Within Class Mammalia and Order Proboscidae, modern day elephants descended from Moeritheriums, which were the approximate size of current day pigs1. Over the course of 50 million years, evolutionary trends have resulted in elephants gradually increasing in size.
Although there are only two species of elephants today, the Asian elephant or Elephas maximus and African elephant or Loxodonta africana, it is believed that a single ancestor, the Paleomastodon, evolved into an estimated 352 different elephant species2. Charles Darwin coined the term “natural selection”, which is “the preservation of a functional advantage that enables a species to compete better in the wild3”. For elephants, this functional advantage was the development of the trunk, …show more content…
Although Moeritheriums had a long flexible upper lip, it eventually evolved to the homologous structure of a Mammoth’s trunk or Proboscis. This particular development of the trunk allowed them to pay attention to their surroundings for predators and other dangers while feeding and drinking, which is an advantage that the primitive Moeritheriums did not have16. Furthermore, it is evident that the 2.5 feet tall Moeritheriums, after they became extinct due to the cooler climates of the Oligocene era, evolved to Mammoths the size of 13 feet9. This was favourable for their environment to keeping warm as larger animals have a smaller surface area to volume ratio and therefore, less heat loss10. In contrast, the African elephant is 10 to 11 feet tall and weighs between 4 and 6 tons, whereas the Asian elephant is 8 to 10 feet tall, weighing 3 to 5 tons9. The Mammoths were more closely related to the Asian elephant, which was demonstrated by Michael Hofreiter and his colleages of the Max Planck Institute in Germany. Their team compared DNA from modern day elephants and DNA extracted from a 33,000 year old frozen mammoth leg found in Siberia 198611. They were compared for their similarity using the mitochondrial DNA (mtDNA), which has its own genome. As approximately one fifth of a cell contains mitochondria organelles, which each have several copies of these genomes, it is easily extractable for comparison, and is useful for tracing the lineage of a species as it is passed from mother to