20 Fun Facts About Evolution Site

The Academy's Evolution Site

Biology is a key concept in biology. The Academies are committed to helping those who are interested in science to comprehend the evolution theory and how it is permeated throughout all fields of scientific research.

This site provides a range of tools for teachers, students and general readers of evolution. It includes key video clip from NOVA and WGBH produced science programs on DVD.

Tree of Life

The Tree of Life is an ancient symbol of the interconnectedness of life. It is a symbol of love and unity in many cultures. It also has important practical uses, like providing a framework for understanding the history of species and how they respond to changing environmental conditions.

Early attempts to describe the world of biology were founded on categorizing organisms on their physical and metabolic characteristics. These methods rely on the collection of various parts of organisms or short fragments of DNA, have significantly increased the diversity of a Tree of Life2. These trees are mostly populated by eukaryotes and bacteria are largely underrepresented3,4.

By avoiding the need for direct observation and 에볼루션 바카라 체험 experimentation, genetic techniques have allowed us to represent the Tree of Life in a more precise way. Trees can be constructed by using molecular methods such as the small subunit ribosomal gene.

Despite the dramatic growth of the Tree of Life through genome sequencing, much biodiversity still is waiting to be discovered. This is especially the case for microorganisms which are difficult to cultivate, and are typically present in a single sample5. A recent analysis of all genomes resulted in a rough draft of a Tree of Life. This includes a wide range of archaea, bacteria and other organisms that have not yet been isolated, or whose diversity has not been fully understood6.

This expanded Tree of Life is particularly useful for assessing the biodiversity of an area, assisting to determine whether specific habitats require special protection. The information is useful in a variety of ways, such as finding new drugs, fighting diseases and enhancing crops. The information is also incredibly beneficial in conservation efforts. It helps biologists determine the areas that are most likely to contain cryptic species with potentially significant metabolic functions that could be vulnerable to anthropogenic change. While funds to protect biodiversity are essential, the best method to protect the world's biodiversity is to empower 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 organisms. Using molecular data as well as morphological similarities and distinctions, or ontogeny (the course of development of an organism), scientists can build an phylogenetic tree that demonstrates the evolutionary relationships between taxonomic groups. Phylogeny is essential in understanding the evolution of biodiversity, evolution and genetics.

A basic phylogenetic Tree (see Figure PageIndex 10 ) determines the relationship between organisms that share similar traits that have evolved from common ancestors. These shared traits could be either homologous or analogous. Homologous traits share their evolutionary roots, while analogous traits look like they do, but don't have the identical origins. Scientists combine similar traits into a grouping known as a the clade. All organisms in a group share a trait, such as amniotic egg production. They all came from an ancestor that had these eggs. A phylogenetic tree is built by connecting the clades to identify the species who are the closest to one another.

Scientists use DNA or RNA molecular information to construct a phylogenetic graph which is more precise and detailed. This data is more precise than the morphological data and provides evidence of the evolutionary background of an organism or group. Molecular data allows researchers to determine the number of organisms who share the same ancestor and estimate their evolutionary age.

The phylogenetic relationships between species can be influenced by several factors, including phenotypic plasticity an aspect of behavior that changes in response to unique environmental conditions. This can cause a characteristic to appear more resembling to one species than another which can obscure the phylogenetic signal. However, this issue can be reduced by the use of methods like cladistics, which combine similar and homologous traits into the tree.

Additionally, phylogenetics can aid in predicting the length and speed of speciation. This information can aid conservation biologists in making choices about which species to protect from disappearance. In the end, it is the conservation of phylogenetic variety that will lead to an ecosystem that is balanced and complete.

Evolutionary Theory

The central theme of evolution is that organisms develop distinct characteristics over time as a result of their interactions with their environments. Several theories of evolutionary change have been developed by a variety of scientists including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who believed that an organism would evolve slowly in accordance with its requirements, 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 causes changes that could be passed on to offspring.

In the 1930s & 1940s, theories from various fields, such as natural selection, genetics & particulate inheritance, merged to form a contemporary evolutionary theory. This explains how evolution happens through the variations in genes within a population and how these variations alter over time due to natural selection. This model, called genetic drift or mutation, gene flow, and sexual selection, is the foundation of modern evolutionary biology and is mathematically described.

Recent discoveries in the field of evolutionary developmental biology have demonstrated that genetic variation can be introduced into a species via mutation, genetic drift, and reshuffling genes during sexual reproduction, as well as through the movement of populations. These processes, along with others such as the directional selection process and the erosion of genes (changes to the frequency of genotypes over time) can lead to evolution. Evolution is defined by changes in the genome over time as well as changes in the phenotype (the expression of genotypes within individuals).

Incorporating evolutionary thinking into all areas of biology education can increase student understanding of the concepts of phylogeny as well as evolution. In a study by Grunspan et al., it was shown that teaching students about the evidence for evolution boosted their understanding of evolution in an undergraduate biology course. For more information on how to teach 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

Traditionally, scientists have studied evolution through studying fossils, comparing species and studying living organisms. Evolution is not a distant event, but an ongoing process that continues to be observed today. Viruses evolve to stay away from new antibiotics and bacteria transform to resist antibiotics. Animals alter their behavior as a result of the changing environment. The results are usually evident.

It wasn't until late 1980s that biologists began realize that natural selection was in play. The key is that different characteristics result in different rates of survival and reproduction (differential fitness) and can be passed down from one generation to the next.

In the past, 에볼루션 바카라 에볼루션 슬롯; Humanlove.Stream, if a certain allele - the genetic sequence that determines colour was present in a population of organisms that interbred, it could become more common than other allele. As time passes, that could mean 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, as with bacteria. Since 1988 biologist Richard Lenski has been tracking twelve populations of E. bacteria that descend from a single strain. samples of each are taken regularly and more than 50,000 generations have now passed.

Lenski's work has demonstrated that a mutation can profoundly alter the speed at which a population reproduces--and so the rate at which it alters. It also shows that evolution is slow-moving, a fact that some people are unable to accept.

Microevolution can be observed in the fact that mosquito genes for pesticide resistance are more prevalent in populations that have used insecticides. This is due to the fact that the use of pesticides creates a selective pressure that favors those with resistant genotypes.

The rapidity of evolution has led to an increasing appreciation of its importance especially in a planet shaped largely by human activity. This includes the effects of climate change, pollution and habitat loss, which prevents many species from adapting. Understanding evolution will help us make better decisions about the future of our planet, as well as the life of its inhabitants.