10 Real Reasons People Hate Evolution Site
The Academy's Evolution Site
The concept of biological evolution is among the most central concepts in biology. The Academies are committed to helping those who are interested in science to comprehend the evolution theory and how it is permeated in all areas of scientific research.
This site provides a wide range of sources for students, teachers as well as general readers about evolution. It contains key video clips from NOVA and WGBH produced science programs on DVD.
Tree of Life
The Tree of Life, an ancient symbol, symbolizes the interconnectedness of all life. It is an emblem of love and unity across many cultures. It can be used in many practical ways as well, including providing a framework for understanding the history of species and how they respond to changing environmental conditions.
The earliest attempts to depict the biological world focused on separating species into distinct categories that were identified by their physical and metabolic characteristics1. These methods, which depend on the collection of various parts of organisms, or fragments of DNA have greatly increased the diversity of a Tree of Life2. These trees are largely composed by eukaryotes, and bacterial diversity is vastly underrepresented3,4.
Genetic techniques have greatly expanded our ability to represent the Tree of Life by circumventing the need for direct observation and experimentation. Particularly, molecular methods enable us to create trees using sequenced markers such as the small subunit ribosomal gene.
Despite the rapid expansion of the Tree of Life through genome sequencing, a large amount of biodiversity is waiting to be discovered. This is particularly relevant to microorganisms that are difficult to cultivate, and are usually present in a single sample5. A recent analysis of all genomes resulted in an unfinished draft of the Tree of Life. This includes a wide range of archaea, bacteria, and other organisms that have not yet been identified or the diversity of which is not thoroughly understood6.
The expanded Tree of Life can be used to evaluate the biodiversity of a specific area and determine if specific habitats require special protection. This information can be used in a variety of ways, such as finding new drugs, battling diseases and enhancing crops. This information is also useful for conservation efforts. 무료에볼루션 can aid biologists in identifying the areas that are most likely to contain cryptic species with potentially important metabolic functions that could be vulnerable to anthropogenic change. While conservation funds are important, the most effective way to conserve the world's biodiversity is to empower more people in developing countries with the necessary knowledge to take action locally and encourage conservation.
Phylogeny
A phylogeny (also called an evolutionary tree) illustrates the relationship between organisms. Scientists can construct a phylogenetic chart that shows the evolution of taxonomic groups using molecular data and morphological differences or similarities. The role of phylogeny is crucial in understanding the relationship between genetics, biodiversity and evolution.
A basic phylogenetic Tree (see Figure PageIndex 10 ) identifies the relationships between organisms that share similar traits that have evolved from common ancestors. These shared traits can be analogous or homologous. Homologous traits are similar in terms of their evolutionary paths. Analogous traits might appear like they are however they do not have the same ancestry. Scientists combine similar traits into a grouping referred to as a the clade. For example, all of the species in a clade share the characteristic of having amniotic eggs and evolved from a common ancestor which had eggs. The clades then join to create a phylogenetic tree to identify organisms that have the closest relationship.
For a more detailed and precise phylogenetic tree scientists rely on molecular information from DNA or RNA to identify the relationships between organisms. This information is more precise and gives evidence of the evolution history of an organism. Researchers can utilize Molecular Data to determine the age of evolution of living organisms and discover the number of organisms that have a common ancestor.
The phylogenetic relationships of organisms can be influenced by several factors, including phenotypic plasticity a type of behavior that changes in response to specific environmental conditions. This can cause a particular trait to appear more similar to one species than another, clouding the phylogenetic signal. This issue can be cured by using cladistics, which incorporates an amalgamation of homologous and analogous features in the tree.
In addition, phylogenetics helps determine the duration and speed of speciation. This information can assist conservation biologists in making decisions about which species to save from the threat of extinction. In the end, it's the preservation of phylogenetic diversity that will create an ecologically balanced and complete ecosystem.
Evolutionary Theory
The main idea behind evolution is that organisms acquire various characteristics over time due to their interactions with their environment. Many theories of evolution have been proposed by a wide variety of scientists such as the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who proposed that a living organism develop slowly according to its requirements as well as the Swedish botanist Carolus Linnaeus (1707-1778) who designed the modern hierarchical taxonomy, as well as Jean-Baptiste Lamarck (1744-1829) who suggested that the use or misuse of traits can cause changes that can be passed on to the offspring.
In the 1930s and 1940s, ideas from different areas, including natural selection, genetics & particulate inheritance, came together to form a contemporary evolutionary theory. This explains how evolution happens through the variations in genes within a population and how these variants alter over time due to natural selection. This model, which includes genetic drift, mutations as well as gene flow and sexual selection is mathematically described.
Recent developments in the field of evolutionary developmental biology have demonstrated that variations can be introduced into a species via mutation, genetic drift and reshuffling of genes in sexual reproduction, as well as by migration between populations. These processes, along with others like directional selection and genetic erosion (changes in the frequency of an individual's genotype over time), can lead to evolution which is defined by changes in the genome of the species over time and also the change in phenotype as time passes (the expression of the genotype in the individual).
Incorporating evolutionary thinking into all aspects of biology education could increase student understanding of the concepts of phylogeny as well as evolution. In a study by Grunspan and co. It was found that teaching students about the evidence for evolution boosted their understanding of evolution during a college-level course in biology. For more information on how to teach about evolution, please read The Evolutionary Potential of all Areas of Biology and Thinking Evolutionarily: A Framework for Infusing the Concept of Evolution into Life Sciences Education.
Evolution in Action
Traditionally scientists have studied evolution through looking back, studying fossils, comparing species, and studying living organisms. But evolution isn't a thing that occurred in the past. It's an ongoing process taking place today. Viruses reinvent themselves to avoid new drugs and bacteria evolve to resist antibiotics. Animals alter their behavior because of a changing world. The results are usually easy to see.
However, it wasn't until late 1980s that biologists understood that natural selection could be seen 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, if one allele - the genetic sequence that determines color - appeared in a population of organisms that interbred, it could be more prevalent than any other allele. In time, this could mean that the number of moths with black pigmentation in a population may increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.
It is easier to observe evolutionary change when a species, such as bacteria, has a high generation turnover. Since 1988, Richard Lenski, a biologist, has tracked twelve populations of E.coli that are descended from one strain. The samples of each population were taken frequently and more than 50,000 generations of E.coli have passed.
Lenski's work has shown that mutations can alter the rate at which change occurs and the rate of a population's reproduction. It also proves that evolution takes time, a fact that many find difficult to accept.
Another example of microevolution is the way mosquito genes that are resistant to pesticides appear more frequently in areas where insecticides are used. Pesticides create a selective pressure which favors individuals who have resistant genotypes.
The rapidity of evolution has led to an increasing awareness of its significance especially in a planet that is largely shaped by human activity. This includes pollution, climate change, and habitat loss that hinders many species from adapting. Understanding evolution can help you make better decisions regarding the future of the planet and its inhabitants.