1. Life from non-life?
2. Asexual to sexual reproduction?
3. Development of “thought”?
And is there an experiment to prove the explanations?
>>1. Life from non-life?<<
That is abiogenesis and has nothing to do with TToE, any more than physics, chemistry or astronomy.
>>2. Asexual to sexual reproduction?<<
Stochastic progression, as explained in the theory.
>>3. Development of “thought”?<<
Clearly a survival need, but it followed the process just like everything else. But there is a lot of debate in the scientific community about that at the detailed level.
Based on moon rocks, we know that the Earth is about 4.5 billion years old. Life on Earth, therefore, originated or arrived inside that time span.
According to my Jones book on evolution, "The balance of isotopes in carbon entrapped in Greenland rocks three thousand eight hundred million years old resembles that of the modern bacteria that live on methane." (page 208)
Another revelation from Jones is ... "About a thousand genes are shared by every organism, however simple or complicated. Although their common ancestor must have lived more than a billion years ago, their shared structure can still be glimpsed. It shows how the grand plan of life has been modified through the course of evolution." (page 284)