Lab 105 Human Species Essay

Anth. 105 Human Species – Lab 4 Report

Rumaysa Sharif

05/14/18

Introduction Primates, apes and humans all have varying body masses, brain sizes and life spans. One species may have a longer life span or a larger brain than the other. This all depends on body mass. Humans have the largest body mass compared to primates and apes. Since they have the largest body mass, they also have the largest brains, the longest life span, reproduce at a much later age and have a large EQ. In this project, we investigated how and when the human-like pattern of large brains, long growth periods, and maximum lifespans evolved by examining and estimating these traits in fossil hominins. We measured the skulls of the fossil hominins: Australopithecus, Homo habilis, Homo erectus, and Neanderthal. We measured the length, height, width and orbit height of their skulls to calculate the estimated brain size and estimated body mass.

Hypothesis 1. For Life History, humans will reproduce earlier than the primates and apes because of their body mass. Apes and primates will reproduce at a younger age than the fossil hominins: Australopithecus, Homo habilis, Homo erectus, and Neanderthal. 2. For Brain size, I expect the Encephalization quotient (EQ) in humans and primates to be larger

First, we measured the skull of the Australopithecus using a caliper. We measured the cranium length, width and height and received different measurements. We used the measurements we found and estimated the brain size by using the formula given: 10^(2.53*log(Orbit Height)-2.29)= Body Mass. After plugging in the measurements, we found that the body mass of an Australopithecus is about 41 kilograms. From this, we can estimate that the brain size of this species is not large because their body mass is not large. The lifespan and EQ of the Australopithecus is also relatively short because of the other variables (brain size, body mass, life span,