Why is glycolysis considered as biochemical proof of evolution?

1. Glycolysis does not require oxygen. Hence it might have been used by earlier organisms for energy production, as there was no free oxygen in atmosphere of primitive earth. 

2. Glycolysis is the first metabolic pathway, an ancient pathway which is common to both aerobic and anaerobic organisms. 

3. All cells have glycolysis in their metabolic pathway. 

4. Upto pyruvate the pathway is similar to all aerobic and anaerobic organisms. Later, the fate of pyruvic acid can be either CO₂ or ethanol or lactic acid depending upon the type of organism. 

5. Hence it is considered as a biochemical proof of evolution.