The Academy's Evolution Site

The concept of biological evolution is among the most central concepts in biology. The Academies have been active for a long time in helping those interested in science comprehend the concept of evolution and how it permeates every area of scientific inquiry.

This site provides a wide range of resources for teachers, students and general readers of evolution. It contains the most important video clips 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 an emblem of love and unity across many cultures. It also has practical applications, such as providing a framework for understanding the evolution of species and how they react to changing environmental conditions.

Early approaches to depicting the biological world focused on the classification of organisms into distinct categories which had been identified by their physical and metabolic characteristics1. These methods depend on the sampling of different parts of organisms, or DNA fragments have greatly increased the diversity of a Tree of Life2. However these trees are mainly composed of eukaryotes; bacterial diversity is not represented in a large way3,4.

Genetic techniques have greatly broadened our ability to depict the Tree of Life by circumventing the requirement for direct observation and experimentation. Particularly, molecular methods allow us to construct trees by using sequenced markers like 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 particularly true for microorganisms that are difficult to cultivate, and are typically found in one sample5. A recent analysis of all known genomes has created a rough draft of the Tree of Life, including many archaea and bacteria that have not been isolated and their diversity is not fully understood6.

The expanded Tree of Life is particularly useful for assessing the biodiversity of an area, helping to determine if certain habitats require protection. The information can be used in a range of ways, from identifying the most effective remedies to fight diseases to enhancing the quality of crops. This information is also extremely valuable in conservation efforts. It can help biologists identify areas most likely to have species that are cryptic, which could have vital metabolic functions and be vulnerable to human-induced change. Although funding to safeguard biodiversity are vital, ultimately the best way to preserve the world's biodiversity is for more people in developing countries to be empowered with the necessary knowledge to act locally to promote conservation from within.

Phylogeny

A phylogeny, also known as an evolutionary tree, shows the relationships between various groups of organisms. Utilizing molecular data, morphological similarities and differences or ontogeny (the process of the development of an organism) scientists can create a phylogenetic tree which illustrates the evolutionary relationship between taxonomic groups. Phylogeny plays a crucial 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 with similar traits that evolved from common ancestors. These shared traits are either homologous or analogous. Homologous traits share their evolutionary roots while analogous traits appear similar but do not have the identical origins. Scientists put 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 who had these eggs. The clades are then linked to form a phylogenetic branch that can identify organisms that have the closest connection to each other.

For a more detailed and accurate phylogenetic tree scientists make use of molecular data from DNA or RNA to establish the relationships among organisms. This information is more precise and gives evidence of the evolution of an organism. Researchers can use Molecular Data to determine the evolutionary age of organisms and determine how many organisms share the same ancestor.

The phylogenetic relationship can be affected by a number of factors, including the phenotypic plasticity. This is a type of behavior that changes due to specific environmental conditions. This can cause a trait to appear more similar to one species than other species, which can obscure the phylogenetic signal. However, this issue can be solved through the use of techniques like cladistics, which combine similar and homologous traits into the tree.

Additionally, phylogenetics can help predict the duration and rate of speciation. This information can assist conservation biologists in making choices about which species to protect from disappearance. In the end, it's the conservation of phylogenetic diversity that will lead to an ecosystem that is balanced and complete.

Evolutionary Theory

The fundamental concept of evolution is that organisms develop different features over time based on their interactions with their surroundings. Many scientists have come up with theories of evolution, including the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that an organism would develop according to its own requirements as well as the Swedish taxonomist Carolus Linnaeus (1707-1778), who created the modern hierarchical taxonomy as well as Jean-Baptiste Lamarck (1844-1829), who believed that the use or absence of traits can cause changes that are passed on to the next generation.

In the 1930s & 1940s, 에볼루션 카지노 concepts from various fields, including genetics, natural selection, and particulate inheritance, merged to form a modern theorizing of evolution. This explains how evolution is triggered by the variations in genes within a population and how these variations change with time due to natural selection. This model, which is known as genetic drift, mutation, gene flow and sexual selection, is a key element of current evolutionary biology, and can be mathematically explained.

Recent developments in the field of evolutionary developmental biology have demonstrated how variation can be introduced to a species by genetic drift, 에볼루션 룰렛카지노사이트 (Articlescad.Com) mutations, reshuffling genes during sexual reproduction and the movement between populations. These processes, along with others such as directional selection and gene erosion (changes to the frequency of genotypes over time) can lead to evolution. Evolution is defined as changes in the genome over time as well as changes in the phenotype (the expression of genotypes within individuals).

Students can gain a better understanding of phylogeny by incorporating evolutionary thinking in all aspects of biology. In a study by Grunspan and co., it was shown that teaching students about the evidence for evolution boosted their understanding of evolution during an undergraduate biology course. To learn more about how to teach about evolution, please see The Evolutionary Potential in 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 by studying fossils, comparing species and studying living organisms. But evolution isn't just something that happened in the past, it's an ongoing process, that is taking place in the present. Bacteria mutate and resist antibiotics, viruses re-invent themselves and are able to evade new medications and animals alter their behavior in response to a changing planet. The results are usually easy to see.

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

In the past, if one allele - the genetic sequence that determines colour was present in a population of organisms that interbred, it might become more prevalent than any other allele. Over time, this would mean that the number of moths that have black pigmentation in a population could 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 rapid generation turnover. Since 1988 biologist Richard Lenski has been tracking twelve populations of E. Coli that descended from a single strain. samples of each are taken every day, and over 500.000 generations have been observed.

Lenski's work has demonstrated that a mutation can profoundly alter the speed at the rate at which a population reproduces, and consequently the rate at which it changes. It also shows that evolution takes time, which is difficult for some to accept.

Microevolution can also be seen in the fact that mosquito genes that confer resistance to pesticides are more common in populations where insecticides are used. This is because pesticides cause an exclusive pressure that favors those who have resistant genotypes.

The rapid pace at which evolution can take place has led to a growing appreciation of its importance in a world that is shaped by human activity--including climate change, pollution, and the loss of habitats which prevent many species from adjusting. Understanding evolution can help you make better decisions about the future of the planet and its inhabitants.