Saturday, May 31, 2008

Photo Hunter: Self-portrait and advice to those contemplating graduate school

So this is not very biological... And normally I object to seeing my face, but I had to share my elation at getting my MS this week! So for the 'biological-minded' considering grad school, I thought I'd share some advice which has helped me.

So, if you are a undergrad or returning student, one thing to do right now is get into a lab. This may mean that you have to volunteer, which is tough if your strapped cash, but necessary. Really, this give you valuable experience as professors are less concerned with grades as they are with experience. When it comes time for letters of reference, you also have a leg up on those who will rely on people they only know from classes. The need for cash can be alleviated, as once you are in the lab, funding and scholarships generally can be found. This will also give you a taste for what graduate school is like. So if you don't like doing research, better to find out now than two years into the program.

Most importantly, it's not the school, it's the person. No matter how much you may like the school's program, you really want to find some one whose research you are interested in and you get along with. You will be working with your advisor for 2 to 5 years, in closer proximity than you would work with someone on a job. So, do some research on them. What have they published, What are they working on now? If interested, you should contact them and meet with them. In many schools, you have to be accepted by the professor to get into the program, and they may not feel comfortable accepting you unseen. Also, this give you a feel for how well you might get along. You can talk with their students as well, but keep in mind what they say might be colored by how they interact with their advisor. (If your talking with them at a meeting, they may have spent the previous weeks being grilled by their advisor to get them ready, so they may not be feeling very charitable)

Finally, if you have a love of learning, go for it!

Thursday, May 29, 2008

Book review!

I just got finished reading Sean Carroll's Endless Forms Most Beautiful, and I thought I'd give my thoughts on it. This book is a little more complex than Your inner fish, so I would not recommend it to a complete science beginner. For this book, I think it is better to have a bit of a background in science, particularly in genetics. The book does try to use simplifying language to explain some of the genetic concepts, but I personally found it more confusing, and found my self having to stop and think about what the correct terminology was to understand it.

That being said, it is a fascinating book, that goes a bit more in depth about evo-devo. For me, I most enjoyed the talk about the genes behind wing formation, as one of the discussions I have with my students is about determining if insect wings are purely outgrowths of the exoskeleton. But even more fascinating was how all of these genes are regulated at the 'beginning'. Now the genes are turned on or off, by the presence or absences of certain proteins. These proteins are made be genes that are turned on by the presence or absence of other proteins, and so on and so forth. So what creates the gradient conditions of proteins to turn on the initial proteins?

Carroll puts for the idea that this may be due to uneven deposition of nutrients in the egg. I find this idea interesting and wonder if it has actually been looked at. Is this unevenness repeated in every egg laid down by the mother? Or caused by the first division or subsequent ones? Is there a difference in the 'unevenness' causation or how the initial genes are turned on between organisms which experience determinate vs. indeterminate cleavage?

So for me, the book was most interesting in the additional questions it raised. It also showcased just what one can do in the evo-devo field, and how that relates to variety of other disciples, including paleontology. So if you're a bit more curious about development and genetics, I would recommend this book.

Wednesday, May 28, 2008

Animalpedia: Navanax (life photo meme)

Kingdom: Animalia

Phylum: Mollusca

Class: Gastropoda

Subclass: Opistobranchia

Order: Cephalaspidea

This is navanax, most likely Navanax inermis. As part of the opistobranch subclass, these have a reduced internalized shell. They are voracious predatory slugs which generally inhabit eelgrass beds and mudflats. They track other opistobranchs (like bubble snails) through the mudflats by following their mucus trail. When they catch up with their prey, they swallow them whole. After the snail has been digested, they excrete the whole empty shell. When disturbed, navanax produces a yellowish fluid which alerts other navanaxs to danger.

Saturday, May 24, 2008

Photohunter: Shoes

Okay, so I am going to try out this meme, and try to keep all of the photos, somewhat biological, in keeping with my blog's 'theme'. This is Puck, sleeping on my briny shoe. Puck's sense of smell is about 14 times that of a human's and he possesses a vomeronasal organ which also picks up smells. The vomeronasal organ has an opening on the roof of the mouth and cats (as well as other mammals who possesses this organ) will lift their upper lip and 'pant' to bring the chemical molecules up into the organ.

Thursday, May 22, 2008

Animalpedia meme: Crayfish reproduction

Kingdom: Animalia

Phylum: Arthropoda

Subphylum: Crustacea

Class: Malacostraca

Order: Decapoda

This is a female crayfish brooding her recently hatched young in my classroom tank. Most malacostracans brood their eggs on their swimmerets (pleopods), until the the eggs hatch into a zoea or a nauplius, however freshwater crayfish have direct development, so they pass through those stages while still in the egg and hatch as crawl-away juveniles.

Male crayfish have specialized pleopods (gonopods) which are larger and stiffer to deliver sperm packets to the female's gonopore. They also tend to have narrower abdomens and the rest of their pleopods are smaller than the females. Reproduction must be timed closely with molting as the female's gonopore is an invagination of her exoskeleton. Mate too soon and the sperm packet will be lost with the old exoskeleton. The Y-organ at the base of the eyestalk is responsible for both gonad development and repression of molting.

Wednesday, May 21, 2008

Animalpedia: Heart Urchin

This is a heart urchin, most likely Lovenia cordifornis. This particular species is relatively shallow-water dwelling, from the intertidal down to 60 feet (18m). It has long guard spines that can be raised when disturbed and folded back when resting. It likes to bury under the sand, but it can scoot around on top of the sand, using its longer spines. They eat detritus, and can create a mucous strand to capture falling particles.

Unlike most urchins, the heart urchin’s test is very fragile, and can be broken easily. This is why they tend to live in deeper calmer waters and under sand and not in rocky areas where you find regular urchins. Like thier sand dollar relatives, they have a the five petaliods, through which most gas diffusion takes place. Unlike most other echinoderms, such as sea stars and 'regular' urchins, heart urchins are not radically symmetrical .

Tuesday, May 20, 2008

Just 'cause...'s so true!

Saturday, May 10, 2008

Invertebrate Fossil Hunting!

I went fossil hunting today and it was really neat. The site was at Silverado, and we went with the Natural History Museum of LA. This is a picture of the near vertical cliff face we were pulling fossils from, and if you look towards the bottom of the cliff, you can see the very algae filled creek you can land in if you make a miss-step.

The site was about 90 million years old, and was the shallow part of the ocean. Mostly there were a lot of shellfish, as it was the site of an oyster/clam bed.

This was my first fossil find, an impression of a coiled ammonite. Unfortunately, I never found a whole ammonite. I am inexperienced in using a pick, so it was difficult for me to extract fossils without breaking them, and near vertical conditions of the cliff made it a little tricky to work on.

Luckily, I never ended up in the creek, although at one point I came very close. I was going for a straight ammonite near the top of the cliff and gravity took over. I first started scrambling for handholds, but after realizing there were not any, I just let myself slide down till I stopped naturally. (Basically, just above the creek)

After, that I decided that looking through the scree at the bottom of the hill was much more productive. Indeed, many of the shells had weathered out of the rock intact, so I got some nice looking specimens. Much better than trying to break them out.

So at the end of the day, I had collected what was believed to be some scaphopod shells (seen top with a modern scaphopod shell), several gastropod shells (top left in bottom picture), scallops, clams (top right in bottom picture), and some straight and coiled ammonite pieces (bottom center in bottom picture). All in all a good day!

Friday, May 9, 2008

Some-what weekly video...

Here's what I've been doing for the past two weeks or so... Frantically hunting the docks for my bryozoans and videotaping the larvae.

I am basically trying to see if there is a relationship between larval size and juvenile size. So, after videotaping my little larvae, I settle them and take a look at the juvenile feeding structure. The idea is that these larvae don't feed until after they are juveniles, so the size they are reflects how much energy they have. Any differences between larval size (and thus energy content) should translate into differences in juvenile size.

These larvae swim using cilia, which is either in several rows around the larvae (1st larva) or in a large band around the center of the larvae (2nd larva). They both have a ciliated groove which not only helps propel them, but they also use to 'smell' the surface (so they can find a good spot to settle on).