11 Creative Ways To Write About Evolution Site

The Academy's Evolution Site

Biology is one of the most important concepts in biology. The Academies are committed to helping those who are interested in science to learn about the theory of evolution and how it can be applied across all areas of scientific research.

This site provides students, teachers and general readers with a wide range of learning resources about evolution. It contains important video clips from NOVA and the WGBH-produced science programs on DVD.

Tree of Life

The Tree of Life is an ancient symbol that represents the interconnectedness of life. It appears in many spiritual traditions and cultures as a symbol of unity and love. It can be used in many practical ways as well, such as providing a framework to understand the history of species and how they react to changing environmental conditions.

The earliest attempts to depict the world of biology focused on the classification of organisms into distinct categories that had been distinguished by their physical and metabolic characteristics1. These methods, which rely on sampling of different parts of living organisms or short fragments of their DNA, significantly expanded the diversity that could be included in the tree of life2. However the trees are mostly composed of eukaryotes; bacterial diversity remains vastly underrepresented3,4.

By avoiding  Full Piece of writing  for direct experimentation and observation, genetic techniques have allowed us to represent the Tree of Life in a more precise way. In particular, 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 dramatically expanded through genome sequencing. However, there is still much diversity to be discovered. This is especially true of microorganisms, which are difficult to cultivate and are usually only found in a single sample5. A recent study of all genomes that are known has produced 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 in assessing the diversity of an area, which can help to determine if certain habitats require special protection. This information can be used in a range of ways, from identifying the most effective medicines to combating disease to improving the quality of crops. The information is also valuable to conservation efforts. It can aid biologists in identifying those areas that are most likely contain cryptic species with potentially important metabolic functions that may be vulnerable to anthropogenic change. While funding to protect biodiversity are important, the best method to protect the world's biodiversity is to equip more people in developing nations with the knowledge they need to act locally and promote conservation.

Phylogeny

A phylogeny, also called an evolutionary tree, illustrates the relationships between various groups of organisms. Using molecular data, morphological similarities and differences or ontogeny (the course of development of an organism) scientists can construct a phylogenetic tree which illustrates the evolutionary relationship between taxonomic groups. The phylogeny of a tree plays an important role in understanding genetics, biodiversity and evolution.

A basic phylogenetic Tree (see Figure PageIndex 10 Finds the connections between organisms with similar traits and have evolved from an ancestor with common traits. These shared traits could be either analogous or homologous. Homologous traits are identical in their underlying evolutionary path and analogous traits appear similar, but do not share the identical origins. Scientists combine similar traits into a grouping called a clade. For instance, all the species in a clade share the characteristic of having amniotic eggs. They evolved from a common ancestor which had these eggs. The clades then join to create a phylogenetic tree to determine which organisms have the closest connection to each other.

Scientists make use of molecular DNA or RNA data to construct a phylogenetic graph which is more precise and precise. This data is more precise than morphological information and gives evidence of the evolutionary history of an organism or group. Researchers can use Molecular Data to calculate the age of evolution of living organisms and discover how many species have an ancestor common to all.

The phylogenetic relationships of organisms can be influenced by several factors including phenotypic plasticity, a type of behavior that alters in response to specific environmental conditions. This can make a trait appear more similar to one species than another and obscure the phylogenetic signals. However, this issue can be reduced by the use of techniques such as cladistics that combine analogous and homologous features into the tree.

In addition, phylogenetics helps determine the duration and speed at which speciation occurs. This information can assist conservation biologists make decisions about the species they should safeguard from the threat of extinction. In the end, it is the conservation of phylogenetic variety that will lead to an ecosystem that is balanced and complete.

Evolutionary Theory

The fundamental concept in evolution is that organisms change over time as a result of their interactions with their environment. Many scientists have developed theories of evolution, such as the Islamic naturalist Nasir al-Din al-Tusi (1201-274), who believed that a living thing would evolve according to its own requirements as well as the Swedish taxonomist Carolus Linnaeus (1707-1778) who conceived the modern hierarchical taxonomy and Jean-Baptiste Lamarck (1844-1829), who suggested that the use or non-use of traits can cause changes that are passed on to the

In the 1930s & 1940s, concepts from various fields, such as natural selection, genetics & particulate inheritance, came together to form a modern evolutionary theory. This explains how evolution is triggered by the variation of genes in the population, and how these variations change over time as a result of natural selection. This model, which is known as genetic drift mutation, gene flow, and sexual selection, is a key element of the current evolutionary biology and can be mathematically explained.

Recent discoveries in the field of evolutionary developmental biology have revealed that genetic variation can be introduced into a species through mutation, genetic drift, and reshuffling of genes in sexual reproduction, as well as through migration between populations. These processes, as well as other ones like directional selection and genetic erosion (changes in the frequency of an individual's genotype over time) can lead to evolution that is defined as changes in the genome of the species over time and the change in phenotype as time passes (the expression of the genotype in the individual).

Incorporating evolutionary thinking into all aspects of biology education can improve student understanding of the concepts of phylogeny as well as evolution. A recent study by Grunspan and colleagues, for example, showed that teaching about the evidence supporting evolution helped students accept the concept of evolution in a college biology course. For more information on 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. However, evolution isn't something that occurred in the past. It's an ongoing process taking place in the present. Bacteria evolve and resist antibiotics, viruses evolve and are able to evade new medications and animals alter their behavior in response to the changing environment. The changes that occur are often evident.

It wasn't until late 1980s when biologists began to realize that natural selection was also at work. The main reason is that different traits confer an individual rate of survival and reproduction, and can be passed on from one generation to another.

In the past, when one particular allele - the genetic sequence that controls coloration - was present in a group of interbreeding organisms, it could quickly become more prevalent than the other alleles. Over time, that would mean that 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.

Observing evolutionary change in action is easier when a particular species has a fast generation turnover like bacteria. Since 1988 the biologist Richard Lenski has been tracking twelve populations of E. bacteria that descend from a single strain; samples of each population are taken on a regular basis, and over fifty thousand generations have passed.

Lenski's work has shown that mutations can alter the rate of change and the rate at which a population reproduces. It also shows that evolution takes time, a fact that is hard for some to accept.

Microevolution can be observed in the fact that mosquito genes for pesticide resistance are more prevalent in areas that have used insecticides. This is due to pesticides causing a selective pressure which favors those who have resistant genotypes.

The rapidity of evolution has led to a growing awareness of its significance especially in a planet which is largely shaped by human activities. This includes the effects of climate change, pollution and habitat loss, which prevents many species from adapting. Understanding evolution can help us make better decisions regarding the future of our planet and the life of its inhabitants.