• Home
  • About
  • Contact
  • Patreon
  • Premium Membership
  • Services

Natural History

by Scottie Westfall

Feeds:
Posts
Comments
« The degeneracy of the pug
Dealing with a high profile troll »

Why is the Sumatran rhino so hairy?

November 1, 2015 by SWestfall3

sumatran rhino

A few days ago, I had a discussion on Facebook with someone about Sumatran rhinoceroses and why they were still hairy. I had posted one of Frans de Waal’s photos of a Sumatra rhino calf, and as calves go, it was very shaggy.

The discussion got to a really interesting question, which I think points out to a misunderstanding of the mechanisms by which evolution happens. The discussion went something like this:

“Sumatran rhinos are hairy. Therefore, there must be some reason they are hairy. Otherwise, there would be selection against having lots of hair in jungles of Southeast Asia, Borneo, and Sumatra.”

The answer I had was that the Sumatran rhino is the closest living relative to the extinct woolly rhino. Woolly rhinos were quite well-furred out, and it’s possible even now for animals to retain primitive traits. You hear people talking all the time about living fossils, but there is usually no understanding that a 20 million-year-old shark that looks very similar to living species most likely is incapable of reproducing with that living species (if the two were made to live contemporaneously with each other.)

The error is in assuming that a trait an animal possesses is always a benefit to it. This is a corollary of thinking the evolutions happens through natural selection alone, when it is actually only one way that it happens. (And it’s actually not the main way).

The truth is the Sumatran rhino is nothing more– or less– than the last survivor a lineage of rhinos that retained their furry bodies of their tapir-like ancestors. (And Sumatran rhinos aren’t even that hairy!).

And it should be noted that there are plenty of mammals in the Sumatran rhino’s range that have much furrier bodies.

Evolution isn’t planned out. It can only work with what genetic material is available in the population. Assuming that Sumatran rhinos retain their excessive fur only because it has some advantage to them is putting the cart before the horse.

Now, there is a possibility that there is some advantage for these rhinos to retain the very furred up bodies. I’ve not seen any literature that explores this possibility, but the fact that this animal is so closely related to the woolly rhino kind of provides the best explanation. This animal retains a primitive trait solely because that’s what its ancestors were. It just can’t magically evolve a relatively hairless body.

So always be careful in assuming that a trait exists solely because there is some advantage to it. That’s a real problem in our popular understanding of evolution.

Be very careful of putting the cart before the horse. Sometimes a trait is advantageous. It’s often just neutral.

Share this:

  • Twitter
  • Facebook
  • Reddit
  • Print
  • Tumblr
  • Pinterest
  • LinkedIn
  • Email

Like this:

Like Loading...

Posted in evolution | Tagged evolution, Sumatran rhino | 4 Comments

4 Responses

  1. on November 1, 2015 at 3:42 pm massugu

    By the same token, the hairiness apparently didn’t impact the survivability of the species enough to effect it’s viability in that climate. So it’s a more or less neutral trait in terms of it’s overall impact.


    • on November 1, 2015 at 4:49 pm casdog1

      Oops, should have read this first, lol. I more or less repeated what you said.


  2. on November 1, 2015 at 4:49 pm casdog1

    It’s not so much “survival of the fittest” but more “survival of the fit enough”. Clearly the hairiness isn’t detrimental to the survival of those genes so it’s stuck around. Doesn’t have to be a benefit, it just has to not be a detriment.


  3. on November 2, 2015 at 2:29 pm Suhail

    I am concerned more about poachers, working for a well organized mafia, wiping all rhinos off within next few years.



Comments are closed.

  • Like on Facebook

    The Retriever, Dog, and Wildlife Blog

    Promote Your Page Too
  • Blog Stats

    • 9,535,603 hits
  • Retrieverman’s Twitter

    • one person followed me // automatically checked by fllwrs.com 9 hours ago
    • retrievermanii.blogspot.com/2021/01/the-di… 1 day ago
    • @SergioJStalin That's like saying the Nazis had a headquarter in Moscow in 1931. LOL 3 days ago
    • one person unfollowed me // automatically checked by fllwrs.com 6 days ago
    • RT @AdamZHerman: I am no longer impressed that Nicholas Cage managed to steal the Declaration of Independence. 1 week ago
  • Google rank

    Check Google Page Rank
  • Archives

    • October 2020
    • September 2020
    • August 2020
    • July 2020
    • June 2020
    • May 2020
    • April 2020
    • February 2020
    • January 2020
    • December 2019
    • November 2019
    • October 2019
    • September 2019
    • August 2019
    • July 2019
    • June 2019
    • May 2019
    • April 2019
    • March 2019
    • February 2019
    • January 2019
    • December 2018
    • November 2018
    • October 2018
    • September 2018
    • August 2018
    • July 2018
    • June 2018
    • May 2018
    • April 2018
    • March 2018
    • February 2018
    • January 2018
    • December 2017
    • November 2017
    • October 2017
    • September 2017
    • August 2017
    • July 2017
    • June 2017
    • May 2017
    • April 2017
    • March 2017
    • February 2017
    • January 2017
    • December 2016
    • November 2016
    • October 2016
    • September 2016
    • August 2016
    • July 2016
    • June 2016
    • May 2016
    • April 2016
    • March 2016
    • February 2016
    • January 2016
    • December 2015
    • November 2015
    • October 2015
    • September 2015
    • August 2015
    • July 2015
    • June 2015
    • May 2015
    • April 2015
    • March 2015
    • February 2015
    • January 2015
    • December 2014
    • November 2014
    • October 2014
    • September 2014
    • August 2014
    • July 2014
    • June 2014
    • May 2014
    • April 2014
    • March 2014
    • February 2014
    • January 2014
    • December 2013
    • November 2013
    • October 2013
    • September 2013
    • August 2013
    • July 2013
    • June 2013
    • May 2013
    • April 2013
    • March 2013
    • February 2013
    • January 2013
    • December 2012
    • November 2012
    • October 2012
    • September 2012
    • August 2012
    • July 2012
    • June 2012
    • May 2012
    • April 2012
    • March 2012
    • February 2012
    • January 2012
    • December 2011
    • November 2011
    • October 2011
    • September 2011
    • August 2011
    • July 2011
    • June 2011
    • May 2011
    • April 2011
    • March 2011
    • February 2011
    • January 2011
    • December 2010
    • November 2010
    • October 2010
    • September 2010
    • August 2010
    • July 2010
    • June 2010
    • May 2010
    • April 2010
    • March 2010
    • February 2010
    • January 2010
    • December 2009
    • November 2009
    • October 2009
    • September 2009
    • August 2009
    • July 2009
    • June 2009
    • May 2009
    • April 2009
    • March 2009
    • February 2009
    • January 2009
    • December 2008
    • November 2008
    • October 2008
    • September 2008
    • August 2008
    • July 2008
  • Recent Comments

    markgelbart on Retiring this Space
    oneforestfragment on Retiring this Space
    The Evolving Natural… on So does the maned wolf break t…
    SWestfall3 on So does the maned wolf break t…
    Ole Possum on So does the maned wolf break t…
  • Meta

    • Register
    • Log in
    • Entries feed
    • Comments feed
    • WordPress.com
  • Enter your email address to subscribe to this blog and receive notifications of new posts by email.

    Join 1,697 other followers

  • Pages

    • About
    • Contact
    • Patreon
    • Premium Membership
    • Services
  • Subscribe to Retrieverman's Weblog by Email
  • Revolver map

    Map

  • Top Posts

    • Were Romulus and Remus really nursed by a she-wolf?
  • SiteCounter

    wordpress analytics
    View My Stats
  • Enter your email address to subscribe to this blog and receive notifications of new posts by email.

    Join 1,697 other followers

  • Donate to this blog

  • Top 50 Northwest Dog Blogs

    top 50 dog blogs

Blog at WordPress.com.

WPThemes.


Cancel
loading Cancel
Post was not sent - check your email addresses!
Email check failed, please try again
Sorry, your blog cannot share posts by email.
%d bloggers like this: