Preface

Thus far, we know all life forms in the universe exist at or near the surface of planet Earth. The life forms on Earth connected through shared history are DNAbased life. Since even distantly related life forms are surprisingly similar genetically and share the same regulatory genes, it would be counterproductive not to take advantage of the full range of variation produced by this great experiment conducted over billions of years. Genetic diversity is the fundamental source of biodiversity and is required for populations to evolve and cope with environmental changes, new diseases, and pest epidemics. Genetic diversity also provides the opportunity for tracing the history of populations, species, and their ancestors. Therefore, the assessment of genetic diversity in species and among populations is important for the conservation of genetic resources. Genetic diversity determination can be based on morphological, biochemical, and molecular types of data. However, molecular markers (RFLP, RAPD, mtDNA, RFLP, SNP, etc.) are superior to both morphological and biochemical markers because they are relatively simple to detect, abundant throughout the genome, completely independent of environmental conditions, and can be detected at virtually any stage of development.

This book provides a glimpse into the dynamic process of genetic diversity by presenting the thoughts of scientists engaged in developing new tools and ideas to reveal genetic diversity, often from very different perspectives. It consists of eight chapters, each focusing on a certain aspect of the genetic diversity of living forms. They give the reader a general idea of where the current research efforts are heading, both within genetic diversity research itself and in interdisciplinary approaches.

Chapter 1 describes the value of genetic diversity in terms of crop protection. Plant mutagenesis, which increases the variation in crop plants that have been inbred for centuries, coupled with high-resolution genotypic or phenotypic screening methods allows breeders to select for traits that were very difficult to breed. Therefore, directed mutations are one of the main tools to enhance genetic diversity in populations. The chapter describes the role of mutation breeding for the intensification of crop production and the economic gain of new mutant varieties.

Chapter 2 reports on the relationship between viruses and their relative hosts. Singlecell genomics has significantly accelerated mammalian and prokaryote studies related to human health, revisions of the tree of life, and biotechnology, as well as enhanced our understanding of the roles that microbes play in ecosystems. The chapter covers methods for linking bacteriophages with their hosts, assessing host–phage relationships from single-cell genomics data, viral tagging, resolving phage–host relationships in complex communities, such as the human gut, and novelty of the viruses recovered by single-cell genomics.

Chapter 3 addresses the status of the genus *Medicago* in Africa in terms of genetic diversity, phenotypic and molecular genetic variation, symbiotic host specificity, fungi–plant interactions, adaptation to abiotic and biotic constraints, and fodder quality. It is well known that genetic diversity is of fundamental importance in the continuity of species, as it provides the necessary adaptation to the prevailing biotic and abiotic environmental stresses.

to realize the vital role that biodiversity plays in sustaining life on Earth. Let us all wish much success to all projects and initiatives dealing with the conservation of

**Dr. Mahmut Çalişkan**

Biology Department, İstanbul University, İstanbul, Turkey

**Dr. Sevcan Aydin** Associate Professor, Biology Department, İstanbul University, İstanbul, Turkey

Professor,

life diversity.

Chapter 4 analyzes the patterns of genetic variability in silver carp populations by employing simple sequence repeat (SSR) molecular markers at five different sites in River Chenab, Pakistan. Eventually, natural populations include a considerable genetic variability that provides genomic flexibility that can be used as a raw material for adaptation. Alternatively, low genetic diversity has been associated with the inability to cope with changing environmental circumstances and various stresses. The current study based on the assessment of SSR molecular markers reveals loss of genetic diversity of silver carp in River Chenab.

Chapter 5 provides some details about the status of sorghum agriculture in Burkina Faso in terms of genotypic and phenotypic variation. Sweet grain sorghum is characterized by a robust, low-sugar stem, longer leaf sheaths, a broad panicle, and lighter grains. The chapter reveals that sweet sorghums are more genetically similar to grain sorghums.

Chapter 6 describes the various molecular markers that are being utilized to study wildlife conservation. It notes that the variation of DNA sequences allows for differentiating genetically differentiated populations, understanding inbred populations, and determining the actual number of males and females contributing to successive generations. Basic data on the genetic and cytogenetics of any species is necessary for wildlife management programs. Applying molecular markers approaches will help solve problems in the management of wild populations and help in identifying the subsequent gene pools.

Chapter 7 describes several powerful molecular techniques and available genetic biomarkers, such as chitinase, SREHP polymorphisms, SNPs, STRs, retrotransposons, and microarrays. It is revealed that such tools can aid in determining the role of *Entamoeba histolytica* genetics in the outcome of infection and can be used for population-based studies as well as to develop an improved evolutionary and phylogenetic framework for the parasite.

Finally, Chapter 8 evaluates the interaction between microbiota diversity and diseases such as depression, anxiety, and stress-related disorders. It is concluded that gut microbiota offers a strong potential target for mental health treatments in the future.

This book is a useful resource for students, researchers, and experts in conservation biology, genetic diversity, and evolutionary biology. The recent development of global warming and climate change studies provides some unique opportunities to realize the vital role that biodiversity plays in sustaining life on Earth. Let us all wish much success to all projects and initiatives dealing with the conservation of life diversity.
