Notes

Why We Do We Love Evolution Site (And You Should Too!)
The Academy's Evolution Site

Biology is a key concept in biology. The Academies have been active for a long time in helping those interested in science understand the theory of evolution and how it permeates all areas of scientific exploration.

This site provides a wide range of resources for students, teachers, and general readers on evolution. It contains key video clips from NOVA and WGBH produced science programs on DVD.

Tree of Life

The Tree of Life, an ancient symbol, represents the interconnectedness of all life. It is used in many religions and cultures as symbolizing unity and love. It also has practical applications, like providing a framework for understanding the history of species and how they react to changing environmental conditions.

Early attempts to represent the world of biology were founded on categorizing organisms on their metabolic and physical characteristics. These methods, which relied on the sampling of various parts of living organisms or on small fragments of their DNA significantly expanded the diversity that could be included in the tree of life2. However, these trees are largely comprised of eukaryotes, and bacterial diversity is still largely unrepresented3,4.

In avoiding the necessity of direct experimentation and observation, genetic techniques have allowed us to depict the Tree of Life in a more precise manner. We can create trees using molecular techniques, such as the small-subunit ribosomal gene.

The Tree of Life has been greatly expanded thanks to genome sequencing. However there is a lot of biodiversity to be discovered. This is particularly true of microorganisms that are difficult to cultivate and are often only represented in a single sample5. Recent analysis of all genomes has produced an initial 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 well understood6.


This expanded Tree of Life is particularly useful in assessing the diversity of an area, which can help to determine whether specific habitats require protection. This information can be utilized in a variety of ways, such as finding new drugs, fighting diseases and improving crops. The information is also useful to conservation efforts. It can aid biologists in identifying the areas most likely to contain cryptic species with important metabolic functions that may be vulnerable to anthropogenic change. While weblink to protect biodiversity are essential but the most effective way to preserve the world's biodiversity is for more people in developing countries to be equipped with the knowledge to take action locally to encourage conservation from within.

Phylogeny

A phylogeny (also called an evolutionary tree) depicts the relationships between species. Scientists can construct a phylogenetic chart that shows the evolution of taxonomic categories using molecular information and morphological differences or similarities. The concept of phylogeny is fundamental to understanding biodiversity, evolution and genetics.

A basic phylogenetic Tree (see Figure PageIndex 10 ) identifies the relationships between organisms that share similar traits that evolved from common ancestors. These shared traits can be analogous, or homologous. Homologous traits share their underlying evolutionary path while analogous traits appear similar, but do not share the same ancestors. Scientists organize similar traits into a grouping called a clade. All members of a clade share a characteristic, for example, amniotic egg production. They all evolved from an ancestor with these eggs. The clades then join to form a phylogenetic branch to determine which organisms have the closest relationship to.

For a more detailed and accurate phylogenetic tree scientists use molecular data from DNA or RNA to identify the relationships among organisms. This data is more precise than morphological information and provides evidence of the evolutionary background of an organism or group. The use of molecular data lets researchers determine the number of species who share the same ancestor and estimate their evolutionary age.

The phylogenetic relationship can be affected by a number of factors, including the phenomenon of phenotypicplasticity. This is a type behavior that changes due to particular environmental conditions. This can cause a trait to appear more similar to a species than to another and obscure the phylogenetic signals. However, this problem can be solved through the use of techniques like cladistics, which incorporate a combination of similar and homologous traits into the tree.

In addition, phylogenetics can aid in predicting the time and pace of speciation. This information can aid conservation biologists in making choices about which species to save from disappearance. In the end, it's the preservation of phylogenetic diversity that will result in an ecologically balanced and complete ecosystem.

Evolutionary Theory

The central theme in evolution is that organisms change over time due to their interactions with their environment. Several theories of evolutionary change have been developed by a wide variety of scientists, including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who believed that an organism would evolve slowly according to its needs, the Swedish botanist Carolus Linnaeus (1707-1778) who designed modern hierarchical taxonomy, and Jean-Baptiste Lamarck (1744-1829) who suggested that the use or non-use of traits causes changes that can be passed onto offspring.

In the 1930s and 1940s, theories from various fields, such as genetics, natural selection and particulate inheritance, merged to create a modern evolutionary theory. This describes how evolution is triggered by the variation in genes within the population and how these variations change with time due to natural selection. This model, which incorporates mutations, genetic drift in gene flow, and sexual selection, can be mathematically described.

Recent advances in the field of evolutionary developmental biology have revealed how variation can be introduced to a species via genetic drift, mutations or reshuffling of genes in sexual reproduction and the movement between populations. These processes, as well as others like directional selection and genetic erosion (changes in the frequency of a 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 an individual).

Students can gain a better understanding of phylogeny by incorporating evolutionary thinking throughout all areas of biology. In a recent study by Grunspan et al., it was shown that teaching students about the evidence for evolution boosted their acceptance of evolution during an undergraduate biology course. For more information on how to teach about evolution, see The Evolutionary Power of Biology 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 by studying fossils, comparing species and observing living organisms. Evolution isn't a flims event, but an ongoing process that continues to be observed today. The virus reinvents itself to avoid new antibiotics and bacteria transform to resist antibiotics. Animals adapt their behavior because of a changing world. The changes that occur are often visible.

However, it wasn't until late 1980s that biologists realized that natural selection could be observed in action as well. The key is that different traits have different rates of survival and reproduction (differential fitness) and are passed from one generation to the next.

In the past, if one allele - the genetic sequence that determines colour - appeared in a population of organisms that interbred, it might become more prevalent than any other allele. As time passes, this could mean that the number of moths with black pigmentation in a group may 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 species has a rapid generation turnover, as with bacteria. Since 1988, biologist Richard Lenski has been tracking twelve populations of E. coli that descended from a single strain. samples of each population are taken regularly, and over 500.000 generations have passed.

Lenski's research has shown that a mutation can dramatically alter the rate at which a population reproduces and, consequently, the rate at which it changes. It also demonstrates that evolution takes time, something that is difficult for some to accept.

Microevolution can be observed in the fact that mosquito genes for pesticide resistance are more common in populations where insecticides have been used. This is because the use of pesticides creates a selective pressure that favors people with resistant genotypes.

The rapidity of evolution has led to a growing recognition of its importance particularly in a world that is largely shaped by human activity. This includes pollution, climate change, and habitat loss, which prevents many species from adapting. Understanding the evolution process will assist you in making better choices about the future of our planet and its inhabitants.

Website: https://hatfield-sharma.hubstack.net/this-weeks-most-popular-stories-about-free-evolution-free-evolution