The Most Significant Issue With Evolution Site, And How You Can Solve It

The Academy’s Evolution Site

The concept of biological evolution is among the most important concepts in biology. The Academies have long been involved in helping those interested in science understand the theory of evolution and how it permeates all areas of scientific research.

This site provides a range of sources for teachers, students and general readers of evolution. It includes the most important video clips from NOVA and WGBH’s science programs on DVD.

Tree of Life

The Tree of Life is an ancient symbol that represents the interconnectedness of all life. It is a symbol of love and unity across many cultures. It also has many practical applications, like providing a framework for understanding the evolution of species and how they react to changes in environmental conditions.

Early approaches to depicting the world of biology focused on separating species into distinct categories that were identified by their physical and metabolic characteristics1. These methods, which rely on the sampling of different parts of living organisms or on sequences of small fragments of their DNA, significantly increased the variety that could be included in a tree of life2. These trees are largely composed by eukaryotes, and the diversity of bacterial species is greatly underrepresented3,4.

By avoiding the need for direct experimentation and observation, genetic techniques have made it possible to depict the Tree of Life in a more precise way. Particularly, molecular techniques allow us to construct trees using sequenced markers such as the small subunit ribosomal gene.

Despite the dramatic expansion of the Tree of Life through genome sequencing, a large amount of biodiversity is waiting to be discovered. This is particularly true for microorganisms, which can be difficult to cultivate and are typically only found in a single specimen5. A recent analysis of all genomes known to date has produced a rough draft version of the Tree of Life, including numerous archaea and bacteria that are not isolated and which are not well understood.

This expanded Tree of Life is particularly useful for assessing the biodiversity of an area, assisting to determine if certain habitats require protection. The information can be used in a variety of ways, from identifying new remedies to fight diseases to improving crops. The information is also useful to conservation efforts. It helps biologists determine the areas that are most likely to contain cryptic species with important metabolic functions that may be vulnerable to anthropogenic change. Although funding to protect biodiversity are crucial, 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 necessary knowledge to take action locally to encourage conservation from within.

Phylogeny

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

A basic phylogenetic Tree (see Figure PageIndex 10 ) determines the relationship between organisms with similar traits that evolved from common ancestral. These shared traits can be either homologous or analogous. Homologous traits are similar in their evolutionary roots and analogous traits appear similar but do not have the same origins. Scientists group similar traits together into a grouping called a the clade. For instance, all the species in a clade have the characteristic of having amniotic eggs. They evolved from a common ancestor which had these eggs. A phylogenetic tree can be constructed by connecting clades to identify the organisms which are the closest to each other.

Scientists utilize molecular DNA or RNA data to create a phylogenetic chart that is more precise and evolutionkr.Kr detailed. This data is more precise than morphological data and provides evidence of the evolution background of an organism or group. Researchers can utilize Molecular Data to calculate the evolutionary age of living organisms and discover how many species share the same ancestor.

The phylogenetic relationships of a species can be affected by a number of factors such as the phenotypic plasticity. This is a type behavior that alters in response to particular environmental conditions. This can cause a characteristic to appear more similar in one species than another, clouding the phylogenetic signal. However, this problem can be solved through the use of techniques such as cladistics which incorporate a combination of analogous and homologous features into the tree.

Additionally, phylogenetics can help determine the duration and rate at which speciation occurs. This information can assist conservation biologists in deciding which species to protect from disappearance. In the end, it is the conservation of phylogenetic variety that will result in an ecosystem that is complete and balanced.

Evolutionary Theory

The fundamental concept in evolution is that organisms alter over time because of their interactions with their environment. Many scientists have come up with 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 needs, the Swedish taxonomist Carolus Linnaeus (1707-1778) who developed the modern hierarchical system of taxonomy as well as 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 and 1940s, theories from a variety of fields — including natural selection, genetics, and particulate inheritance–came together to form the modern synthesis of evolutionary theory which explains how evolution is triggered by the variations of genes within a population and how those variants change over time as a result of natural selection. This model, which encompasses genetic drift, mutations, gene flow and sexual selection can be mathematically described.

Recent discoveries in the field of evolutionary developmental biology have revealed how variation can be introduced to a species via genetic drift, mutations, reshuffling genes during sexual reproduction, and even migration between populations. These processes, along with other ones like directional selection and genetic erosion (changes in the frequency of an individual’s genotype over time), can lead to evolution, which is defined by change in the genome of the species over time and the change in phenotype over time (the expression of that genotype in the individual).

Students can better understand the concept of phylogeny through incorporating evolutionary thinking throughout all areas of biology. A recent study conducted by Grunspan and colleagues, for instance revealed that teaching students about the evidence supporting evolution helped students accept the concept of evolution in a college-level biology course. For more details on how to teach evolution, see The Evolutionary Power of Biology in All Areas of Biology or Thinking Evolutionarily: a Framework for Integrating Evolution into Life Sciences Education.

Evolution in Action

Traditionally scientists have studied evolution through looking back–analyzing fossils, comparing species, and observing living organisms. Evolution is not a past moment; it is an ongoing process. Bacteria mutate and resist antibiotics, viruses reinvent themselves and escape new drugs, and animals adapt their behavior to a changing planet. The changes that result are often easy to see.

But it wasn’t until the late 1980s that biologists understood that natural selection can be observed in action as well. The key is that various traits confer different rates of survival and reproduction (differential fitness), and can be passed from one generation to the next.

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

Monitoring evolutionary changes in action is much easier when a species has a rapid generation turnover like bacteria. Since 1988, Richard Lenski, a biologist, has tracked twelve populations of E.coli that descend from a single strain. Samples of each population have been taken regularly, and more than 50,000 generations of E.coli have passed.

Lenski’s research has shown that mutations can drastically alter the rate at the rate at which a population reproduces, and consequently, the rate at which it alters. It also demonstrates that evolution takes time, something that is hard for some to accept.

Microevolution can be observed in the fact that mosquito genes that confer resistance to pesticides are more prevalent in areas where insecticides are used. This is due to the fact that the use of pesticides creates a selective pressure that favors people who have resistant genotypes.

The rapidity of evolution has led to an increasing appreciation of its importance especially in a planet that is largely shaped by human activity. This includes the effects of climate change, pollution and habitat loss that hinders many species from adapting. Understanding the evolution process will help us make better choices about the future of our planet as well as the life of its inhabitants.