15 Amazing Facts About Evolution Site
The Academy's Evolution Site
The concept of biological evolution is a fundamental concept in biology. The Academies have long been involved in helping those interested in science comprehend the theory of evolution and how it affects all areas of scientific exploration.
This site provides a wide range of resources for students, teachers and general readers of evolution. It has key video clips from NOVA and the WGBH-produced science programs on DVD.
Tree of Life
The Tree of Life, an ancient symbol, represents the interconnectedness of all life. It is used in many spiritual traditions and cultures as an emblem of unity and love. It also has practical applications, such as providing a framework for understanding the evolution of species and how they react to changes in environmental conditions.
Early attempts to represent the world of biology were founded on categorizing organisms on their metabolic and physical characteristics. These methods, which depend on the collection of various parts of organisms, or fragments of DNA have significantly increased the diversity of a Tree of Life2. These trees are largely composed of eukaryotes, while bacteria are largely underrepresented3,4.
By avoiding the necessity for direct experimentation and observation genetic techniques have allowed us to depict the Tree of Life in a more precise way. We can create trees using molecular methods, such as the small-subunit ribosomal gene.
The Tree of Life has been dramatically expanded through genome sequencing. However there is a lot of biodiversity to be discovered. This is especially true of microorganisms that are difficult to cultivate and are typically only represented in a single specimen5. A recent study of all genomes that are known has produced a rough draft of the Tree of Life, including many bacteria and archaea that are not isolated and which are not well understood.
The expanded Tree of Life can be used to assess the biodiversity of a specific area and determine if specific habitats require special protection. sell is useful in a variety of ways, including finding new drugs, battling diseases and improving crops. The information is also beneficial in 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 the effects of human activity. Although funding to protect biodiversity are crucial however, the most effective method to protect the world's biodiversity is for more people living in developing countries to be equipped with the knowledge to take action locally to encourage conservation from within.
Phylogeny
A phylogeny is also known as an evolutionary tree, shows the connections between various groups of organisms. Utilizing molecular data, morphological similarities and differences, or ontogeny (the course of development of an organism), scientists can build an phylogenetic tree that demonstrates the evolutionary relationship between taxonomic groups. The concept of phylogeny is fundamental to understanding evolution, biodiversity and genetics.
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 are either homologous or analogous. Homologous traits are identical in their evolutionary origins while analogous traits appear similar but do not have the identical origins. Scientists group similar traits together into a grouping referred to as a Clade. Every organism in a group share a characteristic, for example, amniotic egg production. They all came from an ancestor that had these eggs. page can be constructed by connecting clades to identify the organisms who are the closest to each other.
For a more detailed and accurate phylogenetic tree scientists make use of molecular data from DNA or RNA to identify the relationships among organisms. This information is more precise and gives evidence of the evolution history of an organism. The use of molecular data lets researchers identify the number of species who share the same ancestor and estimate their evolutionary age.
The phylogenetic relationships between organisms are influenced by many factors, including phenotypic flexibility, an aspect of behavior that changes in response to specific environmental conditions. This can make a trait appear more similar to one species than to another and obscure the phylogenetic signals. However, this issue can be cured by the use of techniques like cladistics, which incorporate a combination of homologous and analogous features into the tree.
Additionally, phylogenetics can help determine the duration and speed of speciation. This information can assist conservation biologists in deciding which species to safeguard from the threat of extinction. Ultimately, it is the preservation of phylogenetic diversity that will create an ecologically balanced and complete ecosystem.
Evolutionary Theory
The fundamental concept in evolution is that organisms change over time due to their interactions with their environment. A variety of theories about evolution have been developed by a wide range of scientists such as the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who believed that an organism would evolve gradually according to its requirements as well as the Swedish botanist Carolus Linnaeus (1707-1778) who conceived the modern hierarchical taxonomy Jean-Baptiste Lamarck (1744-1829) who suggested that use or disuse of traits cause changes that can be passed onto offspring.
In the 1930s & 1940s, theories from various fields, such as genetics, natural selection, and particulate inheritance, merged to form a contemporary synthesis of evolution theory. This defines how evolution happens through the variations in genes within the population and how these variations change with time due to natural selection. This model, which incorporates mutations, genetic drift in gene flow, and sexual selection is mathematically described mathematically.
Recent developments in the field of evolutionary developmental biology have revealed that variation can be introduced into a species through mutation, genetic drift, and reshuffling genes during sexual reproduction, and also through the movement of populations. These processes, along with others such as 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 and changes in the phenotype (the expression of genotypes within individuals).
Incorporating evolutionary thinking into all areas of biology education can improve student understanding of the concepts of phylogeny and evolution. 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 class. For more details on how to teach about evolution, see The Evolutionary Potential in all Areas of Biology or Thinking Evolutionarily A Framework for Infusing Evolution into Life Sciences Education.
Evolution in Action
Scientists have traditionally studied evolution through looking back in the past, studying fossils, and comparing species. page observe living organisms. Evolution is not a past event; it is an ongoing process. The virus reinvents itself to avoid new antibiotics and bacteria transform to resist antibiotics. Animals adapt their behavior in the wake of a changing environment. The resulting changes are often visible.
It wasn't until the 1980s when biologists began to realize that natural selection was also at work. The key is that various traits have different rates of survival and reproduction (differential fitness), and can be transferred from one generation to the next.
In the past, if one allele - the genetic sequence that determines colour appeared in a population of organisms that interbred, it could be more prevalent than any other allele. In time, this could mean the number of black moths within a particular population could rise. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.
It is easier to see evolutionary change when the species, like bacteria, has a high generation turnover. Since 1988, Richard Lenski, a biologist, has studied twelve populations of E.coli that are descended from a single strain. Samples of each population have been taken frequently and more than 50,000 generations of E.coli have passed.
Lenski's work has demonstrated that a mutation can profoundly alter the efficiency with the rate at which a population reproduces, and consequently the rate at which it changes. It also proves that evolution takes time--a fact that some find difficult to accept.
Microevolution is also evident in the fact that mosquito genes for pesticide resistance are more common in populations that have used insecticides. Pesticides create an exclusive pressure that favors individuals who have resistant genotypes.
The speed at which evolution can take place has led to a growing awareness of its significance in a world shaped by human activity--including climate change, pollution, and the loss of habitats that prevent many species from adjusting. Understanding evolution can aid you in making better decisions about the future of our planet and its inhabitants.