20 Fun Infographics About Evolution Site
The Academy's Evolution Site
The concept of biological evolution is a fundamental concept in biology. The Academies are involved in helping those interested in the sciences understand evolution theory and how it is permeated across all areas of scientific research.
This site provides students, teachers and general readers with a range of learning resources about evolution. It includes key video clip from NOVA and WGBH produced science programs on DVD.
Tree of Life
The Tree of Life, an ancient symbol, represents the interconnectedness of all life. It is an emblem of love and unity in many cultures. It also has practical applications, like providing a framework for understanding the evolution of species and how they respond to changes in the environment.
Early attempts to represent the world of biology were built on categorizing organisms based on their physical and metabolic characteristics. These methods, based on sampling of different parts of living organisms, or small fragments of their DNA significantly expanded the diversity that could be represented in the tree of life2. The trees are mostly composed by eukaryotes, and 에볼루션 bacteria are largely underrepresented3,4.
By avoiding the necessity for direct observation and experimentation genetic techniques have allowed us to depict the Tree of Life in a much more accurate way. Particularly, molecular techniques enable us to create trees using sequenced markers like the small subunit ribosomal gene.
Despite the massive expansion of the Tree of Life through genome sequencing, a lot of biodiversity is waiting to be discovered. This is particularly relevant to microorganisms that are difficult to cultivate, and which are usually only present in a single sample5. A recent analysis of all genomes that are known has produced a rough draft of the Tree of Life, including a large number of bacteria and archaea that are not isolated and whose diversity is poorly understood6.
This expanded Tree of Life can be used to assess the biodiversity of a particular area and determine if certain habitats need special protection. The information can be used in a variety of ways, from identifying the most effective treatments to fight disease to enhancing crops. It is also beneficial for conservation efforts. It helps biologists discover areas most likely to have cryptic species, which could perform important metabolic functions, and could be susceptible to human-induced change. Although funds to safeguard biodiversity are vital, ultimately the best way to protect the world's biodiversity is for more people living in developing countries to be empowered with the necessary knowledge to act locally in order to promote conservation from within.
Phylogeny
A phylogeny (also known as an evolutionary tree) depicts the relationships between species. Scientists can create a phylogenetic diagram that illustrates the evolutionary relationship of taxonomic groups using molecular data and 에볼루션게이밍 morphological similarities or differences. The concept of phylogeny is fundamental to understanding biodiversity, evolution and genetics.
A basic phylogenetic tree (see Figure PageIndex 10 Finds the connections between organisms that have similar characteristics and have evolved from a common ancestor. These shared traits can be either homologous or analogous. Homologous traits are the same in terms of their evolutionary path. Analogous traits may look similar however they do not have the same ancestry. Scientists organize similar traits into a grouping called a Clade. Every organism in a group have a common characteristic, for example, amniotic egg production. They all came from an ancestor with these eggs. A phylogenetic tree can be constructed by connecting the clades to identify the species which are the closest to one another.
To create a more thorough and accurate phylogenetic tree scientists rely on molecular information from DNA or RNA to identify the relationships among organisms. This data is more precise than the morphological data and gives evidence of the evolutionary history of an individual or group. Researchers can use Molecular Data to estimate the age of evolution of organisms and determine the number of organisms that have an ancestor common to all.
The phylogenetic relationships between species are influenced by many factors, including phenotypic flexibility, a type of behavior that alters in response to unique environmental conditions. This can make a trait appear more similar to one species than another, obscuring the phylogenetic signals. This issue can be cured by using cladistics, which is a an amalgamation of analogous and homologous features in the tree.
Additionally, phylogenetics can help predict the duration and rate of speciation. This information can help conservation biologists make decisions about the species they should safeguard from extinction. In the end, it's the conservation of phylogenetic diversity that will result in an ecosystem that is balanced and complete.
Evolutionary Theory
The central theme in evolution is that organisms alter over time because of their interactions with their environment. A variety of theories about evolution have been proposed by a wide range of scientists including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who proposed that a living organism develop slowly in accordance with its requirements, the Swedish botanist Carolus Linnaeus (1707-1778) who developed the modern hierarchical taxonomy, as well as Jean-Baptiste Lamarck (1744-1829) who suggested that the use or misuse of traits causes changes that can be passed on to the offspring.
In the 1930s and 1940s, concepts from a variety of fields -- including natural selection, genetics, and particulate inheritance -- came together to create the modern synthesis of evolutionary theory which explains how evolution occurs through the variation of genes within a population, and how those variants change in time due to natural selection. This model, known as genetic drift, mutation, gene flow, and sexual selection, is a cornerstone of current evolutionary biology, and can be mathematically explained.
Recent developments in the field of evolutionary developmental biology have revealed the ways in which variation can be introduced to a species through mutations, genetic drift or reshuffling of genes in sexual reproduction and the movement between populations. These processes, as well as other ones like directional selection and genetic erosion (changes in the frequency of an individual's genotype over time) can lead to evolution that is defined as change in the genome of the species over time and also the change in phenotype as time passes (the expression of the genotype in an individual).
Students can gain a better understanding of the concept of phylogeny by using evolutionary thinking in all areas of biology. In a recent study conducted by Grunspan et al., it was shown that teaching students about the evidence for evolution boosted their understanding of evolution during an undergraduate biology course. To learn more about how to teach about evolution, look up The Evolutionary Potential of All Areas of Biology and Thinking Evolutionarily: A Framework for Infusing Evolution in Life Sciences Education.
Evolution in Action
Traditionally, scientists have studied evolution through studying fossils, comparing species and studying living organisms. Evolution is not a distant moment; it is an ongoing process that continues to be observed today. Bacteria evolve and resist antibiotics, viruses reinvent themselves and are able to evade new medications, and animals adapt their behavior to the changing environment. The changes that occur are often evident.
It wasn't until late 1980s that biologists understood that natural selection can be observed in action as well. The main reason is that different traits result in a different rate of survival and reproduction, and they can be passed on from one generation to the next.
In the past, when one particular allele - the genetic sequence that controls coloration - was present in a population of interbreeding organisms, it could quickly become more prevalent than other alleles. As time passes, that could mean that the number of black moths within the population could increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.
The ability to observe evolutionary change is easier when a particular species has a rapid turnover of its generation like bacteria. Since 1988, 에볼루션카지노 Richard Lenski, a biologist, has been tracking twelve populations of E.coli that are descended from a single strain. The samples of each population have been collected regularly and more than 50,000 generations of E.coli have passed.
Lenski's research has demonstrated that mutations can alter the rate at which change occurs and 에볼루션 바카라 무료 the effectiveness at which a population reproduces. It also demonstrates that evolution takes time, a fact that is difficult for some to accept.
Another example of microevolution is how mosquito genes for resistance to pesticides show up more often in areas in which insecticides are utilized. This is due to pesticides causing a selective pressure which favors those who have resistant genotypes.
The rapid pace of evolution taking place has led to a growing awareness of its significance in a world shaped by human activity--including climate changes, pollution and the loss of habitats which prevent the species from adapting. Understanding the evolution process will aid you in making better decisions about the future of our planet and its inhabitants.