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:Explain the different ways natural selection can shape populationsDescribe how these different forces can lead to different outcomes in terms of the population variation

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:

"Tetramates are bioactive natural products that feature a pyrrolidine-2,4-dione ring. Approximately 14% of sequenced strains of Streptococcus mutans, a causative agent of human dental caries, bear the muc biosynthetic gene cluster (BGC) to produce mutanocyclin (MUC). MUC is a tetramate that inhibits leukocyte activity, which protects S. mutans from the host’s immune attacks. Some S. mutans strains can also accumulate the intermediates of MUC biosynthesis called reutericyclins (RTCs), which have antibacterial activity. A recent study revealed that the feature ring in MUC is closed via lactam bond formation. This contrasts with most other tetramates, which form their rings via Dieckmann cyclization. It was found that RTC is converted to MUC via the deacylase MucF. Distribution analysis revealed that BCGs like muc are widespread in human-associated bacteria..."

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

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:

"Interactions among probiotics, resident gut microbes and host factors affect probiotic engraftment and the resulting therapeutic effects. These interactions depend on gut-adaptive evolution of the probiotic strains, but the underlying processes—and their differences among host species—are unclear. In addition, the evolutionary effects of probiotics on native gut microbes are not well characterized. A recent genomics study examined the evolution and effects of the probiotic Lactiplantibacillus plantarum HNU082 (Lp082) in the human, mouse, and zebrafish gut. In all three species, Lp082 acquired single-nucleotide mutations. In vitro, the gut-adapted strains exhibited improved fitness related to carbohydrate utilization and acid tolerance and remained genetically stable for three months. In the human and mouse gut, Lp082 engraftment increased the numbers of mutations of the resident gut microbiota (GM) by 10- to 70-fold..."

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