Thursday, 3 May 2007

A little bit about my job…

I’m a palaeontologist at the University of Bristol, currently in the (yikes!) third year of my PhD. But what exactly DO I DO?!?!? Well I don’t fit into the stereotypes of Jurassic Park and Ross from Friends. I don’t spend most of my days in the hot Mongolian desert carefully brushing sand away to reveal amazing and perfectly intact dinosaur skeletons. Sometimes I wish I did though, because to be honest I spend most of my time in the office, counting.

Yes, counting, This is what I do, count animals form different parts of Earths’ past and from all over the world. But to what end? I’m a ‘Macroevolutionist’ so I like to think about the ‘Big picture’, which sounds grand but to be honest can be a bit tedious because big picture stuff often means gathering lots of data, compiling it, and producing graphs. To add a little excitement to my day sometimes I add colour to my graphs and occasionally throw in a pie chart just to be a little crazy.

Seriously though, my supervisor, Mike Benton, has spent a lot of his career counting and has come up with some pretty intriguing insights about biodiversity and Earth’s past. One of his biggest contributions has been the this graph, which is a count of the all of the tetrapods (amphibians, reptiles, mammals and birds) that we have found in the fossil record, from their origin, almost 400 million years ago to the present. As you can see the diversity of tetrapods has risen almost exponentially since their origin to the present day, punctuated occasionally by a mass extinction event, such as the Permo-Triassic event 250 million years ago, when over 90% of Earth’s species went extinct.

But the trouble with this graph is that counting the number of fossils we have from different times is Earth’s history reveals a similar pattern, so it is difficult to say whether Mike’s graph is a true reflection of diversity or simply an artifact of the rock record. This is where my research comes in. I am studying the diversity within communities through time, a study that is independent of these artifacts so I will see if community diversity is similar to global diversity and what the implications are. If you’re still with me and haven’t fallen asleep, tomorrow I will discuss some of early research, including (just for you Will:), Romer’s Gap.


Laelaps said...

Thanks for the job description; so many people don't really understand what being a paleontologist is all about (it's not moving from one fully articulated skeleton to the next, for one thing...). My favorite media version of a paleontologist, however, is Cary Grant in the movie "Bringing Up Baby" where all he wants to do is finishing his "Brontosaurus" but instead gets dragged around the countryside with a leopard named Baby and Katharine Hepburn.

Anyway, keep the good stuff coming; I'm definitely looking forward to your post on Romer's Gap.

Anne-Marie said...

Wow, Mike Benton is your supervisor? I've read a lot of his work, I bet it is fascinating getting to work with him! Thanks for the description of what you do, very interesting!

Gufo said...

Nice job description. To be quite frank most science nowadays is "counting".

I would also like to know something about the graph: since you seem to have both the number of tetrapod fossils, and the number of ALL fossils for every time (or so), wouldn't it be wise to divide one by the other so to correct for relative abundance of fossil from a given period? That is, assuming that tetrapod aren't more or less likely to become fossil than other species.

This way you would get a normalised picture, although I can see some hitches, such as the mass extinctions disappearing, if both tetrapods and ALL suffer to the same extent.

Sarda Sahney said...

Laelaps - I have been meaning to watch that film for a while, Thanks for reminding me I think I will finally get around to renting it.

Anne-Marie - Mike is a great guy to work with and friendly so don't feel shy introducing yourself if you see him at a meeting or conference. The entire research group in Bristol is fantastic. If palaeo is your thing, I highly recommend visiting Bristol.

Gufo - you have made a point but to clarify, the information displayed in the graph is not strictly speaking the number of fossils, it is the number of fossil families. The information on fossiliferous rock estimates the amount of rock (volume), again not the actual number of specimens. And of course at the end of the day, the preservational potential of tetrapods is far lower than say marine invertebrates. Palaeontology is so riddled with frustration!

Gufo said...

Thanks Sarda. I thought my questions were naive, and the pro in the field would know their job - I just wanted to know how they did.