Question

The late paleontologist Steven Jay Gould proposed the following thought experiment, imagine you could “rewind the tape” back to immediately after the first life appeared on the Earth. Further, assume that the physical ABOTIC events of history did not change, in other words, Earth experienced the same volcanic eruptions, the same asteroid strikes, and so forth. Given this scenario, do you believe we would end up with very similar life forms to what we observe today, or would life forms be fundamentally different?

Answer 1

Answer: Steven Jay Gould proposed the theory of punctuated equilibrium. He spoke and suggested that instead of species are evolving through millennia, they actually evolved from the geological shifts. They did not really change gradually over the longer period of time, but they had changed from the various events that took place, and once a species is formed it did not change much to form other species, but become stable.

According to this proposal, we can say that evolution is thought to be an adaptive and change mechanism that has shaped the earth. There were theories of 'panspermia'. We have seen from Urey and Miller's experiment which has shown us the early Earth's conditions. From there we have seen the convincing theories of life, as scientific theories suggest the evolution and the formation of organic compounds. From there we have the formation of genetic material known as the RNA. Then the formation of prokaryotic life. Slowly evolving to the more complex life forms.

Now, here we are suggested to say that 'first life appeared on the Earth'. Further, we have the turbulence of this earth's formation as 'volcanic eruptions, the same asteroid strikes, and so forth'. These things have shown us that life forms might appear to be of the same kind or fundamentally different.

Scenario 1: Life forms will be the same- When we can have a persistent abiotic compound ruling this earth, we are not saying that some different molecules might form instead of nitrogen, carbon, sulfur. These abiotic substances still remain the same, some alien species coming and taking over it is less likely or no chance at all.

If the abiotic factors truly give rise to the same organic molecules later from the 'primordial soup', then delayed formation of life would still have similar life forms in its fundamental nature. Natural selection would still be in a place where we would see small gradual changes continuously accumulated.

Scenario 2: Life forms will be different- In this scenario, life forms would have havoc over them, especially after the first life form appeared. There would be changes in the structure and formation of abiotic substances and molecules arising form that concoction. A belief might arise that instead of gaining a normal situation which is friendly for the Earth's environment to nurture the formation of molecules which would be organic, there would be different life form arise from a new type of substance.

I would believe that we would still end up having similar life forms as today. Maybe, their patterns of natural selection and change occur differently.