Hydrothermal ventA hydrothermal vent is a fissure on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hotspots. Hydrothermal deposits are rocks and mineral ore deposits formed by the action of hydrothermal vents. Hydrothermal vents exist because the earth is both geologically active and has large amounts of water on its surface and within its crust.
Population geneticsPopulation genetics is a subfield of genetics that deals with genetic differences within and among populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as adaptation, speciation, and population structure. Population genetics was a vital ingredient in the emergence of the modern evolutionary synthesis. Its primary founders were Sewall Wright, J. B. S. Haldane and Ronald Fisher, who also laid the foundations for the related discipline of quantitative genetics.
Disturbance (ecology)In ecology, a disturbance is a temporary change in environmental conditions that causes a pronounced change in an ecosystem. Disturbances often act quickly and with great effect, to alter the physical structure or arrangement of biotic and abiotic elements. A disturbance can also occur over a long period of time and can impact the biodiversity within an ecosystem. Major ecological disturbances may include fires, flooding, storms, insect outbreaks and trampling.
Deep sea miningDeep sea mining is a growing subfield of experimental seabed mining that involves the retrieval of minerals and deposits from the ocean floor found at depths of , up to . As of 2021, the majority of marine mining efforts are limited to shallow coastal waters only, where sand, tin and diamonds are more readily accessible. There are three types of deep sea mining that have generated great interest: polymetallic nodule mining, polymetallic sulphide mining, and the mining of cobalt-rich ferromanganese crusts.
Population structure (genetics)Population structure (also called genetic structure and population stratification) is the presence of a systematic difference in allele frequencies between subpopulations. In a randomly mating (or panmictic) population, allele frequencies are expected to be roughly similar between groups. However, mating tends to be non-random to some degree, causing structure to arise. For example, a barrier like a river can separate two groups of the same species and make it difficult for potential mates to cross; if a mutation occurs, over many generations it can spread and become common in one subpopulation while being completely absent in the other.
Deep-sea communityA deep-sea community is any community of organisms associated by a shared habitat in the deep sea. Deep sea communities remain largely unexplored, due to the technological and logistical challenges and expense involved in visiting this remote biome. Because of the unique challenges (particularly the high barometric pressure, extremes of temperature and absence of light), it was long believed that little life existed in this hostile environment. Since the 19th century however, research has demonstrated that significant biodiversity exists in the deep sea.
Gene flowIn population genetics, gene flow (also known as migration and allele flow) is the transfer of genetic material from one population to another. If the rate of gene flow is high enough, then two populations will have equivalent allele frequencies and therefore can be considered a single effective population. It has been shown that it takes only "one migrant per generation" to prevent populations from diverging due to drift. Populations can diverge due to selection even when they are exchanging alleles, if the selection pressure is strong enough.
Mid-ocean ridgeA mid-ocean ridge (MOR) is a seafloor mountain system formed by plate tectonics. It typically has a depth of about and rises about above the deepest portion of an ocean basin. This feature is where seafloor spreading takes place along a divergent plate boundary. The rate of seafloor spreading determines the morphology of the crest of the mid-ocean ridge and its width in an ocean basin. The production of new seafloor and oceanic lithosphere results from mantle upwelling in response to plate separation.
Genetic driftGenetic drift, also known as random genetic drift, allelic drift or the Wright effect, is the change in the frequency of an existing gene variant (allele) in a population due to random chance. Genetic drift may cause gene variants to disappear completely and thereby reduce genetic variation. It can also cause initially rare alleles to become much more frequent and even fixed. When few copies of an allele exist, the effect of genetic drift is more notable, and when many copies exist, the effect is less notable.
Conservation biologyRedirect2|Biological conservation|ConservationBiology (journal)|and|Biological Conservation (journal)Biological Conservation (journal)|and|Conservation Ecology (journal)Conservation Ecology (journal)|the popular movement|Conservationism Conservation biology is the study of the conservation of nature and of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions.
Allele frequencyAllele frequency, or gene frequency, is the relative frequency of an allele (variant of a gene) at a particular locus in a population, expressed as a fraction or percentage. Specifically, it is the fraction of all chromosomes in the population that carry that allele over the total population or sample size. Microevolution is the change in allele frequencies that occurs over time within a population. Given the following: A particular locus on a chromosome and a given allele at that locus A population of N individuals with ploidy n, i.
Population growthPopulation growth is the increase in the number of people in a population or dispersed group. Actual global human population growth amounts to around 83 million annually, or 1.1% per year. The global population has grown from 1 billion in 1800 to 7.9 billion in 2020. The UN projected population to keep growing, and estimates have put the total population at 8.6 billion by mid-2030, 9.8 billion by mid-2050 and 11.2 billion by 2100.
Population ageingPopulation ageing is an increasing median age in a population because of declining fertility rates and rising life expectancy. Most countries have rising life expectancy and an ageing population, trends that emerged first in developed countries but are now seen in virtually all developing countries. That is the case for every country in the world except the 18 countries designated as "demographic outliers" by the United Nations. The aged population is currently at its highest level in human history.
Landscape connectivityIn landscape ecology, landscape connectivity is, broadly, "the degree to which the landscape facilitates or impedes movement among resource patches". Alternatively, connectivity may be a continuous property of the landscape and independent of patches and paths. Connectivity includes both structural connectivity (the physical arrangements of disturbance and/or patches) and functional connectivity (the movement of individuals across contours of disturbance and/or among patches).
Genetic diversityGenetic diversity is the total number of genetic characteristics in the genetic makeup of a species, it ranges widely from the number of species to differences within species and can be attributed to the span of survival for a species. It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary. Genetic diversity serves as a way for populations to adapt to changing environments. With more variation, it is more likely that some individuals in a population will possess variations of alleles that are suited for the environment.
Deep seaThe deep sea is broadly defined as the ocean depth where light begins to fade, at an approximate depth of 200 metres (656 feet) or the point of transition from continental shelves to continental slopes. Conditions within the deep sea are a combination of low temperatures, darkness and high pressure. The deep sea is considered the least explored Earth biome as the extreme conditions make the environment difficult to access and explore. Organisms living within the deep sea have a variety of adaptations to survive in these conditions.
Fixation indexThe fixation index (FST) is a measure of population differentiation due to genetic structure. It is frequently estimated from genetic polymorphism data, such as single-nucleotide polymorphisms (SNP) or microsatellites. Developed as a special case of Wright's F-statistics, it is one of the most commonly used statistics in population genetics. Its values range from 0 to 1, with 0.15 being substantially differentiated and 1 being complete differentiation.
Human genetic variationHuman genetic variation is the genetic differences in and among populations. There may be multiple variants of any given gene in the human population (alleles), a situation called polymorphism. No two humans are genetically identical. Even monozygotic twins (who develop from one zygote) have infrequent genetic differences due to mutations occurring during development and gene copy-number variation. Differences between individuals, even closely related individuals, are the key to techniques such as genetic fingerprinting.
GenomicsGenomics is an interdisciplinary field of biology focusing on the structure, function, evolution, mapping, and editing of genomes. A genome is an organism's complete set of DNA, including all of its genes as well as its hierarchical, three-dimensional structural configuration. In contrast to genetics, which refers to the study of individual genes and their roles in inheritance, genomics aims at the collective characterization and quantification of all of an organism's genes, their interrelations and influence on the organism.
Race and geneticsResearchers have investigated the relationship between race and genetics as part of efforts to understand how biology may or may not contribute to human racial categorization. Many constructions of race are associated with phenotypical traits and geographic ancestry, and scholars like Carl Linnaeus have proposed scientific models for the organization of race since at least the 18th century. Following the discovery of Mendelian genetics and the mapping of the human genome, questions about the biology of race have often been framed in terms of genetics.
