Species Diversity: Humans Vs. Chimpanzees

This document discusses the species diversity between humans and chimpanzees. It explores their physical features, the evolution of bipedalism, and the environmental challenges overcome by bipedalism. The document also highlights the opportunities opened with bipedalism.

Running Head: Species Diversity
Discussion
Species Diversity
Humans Vs. Chimpanzees
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Species Diversity 2
Humans Vs. Chimpanzees
The humans are bipedal while the Chimpanzees have both the hominids and bipedal
features.
Binomial Name of Chimpanzees: Pan troglodytes
Kingdom-Animalia
Phylum- Chordata
Class-Mammalia
Order-Primates
Family-Homonidae
Genus-Pan
Species- Pan troglodytes
Nearest relatives- Pan paniscus
Scientific names are used to locate the nearest relatives of the species by moving up in the
hierarchy where the genus, family and order and above domains may be same but just the species
name changes. For example: Homo sapiens and Homo erectus are the nearest relatives.
Pan troglodytes and Pan paniscus have similar dental development like dental measurements
and crown height. However, there are differences in the growth of enamel in upper incisor. It
makes possible that there are variations in the perikymata distribution (O’Hara & Steinberg,
2015).
Major Innovation

Species Diversity 3
Present-day humans and chimpanzees clearly differ in two major physical features:
Humans are bipedal (walk upright) and have much larger brains. When did these features
emerge? (Simon 364).
Bipedalism can be defined as terrestrial locomotion with help of two legs (Department of
Anthropology, n.d.) The bipedalism evolved and remained as an important adaptation driven by
the principle of Darwin’s Natural Selection. It helped the human ancestors in their survival,
assisting them to adapt to better environments, in getting more food, and protecting their progeny
from predators. The transition to bibedalism was beneficial for the hominids. There are many
theories explaining the origin of bipedalism like Savanna based Theory and Postural Feeding
Hypothesis (Ko, 2015).
Savanna based theory asserts that the hominids were compelled to adjust to the
environment of open savanna after leaving the trees. As per the theory, such environment forced
them to use two feet by walking straight. Bipedal posture helped them to look above tall grass of
savanna for the potential predators and to hunt successfully. However, the fossil records and
evidences of paleoclimatological relevance depict that the early hominids were also used to
climb on trees in addition to using bipedal locomotion.
The Postural Feeding Hypothesis postulates that the bipedal movements were easier in
maintaining balance and grabbing the foods. It is identified that the chimps used to sit on two
feet only when they ate food. The theory favors the evolution of bipedalism as a feeding posture
rather than as a posture used for walking. According to Darwin’s Hunting Hypothesis, it freed
their hands to hold tools and weapons.

Species Diversity 4
Environmental Challenges overcome by the bipedalism
The bipedalism was favorable in watching out through the savanna grass, freeing up the
hands, throwing, reaching to the food, carrying food and infant (Norton & Company, 2010). An
increase in the body weight gradually led to bipedal motion for longer distances. They could find
out new resources of food by walking on two feet. The issues associated with shallow waters and
terrestrial life. There were high numbers of predators in dry land areas than in the shallow
waters. So, better parenting and protection was possible for the children on the trees. It might
have led them to stand erect to reach the trees.
The anatomical adaptations of major parts of upper body like head, back and shoulders to
exchange the heat helped in thermoregulation while the lower body parts like hips, and abdomen
are insulated. Climatic changes led to more seasonal adaptations in African forests with
variability in environment. With 4 feet it was highly time consuming to reach new food resources
and rear the children. According to patchy forest hypothesis, Shrinking of forests compelled the
hominids to descend from forest trees to the grasses habitats. Bipedal locomotion was the most
efficient way to walk in such conditions (Wayman, 2012).
Partly terrestrial and arboreal hominids walking on four feet also expanded their movement
wading at the shores of the water bodies. Utilization of upper body extremities was freer in
bipedalism than the quadruple locomotion.
Opportunities opened with Bipedalism

Species Diversity 5
The early hominids were small in size. For example Lucy who was just 60 pounds in weight. It
was quite dangerous to walk in tall grasslands with such a small size (Norton & Company,
2010). It was favorable to stand straight and look for the predators and other carnivores in
Savannah. Walking slow could have easily made these tiny animals fall prey.
The upright body posture also helped the people in maintain the body temperature under the sun.
The bipedal adaptation offered the mates an opportunity to enable good quality food to the
family and protect them from the potential dangers. It was beneficial in behavioral and
biologically significance. In open land environments the free hands were an added advantage to
grab the available resources at the earliest and remain active to survive. Bipedalism led to further
innovation sin the lives of the humans such as making of tools, enlargement of brain and the
improvements in intelligence from Australopithecines to Homo erectus (Niemitz, 2010).
References
Department of Anthropology (n.d.). What is Bipedalism? Retrieved from
http://efossils.org/book/what-bipedalism
Norton & Company (2010). Primate Origins And Evolution: The First 50 Million Years.
Retrieved from
http://www.wwnorton.com/college/anthro/our-origins2/ch/09/answers.aspx

Species Diversity 6
Ko, K. H. (2015). Origins of Bipedalism. Brazilian Archives of Biology and Technology, 58(6),
929-934. Retrieved from https://dx.doi.org/10.1590/S1516-89132015060399
Niemitz C. (2010). The evolution of the upright posture and gait--a review and a new
synthesis. Die Naturwissenschaften, 97(3), 241-63.
O'Hara, M. & Steinberg, G. D. (2015). A comparison of Pan paniscus and Pan troglodytes
perikymata distribution in upper incisors and lower canines by crown length and
height. Retrieved from
https://www.researchgate.net/publication/274194249_A_comparison_of_Pan_pani
scus_and_Pan_troglodytes_perikymata_distribution_in_upper_incisors_and_lower
_canines_by_crown_length_and_height
Simon, E. J., Jean, D., Jane R., & Kelly H.(2015). Campbell Essential Biology with Physiology,
5th Edition. VitalBook file. Pearson Learning Solutions, 1--2015.
Wayman,E.(2012). Becoming Human: The evolution of walking upright. Retrieved from
https://www.smithsonianmag.com/science-nature/becoming-human-the-evolution-
of-walking-upright-13837658/