AP bio question relating to glycolysis?

Question

"It is theorized that, evolutionary, glycolysis was the first metabolic pathway for producing ATP"

What are 3 pieces of evidence that could argue this quote?

Answer 1

1. Glycolysis happens in the cytoplasm and does not require mitochondria or any other specialized structure.
2. Glycolysis happens whether there is oxygen present or not.
3. ......... I'm out for now ......... Unless that it's not very efficient, and aerobic respiration may have come along later with more efficiency ......... but I doubt if that's it.

Answer 2

During the metabolism of carbohydrates Glycolysis precedes the ATP energy production from the Kreb's cycle and the electron transport chain, therefore it probably develped first.

1) the kreb's cycle produces a lot of ATP, but it is found in the Mitochondria which is a 'late' evolutionary inclusion into animal cells.

2) most ATP is produced by the electron transport chain - also a part of the Mitochondria and, therefore, a "late" development.

3) glycolysis can produce ATP in an anaerobic environment - anaerobes certainly preceded the evolutionary development of aerobes.

Hope this helps!