It is well said that all organic beings have been formed on two great laws: unity of type, and adaptation to the conditions of existence.
This hits the nail on the head of how we got to where we are. All lifeforms have survive to this point in time because of these things exactly. Power in numbers and being able to adapt on a genetic and psychological level to the changing conditions around us throughout the course of time and the many changes our planet has seen around us.
There is no exception to the rule that every organic being naturally increases at so high a rate that, if not destroyed, the earth would soon be covered by the progeny of a single pair.
This statement also feeds into the necessity of the Natural Selection theory in the sense of the importance of each organism in our world. Everything in our world relies upon another or feeds upon another that keeps a natural check and balance to the world so that one species doesn't grow so quickly to overwhelm and become a nuisance to the rest of the worlds population. Each species in it's own regard has some play in maintaining another species natural population limit
. Some variability of animals and plants in nature; 2. The absence of any definite distinction between slight variations, and varieties of the highest grade;
I think this part speaks to the volume of different types of subspecies within a species. Take humans for example, we have different sizes, skin tones, genetic differences, and many other things that fall under this statement in the regard that variations found within a species.
It is said that all domestic varieties, if left to run wild, would revert to their aboriginal stocks.
This part is a very accurate statement on our domesticated culture today. You can see this all the time with animals in particular. Say a dog for example, who is house trained and used to that lifestyle, when left outside or runs away instinctually knows how to revert back to a primal state in order to survive although it may have never even experienced that mentality before it's something inside all of us when needed.
"It is a truly wonderful fact -- the wonder of which we are apt to overlook from familiarity -- that all animals and all plants throughout all time and space should be related to each other in group subordinate to group
I think this line is particularly relevant as well because it brings in the importance that we were all created from the same place and have over time relied upon each other in some way to sustain prolonged life and harmony with one another throughout time.
He goes farther, and this volume is a protracted argument intended to prove that the species we recognize have not been independently created, as such, but have descended, like varieties, from other species
Like a comment i made on the above annotation, this is important because it can be applied for many species including humans linking us starting from another species, such as apes, and evolving into what we are today. This is crazy scientific research in the way that species can transform generationally over time in the right conditions.
The ordinary and generally-received view assumes the independent, specific creation of each kind of plant and animal in a primitive stock, which reproduces its like from generation to generation, and so continues the species. Taking the idea of species from this perennial succession of essentially similar individuals, the chain is logically traceable back to a local origin in a single stock, a single pair, or a single individual,
This is an important statement because through time and science, all mammals can be traced back at different stages and developmental times throughout history, like how humans are evolved forms of apes. Further, humans in specific, our genealogy can be traced through our own lineage for generations through DNA and other methods dating back some time.
"Natural Selection," the weaker ones be destroyed in the process, and the strongest in the long-run alone survive.
This is alway one of my favorite one -liner description of natural selection. Sure there is a lot more regarding the science and psychology of natural selection but this quote sums it up fairly quickly in the fact that all species jointly live by the strongest survive mantra and that it has always been that way since the dawn of time, and that every living thing on the planet over time has found our natural and perfect harmony among each other in that regard.