Group items tagged

Deep-sea mystery solved: astonishing larval transformation and extreme sexual dimorphism unite three fish families by Johnson, et al. (2009)* published in Biology Letters, Royal Society. The deep sea fishes at the heart of the investigation and this activity were historically classified into three families or clades based on the obvious morphological differences between the members of each group. 

Taxonomy groups species by common traits. Modern taxonomy emphasizes evolutionary relatedness. Explore some principles of taxonomy by sorting twenty shells by their morphological characteristics. Whenever a pictorial index of shells appears, you can click on an image of a shell to open it in a separate window. There you can click and drag your mouse over the shell to rotate it for a more detailed examination. Additionally, you can use the small buttons in the lower right corner of the window to rotate the shell.

The seashell phylogeny and evolution activity is an interactive online activity that can be done in class or assigned as homework. The Teacher's Guide describes supporting resources that can be used to teach students about seashells and a pre-activity exercise that uses the downloadable picture cards to familiarize students with the concept of sorting organisms.

A phylogenetic tree, also known as a phylogeny, is a diagram that depicts the lines of evolutionary descent of different species, organisms, or genes from a common ancestor. Phylogenies are useful for organizing knowledge of biological diversity, for structuring classifications, and for providing insight into events that occurred during evolution. Furthermore, because these trees show descent from a common ancestor, and because much of the strongest evidence for evolution comes in the form of common ancestry, one must understand phylogenies in order to fully appreciate the overwhelming evidence supporting the theory of evolution.