O'Grady Lab
  • Home
  • News and Events
  • People
    • Current Members
    • Undergraduate Research
    • Past Members
  • Research
  • Publications
  • Data
    • Mitochondrial Primers
    • Nuclear Primers
    • Accession Numbers
  • Photos
  • Courses
  • Educational Outreach
  • Links

Genetic barcoding and mythical creatures

10/12/2012

1 Comment

 
As a fly enthusiast, I understand how daunting a task identifying species can be. The minute details, the crazy terms: it can all make you lose your head, especially when you’ve gathered a seemingly infinite amount of specimens. But, what’s a scientist to do? 

You could hunker down at a microscope and wait until your eyes cross, or you could head down the road of genetic barcoding. Now, simmer down, you taxonomists. I don’t plan to argue you guys out of your jobs. In fact, I have my own criticisms of barcoding, but just humor me for a moment.  

Genetic barcoding works by sequencing small DNA portions from unknown organisms and comparing those sequences to a barcode library. So say you’ve collected a bunch of something, let’s say unicorns from the North Pole as everyone knows all magical ponies live in the wintery north. Well, as a well-known unicorn scientist you are aware that there are several cryptic species of unicorns. This means that two or more species appear morphologically similar but, by at least one of the many species concepts, are still considered separate species. A quick PCR analysis, PCR gods forgiving, and a BLAST to the NCBI database could tell you which mythical unicorn species you now possess (should the barcode library of unicorns be complete).

Okay, I may have lied. Unicorns don’t really exist (outside the imagination of yours truly), but the problem of cryptic species does, along with a myriad of other identification issues such as morphological variation within species and even between adults and juveniles. Have you ever looked at drosophila larvae? They all look like squiggly, little, wormy things, every single one of them. Aside from some neat distinguishing behaviors –  a few fling themselves like trapeze artists – you couldn’t tell them apart.

So, it makes sense that a useful tool like barcoding has received so much attention, but let’s not get carried away. This isn’t the messiah come here to solve all our problems. The way I see it genetic barcoding is the microwave of the 1970’s housewife: a new tool for the modern taxonomist. It heats your food in mere minutes, but you can still burn the pot roast. Criticisms include incorrectly identified species sequences, a substantial error rate, and lowered ability to distinguish between recently diverged species. These comments all point towards the necessity of well-studied taxonomists to make final decisions.  

Me? I’m sticking to the microscope for now. Having a good grasp on taxonomic identification seems like it will always be a useful tool.

Jessica Craft
1 Comment

    Patrick

    Professor
    Cornell University

    Archives

    April 2018
    March 2018
    August 2017
    March 2017
    January 2017
    September 2015
    May 2015
    March 2015
    January 2015
    October 2014
    April 2014
    March 2014
    February 2014
    September 2013
    May 2013
    April 2013
    February 2013
    January 2013
    November 2012
    October 2012
    September 2012
    August 2012
    July 2012
    June 2012
    May 2012
    January 2012
    November 2011
    October 2011
    May 2011
    February 2011

    Categories

    All
    1090
    1091
    Alumni
    Aquatic Insects
    Arizona
    Asteia
    Barcoding
    Bennett
    Blog
    Career
    Celebrations
    Chelsea
    Climate Change
    Cornell
    Craft
    Dicranota
    Dolichopodidae
    Drosophila
    Ephydra
    Ephydridae
    Field Work
    Funding
    Goodman
    Hawaiian Drosophila
    Keys
    Kidwell
    Lapoint
    Limonia
    Magnacca
    Marrack
    Montana
    Nesophrosyne
    New Species
    Ogrady
    Ort
    Paceyn
    Pak
    Panbiogeography
    Pediciidae
    Peterson
    Phylogenetic Methods
    Publications
    Readings
    Rhaphidolabis
    Scaptomyza
    Scatella
    Schedule
    Stauffer
    Sylvain
    Talks
    Taxonomy
    Tipula
    Undergraduates
    Unicorns
    Whiteman Lab
    Wojciechowski
    Wolbachia
    Wyoming
    Yeast And Fungi

    RSS Feed

Powered by Create your own unique website with customizable templates.