Transformational stages in evolutionary history

Transformational stages in evolutionary history

Living organisms have passed many different stages to be where they are today. They evolve from stage to stage with varying characteristics. Some of these characteristics are adaptive to many conditions such as climatic conditions, type of feed and even their enemies and many others (Szalay & Delson, 2013). Some of these transformational stages include the following; early amphibians, pelycosaurs, Therapsids, early mammals, early arthropods, Miocene apes, early hominines , Australopithecus, Homo habilis, Homo erectus, Homo sapiens, Homo sapiens sapiens . Discussed below are the adaptations associated with the above stages of development in organisms.

Early amphibians

• They had fins around their body. These fins acted as legs and also helped them to crawl in and out of water. They also helped them in swimming.
• They hand limbs and lungs which helped them to move by not depending on buoyancy of water.
• These early amphibians still contained gills which they used for respiration. Gills were used for respiration under water as the only mean which was available to them.
• They hind legs were powerful and strong. This was so to assist in leaping and also swimming. This feature facilitated easy leaping in the amphibians.
• They had a thin skin to make respiration simple and easy.
• They laid many eggs to cater for those destroyed by other organism or any other conditions.

Pelycosaurs

• They had strong canine teeth for tearing meat. This was so because they were carnivores.
• They had strong limbs. This helped them for support to their heavy bodies.

Therapsids

• Their limbs were close to one another. This helped them to decrease the lateral undulation of their bodies. It also enhanced freedom of movement and respiration process to increase aerobic activities.

Early mammals

• The upper jaws had cusps rows. This helped them in chewing.

Early arthropods

• They had hard exoskeleton which helped in protecting them from predators and also helped to reduced water lose.
• They have strong and jointed legs which help them in movement and location.

Miocene apes.

• They had high visual ability. This helped them to see their enemies from far and hence escape.

The earliest hominines

• They had short pelvic bones. This helped them for support in movement and even while standing.
• They had developed long feet. It helped them in support to walk.
• They also had well developed hands. These hands were useful in holding objects and babies.

Australopithecus

• They had a straight walking and a standing posture. This helped them to search for food in an easy way and also see their enemies from far.
• They had powerful arms. These arms were useful in holding objects and also carrying out various tasks.

Homo habilis

• They had long arms and feet. This helped them in walking and support and even in digging for food.
• They had large brains. This helped them in designing and making instruments sand tools which in turn helped them carry out their day to day activities in a simple way.
• They had short legs. Their short legs helped them to offer support to their bodies.

Homo erectus

• They had well and large developed feet which assisted them in running.
• Their hips joint was towards the center to enhance balanced.
• Their spine had a slight curve. This helped to center the weight of the upper part of their bodies.

Homo sapiens

• They had short, slender trunks and long limbs to enable them survive in the tropical regions for cooling and retaining body heat.
• Their jaws had protruding bone to enhance its strength for chewing.

Homo sapiens sapiens

• They had a full straight standing posture. This helped them to see the enemies from far.
• They had a high brain capacity. This helped them to enhance their lifestyle and living standards.

Differences between living organisms and Stone Age artifacts

The early artifacts made by the early man in Aegyptoithecus and other stages of the nearly man differed greatly from the current human beings non the bases o the cell theory , nature of their genes, the composition and the functions of the DNA materials in theory bodies, the heredity process , the geologic time scale and finally the trees of life (Eliade, 2014).

Cell theory

Biologically, a cell is defined as the functional or the basic unit of any living organism. The cell theory helps in explaining the composition of an organism that makes it able to execute functions or considered as part of the basic organism in life. All living organisms are made of small microscopic units in their bodies that help them undergoing the various body processes for survival (Harris & Hillman, 2014).  These metabolic processes may include transpiration and photosynthesis in plants and respiration, reproduction, growth and developments in animals. However, the artifacts such as hammer stone, core and hand axes during the Stone Age period did not exhibit these characteristics. Basically, being made from stones, they never contained any cell in their bodies for functional purposes.  Perhaps, the tools were use by the living organisms; the early man in production of other living organisms; the crops (Harris & Hillman, 2014). Other tools were made from plants that had dried up. The biological law asserts that a plant dries up as results of death of the cells found in it.

Nature of genes

                 Genes are characters found in the cells whose function is to design the features of living organisms. For instance, in living organisms, there is gene for tallness and the gene for dwarfness. Consequently, there are both short and tall people that exist in a man (Buss, 2015). In consideration to the tools that were made by the early man, the artifacts were not made of genes because they were non-living. Genes are only found in living organisms.  The characteristics exhibited by those organisms were designed by the Homo erectus and the Homo habilis because they were the hominids that existed in the Stone Age period. For example the acheullian bifaces were the tools sharpened both sides that could be used by man in digging (Szalay & Delson, 2013). Also, there were the sharp-headed tools used by early man for digging roots. Significantly, these features were not gene-orientated rather they were designed by the hominids for various activities.

Functions of DNA

DNA is involved in every process of a living organism.  In living organisms DNA are controllers of chemical reactions. In addition, the Deoxyribonucleic Acid in the cells facilitates the storage of the important information in the bodies of living organism. The kind of information stored includes the genetic makeup of organism. As stated earlier, it is this genetic makeup that determines various features in living organism. On the other hand, the Acheulian artifacts and the other tools made during the Stone Age period lacked the DNA as they did not have cell compositions in their bodies.

Process of heredity

In living organisms genes are passed from one generation to the other as characteristics would be passed over to the off springs .On the other hand auchellian artifacts and other tools made during the Stone Age period would not pass it genes to its off springs and hence would not have similar characteristics.

Geologic time series

This is a chronological dating of artifacts. Miners were the first to understand the dating. Acheulian artifacts and other tools made during the Stone Age period were dated while the living organisms have no chronological dating.

Tree of life

Over the years, there has been a phylogenetic tree of common decent based on religion and philosophy. After the development of religion in Homo erectus period, various improvements have been done on the same. In additionally, a keen look of the characteristics of the previous early in many years ago kept on improving from stage to another. For instance, the Aegyptopithecus had bigger but the teeth kept on wearing as the time went by. There are less of those changes in the present living organisms.

 References

Buss, D. (2015). Evolutionary psychology: The new science of the mind. Psychology Press.

Eliade, M. (2014). History of Religious Ideas, Volume 1: From the Stone Age to the Eleusinian      Mysteries. University of Chicago Press.

Harris, D. R., & Hillman, G. C. (2014). Foraging and farming: the evolution of plant          exploitation (Vol. 31). Routledge Harris, D. R., & Hillman, G. C. (2014). Foraging and     farming: the evolution of plant exploitation (Vol. 31). Routledge.

Szalay, F. S., & Delson, E. (2013). Evolutionary history of the primates. Academic Press.