All About Secon Life

Now that I have my drift and selection modules in hand, the next goal is to working on activities that can be fit around them. I know this is a bit backwards on the surface, but what I want to focus on in my evolution module is mainly the agents of evolution. These are basically:

• Mutation
• Genetic Drift
• Non random mating (of which there are several types!)
• Migration
• Selection

To house the activities related to these agents, I have deviated from my photosynthesis and genetics design and come up with a series of open activity arenas. Each one will have a sensor driven script for tracking visitors, an simple activity rezzer of my own design, built into one of the corner posts. Rather than use my Carmine land, I am building the agents of evolution site at my College's island. The design challenge is to work with in a 281 prim limit.

The natural selection and drift modules use temporary prims so only the rezzers for these count. My 5 activity arenas and office take up a grand total of 67 prims so that leaves me a budget of 220 prims. Now I can stretch that, since activities will not be rezzed all at the same time since each arena but each activity has a "budget" of 40 prims. Ah but each activity arena can hold multiple activities in waiting so the "budget" isn't so draconian after all. 220/5 activity arenas.

Oh and my goal is to have this done by May 7th. At least now I can focus on design more rather than the arcanity of the LSL's llfrand function and other such issues. Plus I will have two radically different design approaches to compare, the module in a box approach of my photosynthesis and gentics builds versus my more open arena centered approach.





Evolution lends itself to the more open approach, and this summer I will install photosynthesis and the Cami genetics modules in Carmine using the arena centered approach. That way I can have the same material side by side with different design features to begin to assess what works best with students.

Well no, how about 30 Caminalcules after selection favoring a recessive allele for 8 generations. The natural selection module beta is finished and works very well. The basic strategy is to have the user or users act as visual predators removing camis from the population. The module might for instance be on a certain background where some cami phenotypes are real obvious while others are not.

The "predators" remove cami's by touching them, and the population is up dated. After a set period of time say 1 minute the remaining cami's are used to make a new population, which the module generates when it is touched and the cycle is repeated until only one genotype remains or until the users give up.

At the start of each generation the module generates a report in chat on the screen showing the allele frequencies for both of the cami loci.

If Cami's are never "eaten" the result is genetic drift. So this module really combines genetic drift and natural selection. It does not use or even compute selection coefficients, but one could add that to a report.

My biology viewers might recognise what this SL model is supposed to be.



This is a preliminary prototype for a neuron membrane showing stylised transport proteins (purple). The round guys with the lids are gated sodium proteins the lidless tubes are gated potassium channel proteins. The "lids" on the sodium gates will be scripted to pop open to let Na+ ions through while the bottoms of the K+ channels will flip open and closed.

The oval shaped guy on the right is part of a Na+/K+ pump.

All these proteins are embedded in a stylised plasma membrane (red fatty acid residues connected to white polar heads with phosphorus for the phospholipids).

This project is actually part of a planned metabolism build which uses the neuron to illustrate how cells use active and passive transport for complex processes. So it's not meant as a full action potential simulation though my scripting strategy will take that possibility into account.

The Caminalcules (camis for short) have been safely installed in a Mendelian Genetics lab module called the Cami Lab. I use my note card configurable camis to illustrate dominance relations, monohybrid crosses, and dihybrid crosses. The evolution module will be directly underneath.

I have had to readjust my land and merge several parcels to give me some prim breathing room. Feel free to come and visit Cami Lab currently at:

http://slurl.com/secondlife/Carmine/128/144/136

As part of this, I rescripted my simple viewer to use Erich Bremer's double buffering script which makes loading much faster. My essentially new viewer uses LSL's way cool llDetectedTouchST function. This function detects where on a prim's surface you are touching and returns that as the x and y terms of a vector.

You can then access, these to do things like change a slide or teleport. What is really cool is that the coordinates are normalized to the size of the prim so they are presented as a float between 0.0 and 1.0, so if you stretch, say a viewer, the detected function still works properly.