10 Myths Your Boss Is Spreading About Evolution Site

The Academy's Evolution Site

Biological evolution is one of the most central concepts in biology. The Academies have long been involved in helping people who are interested in science understand the concept of evolution and how it affects every area of scientific inquiry.

This site provides students, teachers and general readers with a range of learning resources about 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 symbolizes the interconnectedness of life. It is an emblem of love and 바카라 에볼루션 harmony in a variety of cultures. It can be used in many practical ways in addition to providing a framework to understand the evolution of species and how they respond to changes in environmental conditions.

The earliest attempts to depict the world of biology focused on the classification of organisms into distinct categories that were distinguished by physical and metabolic characteristics1. These methods are based on the sampling of different parts of organisms or DNA fragments, have greatly increased the diversity of a tree of Life2. However the trees are mostly comprised of eukaryotes, and bacterial diversity is not represented in a large way3,4.

By avoiding the need for direct experimentation and observation genetic techniques have enabled us to depict the Tree of Life in a more precise manner. Particularly, molecular methods allow us to build trees using sequenced markers such as the small subunit of ribosomal RNA gene.

The Tree of Life has been greatly expanded thanks to genome sequencing. However there is a lot of diversity to be discovered. This is especially true for microorganisms that are difficult to cultivate and which are usually only found in a single specimen5. A recent analysis of all genomes resulted in a rough draft of a Tree of Life. This includes a wide range of bacteria, archaea and other organisms that haven't yet been isolated or the diversity of which is not fully understood6.

The expanded Tree of Life is particularly useful in assessing the diversity of an area, helping to determine whether specific habitats require protection. This information can be used in many ways, including finding new drugs, fighting diseases and improving crops. The information is also valuable for conservation efforts. It can help biologists identify the areas that are most likely to contain cryptic species with potentially important metabolic functions that may be at risk of anthropogenic changes. While funds to protect biodiversity are essential, the best method to protect the biodiversity of the world is to equip the people of developing nations with the necessary knowledge to take action locally and encourage conservation.

Phylogeny

A phylogeny, also known as an evolutionary tree, shows the connections between different groups of organisms. Scientists can construct a phylogenetic diagram that illustrates the evolutionary relationships between taxonomic groups using molecular data and morphological similarities or differences. Phylogeny plays a crucial role in understanding the relationship between genetics, biodiversity and evolution.

A basic phylogenetic Tree (see Figure PageIndex 10 Identifies the relationships between organisms with similar characteristics and have evolved from an ancestor that shared traits. These shared traits can be either analogous or homologous. Homologous traits are the same in their evolutionary path. Analogous traits could appear like they are however they do not have the same origins. Scientists combine similar traits into a grouping called a Clade. All organisms in a group share a characteristic, for example, amniotic egg production. They all came from an ancestor that had these eggs. A phylogenetic tree can be constructed by connecting clades to identify the species that are most closely related to one another.

For a more precise and accurate phylogenetic tree scientists rely on molecular information from DNA or RNA to determine the relationships between organisms. This information is more precise than morphological information and gives evidence of the evolutionary history of an organism or group. The use of molecular data lets researchers identify the number of organisms that have the same ancestor and estimate their evolutionary age.

The phylogenetic relationship can be affected by a variety of factors such as phenotypicplasticity. This is a type of behavior that alters in response to specific environmental conditions. This can cause a characteristic to appear more similar in one species than another, clouding the phylogenetic signal. However, this issue can be cured by the use of techniques such as cladistics that incorporate a combination of analogous and homologous features into the tree.

Additionally, phylogenetics can help predict the length and speed of speciation. This information can assist conservation biologists in deciding which species to safeguard from disappearance. Ultimately, it is the preservation of phylogenetic diversity that will result in a complete and balanced ecosystem.

Evolutionary Theory

The central theme of evolution is that organisms develop distinct characteristics over time based on their interactions with their environment. Several theories of evolutionary change have been proposed by a variety of scientists such as the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who proposed that a living organism develop gradually according to 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 use or disuse of traits causes changes that could be passed onto offspring.

In the 1930s & 1940s, concepts from various fields, including natural selection, genetics & particulate inheritance, were brought together to create a modern synthesis of evolution theory. This explains how evolution is triggered by the variation in genes within a population and how these variations change with time due to natural selection. This model, called genetic drift or mutation, gene flow and sexual selection, is a cornerstone of current evolutionary biology, and is mathematically described.

Recent developments in the field of evolutionary developmental biology have shown the ways in which variation can be introduced to a species by genetic drift, mutations and reshuffling of genes during sexual reproduction, and even migration between populations. These processes, as well as others such as directional selection or 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 the change in phenotype as time passes (the expression of that genotype in an individual).

Incorporating evolutionary thinking into all aspects of biology education can increase student understanding of the concepts of phylogeny and evolution. A recent study conducted by Grunspan and colleagues, for example demonstrated that teaching about the evidence that supports evolution increased students' acceptance of evolution in a college biology class. For more information on how to teach about evolution, see The Evolutionary Potential of all Areas of Biology and Thinking Evolutionarily: A Framework for Infusing Evolution in Life Sciences Education.

Evolution in Action

Scientists have traditionally studied evolution through looking back in the past--analyzing fossils and 에볼루션 바카라 무료체험 게이밍 (try what she says) comparing species. They also observe living organisms. Evolution isn't a flims event; it is a process that continues today. Bacteria transform and resist antibiotics, viruses re-invent themselves and escape new drugs and animals alter their behavior in response to a changing planet. The results are often apparent.

However, it wasn't until late 1980s that biologists understood that natural selection can be seen in action, as well. The key to this is that different traits can confer the ability to survive at different rates and reproduction, and can be passed on from one generation to the next.

In the past, when one particular allele--the genetic sequence that defines color in a population of interbreeding organisms, it could quickly become more prevalent than all other alleles. As time passes, that could mean that the number of black moths in 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 observe evolution when the species, like bacteria, has a rapid generation turnover. Since 1988, Richard Lenski, 에볼루션게이밍 a biologist, has been tracking twelve populations of E.coli that are descended from a single strain. The samples of each population were taken frequently and more than 500.000 generations of E.coli have been observed to have passed.

Lenski's research has revealed that mutations can alter the rate at which change occurs and the effectiveness of a population's reproduction. It also demonstrates that evolution takes time, something that is difficult for some to accept.

Another example of microevolution is the way mosquito genes that confer resistance to pesticides show up more often in populations in which insecticides are utilized. Pesticides create a selective pressure which favors individuals who have resistant genotypes.

The speed of evolution taking place has led to a growing awareness of its significance in a world that is shaped by human activities, including climate change, pollution and the loss of habitats which prevent many species from adapting. Understanding the evolution process can assist you in making better choices about the future of the planet and its inhabitants.