mutation ...

"objectivity cannot be equated with mental blankness, but resides in recognizing your preferences and then subjecting them to especially harsh scrutiny, and also in a willingness to revise or abandon your theories when the tests fail (as they usually do)" - doesnt matter

at the molecular level, life’s ability to reproduce begins with the replication of DNA, during which two new spirals are created that are exact replicas of the original molecule. sometimes a change in the sequence is called a "mutation".

mutations can occur randomly, from radiation damage (impact with high energy g-rays or cosmic rays), from exposure to chemical agents called mutagens, viruses or simply by error in the DNA replication process.

mutations are considered the driving force of evolution, where less favorable mutations are removed from the gene pool by natural selection, while more favorable ones tend to accumulate.

"adaptations" according to the surroundings can also be referred to as mutation. overwhelming majority of mutations have no significant effect on evolution.

can't say how or when sexual reproduction came to take a hold in nature, but high mutation rates can, under the right conditions, force an asexual organism like bacteria to become sexual and pass on higher mutation rates.

the rate of progressive evolution (the accumulation of beneficial mutations) is faster in populations that reproduce sexually.