Phylostratum is a set of genes from an organism that coalesce to founder genes having common phylogenetic origin. [1] [2] [3] This term was coined by Domazet and Tautz to discribe the gene origination. [3]
A multicellular organism is an organism that consists of more than one cell, unlike unicellular organisms. All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- and partially multicellular, like slime molds and social amoebae such as the genus Dictyostelium.
Dactyloidae are a family of lizards commonly known as anoles and native to warmer parts of the Americas, ranging from southeastern United States to Paraguay. Instead of treating it as a family, some authorities prefer to treat it as a subfamily, Dactyloinae, of the family Iguanidae. In the past they were included in the family Polychrotidae together with Polychrus, but the latter genus is not closely related to the true anoles.
Anolis is a genus of anoles, iguanian lizards in the family Dactyloidae, native to the Americas. With more than 425 species, it represents the world's most species-rich amniote tetrapod genus, although many of these have been proposed to be moved to other genera, in which case only about 45 Anolis species remain. Previously, it was classified under the family Polychrotidae that contained all the anoles, as well as Polychrus, but recent studies place it in the Dactyloidae.
The pharyngula is a stage in the embryonic development of vertebrates. At this stage, the embryos of all vertebrates are similar, having developed features typical of vertebrates, such as the beginning of a spinal cord. Named by William Ballard, the pharyngula stage follows the blastula, gastrula and neurula stages.
Davor Domazet-Lošo is a Croatian politician, writer, and a retired admiral of the Croatian Navy.
Orphan genes, ORFans, or taxonomically restricted genes (TRGs) are genes that lack a detectable homologue outside of a given species or lineage. Most genes have known homologues. Two genes are homologous when they share an evolutionary history, and the study of groups of homologous genes allows for an understanding of their evolutionary history and divergence. Common mechanisms that have been uncovered as sources for new genes through studies of homologues include gene duplication, exon shuffling, gene fusion and fission, etc. Studying the origins of a gene becomes more difficult when there is no evident homologue. The discovery that about 10% or more of the genes of the average microbial species is constituted by orphan genes raises questions about the evolutionary origins of different species as well as how to study and uncover the evolutionary origins of orphan genes.
Genomic phylostratigraphy is a novel genetic statistical method developed in order to date the origin of specific genes by looking at its homologs across species. It was first developed by Ruđer Bošković Institute in Zagreb, Croatia. The system links genes to their founder gene, allowing us to then determine their age. This could help us better understand many evolutionary processes such as patterns of gene birth throughout evolution, or the relationship between the age of a transcriptome throughout embryonic development. Bioinformatic tools like GenEra have been developed to calculate relative gene ages based on genomic phylostratigraphy.
Important structures in plant development are buds, shoots, roots, leaves, and flowers; plants produce these tissues and structures throughout their life from meristems located at the tips of organs, or between mature tissues. Thus, a living plant always has embryonic tissues. By contrast, an animal embryo will very early produce all of the body parts that it will ever have in its life. When the animal is born, it has all its body parts and from that point will only grow larger and more mature. However, both plants and animals pass through a phylotypic stage that evolved independently and that causes a developmental constraint limiting morphological diversification.
Plant evolution is the subset of evolutionary phenomena that concern plants. Evolutionary phenomena are characteristics of populations that are described by averages, medians, distributions, and other statistical methods. This distinguishes plant evolution from plant development, a branch of developmental biology which concerns the changes that individuals go through in their lives. The study of plant evolution attempts to explain how the present diversity of plants arose over geologic time. It includes the study of genetic change and the consequent variation that often results in speciation, one of the most important types of radiation into taxonomic groups called clades. A description of radiation is called a phylogeny and is often represented by type of diagram called a phylogenetic tree.
18S ribosomal RNA is a part of the ribosomal RNA in eukaryotes. It is a component of the Eukaryotic small ribosomal subunit (40S) and the cytosolic homologue of both the 12S rRNA in mitochondria and the 16S rRNA in plastids and prokaryotes. Similar to the prokaryotic 16S rRNA, the genes of the 18S ribosomal RNA haven been widely used for phylogenetic studies and biodiversity screening of eukaryotes.
Genetic admixture occurs when previously isolated populations interbreed resulting in a population that is descended from multiple sources. It can occur between species, such as with hybrids, or within species, such as when geographically distant individuals migrate to new regions. It results in gene pool that is a mix of the source populations.
Operation Whirlwind was a failed Croatian Army (HV) offensive in the Banovina region of Croatia, fought from 11–13 December 1991, during the early stages of the Croatian War of Independence. The offensive employed a single infantry brigade as the main attacking force, supported by a bridging unit and a handful of tanks and armoured personnel carriers. Although the offensive met hardly any resistance in its initial stage, achieving tactical surprise, the operation was poorly planned, supported and executed as a result of limited training and combat experience. The offensive established a short-lived bridgehead, evacuated in panic two days after the operation commenced, under tank and mortar fire from the Yugoslav People's Army (JNA) deployed north of Glina.
Peto's paradox is the observation that, at the species level, the incidence of cancer does not appear to correlate with the number of cells in an organism. For example, the incidence of cancer in humans is much higher than the incidence of cancer in whales, despite whales having more cells than humans. If the probability of carcinogenesis were constant across cells, one would expect whales to have a higher incidence of cancer than humans. Peto's paradox is named after English statistician and epidemiologist Richard Peto, who first observed the connection.
Diethard Tautz is a German biologist and geneticist, who is primarily concerned with the molecular basis of the evolution of mammals. Since 2006 he is director at the Max Planck Institute for Evolutionary Biology in Plön.
Operation Baranja was an aborted offensive of the Croatian Army north of the towns of Belišće and Valpovo, Croatia on 3 April 1992 during the Croatian War of Independence. The offensive quickly gained ground after the HV advanced north of the Drava River into Baranja. The defending force of the Croatian Serb Territorial Defence Force supported by the Yugoslav People's Army artillery were caught unprepared and offered light resistance.
The thanatotranscriptome denotes all RNA transcripts produced from the portions of the genome still active or awakened in the internal organs of a body following its death. It is relevant to the study of the biochemistry, microbiology, and biophysics of thanatology, in particular within forensic science. Some genes may continue to be expressed in cells for up to 48 hours after death, producing new mRNA. Certain genes that are generally inhibited since the end of fetal development may be expressed again at this time.
In embryology a phylotypic stage or phylotypic period is a particular developmental stage or developmental period during mid-embryogenesis where embryos of related species within a phylum express the highest degree of morphological and molecular resemblance. Recent molecular studies in various plant and animal species were able to quantify the expression of genes covering crucial stages of embryo development and found that during the morphologically defined phylotypic period the evolutionary oldest genes, genes with similar temporal expression patterns, and genes under strongest purifying selection are most active throughout the phylotypic period.
Tomislav Domazet-Lošo is a Croatian geneticist. His fields of interest are evolutionary genetics, evolutionary developmental biology, macroevolution, and tumor evolution. He is currently employed at the Ruđer Bošković Institute as a researcher.
De novo gene birth is the process by which new genes evolve from non-coding DNA. De novo genes represent a subset of novel genes, and may be protein-coding or instead act as RNA genes. The processes that govern de novo gene birth are not well understood, although several models exist that describe possible mechanisms by which de novo gene birth may occur.
Tadashi Fukami is an associate Professor of Biology and community ecologist at Stanford University. He is currently the head of Fukami Lab which is a community ecology research group that focuses on "historical contingency in the assembly of ecological communities." Fukami is an elected Fellow of the Ecological Society of America.