I offered extra credit on a test today.  I asked the students to draw me a fish to earn a couple extra points on our first honors test of the year.  The kids responded with a huge variety of offerings.  I cut the drawings out, pasted them into a document (a few pages long) and, tomorrow, I am going to use them to start conversation about agnathans, chondrichthyes, osteichthyes... and their appearance in the fossil record as well as advances within each group and misrepresentations that the "artists" of each drawing has demonstrated.  

Most kids submit a rudimentary "fish" and I can espouse on gill slit number and operculum, and things like embryonic tissue layers, protostome vs. dueterostome, radial vs spiral cleavage... we can talk about ... etc....  I can even look ahead to amphibians and reptiles.  Some deliver "religious fish" which I use to illustrate the establishment of world view and how these drawings "bumpersticker" a serious discourse....

I have come to  realize that the order that all animals appear in the fossil record is essential to the kids' understanding of the big picture.  If they encounter all animals in a haphazard presentation, they take little away (a strategy of evolution deniers); if they encounter the animals in the order that they appear in the fossil record, then they are likely to observe and internalize patterns that show evolution's logic.  

I have heard of how teachers "poison" their students... how my presentation of this material might "make or break" a young person's future perception and involvement in this MOST important topic.  I ask you all to reminisce about your formative lessons and experience that either drove you away from these concepts or drove you toward them.