An interesting question posed in this topic thread is "How many beneficial mutations do you suppose it would take to get from
Little Foot or Lucy to Homo Sapien in the proposed ~ 3 Million years?" In order to accurately calculate that we would need to know what the genome was for Little Foot and for Lucy. But we don't have that information because none of their genetic code has been preserved intact in their fossils, because the fossils are far to old. But even without that information there might be a way to estimate it.
What we do know is that the genetic code of modern day common chimpanzees and bonobos is about 96% the same with modern day Homo sapiens (previously the percentage was thought to be 98.8%; the 98.8% was
calculated based only upon "single-nucleotide changes to the genetic
code"). [See https://www.nationalgeographic.com/science/article/chimps-humans-96-percent-the-same-gene-study-finds .] Both Little Foot and Lucy are much more closely related to us (which is known based upon comparisons of their skeletal structure) than modern day common chimpanzees and bonobos. As a result the genetic code of them when they were alive must have been even more identical to ours than are the chimps and bonobos to us. [Note: When some scientists use the word chimpanzees they are including bonobos in the classification called chimpanzees, along with the common chimpanzees, thus classifying two different species as chimpanzees. The bonobo, in the past was commonly also referred to as the "pygmy chimpanzee", and today it still sometimes is. Both common chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) are of the same taxonomic genus, namely Pan. The genus name "Pan" means "chimpanzee".]
https://en.wikipedia.org/wiki/Pan_(genus) says "The chimpanzee (P. troglodytes) who lives north of the Congo River, and the bonobo (P. paniscus) who lives south of it, were once considered to be the same species, but since 1928 they have been recognized as distinct.[6] In addition, P. troglodytes is divided into four subspecies, while P. paniscus is undivided. Based on genome sequencing, these two extant Pan species diverged around one million years ago. ... Chimpanzees and bonobos are equally humanity's closest living relatives." Sadly the article also says "Both Pan species are considered to be endangered as human
activities have caused severe declines in the populations and ranges of
both species."
https://www.nationalgeographic.com/science/article/chimps-humans-96-percent-the-same-gene-study-finds says the following.
"The number of genetic differences between humans and chimps is ten times smaller than that between mice and rats.
...
Despite the similarities in human and chimp genomes, the scientists
identified some 40 million differences among the three billion DNA
molecules, or nucleotides, in each genome.
The vast majority of
those differences are not biologically significant, but researchers were
able to identify a couple thousand differences that are potentially
important to the evolution of the human lineage.
...
Eichler and his colleagues found that the human and chimp sequences
differ by only 1.2 percent in terms of single-nucleotide changes to the
genetic code.
But 2.7 percent of the genetic difference between
humans and chimps are duplications, in which segments of genetic code
are copied many times in the genome."
Some scientists go so far as to say that humans are apes.
The above article also says the following.
"Humans and chimps originate from a common ancestor, and scientists believe they diverged some six million years ago.
Given
this relatively short time since the split, it's likely that a few
important mutations are responsible for the differences between the two
species, according to Wen-Hsiung Li, a molecular evolutionist at the
University of Chicago in Illinois.
...
There are several hypotheses that account for the evolution of human
traits. Li believes these traits come from changes in the parts of the
genome that regulate other gene activity."
See also https://www.amnh.org/exhibitions/permanent/human-origins/understanding-our-past/dna-comparing-humans-and-chimps and https://humanorigins.si.edu/evidence/genetics .
Regarding information of how life might have got started (abiogenesis) an excellent book on that topic (besides those listed in another post of mine in this topic thread) is Genesis: The Scientific Quest for Life's Origin, by Robert M Hazen (with a Forward by David W Deamer). See https://www.nhbs.com/genesis-the-scientific-quest-for-lifes-origin-book for a description of that book. I very much enjoyed reading that book.
