15 Gifts For That Evolution Site Lover In Your Life
The Academy's Evolution Site
The concept of biological evolution is a fundamental concept in biology. The Academies are involved in helping those 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 a wide range of sources for students, teachers and general readers of evolution. It has important video clips from NOVA and the WGBH-produced science programs on DVD.
Tree of Life
The Tree of Life, an ancient symbol, symbolizes the interconnectedness of all life. It is a symbol of love and unity in many cultures. It also has important practical applications, like providing a framework for understanding the history of species and how they react to changes in environmental conditions.
Early attempts to represent the biological world were built on categorizing organisms based on their physical and metabolic characteristics. These methods depend on the collection of various parts of organisms or short fragments of DNA, have greatly increased the diversity of a Tree of Life2. These trees are mostly populated by eukaryotes and bacterial diversity is vastly underrepresented3,4.
Genetic techniques have greatly broadened our ability to represent the Tree of Life by circumventing the need for direct observation and experimentation. Particularly, molecular methods allow us to build trees by using sequenced markers, such as the small subunit ribosomal gene.
The Tree of Life has been significantly expanded by genome sequencing. However there is a lot of biodiversity to be discovered. This is particularly true for microorganisms that are difficult to cultivate and are typically present in a single sample5. Recent analysis of all genomes resulted in an initial draft of a Tree of Life. This includes a variety of archaea, bacteria and other organisms that have not yet been identified or their diversity is not thoroughly understood6.
This expanded Tree of Life can be used to evaluate the biodiversity of a specific area and determine if particular habitats require special protection. This information can be used in many ways, including finding new drugs, battling diseases and improving the quality of crops. The information is also incredibly valuable for conservation efforts. It can aid biologists in identifying the areas that are most likely to contain cryptic species that could have significant metabolic functions that could be vulnerable to anthropogenic change. While funding to protect biodiversity are essential, the best way to conserve the world's biodiversity is to empower the people of developing nations with the knowledge they need to act locally and promote conservation.
Phylogeny
A phylogeny (also known as an evolutionary tree) shows the relationships between species. Scientists can create a phylogenetic chart that shows the evolutionary relationship of taxonomic categories using molecular information and morphological similarities or differences. The role of phylogeny is crucial in understanding the relationship between genetics, biodiversity and evolution.
A basic phylogenetic tree (see Figure PageIndex 10 Determines the relationship between organisms that have similar characteristics and have evolved from an ancestor that shared traits. These shared traits could be analogous or homologous. Homologous traits are the same in their evolutionary path. Analogous traits may look like they are but they don't have the same ancestry. Scientists combine similar traits into a grouping known as a clade. Every organism in a group have a common characteristic, like amniotic egg production. They all evolved from an ancestor that had these eggs. The clades are then connected to create a phylogenetic tree to identify organisms that have the closest connection to each other.
Scientists utilize DNA or RNA molecular data to create a phylogenetic chart which is more precise and precise. This information is more precise than the morphological data and provides evidence of the evolution background of an organism or group. Molecular data allows researchers to identify the number of organisms that share an ancestor common to them and estimate their evolutionary age.
The phylogenetic relationships between organisms can be influenced by several factors including phenotypic plasticity, a kind of behavior that alters 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 mitigated by using cladistics, which is a an amalgamation of homologous and analogous features in the tree.
Additionally, phylogenetics can help predict the duration and rate at which speciation takes place. This information can assist conservation biologists in making decisions about which species to save from disappearance. In the end, it's the preservation of phylogenetic diversity that will result in an ecosystem that is complete and balanced.
Evolutionary Theory
The central theme of evolution is that organisms develop distinct characteristics over time due to their interactions with their environments. Many theories of evolution have been developed by a wide range of scientists including the Islamic naturalist Nasir al-Din al-Tusi (1201-1274) who proposed that a living organism develop slowly according to its needs as well as the Swedish botanist Carolus Linnaeus (1707-1778) who conceived the modern hierarchical taxonomy, as well as Jean-Baptiste Lamarck (1744-1829) who suggested that the use or non-use of traits can cause changes that can be passed on to offspring.
In the 1930s & 1940s, concepts from various areas, including natural selection, genetics & particulate inheritance, merged to create a modern theorizing of evolution. This describes how evolution is triggered by the variations in genes within the population, and how these variations change with time due to natural selection. This model, known as genetic drift, mutation, gene flow and sexual selection, is a cornerstone of modern evolutionary biology and is mathematically described.
Recent developments in the field of evolutionary developmental biology have shown that genetic variation can be introduced into a species by mutation, genetic drift, and reshuffling genes during sexual reproduction, and also through migration between populations. These processes, along with other ones 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 by changes in phenotype over time (the expression of the genotype in an individual).
Students can gain a better understanding of phylogeny by incorporating evolutionary thinking in all aspects of biology. A recent study by Grunspan and colleagues, for example, showed that teaching about the evidence supporting evolution increased students' understanding of evolution in a college-level biology course. For more information about how to teach evolution read The Evolutionary Power of Biology in All Areas of Biology or Thinking Evolutionarily as a Framework for Integrating Evolution into Life Sciences Education.
Evolution in Action
Traditionally scientists have studied evolution by looking back, studying fossils, comparing species and observing living organisms. But evolution isn't a thing that occurred in the past, it's an ongoing process that is that is taking place today. Bacteria mutate and resist antibiotics, viruses reinvent themselves and are able to evade new medications and animals change their behavior to the changing environment. The results are often evident.
It wasn't until the 1980s when biologists began to realize that natural selection was also at work. Discover More Here is the fact that different traits result in a different rate of survival and reproduction, and can be passed on from generation to generation.
In the past, if one allele - the genetic sequence that determines color - was found in a group of organisms that interbred, it could become more common than other allele. Over time, this would mean that the number of moths sporting 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 high 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 on a regular basis, and over fifty thousand generations have passed.
Lenski's research has revealed that a mutation can dramatically alter the efficiency with which a population reproduces--and so the rate at which it alters. It also proves that evolution takes time--a fact that some find difficult to accept.
Microevolution is also evident in the fact that mosquito genes for pesticide resistance are more prevalent in populations where insecticides have been used. This is because pesticides cause a selective pressure which favors those 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 activity, including climate changes, pollution and the loss of habitats that prevent the species from adapting. Understanding the evolution process will assist you in making better choices regarding the future of the planet and its inhabitants.