International researchers studying the living genomes of primates have unearthed a robust new phylogenetic tree which offers greater insight into human evolution.
The phylogenetic analysis published in the open-access journal PLoS Genetics on March 17, was conducted to determine the origin, evolution, patterns of speciation, and unique features in genome divergence among primate lineages.
The authors sequenced 54 gene regions from 186 species spanning the primate radiation. Highlighting the importance of resolving complex, species-rich phylogenies using large-scale comparative genomic approach. Patterns of species and gene sequence evolution and adaptation relate not only to human genome organization and genetic disease sensitivity, but also to global emergence of zoonoses (human pathogens originating from non-human disease reservoirs), to mammalian comparative genomics, to primate taxonomy and to species conservation.
To date, available molecular genetic data applied to primate systematics has been informative, but limited in scope and constrained to just specific subsets of taxa. Now, a team of international researches from the US, Brazil, France and Germany, have provided a highly robust depiction of the divergence hierarchy, mode and tempo governing the extraordinarily divergent primate lineages. The findings illustrate events in primate evolution from ancient to recent and clarify numerous taxonomic controversies. Ongoing speciation, reticulate evolution, ancient relic lineages, unequal rates of evolution and disparate distributions of genetic insertions/deletions among the reconstructed primate lineages are uncovered.
The authors said: “Advances in human biomedicine, including those focused on changes in genes triggered or disrupted in development, resistance/susceptibility to infectious disease, cancers, and mechanisms of recombination and genome plasticity, can not be adequately interpreted in the absence of a precise evolutionary context or hierarchy. Resolution of the primate species phylogeny here provides a validated framework essential in the development, interpretation and discovery of the genetic underpinnings of human adaptation and disease.”
Source: Public Library of Science via EurekAlert
From primates to plants how evolutionary insights can help us grow!
In a different study at the University of Florida, researchers ‘caught evolution in the act’ when they used two flowering plants to cross produce a new hybrid species with greater genetic variability.
Researchers say the study, to be published March 17 in Current Biology, could lead to a better understanding of how to best grow more stable and higher yielding agricultural crops.
“New and diverse patterns of gene expression may allow the new species to rapidly adapt in new environments” said Doug Soltis, a distinguished professor in UF’s biology department and study co-author.
The study shows the new plant species had relaxed control of gene expression in its earliest generations. But today, after 80 years of evolution, control has been regained, allowing for the production of different patterns of gene expression in different plants. The new species was remade in UF greenhouses as well as studied in its natural habitat.
Researchers analysed 144 duplicated gene pairs from the 40-generation-old Tragogogon miscellus, whose common name is goatsbeard. A species in the daisy family that originated naturally through hybridization in the northwest U.S. about 80 years ago. The new species formed when two species introduced from Europe mated to produce a hybrid offspring. The species mated before in Europe, but the hybrids were never successful. However, in America something new happened – the number of chromosomes in the hybrid spontaneously doubled, and at once it became larger than its parents and quickly spread.
Hybridization with chromosome doubling is a prominent mode of species formation and through this study scientists can better understand how different plant groups originated.
“Understanding the impacts this process has on genome structure may help understand how best to breed crops for high and stable yields,” said study co-author Pat Schnable, director of the Center for Plant Genomics at Iowa State University.
Before discovering their relaxed gene expression, the team had expected the artificial hybrids to exhibit a combination of the parents’ genes, said study co-author Pam Soltis, curator of molecular systematics and evolutionary genetics at the Florida Museum of Natural History on the UF campus.
The expression of the hybrid plant’s genes in all tissues at all times allowed natural selection to shape what would emerge generations later, Pam Soltis said. With this form of hybridization, there is the opportunity for parental patterns to be equalized, as if the hybrid has a fresh chance to exhibit a wide variety of genetic expressions over time.
“The Soltises are showing at the genetic level how this really important process of genome doubling generates new biological diversity,” said Jonathan Wendel, professor and chairman of the department of ecology, evolution, and organismal biology at Iowa State University. “This leads to new questions and the design of new experiments that can help us understand the ecological and evolutionary consequences of the genetic changes they’re observing.”
Source: University of Florida via EurekAlert
