14 Misconceptions Commonly Held About Evolution Site
The Academy's Evolution Site
Biological evolution is one of the most important concepts in biology. The Academies have been active for a long time in helping people who are interested in science comprehend the theory of evolution and how it permeates every area of scientific inquiry.
This site offers a variety of sources for students, teachers, and 에볼루션 코리아 general readers on evolution. It contains key video clips from NOVA and WGBH produced science programs on DVD.
Tree of Life
The Tree of Life is an ancient symbol that represents the interconnectedness of life. It is seen in a variety of religions and cultures as an emblem of unity and love. It also has important practical applications, like providing a framework for understanding the history of species and how they react to changing environmental conditions.
The earliest attempts to depict the biological world focused on the classification of organisms into distinct categories which were distinguished by physical and metabolic characteristics1. These methods rely on the sampling of different parts of organisms or short fragments of DNA, have significantly increased the diversity of a tree of Life2. These trees are largely composed by eukaryotes and bacteria are largely underrepresented3,4.
In avoiding the necessity of direct experimentation and observation, genetic techniques have enabled us to represent the Tree of Life in a much more accurate way. Particularly, molecular techniques allow us to construct trees by using sequenced markers, such as the small subunit ribosomal RNA gene.
The Tree of Life has been greatly expanded thanks to genome sequencing. However, there is still much biodiversity to be discovered. This is particularly true for microorganisms, which are difficult to cultivate and are usually only present in a single specimen5. Recent analysis of all genomes has produced a rough draft of a Tree of Life. This includes a variety of archaea, bacteria, and other organisms that haven't yet been isolated, or whose diversity has not been fully understood6.
This expanded Tree of Life is particularly beneficial in assessing the biodiversity of an area, assisting to determine whether specific habitats require special protection. This information can be utilized in a variety of ways, such as finding new drugs, fighting diseases and improving the quality of crops. This information is also valuable to conservation efforts. It helps biologists discover areas that are likely to have species that are cryptic, which could have vital metabolic functions and are susceptible to human-induced change. While funding to protect biodiversity are important, the most effective method to protect the biodiversity of the world is to equip more people in developing nations with the necessary knowledge to act locally and promote conservation.
Phylogeny
A phylogeny (also known as an evolutionary tree) illustrates the relationship between species. Utilizing molecular data similarities and differences in morphology or ontogeny (the process of the development of an organism) scientists can create a phylogenetic tree that illustrates the evolutionary relationship between taxonomic groups. The phylogeny of a tree plays an important role in understanding the relationship between genetics, biodiversity and evolution.
A basic phylogenetic tree (see Figure PageIndex 10 ) is a method of identifying the relationships between organisms that share similar traits that evolved from common ancestral. These shared traits can be homologous, or analogous. Homologous traits are similar in terms of their evolutionary path. Analogous traits could appear similar but they don't share the same origins. Scientists organize similar traits into a grouping referred to as a Clade. Every organism in a group have a common trait, such as amniotic egg production. They all derived from an ancestor with these eggs. The clades are then connected to create a phylogenetic tree to determine which organisms have the closest relationship to.
Scientists utilize molecular DNA or RNA data to build a phylogenetic chart that is more accurate and precise. This information is more precise than morphological information and provides evidence of the evolutionary history of an individual or group. The use of molecular data lets researchers determine the number of species that have an ancestor common to them and estimate their evolutionary age.
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 cause a trait to appear more resembling to one species than to the other and obscure the phylogenetic signals. This problem can be mitigated by using cladistics. This is a method that incorporates a combination of homologous and analogous traits in the tree.
Furthermore, phylogenetics may aid in predicting the length and speed of speciation. This information can aid conservation biologists to make decisions about which species they should protect from extinction. Ultimately, it is the preservation of phylogenetic diversity which will lead to an ecosystem that is complete and balanced.
Evolutionary Theory
The central theme of evolution is that organisms develop various characteristics over time based on their interactions with their surroundings. A variety of theories about evolution have been developed by a wide variety of scientists such as the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who believed that an organism would evolve slowly in accordance with its requirements and 에볼루션 슬롯 needs, the Swedish botanist Carolus Linnaeus (1707-1778) who designed the modern hierarchical taxonomy Jean-Baptiste Lamarck (1744-1829) who suggested that the use or non-use of traits can cause changes that can be passed onto offspring.
In the 1930s & 1940s, ideas from different fields, including genetics, natural selection, and particulate inheritance, came together to form a contemporary theorizing of evolution. This defines how evolution occurs by the variations in genes within the population and how these variations alter over time due to natural selection. This model, which incorporates mutations, genetic drift as well as gene flow and sexual selection is mathematically described.
Recent discoveries in evolutionary developmental biology have shown how variations can be introduced to a species via genetic drift, mutations, reshuffling genes during sexual reproduction and migration between populations. These processes, as well as other ones like the directional selection process and the erosion of genes (changes in frequency of genotypes over time) can result in evolution. Evolution is defined by changes in the genome over time, as well as changes in phenotype (the expression of genotypes within individuals).
Students can gain a better understanding of phylogeny by incorporating evolutionary thinking in all aspects of biology. A recent study conducted by Grunspan and colleagues, for example, showed that teaching about the evidence supporting evolution increased students' acceptance of evolution in a college-level biology course. For more information about how to teach evolution look up The Evolutionary Power of Biology in all Areas of Biology or Thinking Evolutionarily as a Framework for Infusing Evolution into Life Sciences Education.
Evolution in Action
Scientists have traditionally studied evolution by looking in the past--analyzing fossils and comparing species. They also observe living organisms. However, 에볼루션사이트 evolution isn't something that happened in the past, it's an ongoing process that is taking place in the present. Bacteria mutate and resist antibiotics, viruses reinvent themselves and elude new medications, and animals adapt their behavior in response to a changing planet. The changes that occur are often visible.
It wasn't until late-1980s that biologists realized that natural selection could be observed in action as well. The reason is that different traits have different rates of survival and reproduction (differential fitness) and can be passed down 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 might quickly become more common than other alleles. As time passes, this could mean that the number of moths with black pigmentation in a population could increase. The same is true for 에볼루션 코리아 many other characteristics--including morphology and behavior--that vary among populations of organisms.
Monitoring evolutionary changes in action is easier when a particular species has a rapid turnover of its generation like bacteria. Since 1988 the biologist Richard Lenski has been tracking twelve populations of E. Coli that descended from a single strain; samples of each population are taken on a regular basis and more than 500.000 generations have been observed.
Lenski's work has shown that mutations can alter the rate of change and the effectiveness of a population's reproduction. It also demonstrates that evolution takes time, a fact that some find hard to accept.
Another example of microevolution is how mosquito genes for resistance to pesticides are more prevalent in areas where insecticides are used. This is due to the fact that the use of pesticides causes a selective pressure that favors people with resistant genotypes.
The rapidity of evolution has led to a greater recognition of its importance, especially in a world shaped largely by human activity. This includes climate change, pollution, and habitat loss, which prevents many species from adapting. Understanding the evolution process can assist you in making better choices about the future of the planet and its inhabitants.