How Does Isolation and Migration Change Genetic Features of Elephants?

“Six million years ago, a common ancestor of the elephant diverged into two separate species…Each type of elephant has its own various characteristics that allow them to survive and thrive in their respective environments. ”

How Does Isolation and Migration Change Genetic Features of Elephants? BySohumTripathi

Six millionyearsago, acommonancestorofmodernelephantsdivergedintotwospecies; the African elephant and the Asian elephant. The African elephant species diverged into two subspecies; the Savanna elephant and the forest elephant. The Indianelephantdivergedintotwo subspecies as well; Asian alpha and Asian beta.

The differences between African elephants and Asian elephants are numerous. To start with, African elephants have much larger ears that look, from a perspective, as the continent of Africa. Asian elephants have much smaller and rounder ears. African elephants have rounded heads, while Asian elephants have a twin-domed head meaning thatthereisadivotlinerunning down the head. (Britannica.com) Both male and female African elephants have tusks but only male Asian elephants can grow them.

It is important to know, however, that not all African or Asian males necessarily develop tusks. In terms ofweight, African elephants generally weigh around 8000 kg (9 tons) whereas their Asian counterparts only weigh about 5,500 kg (around 6 tons). Along with all the differences listed above, there are several minute differences such as skin texture, number of toenails and trunk characteristics between the two subspecies. The differences between African and Asian elephants can be viewed as an example as to how migration changes the genetic features of elephants. (This image shows an African Elephant and an Asian elephant side by side)

“The isolated populations may develop different genetic mutations and variations in a new environment.” “After many generations, the isolated population may look completely different from the main population and may eventually become a new species, unable to breed with the original population.” (Giesen 448). In Borneo, a group ofelephants became isolated from the Asian beta subspecies in Borneo. To further understand this situation we have to see where exactly AsianalphaandAsianbetaspeciesarelocated. AccordingtotheNewYorktimes, Asian alpha species are mainly located onthemainlandandAsianbetaspeciesaremostlyfound on the islands of Sumatra and Borneo (The New York Times). The elephant in Borneo has

followed itsownevolutionarypathanditisdistinctlydifferentfromotherAsianelephantsdueto the isolation. Borneo elephants diverged from the Beta elephants 300,000 years ago.

Dr.Prithiviraj Fernando, the main author andascientist attheColumbiaUniversityCenterforEnvironmentalResearchand Conservation states: “The current population (estimated at 1,000 - 2,500) lack genetic variation, which indicates that the population arose from a small number of founders, which was never very numerous and highly inbred.” The reason as to why the isolated Borneo elephants are inbred and possibly trapped in a genetic bottleneckisbecausewhensealevelsrose, theybecametrappedon the island ofBorneo. The Borneo elephant also possesses its own selection ofunique features. According to Dr.Michael Stuewe, the Borneo elephant doesn’t attack humans when harmed or violated, unlike it’s AfricanandIndiancounterparts. Theelephantissmaller than others in Asia with larger ears and straighter tusks. This can be viewed as an example ofhow isolation from the main species changes genetic features. (This image shows a Borneo pygmy elephant.

To wrapupthisinformationabouthowmigrationandisolationchangegeneticfeaturesin elephants, this quote from Quote Master about differences. “Strength lies in differences, not in similarities” -- Stephen Covey. Each Type ofelephant has its own various characteristics that enable them to survive and thrive in their respective environments.

WorksCited:

Derr, Mark. “Small, Isolated Elephants Follow Own Evolutionary Path.” The New York Times, The New York Times, 30 Sept. 2003, www.nytimes.com/2003/09/30/science/small-isolated-elephants-follow-own-evolutionarypath.html.

Grannan, Cydney. “What's the Difference Between Asian and African Elephants?” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 2015, www.britannica.com/story/whats-the-difference-between-asian-and-african-elephants.

Geisen, Michael. “Evolution.” Everything You Need to Ace Science in One Big Fat Notebook: the Complete Middle School Study Guide, by Michael Geisen and Chris Pearce, Workman Publishing, 2019, pp. 448–448.

Images:

Potter, John Micheal Evan. Side by Side photograph of African and Asian elephants. Britannica online, 2015, https://www.britannica.com/story/whats-the-difference-between-asian-and-african-elephant s. Accessed 26 May 2020.

Williams, Christy. Borneo Pygmy Elephant. Worldwildlife.org, 2016, https://www.worldwildlife.org/species/borneo-pygmy-elephant. Accessed 26 May 2020