Evolution of Animals and Their Organ Systems

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All organisms in the world have a range of systems and organs in their body. Some organisms may share similar body systems while others have absolutely nothing in common. Several of those organisms include humans, pigs, crayfish, and earthworms. From their mushy, gushy organs to their soft, gentle skin, you may think, “How are humans and pigs possibly alike? Or a crayfish and an earthworm?” In many ways they may not be, but in other ways, they are very much alike. The body systems that will be compared and contrasted of these organisms are the nervous, circulatory, reproductive, muscular, integumentary, digestive, excretory, and skeletal systems.

During the spring semester of my sophomore year, I had the opportunity to study in Singapore. My coursework included a wide selection of advanced-level biology classes that spanned the spectrum from anatomy to ecology. I was intrigued by the complexity that emerged at all levels of life. The way organelles work together to complete

Most animals don’t have similar structures, but they all have same function to stay alive. All animals have a reproductive system, digestive system, nervous system

Cells come in different types serve a certain purpose. Cells are unique for a reason, and in most cells there are some similarities. But, in plants and animals the difference could not be any more evident. Plants do not have a skeleton, while animals do. I learned plants are firm and strong because of their cell wall, which is made of cellulose and chloroplast. Cells are a living thing with different entities, which allows the cell to live and function on a daily basis. According to (1998-1999),

The Earthworm, starfish, frog, fetal pig, and human all have much in common; however, some have more in common than others. Many have a matching digestive system but not a matching skeletal or circulatory system. Thought numerous dissections we can compare and contrast the various animal systems and gain knowledge on more than just the external side of an animal.

Knowledge of relationships between animals may allow us to deduce the answer: the two main branches of the animal tree are protostomes and deuterostomes, while the trunk of the tree includes sponges and cnidarians. The first appearance of these protostome and deuterostome groups is arguably in the Cambrian period – while arguments have been made for an earlier bilaterian, for instance the 555 million year old Kimberella, they are not persuasive – for reasons discussed later in this essay. We can assert that whatever was shared by two or more groups was likely to have been present in their last common ancestor. In this case, all members have bilateral organization in their life stages. Thus, the theory of the common ancestor of bilaterians – Urbilateria – arose (De Robertis & Sasai,

There are about thirty modern animal phyla, including chordates, arthropods, annelids, corals, sponges, mollusks and echinoderms. All of which trace back to the Cambrian time period, 530 to 525 million years ago.

Sponges are believed to have been the first animals to inhabit earth and regarded as the origin of every animal species. Since sponges are the base of the animal family tree that gave rise to all forms of animal life, they could be viewed as the “animal eve”.

Sponges are one of the most primitive, ancient types of multicellular animal. The vast majority are marine, but a few species dwell in fresh water. Sponges are often found attached to rocks, reefs, or other animals, and feed by straining granular particles from the water. Their frequently irregular body shape can be rather large because their interlocking spicules form a harder skeleton, which are often found preserved as fossils. Sponges are made up of only a few varieties of cells, some cells are unique to a specific phylum and do not have a genuine nervous, digestive, or circulatory systems. For these reasons, they are not immediately ancestral to more complex animal

In the single origin of neurons, comb jellies are said to the oldest in the clade coming before Porifera, Placozoa, jelly and bilateria (Bucher 2015). In the process of evolution the sponges and Placozoa lost their ability to send rapid signals and their neurons. The loss of their nervous system is still uncertain, however there could be an environmental role that could have played a role in the evolutionary process. The phylum Placozoa only has one species called Trichoplax adhaerens. This particular species have been identification with six somatic cell types containing proteins that are normally in neurosecretory cells. Which includes FMRFamid-like peptide, opening the door to the possibility of neuronal like cell existence in the phylum (Bucher 2015). Only Hexactinellida also recognized as the glass sponges practice electrical impulses that send brisk signals to the current. Primary cilia are present in the cell of vertebrate, invertebrate and also in sponges. Primary cilia’s function is similar to one another. Similarly, the cilium are involved in sensing chemical activity, sending signals through calcium wave. By removing the cilia or the osculum, sponges lose their ability to ‘sneeze”, which is used by freshwater sponges to unload their waste. Cilia is present in the osculum of all sponges that have been examined, displays the common sensory organ in Porifera (Leys 2015). The nervous system did evolve once through the common ancestry, however sponges and Placozoa lost their nervous system in their development

These seven organisms are organized in this way because I believe that these organisms evolved over the time. There are a lot differences that every organism had. For instance, all of these organisms are Eukaryotes, they developed over time and evolved over time due to environmental effects and genetic evolvement. For that, they developed and apparently have different shapes and sizes. Amoeba evolved such that it evolved and shaped a fish. It began as a unicellular organism but then became a multicellular organism that evolved all over again and again till it shaped the fish with fins, gills, eyes and gills.

As the years have passed animals have evolved from very simple animals to more advanced animals. Their individual respiratory systems have developed depending on their habitat. Even though the Orcinus lives in water and the Trochilidae lives on land their respiratory systems are worth observing, as we can see how specific organisms can develop different ways in which their respiratory systems evolved. By looking at the way they have evolved from past ancestors and how they are respectively similar. Looking forward into the way these to species have evolved we can create a deeper understanding of the respiratory system and how it has changed throughout the years. This paper will focus on how different their respiratory systems affect them with

First, I’m going to discuss is the phyla Protists. Some protists are autotrophs, a photosynthetic group of phyla referred to as the algae. Some protists are heterotrophs. Heterotrophs get their energy by consuming other organisms. Protists reproduce asexually by binary fission, and a few species are capable of sexual reproduction. Protists are so small they don’t have any special organs to exchange gases or get rid of waste. They rely on diffusion which is movement from a high concentration

Eukaryotes come in two grades of organization: single-celled (protists) and multicellular (plants, animals, and fungi). The world today is full of complex multicellular plants and animals: how, why, and when did they evolve from protists?