7 Things About Evolution Site You'll Kick Yourself For Not Knowing

The Academy's Evolution Site

Biological evolution is one of the most fundamental concepts in biology. The Academies are committed to helping those interested in science to understand evolution theory and how it can be applied across all areas of scientific research.

This site provides a wide range of sources for teachers, students, and general readers on evolution. It has 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 seen in a variety of spiritual traditions and cultures as symbolizing unity and love. It has many practical applications as well, including providing a framework for understanding 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, which rely on the sampling of various parts of living organisms, or small fragments of their DNA significantly expanded the diversity that could be included in the tree of life2. However, these trees are largely composed of eukaryotes; bacterial diversity is still largely unrepresented3,4.

Genetic techniques have greatly expanded our ability to depict the Tree of Life by circumventing the need for direct observation and experimentation. Particularly,  에볼루션 게이밍  allow us to construct trees using sequenced markers like the small subunit ribosomal gene.

The Tree of Life has been significantly expanded by genome sequencing. However there is a lot of diversity to be discovered. This is especially the case for microorganisms which are difficult to cultivate and are usually found in one sample5. A recent analysis of all known genomes has produced a rough draft version of the Tree of Life, including a large number of archaea and bacteria that have not been isolated and their diversity is not fully 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 used in a variety of ways, from identifying the most effective remedies to fight diseases to enhancing crop yields. The information is also valuable for conservation efforts. It can aid biologists in identifying areas that are likely to have cryptic species, which may have vital metabolic functions and are susceptible to the effects of human activity. Although funding to protect biodiversity are essential, ultimately the best way to ensure the preservation of biodiversity around the world is for more people living in developing countries to be empowered with the knowledge to act locally to promote conservation from within.

Phylogeny

A phylogeny is also known as an evolutionary tree, illustrates the relationships between various groups of organisms. Using molecular data as well as morphological similarities and distinctions, or ontogeny (the process of the development of an organism), scientists can build a phylogenetic tree that illustrates the evolution of taxonomic groups. The phylogeny of a tree plays an important role in understanding the relationship between genetics, biodiversity and evolution.

A basic phylogenetic Tree (see Figure PageIndex 10 ) identifies the relationships between organisms with similar traits that evolved from common ancestral. These shared traits can be analogous, or homologous. Homologous traits are identical in their evolutionary roots, while analogous traits look similar, but do not share the identical origins. Scientists combine similar traits into a grouping known as a the clade. For instance, all the organisms in a clade share the characteristic of having amniotic eggs and evolved from a common ancestor who had eggs. A phylogenetic tree is then built by connecting the clades to identify the species who are the closest to one another.

To create a more thorough and precise phylogenetic tree scientists rely on molecular information from DNA or RNA to identify the relationships among organisms. This information is more precise and gives evidence of the evolution of an organism. Researchers can utilize Molecular Data to calculate the evolutionary age of organisms and determine how many species share the same ancestor.

The phylogenetic relationships between species can be affected by a variety of factors, including phenotypic plasticity a type of behavior that alters in response to specific environmental conditions. This can cause a characteristic to appear more resembling to one species than to another which can obscure the phylogenetic signal. However, this issue can be cured by the use of methods such as cladistics that include a mix of homologous and analogous features into the tree.

Additionally, phylogenetics can help determine the duration and speed at which speciation takes place. This information can help conservation biologists decide which species to protect from the threat of extinction. In the end, it is the preservation of phylogenetic diversity that will result in an ecosystem that is complete and balanced.

Evolutionary Theory

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

In the 1930s & 1940s, ideas from different fields, including genetics, natural selection and particulate inheritance, came together to form a contemporary evolutionary theory. This explains how evolution occurs by the variation of genes in a population and how these variants change with time due to natural selection. This model, which encompasses mutations, genetic drift, gene flow and sexual selection can be mathematically described mathematically.

Recent discoveries in the field of evolutionary developmental biology have shown that variation can be introduced into a species via mutation, genetic drift and reshuffling of genes during sexual reproduction, as well as through the movement of populations. These processes, as well as other ones like directionally-selected selection and erosion of genes (changes in frequency of genotypes over time) can lead to evolution. Evolution is defined by changes in the genome over time, as well as changes in the phenotype (the expression of genotypes in an individual).

Incorporating evolutionary thinking into all areas of biology education can improve students' understanding of phylogeny and evolution. A recent study conducted by Grunspan and colleagues, for instance revealed that teaching students about the evidence that supports evolution increased students' acceptance of evolution in a college-level biology course. For more information about how to teach evolution look up 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 through studying fossils, comparing species, and studying living organisms. But evolution isn't a thing that happened in the past, it's an ongoing process that is taking place right now. Bacteria evolve and resist antibiotics, viruses re-invent themselves and elude new medications, and animals adapt their behavior to a changing planet. The changes that occur are often apparent.

However, it wasn't until late-1980s that biologists realized that natural selection could be observed in action as well. The reason is that different traits confer different rates of survival and reproduction (differential fitness) and are 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 could be more common than other allele. In time, this could mean the number of black moths within 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 fast 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 profoundly alter the rate at the rate at which a population reproduces, and consequently the rate at which it changes. It also demonstrates that evolution takes time, which is hard for some to accept.

Another example of microevolution is the way mosquito genes for resistance to pesticides appear more frequently in populations in which insecticides are utilized. That's because the use of pesticides creates a selective pressure that favors individuals with resistant genotypes.

The rapidity of evolution has led to a greater appreciation of its importance, especially in a world that is largely shaped by human activity. This includes climate change, pollution, and habitat loss that prevents many species from adapting. Understanding the evolution process will help you make better decisions about the future of the planet and its inhabitants.