Hey everyone,

I'm an 8th grade science teacher. We will be coming up in a couple of months in my curriculum on geologic time and evolution. I have been looking for some sort of a graphic representation of a concept to help my students grasp the idea, and I'm hoping this community might be able to help.

I've used, as a lecture tactic, the idea of the hairpin turn from Dawkin's book. I also discuss the idea of looking at pictures of individuals in adjacent generations compared to many generations apart as a way to describe evolutionary change. My goal is to get my students to understand that our concept of species is more of a snapshot in time, as opposed to a continuous concept through time. That, when considering many generations, its a clearer idea to follow lines of descent.

My thought is a simple demo, using something like Prezi perhaps. Picture a long string of file cards, each with a "picture" of an individual (actual image/artist rendering/simple silhouette, etc). Picking ones next to each other, or a few cards away from each other, shows little change, but picking them far enough apart shows larger and larger changes. When viewed at a great enough remove, we call them different species, even if there is no place along the line between where two cards show that step.

I'm sure you all get the idea as a concept. What I am hoping is that someone might have actually seen something like this, or a similar concept. Some sort of relatively straight forward visual aid to help get this idea across.

I MAY be able to muscle a Prezi into shape to make this happen, but I'm no where near confident of my abilities in that area. 

Hoping for the best here :) Thanks for reading!