Is Technology Making Evolution Site Better Or Worse?

The Academy's Evolution Site

Biology is one of the most central concepts in biology.  에볼루션 바카라  have been for a long time involved in helping those interested in science comprehend the theory of evolution and how it influences all areas of scientific research.

This site provides teachers, students and general readers with a variety of learning resources about 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 that represents the interconnectedness of life. It appears in many spiritual traditions and cultures as an emblem of unity and love. It can be used in many practical ways as well, including providing a framework to understand the history of species, and how they respond to changes in environmental conditions.

The first attempts to depict the biological world were based on categorizing organisms based on their physical and metabolic characteristics. These methods are based on the sampling of different parts of organisms, or fragments of DNA have greatly increased the diversity of a Tree of Life2. These trees are mostly populated by eukaryotes, and the diversity of bacterial species is greatly underrepresented3,4.

Genetic techniques have greatly expanded our ability to visualize the Tree of Life by circumventing the requirement for direct observation and experimentation. Particularly, molecular techniques allow us to build trees by using sequenced markers such as the small subunit ribosomal gene.

Despite the dramatic expansion of the Tree of Life through genome sequencing, a lot of biodiversity is waiting to be discovered. This is especially the case for microorganisms which are difficult to cultivate, and are usually found in a single specimen5. A recent study of all genomes that are known has produced a rough draft of the Tree of Life, including a large number of bacteria and archaea that have not been isolated, and their diversity is not fully understood6.

This expanded Tree of Life can be used to determine the diversity of a particular area and determine if specific habitats require special protection. This information can be used in a variety of ways, from identifying new remedies to fight diseases to improving crops. The information is also incredibly valuable in conservation efforts. It can aid biologists in identifying areas that are likely to have cryptic species, which may have vital metabolic functions, and could be susceptible to human-induced change. While conservation funds are important, the most effective method to protect the world's biodiversity is to equip the people of developing nations with the necessary knowledge to take action locally and encourage conservation.

Phylogeny

A phylogeny (also called an evolutionary tree) shows the relationships between different organisms. Scientists can construct an phylogenetic chart which shows the evolutionary relationship of taxonomic categories using molecular information and morphological similarities or differences. Phylogeny plays a crucial role in understanding genetics, biodiversity and evolution.

A basic phylogenetic tree (see Figure PageIndex 10 ) is a method of identifying the relationships between organisms that share similar traits that have evolved from common ancestors. These shared traits can be either homologous or analogous. Homologous traits are the same in terms of their evolutionary path. Analogous traits might appear like they are, but they do not share the same origins. Scientists arrange similar traits into a grouping called a the clade. All organisms in a group have a common trait, such as amniotic egg production. They all evolved from an ancestor who had these eggs. The clades are then connected to form a phylogenetic branch that can determine which organisms have the closest relationship to.

Scientists utilize DNA or RNA molecular data to build a phylogenetic chart which is more precise and detailed. This information is more precise and provides evidence of the evolutionary history of an organism. Researchers can use Molecular Data to estimate the evolutionary age of organisms and determine how many organisms have a common ancestor.

The phylogenetic relationships between organisms can be affected by a variety of factors, including phenotypic flexibility, a type of behavior that changes in response to specific environmental conditions. This can cause a trait to appear more resembling to one species than to another, obscuring the phylogenetic signals. This problem can be addressed by using cladistics, which incorporates the combination of homologous and analogous features in the tree.

In addition, phylogenetics helps predict the duration and rate at which speciation takes place. This information can assist conservation biologists make decisions about which species they should protect from extinction. It is ultimately the preservation of phylogenetic diversity which will lead to an ecologically balanced and complete ecosystem.

Evolutionary Theory

The central theme of evolution is that organisms acquire distinct characteristics over time based on their interactions with their environments. Several theories of evolutionary change have been proposed by a wide range of scientists including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who envisioned an organism developing slowly according to its requirements and needs, the Swedish botanist Carolus Linnaeus (1707-1778) who designed the modern hierarchical taxonomy Jean-Baptiste Lamarck (1744-1829) who suggested that the use or non-use of traits causes changes that could be passed on to the offspring.

In the 1930s & 1940s, concepts from various fields, such as genetics, natural selection, and particulate inheritance, came together to form a modern evolutionary theory. This defines how evolution occurs by the variation of genes in the population, and how these variants alter over time due to natural selection. This model, called genetic drift mutation, gene flow, and sexual selection, is the foundation of modern evolutionary biology and can be mathematically explained.

Recent developments in the field of evolutionary developmental biology have shown that variation can be introduced into a species via genetic drift, mutation, and reshuffling of genes during sexual reproduction, and also through the movement of populations. These processes, along with others like directional selection and genetic erosion (changes in the frequency of the genotype over time), can lead to evolution that is defined as change in the genome of the species over time, and also the change in phenotype over time (the expression of that genotype within the individual).

Incorporating evolutionary thinking into all aspects of biology education can improve student understanding of the concepts of phylogeny and evolution. A recent study conducted by Grunspan and colleagues, for instance demonstrated that teaching about the evidence for evolution helped students accept the concept of evolution in a college biology class. For more information on how to teach about evolution, please look up 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 comparing species. They also observe living organisms. Evolution is not a past moment; it is an ongoing process. Viruses reinvent themselves to avoid new antibiotics and bacteria transform to resist antibiotics. Animals alter their behavior because of the changing environment. The changes that occur are often visible.

It wasn't until late 1980s that biologists began to realize that natural selection was also in play. The main reason is that different traits result in the ability to survive at different rates and reproduction, and can be passed on from generation to generation.

In the past when one particular allele, the genetic sequence that defines color in a population of interbreeding species, it could quickly become more prevalent than all other alleles. In time, this could mean the number of black moths in a population could increase. The same is true for many other characteristics--including morphology and behavior--that vary among populations of organisms.

Observing evolutionary change in action is much easier when a species has a rapid turnover of its generation, as with bacteria. Since 1988, Richard Lenski, a biologist, has been tracking twelve populations of E.coli that descend from one strain. The samples of each population have been collected frequently and more than 500.000 generations of E.coli have passed.

Lenski's research has demonstrated that mutations can alter the rate of change and the efficiency at which a population reproduces. It also shows that evolution takes time, a fact that some people find hard to accept.

Microevolution is also evident in the fact that mosquito genes for resistance to pesticides are more prevalent in areas that have used insecticides. That's because the use of pesticides causes a selective pressure that favors those with resistant genotypes.

The rapidity of evolution has led to a growing awareness of its significance, especially in a world that is largely shaped by human activity. This includes pollution, climate change, and habitat loss that prevents many species from adapting. Understanding evolution can aid you in making better decisions about the future of the planet and its inhabitants.