Hi Friends, is there any possibility of the existence of any pathway that leads to ERK activation, but by passes Mek?

Yes indeed there is. See the following papers:

1: Levin-Salomon V, Kogan K, Ahn NG, Livnah O, Engelberg D.
Isolation of intrinsically active (MEK- independent) variants of the ERK family
of map kinases.
J Biol Chem. 2008 Oct 1. [Epub ahead of print]
PMID: 18829462 [PubMed - as supplied by publisher]

2: Edelblum KL, Washington MK, Koyama T, Robine S, Baccarini M, Polk DB.
Raf protects against colitis by promoting mouse colon epithelial cell survival
through NF-kappaB.
Gastroenterology. 2008 Aug;135(2):539-51. Epub 2008 Apr 30.
PMID: 18598699 [PubMed - indexed for MEDLINE]

3: García S, López E, López-Colomé AM.
Glutamate accelerates RPE cell proliferation through ERK1/2 activation via
distinct receptor-specific mechanisms.
J Cell Biochem. 2008 May 15;104(2):377-90.
PMID: 18022816 [PubMed - indexed for MEDLINE]

4: Tapinos N, Rambukkana A.
Insights into regulation of human Schwann cell proliferation by Erk1/2 via a
MEK-independent and p56Lck-dependent pathway from leprosy bacilli.
Proc Natl Acad Sci U S A. 2005 Jun 28;102(26):9188-93. Epub 2005 Jun 20.
PMID: 15967991 [PubMed - indexed for MEDLINE]

5: Vogel S, Kubin T, von der Ahe D, Deindl E, Schaper W, Zimmermann R.
MEK hyperphosphorylation coincides with cell cycle shut down of cultured smooth
muscle cells.
J Cell Physiol. 2006 Jan;206(1):25-34. Erratum in: J Cell Physiol. 2006
Jan;206(1):280-1.
PMID: 15920755 [PubMed - indexed for MEDLINE]

6: Guberman AS, Scassa ME, Cánepa ET.
Repression of 5-aminolevulinate synthase gene by the potent tumor promoter, TPA,
involves multiple signal transduction pathways.
Arch Biochem Biophys. 2005 Apr 15;436(2):285-96.
PMID: 15797241 [PubMed - indexed for MEDLINE]

7: Karanian DA, Brown QB, Makriyannis A, Bahr BA.
Blocking cannabinoid activation of FAK and ERK1/2 compromises synaptic integrity
in hippocampus.
Eur J Pharmacol. 2005 Jan 31;508(1-3):47-56. Epub 2005 Jan 7.
PMID: 15680253 [PubMed - indexed for MEDLINE]

8: Jung Kang Y, Su Jeon E, Jin Lee H, Oh YS, Suh PG, Sup Jung J, Donowitz M, Ho
Kim J.
NHERF2 increases platelet-derived growth factor-induced proliferation through
PI-3-kinase/Akt-, ERK-, and Src family kinase-dependent pathway.
Cell Signal. 2004 Jul;16(7):791-800.
PMID: 15115658 [PubMed - indexed for MEDLINE]

9: Hynds DL, Spencer ML, Andres DA, Snow DM.
Rit promotes MEK-independent neurite branching in human neuroblastoma cells.
J Cell Sci. 2003 May 15;116(Pt 10):1925-35. Epub 2003 Mar 26.
PMID: 12668729 [PubMed - indexed for MEDLINE]

10: Hanson DA, Ziegler SF.
Regulation of ionomycin-mediated granule release from rat basophil leukemia
cells.
Mol Immunol. 2002 Sep;38(16-18):1329-35.
PMID: 12217403 [PubMed - indexed for MEDLINE]

11: Kinkl N, Sahel J, Hicks D.
Alternate FGF2-ERK1/2 signaling pathways in retinal photoreceptor and glial cells
in vitro.
J Biol Chem. 2001 Nov 23;276(47):43871-8. Epub 2001 Sep 24.
PMID: 11571286 [PubMed - indexed for MEDLINE]

12: Jette C, Thorburn A.
A Raf-induced, MEK-independent signaling pathway regulates atrial natriuretic
factor gene expression in cardiac muscle cells.
FEBS Lett. 2000 Feb 4;467(1):1-6.
PMID: 10664445 [PubMed - indexed for MEDLINE]

13: Janssen RA, Veenstra KG, Jonasch P, Jonasch E, Mier JW.
Ras- and Raf-induced down-modulation of non-muscle tropomyosin are
MEK-independent.
J Biol Chem. 1998 Nov 27;273(48):32182-6.
PMID: 9822696 [PubMed - indexed for MEDLINE]

14: Greulich H, Erikson RL.
An analysis of Mek1 signaling in cell proliferation and transformation.
J Biol Chem. 1998 May 22;273(21):13280-8.
PMID: 9582373 [PubMed - indexed for MEDLINE]

15: Taha C, Tsakiridis T, McCall A, Klip A.
Glucose transporter expression in L6 muscle cells: regulation through insulin-
and stress-activated pathways.
Am J Physiol. 1997 Jul;273(1 Pt 1):E68-76.
PMID: 9252481 [PubMed - indexed for MEDLINE]

16: Grammer TC, Blenis J.
Evidence for MEK-independent pathways regulating the prolonged activation of the
ERK-MAP kinases.
Oncogene. 1997 Apr 10;14(14):1635-42.
PMID: 9135064 [PubMed - indexed for MEDLINE]

17: al-Alawi N, Rose DW, Buckmaster C, Ahn N, Rapp U, Meinkoth J, Feramisco JR.
Thyrotropin-induced mitogenesis is Ras dependent but appears to bypass the
Raf-dependent cytoplasmic kinase cascade.
Mol Cell Biol. 1995 Mar;15(3):1162-8.
PMID: 7862110 [PubMed - indexed for MEDLINE]