Monday, March 9, 2009

The Natural History Museum & How You Describe a New Species!

First..my apologies for the delay in new posts!..my laptop died last week and much needed to be done to remedy the situation...

This week, some "behind the scenes" action about the process of discovering a new species!!!
So, everyone hears about this. New species are discovered daily. Journals are filled with them and statistics repeat how many are found per year. But really, what happens?
What are the dynamics?


So, how does this whole "describing the world's biodiversity" thing work, exactly??
and WHY are Natural History Museums SO important to the process???

First, some background on the Natural History Museum can be found here.(short version: Natural History Museums house many, many specimens...)

Let us now proceed....

1. Exploring the Collection. So, every museum I've ever been to has what's called "the backlog". This is an area (or areas) set aside in the museum collection where all of the incompletely identified material is kept.
Specimens arrive from many different places: expeditions, ecological assessment surveys, vouchers for scientific studies, the list goes on. These speciemens are sorted, processed, labelled, housed in archival materials, and ultimately shelved and stored. (Go see this post to get a flavor of how this works)
BUT most museums don't always have the resources to completely identify and process all of the specimens they've collected.

Big museums often receive specimens from all over the world. The Smithsonian has stuff from everywhere in the world. Paris, Cal Academy in San Francisco..every primary natural history museum has material collected from all over the world.

All these big international expeditions you hear about? Like this one and this one? If specimens are collected, they end up in a big museum.

Most museums don't consider a specimen "done" until its been identified to species (or subspecies) and, so they go into a special holding area to await a time when a knowledgeable person can go through it. The wait for such a person can literally be YEARS.

I've seen some museums that still have unidentified or unprocessed material from the Research Steamer USFC Albatross from the early 20th Century!! and people can STILL find new species in "old stuff" like that as well...
This lag in finding experts to help "shrink the backlog" can be for many reasons, none of which are mutually exclusive.
  • The animal group is big and you find lots of them (e.g., worms or shrimps)
  • The specialists for the group are far and few between (The number of starfish people in the world can be counted on one hand)
  • A specific animal group is hard to identify and/or requires special methods to ID (e.g., taking histological sections)
  • A small collection of that specific group that one doesn't normally associate with being at a particular museum (e.g., recent starfish at a museum in Utah)
So, when a specialist DOES reach this collection?? Its a win-win.

The museum folk are usually happy to tie up this HUGE "loose end" and get the collection put away, cataloged and available to the scientific community.

The expert/researcher gets to spend a big chunk of time going through a bunch of specimens with the possibility of discoveries!!! Older, previous collections may often come from surprising or unusual places: deep-sea, distant seas, localities that are now gone or difficult to access for political or other reasons.

While travelling to these places-I have spent up to a MONTH just going through 'backlog' collections.

So, you find something you haven't been able to identify as a known species-what next???

2. The Study/Comparison Process.
Next thing that happens? You need to make sure you got something new!! and not just something known.

THIS is where the specimens in a Natural History museum come in handy-because you have an instant reference for comparing known versus unknown specimens. (and also why its very important that when the aforementioned experts DO identify something that they do it correctly!)
And of course, where you don't have specimens, you often need to fall back on the scientific literature for comparative descriptions of other similar or dissimilar species.

This can often be very tricky because the animal in question may be VERY close to something that is known and specimens are the best way to compare features.
During this process, its often common to actually discover MORE new species. Mainly because when you learn the taxonomic 'concept' of the known species (i.e., what the original author used to distinguish his/her species) you get a good notion of what a separate and new species would be like.

3. Description & Analysis. The next step is to compare and describe your potentially new species relative to what's already known.

In the historical and classical taxonomic style, this usually just involved an identification guide called a key or some other kind of table describing your species using relevant body characteristics (e.g., # of spines on each species, shape of granules on each species, shape of body on each species)

This usually involves describing the new species in highly specialized terminology outlining the specific features, especially as they pertain to similarities across ALL of the known species.

So, if all of the species you look at have a big glassy knob, then you look at how that glassy knob varies (if it does at all) across all of the species you're trying to compare it against.
Its often common practice to describe new species in the context of a phylogenetic analysis. And that usually involves further processing different characters (whether from morphological features or DNA) from the subject animals into a computer and analysing those results in order to get a tree that supports evolutionary relationships.
(note snazzy new laptop!)
So, in addition to your new species-you have a good comparative/evolutionary context!

What happens next? Write it up and publish it! But that's another story!! (soon!)

3 comments:

Mary Ellen Petrich said...

I just got to visit the Cal Academy Archives. They spoke a little about disaster planning, especially since the museum was basically entirely destroyed in 1906. (There's a story about one of the staff members who filled up a cart, her pockets, her undergarments, to save a few of the more important specimens.) They mentioned that 'alcohol' collections have different sprinkler systems. At first I thought they meant film or paper that had some alcohol treatment. Then finally a light dawned, --all those thousands of jars that are filled with alcohol!!! If it gets hot those jars start to heat and explode. Fun!

GenghisPrawn said...

What program is it that I see running on your laptop? Are you using continuous or discrete characters? I've been using Mesquite and have been considering a switch to other software.

ChrisM said...

I was just using MacClade. A datafile using morphological characters from one of my many projects..:-)