Chihuahua the Free and Sovereign State of Chihuahua, is one of the 31 states of Mexico. It is located in Northwestern Mexico and is bordered by the states of Sonora to the west, Sinaloa to the southwest, Durango to the south, Coahuila to the east. To the north and northeast, it has a long border with the U. S. adjacent to the U. S. states of New Texas. Its capital city is Chihuahua City. Although Chihuahua is identified with the Chihuahuan Desert for namesake, it has more forests than any other state in Mexico, with the exception of Durango. Due to its variant climate, the state has a large variety of flora; the state is characterized by rugged mountainous terrain and wide river valleys. The Sierra Madre Occidental mountain range, part of the continental spine that includes the Rocky Mountains, dominates the state's terrain and is home to the state's greatest attraction, Las Barrancas del Cobre, or Copper Canyon, a canyon system larger and deeper than the Grand Canyon. On the slope of the Sierra Madre Occidental mountains, there are vast prairies of short yellow grass, the source of the bulk of the state's agricultural production.
Most of the inhabitants live along the Conchos River Valley. The etymology of the name Chihuahua has long been disputed by linguists; the most accepted theory explains that the name was derived from the Nahuatl language meaning "The place where the water of the rivers meet". Chihuahua is the largest state in Mexico by area, with an area of 247,455 square kilometres, it is larger than the United Kingdom and smaller than Wyoming, tenth US state in area; the state is known under the nickname El Estado Grande. Chihuahua has a diversified state economy; the three most important economic centers in the state are: Ciudad Juárez, an international manufacturing center. Today Chihuahua serves as an important commercial route prospering from billions of dollars from international trade as a result of NAFTA. On the other hand the state suffers the fallout of illicit trade and activities at the border; the earliest evidence of human inhabitants of modern day Chihuahua was discovered in the area of Samalayuca and Rancho Colorado.
Clovis points have been found in northeastern Chihuahua that have been dated from 12,000 BC to 7000 BC. It is thought. Inhabitants of the state developed farming with the domestication of corn. An archeological site in northern Chihuahua known as Cerro Juanaqueña revealed squash cultivation, irrigation techniques, ceramic artifacts dating to around 2000 BC. Between AD 300 and 1300 in the northern part of the state along the wide, fertile valley on the San Miguel River the Casas Grandes culture developed into an advanced civilization; the Casas Grandes civilization is part of a major prehistoric archaeological culture known as Mogollon, related to the Ancestral Pueblo culture. Paquime was the center of the Casas Grandes civilization. Extensive archaeological evidence shows commerce and hunting at Paquime and Cuarenta Casas. La Cueva De Las Ventanas, a series of cliff dwellings along an important trade route, Las Jarillas Cave scrambled along the canyons of the Sierra Madre in Northwestern Chihuahua date between AD 1205 and 1260 and belong to the Paquimé culture.
Cuarenta Casas is thought to have been a branch settlement from Paquime to protect the trade route from attack. Archaeologists believe the civilization began to decline during the 13th century and by the 15th century the inhabitants of Paquime sought refuge in the Sierra Madre Occidental while others are thought to have emigrated north and joined the Ancestral Pueblo peoples. According to anthropologist current natives tribes are descendants of the Casas Grandes culture. During the 14th century in the northeastern part of the state nomad tribes by the name of Jornado hunted bison along the Rio Grande; when the Spanish explorers reached this area they found their descendants and Manso tribes. In the southern part of the state, in a region known as Aridoamerica, Chichimeca people survived by hunting and farming between AD 300 and 1300; the Chichimeca are the ancestors of the Tepehuan people. Nueva Vizcaya was the first province of northern New Spain to be explored and settled by the Spanish. Around 1528, a group of Spaniard explorers, led by Álvar Núñez Cabeza de Vaca, first entered the territory of what is now Chihuahua.
The conquest of the territory lasted nearly one century and encountered fierce resistance from the Conchos tribe, but the desire of the Spanish Crown to transform the region into a bustling mining center led to a strong strategy to control the area. In 1562 Francisco de Ibarra headed a personal expedition in search of the mythical cities of Cibola and Quivira. Francisco de Ibarra is thought to have been the first European to see the ruins of Paquime. In 1564 Rodrigo de Río de Loza, a lieutenant under Francisco de Ibarra, stayed behind after the expedition and found gold at the foot of the mountains of the Sierra Madre Occidental.
Mesoamerica is a historical region and cultural area in North America. It extends from central Mexico through Belize, Guatemala, El Salvador, Honduras and northern Costa Rica, within this region pre-Columbian societies flourished before the Spanish colonization of the Americas. In the 16th century, European diseases like smallpox and measles caused the deaths of upwards of 90% of the indigenous people, it is one of five areas in the world where ancient civilization arose independently, the second in the Americas along with Norte Chico in present-day Peru, in the northern coastal region. As a cultural area, Mesoamerica is defined by a mosaic of cultural traits developed and shared by its indigenous cultures. Beginning as early as 7000 BCE, the domestication of cacao, beans, avocado, vanilla and chili, as well as the turkey and dog, caused a transition from paleo-Indian hunter-gatherer tribal grouping to the organization of sedentary agricultural villages. In the subsequent Formative period and cultural traits such as a complex mythological and religious tradition, a vigesimal numeric system, a complex calendric system, a tradition of ball playing, a distinct architectural style, were diffused through the area.
In this period, villages began to become stratified and develop into chiefdoms with the development of large ceremonial centers, interconnected by a network of trade routes for the exchange of luxury goods, such as obsidian, cacao, Spondylus shells and ceramics. While Mesoamerican civilization did know of the wheel and basic metallurgy, neither of these technologies became culturally important. Among the earliest complex civilizations was the Olmec culture, which inhabited the Gulf Coast of Mexico and extended inland and southwards across the Isthmus of Tehuantepec. Frequent contact and cultural interchange between the early Olmec and other cultures in Chiapas and Oaxaca laid the basis for the Mesoamerican cultural area. All this was facilitated by considerable regional communications in ancient Mesoamerica along the Pacific coast; this formative period saw the spread of distinct religious and symbolic traditions, as well as artistic and architectural complexes. In the subsequent Preclassic period, complex urban polities began to develop among the Maya, with the rise of centers such as El Mirador and Tikal, the Zapotec at Monte Albán.
During this period, the first true Mesoamerican writing systems were developed in the Epi-Olmec and the Zapotec cultures, the Mesoamerican writing tradition reached its height in the Classic Maya hieroglyphic script. Mesoamerica is one of only three regions of the world where writing is known to have independently developed. In Central Mexico, the height of the Classic period saw the ascendancy of the city of Teotihuacan, which formed a military and commercial empire whose political influence stretched south into the Maya area and northward. Upon the collapse of Teotihuacán around 600 AD, competition between several important political centers in central Mexico, such as Xochicalco and Cholula, ensued. At this time during the Epi-Classic period, the Nahua peoples began moving south into Mesoamerica from the North, became politically and culturally dominant in central Mexico, as they displaced speakers of Oto-Manguean languages. During the early post-Classic period, Central Mexico was dominated by the Toltec culture, Oaxaca by the Mixtec, the lowland Maya area had important centers at Chichén Itzá and Mayapán.
Towards the end of the post-Classic period, the Aztecs of Central Mexico built a tributary empire covering most of central Mesoamerica. The distinct Mesoamerican cultural tradition ended with the Spanish conquest in the 16th century. Over the next centuries, Mesoamerican indigenous cultures were subjected to Spanish colonial rule. Aspects of the Mesoamerican cultural heritage still survive among the indigenous peoples who inhabit Mesoamerica, many of whom continue to speak their ancestral languages, maintain many practices harking back to their Mesoamerican roots; the term Mesoamerica means "middle America" in Greek. Middle America refers to a larger area in the Americas, but it has previously been used more narrowly to refer to Mesoamerica. An example is the title of the 16 volumes of The Handbook of Middle American Indians. "Mesoamerica" is broadly defined as the area, home to the Mesoamerican civilization, which comprises a group of peoples with close cultural and historical ties. The exact geographic extent of Mesoamerica has varied through time, as the civilization extended North and South from its heartland in southern Mexico.
The term was first used by the German ethnologist Paul Kirchhoff, who noted that similarities existed among the various pre-Columbian cultures within the region that included southern Mexico, Belize, El Salvador, western Honduras, the Pacific lowlands of Nicaragua and northwestern Costa Rica. In the tradition of cultural history, the prevalent archaeological theory of the early to middle 20th century, Kirchhoff defined this zone as a cultural area based on a suite of interrelated cultural similarities brought about by millennia of inter- and intra-regional interaction. Mesoamerica is recognized as a near-prototypical cultural area, the term is now integrated in the standard terminology of pre-Columbian anthropological studies. Conversely, the sister terms Aridoamerica and Oasisamerica, which refer to northern Mexico and the western United States have not entered into widespread usage; some of the significant cultural traits defining the Mesoamerican cultural tradition are: sedentism based on maize agricultu
Plants are multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. Plants were treated as one of two kingdoms including all living things that were not animals, all algae and fungi were treated as plants. However, all current definitions of Plantae exclude the fungi and some algae, as well as the prokaryotes. By one definition, plants form the clade Viridiplantae, a group that includes the flowering plants and other gymnosperms and their allies, liverworts and the green algae, but excludes the red and brown algae. Green plants obtain most of their energy from sunlight via photosynthesis by primary chloroplasts that are derived from endosymbiosis with cyanobacteria, their chloroplasts contain b, which gives them their green color. Some plants are parasitic or mycotrophic and have lost the ability to produce normal amounts of chlorophyll or to photosynthesize. Plants are characterized by sexual reproduction and alternation of generations, although asexual reproduction is common.
There are about 320 thousand species of plants, of which the great majority, some 260–290 thousand, are seed plants. Green plants provide a substantial proportion of the world's molecular oxygen and are the basis of most of Earth's ecosystems on land. Plants that produce grain and vegetables form humankind's basic foods, have been domesticated for millennia. Plants have many cultural and other uses, as ornaments, building materials, writing material and, in great variety, they have been the source of medicines and psychoactive drugs; the scientific study of plants is known as a branch of biology. All living things were traditionally placed into one of two groups and animals; this classification may date from Aristotle, who made the distincton between plants, which do not move, animals, which are mobile to catch their food. Much when Linnaeus created the basis of the modern system of scientific classification, these two groups became the kingdoms Vegetabilia and Animalia. Since it has become clear that the plant kingdom as defined included several unrelated groups, the fungi and several groups of algae were removed to new kingdoms.
However, these organisms are still considered plants in popular contexts. The term "plant" implies the possession of the following traits multicellularity, possession of cell walls containing cellulose and the ability to carry out photosynthesis with primary chloroplasts; when the name Plantae or plant is applied to a specific group of organisms or taxon, it refers to one of four concepts. From least to most inclusive, these four groupings are: Another way of looking at the relationships between the different groups that have been called "plants" is through a cladogram, which shows their evolutionary relationships; these are not yet settled, but one accepted relationship between the three groups described above is shown below. Those which have been called "plants" are in bold; the way in which the groups of green algae are combined and named varies between authors. Algae comprise several different groups of organisms which produce food by photosynthesis and thus have traditionally been included in the plant kingdom.
The seaweeds range from large multicellular algae to single-celled organisms and are classified into three groups, the green algae, red algae and brown algae. There is good evidence that the brown algae evolved independently from the others, from non-photosynthetic ancestors that formed endosymbiotic relationships with red algae rather than from cyanobacteria, they are no longer classified as plants as defined here; the Viridiplantae, the green plants – green algae and land plants – form a clade, a group consisting of all the descendants of a common ancestor. With a few exceptions, the green plants have the following features in common, they undergo closed mitosis without centrioles, have mitochondria with flat cristae. The chloroplasts of green plants are surrounded by two membranes, suggesting they originated directly from endosymbiotic cyanobacteria. Two additional groups, the Rhodophyta and Glaucophyta have primary chloroplasts that appear to be derived directly from endosymbiotic cyanobacteria, although they differ from Viridiplantae in the pigments which are used in photosynthesis and so are different in colour.
These groups differ from green plants in that the storage polysaccharide is floridean starch and is stored in the cytoplasm rather than in the plastids. They appear to have had a common origin with Viridiplantae and the three groups form the clade Archaeplastida, whose name implies that their chloroplasts were derived from a single ancient endosymbiotic event; this is the broadest modern definition of the term'plant'. In contrast, most other algae not only have different pigments but have chloroplasts with three or four surrounding membranes, they are not close relatives of the Archaeplastida having acquired chloroplasts separately from ingested or symbiotic green and red algae. They are thus not included in the broadest modern definition of the plant kingdom, although they were in the past; the green plants or Viridiplantae were traditionally divided into the green algae (including
Zea diploperennis, the diploperennial teosinte, is a species of grass in the genus Zea and a teosinte. It is perennial. All populations of this teosinte are either threatened or endangered: Z. diploperennis exists in an area of only a few square miles. The Mexican and Nicaraguan governments have taken action in recent years to protect wild teosinte populations, using both in situ and ex situ conservation methods. A large amount of scientific interest exists in conferring beneficial teosinte traits, such as insect resistance and flood tolerance, to cultivated maize lines, although this is difficult due to linked deleterious teosinte traits
In scientific nomenclature, a synonym is a scientific name that applies to a taxon that goes by a different scientific name, although the term is used somewhat differently in the zoological code of nomenclature. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies; this name is no longer in use: it is now a synonym of the current scientific name, Picea abies. Unlike synonyms in other contexts, in taxonomy a synonym is not interchangeable with the name of which it is a synonym. In taxonomy, synonyms have a different status. For any taxon with a particular circumscription and rank, only one scientific name is considered to be the correct one at any given time. A synonym cannot exist in isolation: it is always an alternative to a different scientific name. Given that the correct name of a taxon depends on the taxonomic viewpoint used a name, one taxonomist's synonym may be another taxonomist's correct name. Synonyms may arise whenever the same taxon is named more than once, independently.
They may arise when existing taxa are changed, as when two taxa are joined to become one, a species is moved to a different genus, a variety is moved to a different species, etc. Synonyms come about when the codes of nomenclature change, so that older names are no longer acceptable. To the general user of scientific names, in fields such as agriculture, ecology, general science, etc. A synonym is a name, used as the correct scientific name but, displaced by another scientific name, now regarded as correct, thus Oxford Dictionaries Online defines the term as "a taxonomic name which has the same application as another one, superseded and is no longer valid." In handbooks and general texts, it is useful to have synonyms mentioned as such after the current scientific name, so as to avoid confusion. For example, if the much advertised name change should go through and the scientific name of the fruit fly were changed to Sophophora melanogaster, it would be helpful if any mention of this name was accompanied by "".
Synonyms used in this way may not always meet the strict definitions of the term "synonym" in the formal rules of nomenclature which govern scientific names. Changes of scientific name have two causes: they may be taxonomic or nomenclatural. A name change may be caused by changes in the circumscription, position or rank of a taxon, representing a change in taxonomic, scientific insight. A name change may be due to purely nomenclatural reasons, that is, based on the rules of nomenclature. Speaking in general, name changes for nomenclatural reasons have become less frequent over time as the rules of nomenclature allow for names to be conserved, so as to promote stability of scientific names. In zoological nomenclature, codified in the International Code of Zoological Nomenclature, synonyms are different scientific names of the same taxonomic rank that pertain to that same taxon. For example, a particular species could, over time, have had two or more species-rank names published for it, while the same is applicable at higher ranks such as genera, orders, etc.
In each case, the earliest published name is called the senior synonym, while the name is the junior synonym. In the case where two names for the same taxon have been published the valid name is selected accorded to the principle of the first reviser such that, for example, of the names Strix scandiaca and Strix noctua, both published by Linnaeus in the same work at the same date for the taxon now determined to be the snowy owl, the epithet scandiaca has been selected as the valid name, with noctua becoming the junior synonym. One basic principle of zoological nomenclature is that the earliest published name, the senior synonym, by default takes precedence in naming rights and therefore, unless other restrictions interfere, must be used for the taxon. However, junior synonyms are still important to document, because if the earliest name cannot be used the next available junior synonym must be used for the taxon. For other purposes, if a researcher is interested in consulting or compiling all known information regarding a taxon, some of this may well have been published under names now regarded as outdated and so it is again useful to know a list of historic synonyms which may have been used for a given current taxon name.
Objective synonyms refer to taxa with same rank. This may be species-group taxa of the same rank with the same type specimen, genus-group taxa of the same rank with the same type species or if their type species are themselves objective synonyms, of family-group taxa with the same type genus, etc. In the case of subjective synonyms, there is no such shared type, so the synonymy is open to taxonomic judgement, meaning that th
Nicaragua the Republic of Nicaragua, is the largest country in the Central American isthmus, bordered by Honduras to the northwest, the Caribbean to the east, Costa Rica to the south, the Pacific Ocean to the southwest. Managua is the country's capital and largest city and is the third-largest city in Central America, behind Tegucigalpa and Guatemala City; the multi-ethnic population of six million includes people of indigenous, European and Asian heritage. The main language is Spanish. Indigenous tribes on the Mosquito Coast speak English. Inhabited by various indigenous cultures since ancient times, the Spanish Empire conquered the region in the 16th century. Nicaragua gained independence from Spain in 1821; the Mosquito Coast followed a different historical path, with the English colonizing it in the 17th century and coming under the British rule, as well as some minor Spanish interludes in the 19th century. It became an autonomous territory of Nicaragua in 1860 and the northernmost part of it was transferred to Honduras in 1960.
Since its independence, Nicaragua has undergone periods of political unrest, dictatorship and fiscal crisis, leading to the Nicaraguan Revolution of the 1960s and 1970s and the Contra War of the 1980s. The mixture of cultural traditions has generated substantial diversity in folklore, cuisine and literature the latter given the literary contributions of Nicaraguan poets and writers, such as Rubén Darío. Known as the "land of lakes and volcanoes", Nicaragua is home to the second-largest rainforest of the Americas; the country has set a goal of 90% renewable energy by the year 2020. The biological diversity, warm tropical climate and active volcanoes make Nicaragua an popular tourist destination. There are two prevailing theories on; the first is that the name was coined by Spanish colonists based on the name Nicarao, the chieftain or cacique of a powerful indigenous tribe encountered by the Spanish conquistador Gil González Dávila during his entry into southwestern Nicaragua in 1522. This theory holds that the name Nicaragua was formed from Nicarao and agua, to reference the fact that there are two large lakes and several other bodies of water within the country.
However, as of 2002, it was determined that the cacique's real name was Macuilmiquiztli, which meant "Five Deaths" in the Nahuatl language, rather than Nicarao. The second theory is that the country's name comes from any of the following Nahuatl words: nic-anahuac, which meant "Anahuac reached this far", or "the Nahuas came this far", or "those who come from Anahuac came this far". Paleo-Americans first inhabited what is now known as Nicaragua as far back as 12,000 BCE. In pre-Columbian times, Nicaragua's indigenous people were part of the Intermediate Area, between the Mesoamerican and Andean cultural regions, within the influence of the Isthmo-Colombian area. Nicaragua's central region and its Caribbean coast were inhabited by Macro-Chibchan language ethnic groups, they had coalesced in Central America and migrated to present-day northern Colombia and nearby areas. They lived a life based on hunting and gathering, as well as fishing, performing slash-and-burn agriculture. At the end of the 15th century, western Nicaragua was inhabited by several different indigenous peoples related by culture to the Mesoamerican civilizations of the Aztec and Maya, by language to the Mesoamerican Linguistic Area.
The Chorotegas were Mangue language ethnic groups who had arrived in Nicaragua from what is now the Mexican state of Chiapas sometime around 800 CE. The Pipil-Nicarao people were a branch of Nahuas who spoke the Nahuat dialect, like the Chorotegas, they too had come from Chiapas to Nicaragua in 1200 CE. Prior to that, the Pipil-Nicaraos had been associated with the Toltec civilization. Both the Chorotegas and the Pipil-Nicaraos were from Mexico's Cholula valley, had migrated southward. Additionally, there were trade-related colonies in Nicaragua, set up by the Aztecs starting in the 14th century. In 1502, on his fourth voyage, Christopher Columbus became the first European known to have reached what is now Nicaragua as he sailed southeast toward the Isthmus of Panama. Columbus explored the Mosquito Coast on the Atlantic side of Nicaragua but did not encounter any indigenous people. 20 years the Spaniards returned to Nicaragua, this time to its southwestern part. The first attempt to conquer Nicaragua was by the conquistador Gil González Dávila, who had arrived in Panama in January 1520.
In 1522, González Dávila ventured into the area that became known as the Rivas Department of Nicaragua. It was there that he encountered an indigenous Nahua tribe led by a chieftain named Macuilmiquiztli, whose name has sometimes been erroneously referred to as "Nicarao" or "Nicaragua". At the time, the tribe's capital city was called Quauhcapolca. González Dávila had brought along two indigenous interpreters, taught the Spanish language, thus he was able to have a discourse with Macuilmiquiztli. After exploring and gathering gold in the fertile western valleys, González Dávila and his men were attacked and driven off by the Chorotega, led by the chieftain Diriangen; the Spanish attempted to convert the tribes to Christianity. The first Spanish permanent settlements were founded in 1524; that year, the conquistador
In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus encounter one another. An interbreeding population that splits into two or more distinct species sharing a common range exemplifies sympatric speciation; such speciation may be a product of reproductive isolation – which prevents hybrid offspring from being viable or able to reproduce, thereby reducing gene flow – that results in genetic divergence. Sympatric speciation does not imply secondary contact, speciation or divergence in allopatry followed by range expansions leading to an area of sympatry. Sympatric species or taxa in secondary contact may not interbreed. Four main types of population pairs exist in nature. Sympatric populations contrast with parapatric populations, which contact one another in adjacent but not shared ranges and do not interbreed. Allopatric populations isolated from one another by geographical factors may experience genetic—and phenotypic—changes in response to their varying environments.
These may drive allopatric speciation, arguably the dominant mode of speciation. The lack of geographic isolation as a definitive barrier between sympatric species has yielded controversy among ecologists and zoologists regarding the validity of the term; as such, researchers have long debated the conditions under which sympatry applies with respect to parasitism. Because parasitic organisms inhabit multiple hosts during a life cycle, evolutionary biologist Ernst Mayr stated that internal parasites existing within different hosts demonstrate allopatry, not sympatry. Today, many biologists consider parasites and their hosts to be sympatric. Conversely, zoologist Michael J. D. White considered two populations sympatric if genetic interbreeding was viable within the habitat overlap; this may be further specified as sympatry occurring within one deme. Others question the ability of sympatry to result in complete speciation: until many researchers considered it nonexistent, doubting that selection alone could create disparate, but not geographically separated, species.
In 2003, biologist Karen McCoy suggested that sympatry can act as a mode of speciation only when "the probability of mating between two individuals depend on their genotypes, dispersed throughout the range of the population during the period of reproduction". In essence, sympatric speciation does require strong forces of natural selection to be acting on heritable traits, as there is no geographic isolation to aid in the splitting process. Yet, recent research has begun to indicate that sympatric speciation is not as uncommon as was once assumed. Syntopy is a special case of sympatry, it means the joint occurrence of two species in the same habitat at the same time. Just as the broader term sympatry, "syntopy" is used for close species that might hybridise or be sister species. Sympatric species occur together in the same region, but do not share the same localities as syntopic species do. Areas of syntopy are of interest because they allow to study how similar species may coexist without outcompeting each other.
As an example, the two bat species Myotis auriculus and M. evotis were found to be syntopic in North America. In contrast, the marbled newt and the northern crested newt have a large sympatric range in western France, but differ in their habitat preferences and only occur syntopically in the same breeding ponds; the lack of geographic constraint in isolating sympatric populations implies that the emerging species avoid interbreeding via other mechanisms. Before speciation is complete, two diverging populations may still produce viable offspring; as speciation progresses, isolating mechanisms – such as gametic incompatibility that renders fertilization of the egg impossible – are selected for in order to increase the reproductive divide between the two populations. Sympatric groups show a greater ability to discriminate between their own species and other related species than do allopatric groups; this is shown in the study of hybrid zones. It is apparent in the differences in levels of prezygotic isolation in both sympatric and allopatric populations.
There are two main theories regarding this process: 1) differential fusion, which suggests that only populations with a keen ability to discriminate between species will persist in sympatry. Reinforcement is the process. In sympatry, reinforcement increases species discrimination and sexual adaptation in order to avoid maladaptive hybridization and encourage speciation. If hybrid offspring are either sterile or less-fit than non-hybrid offspring, mating between members of two different species will be selected against. Natural selection decreases the probability of such hybridization by selecting for the ability to identify mates of one's own species from those of another species. Reproductive character displacement strengthens the reproductive barriers between sympatric species by encouraging the divergence of traits that are crucial to reproduction. Divergence