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:Define ecology and the four levels of ecological researchDescribe examples of the ways in which ecology requires the integration of different scientific disciplinesDistinguish between abiotic and biotic components of the environmentRecognize the relationship between abiotic and biotic components of the environment

By the end of this section, you will be able to:Discuss the predator-prey cycleGive examples of defenses against predation and herbivoryDescribe the competitive exclusion principleGive examples of symbiotic relationships between speciesDescribe community structure and succession

Community ecology is the study of interactions between different species of living things, and lets ecologists examine the effects of predator-prey relationships, parasites, and mutually beneficial interactions. In this episode of Crash Course Biology, we’ll examine the myriad interspecies interactions with examples, see how keystone species impact their environment and explore how communities rebuild when they are disrupted, through the lens of the 1980 eruption of Mount St. Helens.

Chapters:
Community Ecology
Community Disturbances
Interspecies Interactions
Competition
Community Regulation
Review & Credits
Credits

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:

"The laboratory and computational tools available to microbiome researchers have greatly improved in recent years, especially in assembling genomes from complex communities. Most of the research to date has focused on macrodiversity, which is classical ecology metrics like population abundance, α-diversity, and β-diversity. But microdiversity — population genetics metrics like single nucleotide polymorphisms (SNPs) and selective pressures — is important to consider. There are several technical and accessibility issues that hinder widespread analysis of microdiversity in metagenomic datasets, but the recently developed open-access software tool MetaPop is designed to close this gap. MetaPop provides a user-friendly interface to analyze both the macro- and microdiversity of microbial and viral community metagenomes. For small datasets, MetaPop can be run on a laptop, making it a practical choice for non-bioinformaticians or labs without access to high-powered computing..."

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:

"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.

We surveyed 807 researchers (494 ecologists and 313 evolutionary biologists) about their use of Questionable Research Practices (QRPs), including cherry picking statistically significant results, p hacking, and hypothesising after the results are known (HARKing). We also asked them to estimate the proportion of their colleagues that use each of these QRPs. Several of the QRPs were prevalent within the ecology and evolution research community. Across the two groups, we found 64% of surveyed researchers reported they had at least once failed to report results because they were not statistically significant (cherry picking); 42% had collected more data after inspecting whether results were statistically significant (a form of p hacking) and 51% had reported an unexpected finding as though it had been hypothesised from the start (HARKing). Such practices have been directly implicated in the low rates of reproducible results uncovered by recent large scale replication studies in psychology and other disciplines. The rates of QRPs found in this study are comparable with the rates seen in psychology, indicating that the reproducibility problems discovered in psychology are also likely to be present in ecology and evolution.

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:

"Freshwater salinization, which can be caused by saltwater intrusion, urbanization, and climate change, is becoming an extensive global environmental problem. Microeukaryotic plankton are key components of aquatic ecosystems and play significant ecological roles. However, few studies have investigated the influences of small salinity shifts on microeukaryotic plankton community assembly and co-occurrence networks in inland freshwaters. In a recent study, researchers used high-throughput sequencing to analyze microeukaryotic plankton communities in a subtropical urban reservoir. They found that increasing salinity altered the community composition and led to a significant decrease in plankton diversity. The salinity changes influenced the microeukaryotic plankton community assembly primarily by regulating the deterministic-stochastic balance. The core plankton sub-network had greater robustness at low salinity levels, while the satellite sub-networks had greater robustness at medium/high salinity levels..."

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