Molecular Evolution and system development

Reference: Wu Zujian, Gaofang, Shen Jianguo. Bioinformatics analysis Practice [M]. Science Publishing House, 2010.

Sirda said that the biological information can not be picky eaters, there is nothing to do.

One of the hotspots in biological information is evolutionary analysis, which infers the evolutionary process of a species throughout the population.

First read a popular article: (Source of genes)

The evolution of organisms refers to changes in the nature of biological groups over time. The development of molecular biology has greatly accelerated the progress of evolutionary research, DNA sequence, by virtue of its relatively stable evolutionary process and enormous information advantages, greatly improved the relationship between the system development of the inference ability. The diversity of genome size and the evolutionary rate of different parts, the molecular features provide a systematic development record from very close to the time of life on earth, and thus can compare the DNA information of species to study the evolutionary relationship of organisms.

Molecular evolution has now become the focus of research on biological evolution. Evolution is mainly based on gene mutation, nucleotide substitution, insertion loss, recombination and reverse of the gene mutation, mutation of the gene or DNA sequence through the population level of genetic drift or natural selection to spread, resulting in new morphological or functional traits, eventually fixed and transmitted to all of its offspring.

The purpose of molecular evolutionary research

Starting from some molecular characteristics of species, we understand the relationship between the biological systems of species, and then we understand the evolution of genes and the inherent laws of biological systems through the homology of nucleic acid and protein sequences.

Homology refers to the conclusion that the two genes or sequences of proteins inferred from some data have a common ancestor, which is a qualitative judgment, which is to add a sequence of sequences with homologous but from different species in order to determine the homologous size between the sequence and other sequences. The commonly used multi-sequence comparison program has clustal-alignment and so on, it is different from the blast local matching search, the multi-sequence alignment mostly uses the global alignment algorithm, which is a very complicated and time-consuming process for the automatic multi-sequence alignment using the computer program. Especially if the sequence data is many and the sequence is long.

The theoretical basis of molecular evolution is that in a variety of developmental lineages and large enough evolutionary time scales, the evolutionary rate of many sequences is almost constant. In fact, although there are many controversies, molecular evolution can really explain the inherent laws of the biological system.

System development Analysis

Phylogenetic studies are the origins and evolutionary relationships of any classification unit, and phylogenetic analysis is to infer or evaluate these evolutionary relationships. Phylogenetic analysis is the study of a group of related genes or proteins through multiple sequence alignment, inferring and evaluating evolutionary relationships among different genes. In the study of biological evolution and system classification, similar tree-like branches are commonly used to summarize the relationships among various organisms, called phylogenetic trees.

Molecular marker selection for system development analysis

Molecular markers are the direct reflection of genetic variation on DNA levels by detecting the difference between organisms directly on the molecule. It is based on mutations of protein and nucleic acid molecules, and detects biological genetic structure and its mutation to reflect the difference between biological individuals. DNA molecular markers can be detected by individuals, tissues, organs and even cells at different stages of development, with a large number of genes throughout the genome, high polymorphism, genetic stability, and not limited by the environment and gene expression. Using DNA sequences to study the common methods of species evolution: first, based on the object and purpose of the study, select the appropriate gene or DNA region and determine the sequence of the target DNA fragment. In the case of the relative species, the region of rapid evolution should be chosen; for distant species, a relatively conservative region should be chosen. Secondly, through the comparison of DNA homologous sequence, a certain system reconstruction pathway and method are used to determine the genetic system tree and the species system tree. Any level of system development problems can be solved by selecting the appropriate molecular markers.

The most rapidly evolving DNA sequence is the mitochondrial DNA of eukaryotic organisms, and it is advantageous to explore the relationship between the species and the relatives. Other DNA molecular markers evolve at a rate between Mt DNA and R DNA. In addition to the coding area, certain clusters contain a wide variety of transcription and non-transcription areas, which also provide a record of phylogeny from the most recent to a long time period. Mitochondrial DNA has been widely used in taxonomy, phylogenetic, population genetics, forensic science and anthropology as a molecular marker.

Professor He Xionglei, Sun Yat-sen University publishes new articles

EVOLUTION. Toward a prospective molecular evolution.

Progressive Loss of Function in a limb enhancer during Snake Evolution

The Seahorse genome and the evolution of its specialized morphology-Huada seahorse

These 4 reports will subvert your understanding of the human organism, the daughter is difficult to buy!

Molecular Evolution and system development