Some of the original shrubs grew wild in the Florida Keys. It became clear that the originally introduced shrubs (now known as "Mexican limes") had modified their fruits. These were darker green than the original Persian limes, they also had a thicker skin.
In biological taxonomy, race is an informal rank below the level of subspecies. It may be used as a higher rank than "strain". There are various definitions. Races may be genetically distinct populations in the same species, or they may be defined in other ways, e.g. geographically, or physiologically. Genetic isolation between races is not complete (some interbreeding takes place between the groups).
However, the genetic differences are not (yet) enough to put the groups into separate species. The term "race" is recognized by some, but is not governed by any of the formal codes of biological classification.
In former times, scientists often divided human beings into races. For example, they called people with a dark skin "Negroid" or "black race". But, human gene sequences are very similar compared to many other animals. This is one reason why modern biology says that there is only one human race.
Phenotype
The phenotype of an organism is the whole set of characters (or traits) of that organism.
It does not mean just 'what you can see on the surface'. Rather, it means anything which can be made visible by suitable means. For example, blood groups are definitely a part of the phenotype. However, they are not visible just by looking at a person.
In biology, the phenotype is distinguished from the genotype. This was proposed by Wilhelm Johannsen in 1911 to make clear the difference between an organism's heredity and what that heredity produces. The distinction is similar to that proposed by August Weismann, who distinguished between "germ plasm" (gametes or their stem cells) and "somatic cells" (the body).
The phenotype is important because it is exposed to natural selection:
Phenotypes are determined mainly by genes and are influenced by environmental factors. So, knowing the genome of an organism does not give an exact prediction of its phenotype.
Traits vary greatly in how much they owe to heredity (nature vs nurture). The interaction between genotype and phenotype has often been conceptualized by the following relationship:
The term 'phenotype' must include characteristics that can be made visible by some technical procedure (such as blood types). Another extension adds behaviour to the phenotype since behaviours are also affected by both genotypic and environmental factors.
The idea of the extended phenotype has been developed by Richard Dawkins to mean all the effects a gene has on the outside world that may influence its chances of being inherited. These can be effects on the organism carrying the trait, the environment, or other organisms. For instance, a beaver dam might be considered a phenotype of beaver genes, the same way beavers' powerful incisor teeth are phenotype expressions of their genes. Dawkins also cites the effect of an organism on the behaviour of another organism (such as the devoted nurturing of a cuckoo by a parent clearly of a different species) as an example of the extended phenotype.
Key lime
The Key lime is a citrus fruit. Its Latin name is "Citrus aurantiifolia" (often, less correctly: "C. aurantifolia"), or "Citrus" x "aurantiifolia" (Christm.) Swingle. It is also known as the Mexican lime, West Indian lime or Bartender's lime. It is a shrub that grows to about 5m in height.
Its fruit is 2.5-5 cm in diameter (1-2 in). The fruit is yellow when ripe but usually it is picked green. It is smaller, seedier, has a higher acidity, a stronger aroma, and a thinner rind than that of the more common Persian lime. It is valued for its unique flavor compared to other lime. The Key lime usually has a more tart and bitter flavor. It is perhaps most distinguished as an ingredient in the Key lime pie.
"C. aurantiifolia" is a shrubby tree, that grows to 5 m (16 ft), with many thorns. Dwarf varieties are popular with home growers and can be grown indoors in winter in colder climates. The trunk rarely grows straight, with many branches that often originate quite far down on the trunk. The leaves are ovate 2.5–9 cm (1–3.5 in) long. They resemble orange leaves (the scientific name "aurantiifolia" refers to the leaves' resemblance). The flowers are 2.5 cm (1 in) in diameter. They are yellowish white with a light purple tinge on the margins. Flowers and fruit appear throughout the year but are most abundant from May to September .
"C. aurantiifolia" originally came from Southeast Asia. It was introduced through the Middle East to North Africa and Europe during the Crusades. Spanish explorers then took it to the West Indies (at some point including the Florida Keys) contemporaneously with Columbus, then tropical and sub-tropical North America including Mexico, Florida, and later California . The English name "lime" was derived from the Persian name لیمو "Limu" in this course. "Key" would seem to have been added some time after the Persian lime cultivar became more important commercially in the United States. This was after the hurricane of 1926. The hurricane destroyed most U.S. "C. aurantiifolia" plants. Some plants growing in the wild in the Keys survived the hurricane. Since the North American Free Trade Agreement came into effect, many Key limes are grown in Mexico and Central America. They are also grown in Texas and California.
Age of Discovery
The Age of Discovery or Age of Exploration was a period from the early 15th century that continued into the early 17th century, during which European ships traveled around the world to search for new trading routes and partners.
They were in search of trading goods such as gold, silver and spices. In the process, Europeans met people and mapped lands previously unknown to them. Among the most famous explorers of the period were Christopher Columbus, Vasco da Gama, Pedro Álvares Cabral, John Cabot, , Juan Ponce de León, Juan Sebastian Elcano, Bartholomeu Dias, Ferdinand Magellan, Willem Barentsz, Abel Tasman, Jean Alfonse, Jacques Cartier, Samuel de Champlain, Willem Blaeu and Captain James Cook.
Henry the Navigator started by paying Portuguese sailors to explore the west coast of Africa. In 1419 Joao Goncalves Zarco discovered the Madeira Islands. Later in the 15th century, Vasco da Gama reached the southwestern tip of Africa and established the city of Cape Town, a Portuguese colony. This opened the way to the Indian Ocean. In the next two centuries, the Portuguese created a great trading empire on coasts of Africa, the Arabian Peninsula, and India. The Portuguese Empire eventually weakened after the Dutch East India Company rose as the major power in Indian Ocean trade.
In a hurry to compete with Portugal for a colonial empire, Spain sent Christopher Columbus to the opposite route of the Portuguese. Instead of going south along the west coast of Africa, Columbus sailed across the Atlantic Ocean. He believed that he came to Asia. Later, some Spanish sailors found out that this land was a different continent than Asia. It is now called the Americas.
In the 16th century, Spanish conquistadores gained the whole of what later became Latin America, except some British and French colonies in northeastern South America, and Brazil, which belonged to Portugal. The Spanish concentrated on conquest, unlike the Portuguese who focused on trading. They eventually developed a vast colonial empire, in contrast to the Portuguese who ruled a few islands and coastal cities along the Indian Ocean. When Spain and Portugal were united under King Philip II of Spain , their combined empire was the largest on earth.
In 1522 the fleet of Ferdinand Magellan returned to Spain. The survivors were the first ever to sail all the way around the world.