International Journal of Molecular Zoology 2024, Vol.14, No.3, 154-165 http://animalscipublisher.com/index.php/ijmz 155 2 Evolutionary History of Felids 2.1 Origins and diversification The evolutionary history of modern felids traces back to relatively recent divergence and speciation events that occurred less than 11 million years ago. This period marked the radiation of modern Felidae, producing successful predatory carnivores that have since spread worldwide. The diversification of felids was facilitated by at least 10 intercontinental migrations, which were influenced by sea-level fluctuations. These migrations and subsequent speciation events have been well-documented through a highly resolved molecular phylogeny, which includes autosomal, X-linked, Y-linked, and mitochondrial gene segments, as well as fossil calibrations1. The fossil record, however, underestimates the first occurrence of felid lineages by an average of 76%, indicating a low representation of felid fossils in paleontological remains (Johnson et al., 2006). 2.2 Phylogenetic relationships The phylogenetic relationships among felids have been elucidated through comprehensive analyses of mitochondrial genomes. These studies have provided robust resolutions of both suprafamilial and intrafamilial relationships within the order Carnivora, to which felids belong. The divergence times among species of Carnivora, including felids, have been estimated using 21 fossil calibration points. These analyses suggest that major groups within Feliformia, the suborder that includes felids, diversified more recently during the Oligocene epoch. The basal divergence of the genus Nandinia, for instance, occurred at the Eocene/Oligocene transition (Hassanin et al., 2021). This phylogenetic framework has been crucial in understanding the evolutionary pathways and relationships among different felid species. 2.3 Major evolutionary events Several major evolutionary events have shaped the history of felids. One significant event was the rapid radiation and spread of nimravid carnivores, which are closely related to modern felids. This radiation occurred during the late Eocene, following the decline or extinction of earlier carnivorous groups such as Mesonychia and Oxyaenodonta. The emergence of nimravids, characterized by hypercarnivorous features, marked a pivotal moment in the evolution of carnivorous mammals. The discovery of Pangurban egiae, an early nimravid from the Eocene of California, provides evidence for the swift diversification of nimravids during a period of global climatic instability. This event highlights the restructuring of North American ecosystems during the Eocene-Oligocene transition, which allowed carnivoraforms, including felids, to occupy high trophic level niches (Poust et al., 2022). In summary, the evolutionary history of felids is marked by recent divergence and speciation events, complex phylogenetic relationships, and significant evolutionary milestones that have contributed to their current diversity and ecological roles. The integration of molecular data and fossil records continues to enhance our understanding of these remarkable carnivores. 3 Genomic Techniques in Conservation Biology 3.1 Sequencing technologies Advancements in sequencing technologies have significantly enhanced our understanding of the genetic diversity and evolutionary history of carnivores, particularly felids (Allio et al., 2021). High-quality reference genomes can now be obtained from various sources, including roadkill samples, which provide valuable genetic material for conservation studies. For instance, the genomes of the bat-eared fox and aardwolf were sequenced using a combination of Nanopore long reads and Illumina short reads, demonstrating the potential of these technologies in generating high-contiguity and gene-complete reference genomes. Additionally, cross-species genome alignments have been employed to discover single nucleotide variants (SNVs) in species such as cheetahs, snow leopards, and Sumatran tigers, using the domestic cat genome as a reference. This method has proven effective in identifying adaptive and deleterious alleles, which are crucial for conservation management (Samaha et al., 2021). 3.2 Genomic data analysis methods Genomic data analysis methods are essential for interpreting the vast amounts of data generated by sequencing technologies. Techniques such as quantitative trait locus (QTL) mapping have been used to investigate the genetic architecture of adaptive traits in carnivores. For example, QTL mapping in haplochromine cichlid fish revealed
RkJQdWJsaXNoZXIy MjQ4ODYzNA==