Essay on Anatomy and Physiology of a Ring-tailed Lemur compared to a HUman

Submitted By kimboslice333
Words: 1252
Pages: 6

When referring to the evolution of species Charles Darwin, a paramount evolutionist (1886) states that, "… it can be inferred from analogy that probably all the organic beings which have ever lived on this earth have descended from some one primordial form, into which life was first breathed." Darwin theorizes that the some 10 billion species that exist on earth descend from a common ancestor, which all stemmed from a single being and over time evolved into remarkable animals each with their own specific anatomical and physiological features.
This report will critically analyse and compare the traits of a Ring-Tailed Lemur and a Human, focusing on the Integumentary, Reproductive and Skeletal systems. These species were distinctively chosen as clear comparisons and differences can be identified. The Human surpasses the wild, terrestrial ring-tailed lemur in evolutionary form highlighting obvious anatomical differences; however these two species belong to the same Order of Primates and are both diurnal species which will allow significant physiological similarities to also be formulated.

Skeletal System Evident anatomical differences are observed when comparing the Human with the Ring-tailed lemur. The Skeletal structures vastly differentiate in size with the average fully grown human ranging between 160 and 180 cm and comprising of 206 bones (Taylor, 2013), while the lemur only reaches an average of height of 42cm, not including their tail which averages around 60cm, and has 156 bones ( National Geographic , 2014).
Despite the size differences and tail- which is used for balance when running, closer inspection reveals that specific skeletal regions of the two species are alike. Both animals are vertebrates and possess four appendages which assist in movement. For the Lemur it is, “… by quadrupedal walking, running, or galloping” (Oakland Zoo, 2013) and bipedal movement for the Human. Woburn (2014) attains that the Lemur has, “… hands similar in structure to a human hand, including an opposable thumb, allowing them to grip when climbing and to hold objects.” (Figure 1) This trait is consistent throughout the primate order and certainly suggests obvious evolutionary links. Additionally the vital organs of the species are enclosed by a protective ribcage and the brain protected by the skull, as seen in figure 2. Encyclopaedia Britannica observes that the primate order also possess a separate radius and ulna in the forearm (figure 2), and a separate tibia and fibula in the lower leg (2014), these endoskeleton bones and multiple others provide the animals with a supportive framework, allowing fluent movement.

Reproductive System

The Reproductive system includes a group of organs that work together with the purpose to produce new life. Close comparisons between the L. catta (Ring-tailed Lemur) and the H. sapiens (Human) can be made, within this system, due to both the species being mammals. The two possess the necessary reproductive organs for successful copulation, like the ovaries and testes, and perform mating in similar ways. Drea and Weil (2008) maintains that the “L. catta possess penile spines and a complex distal penis morphology, including an enlarged glans penis,” which play a role in copulatory plug removal. Despite the penile spines, the male Ring-tailed lemur’s cylindrical external genitalia somewhat mirrors a Human. (Figure 3)
Internal similarities occur with both species fertilized eggs implanting in the uterus and as the foetus develops it is surrounded by a placenta and fed through an umbilical cord. During gestation, according to Benirschke, the excretion of oestrogen, “… which has a major role in building tissue during pregnancy,” (2005) significantly rose in both mammals. Finally the Ring-tailed Lemur and Human both give birth to typically one or two live young, which are fed through secretion of the mammary glands (figure 4). Drea and Weil comments on the close comparison between the…