The great chain of being
This concept, first described by St. Thomas Aquinas, was translated from a Latin word “scala naturae,” which literally means “ladder or stair-way of nature”. This is a conventional Christian and Western medieval concept, which details a divine, hierarchical orderliness of all things and life in a vertically extended chain. The Chain of Being is made up of various hierarchy rankings from the most fundamental segments up through the supreme perfection, that is, God. There is a hierarchy that recognizes God being at the top of, and the Angels can be found down the ladder, even though all exist in an ageless spirit form. Beneath them are people, who are grouped into two, nobles and commoners. This chain extends down to the lowest form of life, that is, plants and natural minerals. In addition to the universal ranking, there is universal interdependence among the different elements of the chain and this is what holds the elements together. However, many scholars have disputed this concept arguing that post-medieval period “disorder” was more evident than “order”, due to discomforts in the classical orderliness.
Fixity of species
This concept argues that all species have remained exactly the same in their present anatomical form ever since their appearance on earth. It claims that our material reality and separate realms of forms are distinct. The world is made up of “imperfect shadows of forms” and the variations people notice in matter around them is irrelevant because it’s due to trivial flaws. Even Charles Darwin believed that God made all matter purposely for its environment. However he rejected this belief after observing species in the Galápagos Islands evolve. However, this concept is normally rejected by many people today due to the large amounts of facts regarding evolution. Also, it does not tell how matter originally came into existence, it only associates a creator.
The theory of transformation
This concept, also known as “heritability of acquired characteristics or soft inheritance,” holds that a species can pass on some of its characteristics, which it got as it developed to its offsprings. During an organism’s lifetime, it gets various individual characteristics, because of its specific experiences, such as starvation, or diseases. Lamarck argued that an organism could undergo transformation if these individually acquired characters were passed on by its off springs and further modification was aggregated with time. Also, it claims that organisms started out simple and constantly get more complex, towards perfection.
Shallow time
This concept argues that humanity came about as a result of system centered on nature divergent to a human centered system. The earth as it is today according to Archbishop Ussher came into being a couple of millenniums ago. This concept came about and is based upon readings from the bible by Ussher. Ussher offers a chronological time frame of the earth’s formation arguing that compilation of the bible was done by various sources and continued over a number of centuries thus gaps could be noticed. Ussher established and proposes the earth’s creation date to be about 4004 BC and gives three very distinctive periods that are fundamental to this line of thought: 1) the early times (includes the creation period to time of King Solomon); 2) the early age of kings (period from king Solomon up to the destruction of Jerusalem and the temple and subsequent capture by Babylon); 3) the late age of kings (period between the time of Ezra and Nehemiah to when Jesus was born).
Homo habilis
Homo habilis, Commonly referred to as “handyman” is believed to have given rise to Homo ergaster who in turn gave rise to Homo erectus. This is the earliest known species of the “genus Homo” that lived from around 2mya at the start of the Pleistocene era. These hominids had the least similar species of the genus to modern man. Homo habilis had a small size about 1.52 m tall and weighed 45 kg. it had abnormally lengthy forearms as compared to modern man, though it had a shorter obtruding face than the australopithecines that were believed to be its descendant. It had a reduced postcanine tooth size. Males were pretty bigger thatn females. These hominids had an upright walk. Homo habilis had a lesser brain capacity of 590-710 cc approximately half of the modern man. It was the first hominid to invent stone tools and had a less specialized diet.
Homo erectus
Homo erectus is believed by anthropologists to have existed in Africa some 1.8million years but soon after swelled to parts of Asia and Europe. It was the longest-lived of the hominids. Compared to its predecessor, homo habilis, It had an increased cranial capacity (erectus about 900 cc., sapiens about 1350 cc.). It had a reduced postcanine dental arrangement, and a reduced skull size. It had shorter vertical face, shorter armbones (particularly the arms) to form a much man-like limb proportion. It had a more developed barrel-shaped chest, had an external nose and had a larger size almost to the modern human. These hominids had a complex lifeway, they were the first genus to live in an hunter-gatherer society and an increased an extent of male-female cooperation. However, it is not clear as to whether these hominids had a developed mode of speech.
Homo ergaster
Homo ergaster, lived in Africa close to about 2.4million years ago however it is an extinct species now and is referred to as working man. As compared to the Homo erectus, the homo ergaster had an increased cranial breadth across the parietal bones, increased occipital bone length, broader nasal bones, broader nasal opening, and shorter cranial base, developed mandibular symphysis, and narrower M1s and lower canines. They had a reduced sexual dimorphism and the males did not compete for females. This diminished competition and dimorphism also corresponded with an increase in cranial capacity and development of tool technology.
Decoupling
Decoupling of behavior from anatomy is the detachment of genus homo species behavior from its anatomy, that is, the physique is not a factor any more to determine the degree of actions or behavior for the species. It was important in the evolution of Homo since the species could now do things that they could not do before. Decoupling enabled the species to be more adaptive to the changing surroundings. For instance, for man tool technology took the place of other bodily characteristics of other hominids, with stone tools, these species could undertake activities that their body alone could not do, they now used stone tools to crack open a bone to extract the marrow. Another example, bipedalism, which allowed the shoulders to sustain a high degree of mobility, helped develop suspensory behaviors. Hunting and gathering societies emerged due to the change in lifestyle and a desire to live a more social kind of life, this was brought by sexual dimorphism and diminished competition among males.