Here’s An Overview About Species
Meaning:
A group of creatures that can naturally reproduce with one another and generate viable progeny is sometimes referred to as a species. However, classifying a species can be challenging and even contentious. You are distinctly human, down to the color of your hair and the shape of your toes. Despite having extremely distinct appearances, all humans belong to the same species, Homo sapiens. Even though the criterion appears simple, classifying a species can be challenging and occasionally fraught with disagreement.
While many organisms do not, some do fulfil this concept of a species quite readily. Asexual organisms do not reproduce with one another because they only have one parent. In the wild, some organisms frequently breed with other species of like kind, creating genetic hybrids. The first wild polar bear-grizzly bear cross was discovered in Canada in 2006. These hybrid bears, sometimes known as "pizzly" or "grolar" bears, can have viable progeny. Because of their varied environmental requirements, polar bears and grizzly bears are currently considered to be separate species.
It is challenging for scientists to designate species precisely because of these naturally occurring wild rule-breakers. The solution may be found in genetics. Scientists can now categorize species based on DNA pattern through genetic research. This technology has revealed several unexpected discoveries as well as new interactions between species. Giraffes, formerly believed to be a single species, are actually four separate species, according to a recent genomic investigation. If researchers find a new endangered species "hiding" among a larger population of similar organisms, their findings could raise conservation concerns.
Threatened/Endangered Species:
An organism that faces extinction is referred to as an endangered species. The two main factors that cause a species to become endangered are habitat loss and genetic diversity loss.
1. Changing Habitat
• Natural occurrences may result in habitat loss. For instance, dinosaurs had their home removed some 65 million years ago. The earth's hot, dry environment during the Cretaceous period abruptly changed, most likely as a result of an asteroid impact. Debris from the asteroid's collision was driven into the atmosphere, which decreased the amount of heat and light that reached the surface of the Earth. The new, cooler habitat proved to be inhospitable to the dinosaurs. Dinosaurs went from being threatened to extinct.
• A loss of habitat can also be caused by human activity. Native organisms' habitats are reduced as a result of development for housing, business, and agriculture. There are numerous ways in which this might take place.
• Native species and habitat can be directly destroyed by development. Hundreds of thousands of acres have been removed by developers in South America's Amazon rain forest. A piece of land is "cleared" when all the trees and vegetation are taken out of it. For logging, urban development, and livestock ranches, the Amazon rain forest is cleared.
• Indirect threats to species might also result from development. Some species, like the fig trees of the rain forest, might serve as a habitat for other creatures. When trees are cut down, species that rely on their habitat may also go extinct. In a rainforest's canopy, or upper layer, tree crowns offer habitat. The rain forest canopy is home to plants like vines, fungi like mushrooms, and insects like butterflies. The same is true for numerous tropical bird species and mammals like monkeys. This habitat is being lost as trees are cut down. There is less space for species to thrive and procreate.
• As development happens throughout a species' range, habitat loss may occur. The range of many species can reach hundreds of square kilometers. For instance, the mountain lion of North America can cover up to 1,000 square kilometers (386 square miles). A single mountain lion explores this much area in order to survive and breed. Urban areas expanded quickly during the 20th century, including Vancouver, British Columbia, Canada, and Los Angeles, California. The habitat of the mountain lion shrunk as these locations grew more remote. The ecosystem can accommodate fewer mountain lions as a result. However, mountain lions are not in danger because substantial portions of the Sierra Nevada, Rocky, and Cascade mountain ranges are still uninhabited.
• Increased contacts between wild creatures and people can result from habitat loss. People may become more exposed to wild species as development pushes them farther into a species' range. Closer to homes and schools may grow poisonous plants and fungus. Additionally, wild creatures are seen more regularly. These animals are merely patrolling their territory, but coming into contact with humans can be fatal. Predators that lose their habitat to buildings, farms, and commercial establishments include polar bears, mountain lions, and alligators. Native species could become endangered as a result of people killing natural animals through pesticides, accidents like collisions with cars, or hunting.
2. Genetic Variation Loss
• The variety within a species is represented by genetic variation. It explains why people can have hair that is blond, red, brown, or black. Species can adapt to environmental changes thanks to genetic diversity. A species' genetic variation typically increases with population size.
• Inbreeding is the practice of breeding inside a small family. Because no new genetic information is transferred to groups of species that are prone to inbreeding, they often have limited genetic variation. Inbred populations are far more likely to contract disease and die from it. Inbred species lack the genetic diversity needed to produce disease resistance. Because of this, fewer kids from inbred groups reach adulthood.
• Genetic diversity can be lost naturally. African and Asian cheetahs are a threatened species. There is hardly any genetic diversity among these large cats. According to biologists, cheetahs had a protracted period of inbreeding during the previous ice age. As a result, cheetahs have extremely little genetic variation. Fewer cheetahs mature because they cannot adjust to environmental changes as quickly as other animals can. Additionally, compared to other big cats like lions, breeding cheetahs in captivity is significantly more challenging.
• Genetic diversity can be lost as a result of human activities. Many animal populations have declined as a result of overfishing and overhunting. A smaller population indicates fewer breeding couples. A breeding pair is two fully grown individuals from the same species that are not related and are capable of giving birth to healthy children. Genetic diversity decreases when breeding pairs become scarcer.
• Monoculture, the practice of cultivating just one type of crop, can also lessen genetic diversity. Monocultures are essential to modern agriculture. For instance, the Russet Burbank is the only species of potato that is primarily grown, traded, and consumed. There are numerous natural kinds of potatoes, which are indigenous to the Andes Mountains in South America. Wild potatoes' genetic diversity enables them to adjust to climatic change and illness. However, because the plant has essentially no genetic variety, growers must employ pesticides and fertilizers to assure good crops.
• To gather genes that will help domesticated plants fight pests, drought and adapt to climate change, plant breeders frequently return to wild variety. Climate change, however, also poses a threat to wild variety. As a result, domesticated plants risk losing a crucial source of characteristics that enable them to combat fresh dangers.
The Red List:
The "Red List of Threatened Species" is maintained by the International Union for Conservation of Nature (IUCN). The seriousness and precise root causes of an endangered species' endangerment are outlined in the Red List. Lesser concern, near threatened, vulnerable, endangered, critically endangered, extinct in the wild, and extinct are the seven conservation levels included on the Red List. Different threat levels are represented by each category.
The first two categories—least concern and near-threatened—are used to classify species that are not in imminent danger of going extinct. The following three classifications—vulnerable, endangered, and critically endangered—are used to group the most endangered species. Extinct in the wild and extinct are the last two classifications, which include all extinct species.
The range and habitat of a species, as well as its actual population, are taken into consideration when classifying it as endangered. Because of this, a species may be least endangered in one region and endangered in another. For instance, the eastern Pacific Ocean, around the coasts of North and South America, is home to a thriving population of grey whales. However, the population in the western Pacific is in grave danger.
1. Least Concern:
The lowest level of conservation is least concern. A species with a large and distributed population is one of least concern. Along with the majority of domestic animals, like dogs and cats, humans are a species of least concern. Numerous wild creatures are also categorized as least concerning, including pigeons and houseflies.
2. Near Threatened:
A species is considered to be near threatened if it is soon to fall under the threat category.
For instance, several violet species, which are indigenous to tropical jungles in South America and Africa, are under danger of extinction. Although their populations are strong, their rain forest environment is rapidly vanishing. Huge tracts of rain forest are being cleared for development and wood. It's conceivable that many violet species will face extinction.
3. Vulnerable Species:
The definitions of the three categories of threats (vulnerable, endangered, and critically endangered) are based on five factors: the pace of population decline, the size of the population, the geographic range, the limits on the population, and the likelihood of extinction.
Different criterion thresholds apply to threatened categories. The species is more in danger as its population and geographic range dwindle:
1) Rate of population decline
• If a species' population has decreased by between 30 and 50 percent, it is considered fragile. This decline is tracked over a period of ten years or three generations, whichever is longer. A generation is the span of time between an animal's birth and its first opportunity to reproduce. When they are around one month old, mice can start reproducing. The majority of mouse population tracking occurs over 10-year intervals. A generation in an elephant lasts roughly 15 years. Therefore, 45-year periods are used to measure elephant numbers.
• If a species' population has decreased by at least 50% and the reason for the drop is recognized, the species is considered fragile. The primary recognized factor for population decline is habitat loss.
• If a species' population has decreased by at least 30% and the reason for the drop is unknown, the species is considered vulnerable. For instance, a novel, undiscovered virus might kill hundreds or even thousands of people before being discovered.
2) Territorial scope
• If a species' "extent of occurrence" is thought to be fewer than 20,000 square kilometers, it is considered fragile (7,722 square miles). The smallest region that might house the entire population of a species is its range of occurrence. The amount of the area in which all members of a species might live would be that area's extent of occurrence.
• If a species' "area of occupancy" is thought to be smaller than 2,000 square kilometers, it is also categorized as vulnerable (772 square miles). The location of a particular population of that species is known as its region of habitation. In a species range, this location is frequently a breeding or nesting site.
3) Population size
• Less than 10,000 adult individuals in a species make it vulnerable. The species is additionally at risk if that population experiences a drop of at least 10% over the course of 10 years or three generations, whichever comes first.
4) Limitations on the population
• Combining population and area of occupancy results in a population constraint. A species is considered fragile if it only has 1,000 mature individuals or occupies an area less than 20 square kilometers (8 square miles).
5) Probability of extinction
There is a 10% chance that an animal may go extinct in the wild in the next 100 years.
To calculate the likelihood of a species going extinct, biologists, anthropologists, meteorologists, and other disciplines have devised sophisticated methods. These equations determine the likelihood that a species can endure in the wild without assistance from humans.
Vulnerable Species:
1. Ethiopian banana frog
The southern Ethiopian highlands are home to the little Ethiopian banana frog (Afrixalus enseticola). Its area of occupancy is less than 2,000 square kilometers, making it a vulnerable species (772 square miles). Its woodland environment is dwindling in size and quality. The destruction of the forest, primarily for agriculture and development, is a threat to this environment.
2. Snaggletooth Shark
The Indian and Pacific Oceans' tropical, coastal waters are home to the snaggletooth shark (Hemipristis elongatus). Its vast occupied territory stretches from China to Australia and from southeast Africa to the Philippines.
However, a steep population decline rate makes the snaggletooth shark a vulnerable species. Over a decade, there has been a more than 10% decline in population. Because of fisheries, particularly in the Java Sea and Gulf of Thailand, shark populations are dropping. Flesh, fins, and liver of snaggletooth sharks are prized as premium cuisine. Both restaurants and commercial fish markets sell them.
3. Galapagos Kelp
Seaweed known as Galapagos kelp (Eisenia galapagensis) can only be found in the Pacific Ocean close to the Galapagos Islands. Due to a population loss of more than 10% over a ten-year period, Galapagos kelp is considered fragile.
The primary factor for Galapagos kelp to diminish is climate change. The primary cause of climate change in this region is El Nino, a normal weather cycle that delivers extremely warm seas to the Galapagos Islands. Being a cold-water species, Galapagos kelp takes a while to adjust to variations in water temperature.
Endangered Species:
1) Rate of population decline
When a species' population has decreased by between 50 and 70 percent, it is deemed endangered. This decline is tracked over a period of ten years or three generations, whichever is longer.
When a species' population has decreased by at least 70% and the reason for the drop is understood, the species is considered endangered. When a species' population has fallen by at least 50% and the reason for the drop is unknown, the species is also considered endangered.
2) Territorial scope
A threatened species' range is no larger than 5,000 square kilometers (1,930 square miles). The range of an endangered species is fewer than 500 square kilometers (193 square miles).
3) Population size
If a species has fewer than 2,500 adult individuals, it is deemed endangered. A species is also considered endangered if its population drops by at least 20% over the course of five years or two generations.
4) Population size
When a species' population is limited to less than 250 adult individuals, it is deemed endangered. A species' area of occupancy is not taken into account when its population is this low.
5) Probability of extinction
Within 20 years or five generations, whichever is longer, there is a minimum 20% chance that an organism will go extinct in the wild.
Endangered Species:
1. Siberian sturgeon
A large fish called the Siberian sturgeon (Acipenser baerii) can be found in rivers and lakes all over Russia's Siberian region. A benthic species is the Siberian sturgeon. Benthic species exist at the water's bottom.
Due to a total population drop of between 50 and 80 percent during the previous 60 years, the Siberian sturgeon is now considered to be an endangered species (three generations of sturgeon). This decline is the result of overfishing, poaching, and dam construction. The sturgeon's reproductive system is aberrant because of pollution from mining activity.
2. Tahiti Reed-warbler
On the Pacific island of Tahiti, there is a songbird called the Tahiti Reed-Warbler (Acrocephalus caffer). With such a limited population, it is an endangered species. The bird's range of occurrence and range of occupancy are both quite small because it is only found on one island.
Human activity has also led to the endangerment of the Tahiti Reed Warbler. A large portion of Tahiti's original vegetation has been replaced by the tropical weed Miconia, a non-native species. Nearly the only habitat for the reed-warbler is Tahiti's bamboo forests. The bird nests in bamboo and eats the local plants' blooms and insects. The Tahiti reed-warbler population is dwindling as a result of development and invasive species like Miconia destroying the bamboo woods.
3. Ebony
Diospyros crassiflora, a type of ebony tree, is a tree that is indigenous to the rain forests of central Africa, including Gabon, Cameroon, and Congo. Because many biologists estimate that ebony will likely go extinct in the wild within five generations, it is an endangered species.
Overharvesting has put ebony in danger. The wood from ebony trees is exceptionally dense and black. Ebony can be mistaken for black marble or other stones when polished. Ebony trees have been harvested for furniture and sculptural purposes, including chess pieces, for ages. However, the majority of ebony is collected to produce musical instruments like piano keys and stringed instrument fingerboards.
Critically Endangered Species- Under Serious Peril:
1) Rate of population decline
The population of a critically endangered species has decreased by between 80% and 90%. This decline is tracked over a period of ten years or three generations, whichever is longer.
When a species' population has decreased by at least 90% and the reason for the drop is recognized, the species is considered critically endangered. When a species' population has fallen by at least 80% and the reason for the drop is unknown, the species is also considered endangered.
2) Territorial scope
The area of occurrence of a critically endangered species is fewer than 100 square kilometers (39 square miles). The estimated range of a critically endangered species is fewer than 10 square kilometers (4 square miles).
3) Population size
When a species has less than 250 adult individuals, it is deemed when the number of adult individuals’ drops by at least 25% within three years or one generation, whichever is longer, a species is also categorized as critically endangered.
4) Limitations on the population
When a species' population is limited to less than 50 adult individuals, it is deemed critically endangered. A species' area of occupancy is not taken into account when its population is this low.
5) Probability of extinction
Within 10 years or three generations, whichever is longer, there is at least a 50% chance that the species will go extinct in the wild.
Critically Endangered Species:
1. Bolivian chinchilla rat
An area of Bolivia's Santa Cruz region is home to the Bolivian chinchilla rat (Abrocoma boliviensis). Due of its extremely limited geographic range (less than 100 square kilometers), it is critically threatened (39 square miles).
The loss of this species' habitat in the cloud forests is its main concern. To make pastures for cattle, people are cutting down forests.
2. Transcaucasian Racerunner
The Armenian Plateau, which spans Armenia, Azerbaijan, Iran, and Turkey, is home to the Transcaucasian racerunner (Eremias pleskei), a lizard. Due to a drastic population reduction that is thought to have reached over 80% over the last 10 years, the Transcaucasian racerunner is now considered to be a critically endangered species.
The salinization, or increased salinity, of soil is one threat to this species. The soil becomes more salinized as a result of fertilizers leaking into the soil during agricultural development. Racerunners cannot adjust to the increased salt in their food and shelter since they dwell in and among the rocks and soil. As rubbish dumps are built on the racerunner's habitat, they also lose that space.
3. White Ferula Mushroom
The critically endangered white ferula mushroom (Pleurotus nebrodensis) is a type of fungus. The mushroom's distribution area is less than 100 square kilometers, making it extremely endangered (39 square miles). It can only be found in the Mediterranean Sea's northernmost region of the Italian island of Sicily.
The two biggest dangers to the survival of white ferula mushrooms are habitat loss and overharvesting. Gourmet foods include white ferula mushrooms. The fungus is harvested by farmers and amateur mushroom hunters for profit and food. The price of the mushrooms might reach $100 per kilogram (2.2 pounds).
Extinct in the Wild:
When an animal, plant, or population only exists as a population outside of its natural range or in captivity (for animals), that species is said to be extinct in the wild. Only after extensive searches have failed to find any individuals in their natural environment or expected habitat, can a species be declared extinct in the wild.
Species:
1. Scimitar-horned Oryx
The antelope species known as the scimitar-horned oryx (Oryx dammah) has lengthy horns. It has a wide geographic range in northern Africa. Since there hasn't been a confirmed sighting of one since 1988, the scimitar-horned oryx is considered extinct in the wild. The main causes of the extinction of the oryx in the wild are overhunting, habitat loss, and competition with domestic cattle.
Today, protected regions in Tunisia, Senegal, and Morocco house captive herds. There are also numerous zoos that house scimitar-horned oryxes.
2. Black Soft-shell Turtle
Freshwater turtles, such as the black soft-shell turtle (Nilssonia nigricans), are restricted to a single man-made pond at the Baizid Bostami Shrine outside of Chittagong, Bangladesh. The 150 to 300 turtles who call the pond home are wholly dependent on people for nourishment. Black soft-shell turtles were common in the wetlands of the Brahmaputra River until the year 2000, and they mostly consumed freshwater fish for food.
Black soft-shell turtles are uncommon in zoos, unlike other species that have gone extinct in the wild. The turtles cannot be taken by anybody, including scientists, according to the shrine's guardians. The reptiles are thought to be decedents of individuals who were allegedly magically transformed into turtles by a saint in the thirteenth century.
3. Mt. Kaala Cyanea
On the island of Oahu in the U.S. state of Hawaii, there is a huge, flowering tree known as the Mt. Kaala cyanea (Cyanea superba). The Mt. Kaala cyanea produces juicy berries and wide, broad leaves. The main reason the tree is no longer found in the wild is invasive species. The cyanea was driven out of its environment by non-native plants, and non-native rodents, snails, and pigs devoured its fruit faster than it could reproduce.
Tropical nurseries and botanical gardens are where Mt. Kaala cyanea trees can still be found. A new population being established in the wild is something that many botanists and environmentalists look forward to.
Extinct
When there is no reasonable doubt to question that the last member of a species has passed away, that species is considered extinct.
Species:
1. Cuban Macaw
The Cuban macaw (Ara tricolour) is a little island off the coast of Cuba called Isla de la Juventud. The birds were hunted and collected for pets, which caused their extinction. In 1864, the last Cuban macaw specimen was obtained.
2. Ridley’s Stick Insect
Pseudobactricia ridleyi, sometimes known as the Ridley's stick insect, is a native of the Singaporean island's tropical jungle. Only one specimen of this insect, whose long, segmented body resembled a tree limb, was ever collected, more than a century ago. Singapore had fast progress in the 20th century. The insect was deprived of its habitat when nearly the whole jungle was destroyed.
3. Sri Lankan Legume Tree
Only found on the island of Sri Lanka in the Indian Ocean, the Sri Lankan legume tree (Crudia zeylanica) was a massive species of legume. Smaller varieties of legumes include peas and peanuts.
The primary cause of the tree's extinction in the wild was habitat loss brought on by development in the 20th century. Up until 1990, only one specimen was kept at the Royal Botanical Garden in Peradeniya, Sri Lanka, however that specimen was also lost.
Endangered Species And Human:
Governments and international groups can act to safeguard a species if it is declared endangered. Laws may place restrictions on hunting and habitat destruction. People and organizations who violate these regulations risk receiving significant fines. Many species have recovered from their endangered status as a result of such initiatives.
For instance, the brown pelican was delisted as an endangered species in 2009. The Caribbean Sea islands as well as the shores of North and South America are home to this seabird. It serves as Louisiana's state bird in the United States. 10,000 brown pelicans were thought to be in the wild as of 1970. The bird was deemed to be in risk.
Governments and environmental organizations attempted to aid the brown pelican's recovery during the 1970s and 1980s. Chicks were raised in hatching locations before being released into the wild. Nesting places had extremely limited human access. DDT, a pesticide that harmed brown pelican eggs, was outlawed. The population of brown pelicans exploded in the 1980s. The brown pelican was "delisted" by the IUCN in 1988. The bird is now considered to be of least concern because its population has reached the hundreds of thousands.
Quick Fact
Biological Diversity Convention
An international agreement called the Convention on Biological Diversity was created to preserve and safeguard the variety of life on Earth. This covers preservation, sustainability, and the equitable distribution of the fruits of genetic study and resources. In order to monitor and conduct research on species' populations and habitats, the Convention on Biological Diversity has created the IUCN Red List of endangered species.
Andorra, the Holy See (Vatican), and the United States are the only three countries that have not ratified the Convention on Biological Diversity.
Little George
The Lonesome George was the planet's most threatened species up until 2012. He was the sole known surviving member of the Pinta Island tortoise species. Only one of the Galapagos Islands, Pinta, is home to the Pinta Island tortoise. A solitary Pinta Island tortoise female may be found, thanks to a $10,000 bounty issued by the Charles Darwin Research Station, a scientific center in the Galapagos. Lonesome George passed away on June 25, 2012, adding another extinct species to the list.