENT The undersigned hereby consent to the joint filing by any of them of a Statement on Schedule 13D and any amendments thereto, whether heretofore or hereafter filed, relating to the securities of Diversa Corporation, and...

                                 EXHIBIT A


                           JOINT FILING AGREEMENT

The undersigned hereby consent to the joint filing by any of them of a
Statement on Schedule 13D and any amendments thereto, whether heretofore or
hereafter filed, relating to the securities of Diversa Corporation, and affirm
that this Schedule 13D is being filed on behalf of each of the undersigned.


Dated: March 19, 2007


RHO CAPITAL PARTNERS, INC.


By:/s/Xxxxxxx X. Xxxxxx
Xxxxxxx X. Xxxxxx, Authorized Signer



XXXXXX XXXX


By:/s/Xxxxxxx X. Xxxxxx
Xxxxxxx X. Xxxxxx, Authorized Signer



XXXXX XXXXXXX

By:/s/Xxxxxxx X. Xxxxxx
Xxxxxxx X. Xxxxxx, Authorized Signer



XXXX XXXXXXX

By:/s/Xxxxxxx X. Xxxxxx
Xxxxxxx X. Xxxxxx, Authorized Signer



RHO MANAGEMENT TRUST II
By: RHO CAPITAL PARTNERS, INC.
    As Investment Advisor


By:/s/Xxxxxxx X. Xxxxxx
Xxxxxxx X. Xxxxxx, Authorized Signer



RHO INVESTMENT PARTNERS "H" L.P.
By: RHO MANAGEMENT PARTNERS, L.P.
    General Partner
By: ATLAS CAPITAL CORP.
    Its General Partner


By:/s/Xxxxxxx X. Xxxxxx
Xxxxxxx X. Xxxxxx, Authorized Signer



RHO MANAGEMENT PARTNERS, L.P.
By: ATLAS CAPITAL CORP.
    Its General Partner


By:/s/Xxxxxxx X. Xxxxxx
Xxxxxxx X. Xxxxxx, Authorized Signer



ATLAS CAPITAL CORP.


By:/s/Xxxxxxx X. Xxxxxx
Xxxxxxx X. Xxxxxx, Authorized Signer