Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.

By the end of this section, you will be able to:Describe the difference between jawless and jawed fishesDiscuss the distinguishing features of sharks and rays compared to other modern fishes

Hank introduces us to ourselves by taking us on a journey through the fascinatingly diverse phyla known as chordata. And the next time someone asks you who you are, you can give them the facts: you're a mammalian amniotic tetrapodal sarcopterygian osteichthyen gnathostomal vertebrate cranial chordate.

Chapters:
1) Chordate Synapomorphies
2) Cephalachordata
3) Urochordata
4) Vertebrata
a) Myxini
b) Petromyzontida
c) Chondrichthyes
d) Osteichthyes
5) Biolography
6) Amphibia
7) Reptilia
8) Mammalia

This resource is a video abstract of a research paper created by Research Square on behalf of its authors. It provides a synopsis that's easy to understand, and can be used to introduce the topics it covers to students, researchers, and the general public. The video's transcript is also provided in full, with a portion provided below for preview:

"Microbiomes share an intimate relationship with the organisms they colonize, even across evolutionary timescales. That’s the basis of a theory called phylosymbiosis. Phylosymbiosis holds that microbial communities evolve as their host evolves and has been confirmed to exist for certain insects and mammals. Researchers recently tested whether that relationship holds among fish. Approximately 420 million years ago, fish made an epic evolutionary split into elasmobranchs -- creatures with all-cartilage skeletons -- and bony fish. Since then, the two have accumulated vast differences in anatomy and physiology, most notably in their skin. That’s where the researchers zeroed in. For a small sample of fish, they used metagenomics to compare the makeup of microbial communities living on fish skin. Between fishes considered closely or distantly related in evolutionary terms, findings revealed that elasmobranchs displayed patterns of phylosymbiosis, while bony fish did not..."

The rest of the transcript, along with a link to the research itself, is available on the resource itself.