Input: Article: The deliberate or accidental hybridising of two or more species of closely related animals through captive breeding is a human activity which has been in existence for millennia and has grown in recent times for economic purposes. The number of successful interspecific mammalian hybrids is relatively small, although it has come to be known that there is a significant number of naturally occurring hybrids between forms or regional varieties of a single species.[citation needed] These may form zones of gradation known as clines. Indeed, the distinction between some hitherto distinct species can become clouded once it can be shown that they may not only breed but produce fertile offspring. Some hybrid animals exhibit greater strength and resilience than either parent. This is known as hybrid vigor. The existence of the mule (donkey sire; horse dam) being used widely as a hardy draught animal throughout ancient and modern history is testament to this. Other well known examples are the lion/tiger hybrid, the liger, which is by far the largest big cat and sometimes used in circuses; and cattle hybrids such as between European and Indian domestic cattle or between domestic cattle and American bison, which are used in the meat industry and marketed as Beefalo. There is some speculation that the donkey itself may be the result of an ancient hybridisation between two wild ass species or sub-species. Hybrid animals are normally infertile partly because their parents usually have slightly different numbers of chromosomes, resulting in unpaired chromosomes in their cells, which prevents division of sex cells and the gonads from operating correctly, particularly in males. There are exceptions to this rule, especially if the speciation process was relatively recent or incomplete as is the case with many cattle and dog species. Normally behavior traits, natural hostility, natural ranges and breeding cycle differences maintain the separateness of closely related species and prevent natural hybridisation. However, the widespread disturbances to natural animal behaviours and range caused by human activity, cities, dumping grounds with food, agriculture, fencing, roads and so on do force animals together which would not normally breed. Clear examples exist between the various sub-species of grey wolf, coyote and domestic dog in North America. As many birds and mammals imprint on their mother and immediate family from infancy, a practice used by animal hybridizers is to foster a planned parent in a hybridization program with the same species as the one with which they are planned to mate.

Now answer this question: What is the name given when zones of gradation exits?

Output: clines

Article: The Byzantine Empire ruled the northern shores of the Sahara from the 5th to the 7th centuries. After the Muslim conquest of Arabia (Arabian peninsula) the Muslim conquest of North Africa began in the mid-7th to early 8th centuries, Islamic influence expanded rapidly on the Sahara. By the end of 641 all of Egypt was in Muslim hands. The trade across the desert intensified. A significant slave trade crossed the desert. It has been estimated that from the 10th to 19th centuries some 6,000 to 7,000 slaves were transported north each year.

Question: What time period did the Muslim conquest of North Africa take place?
Ans: mid-7th to early 8th centuries

Here is a question about this article: The Seljuk Empire soon started to collapse. In the early 12th century, Armenian princes of the Zakarid noble family drove out the Seljuk Turks and established a semi-independent Armenian principality in Northern and Eastern Armenia, known as Zakarid Armenia, which lasted under the patronage of the Georgian Kingdom. The noble family of Orbelians shared control with the Zakarids in various parts of the country, especially in Syunik and Vayots Dzor, while the Armenian family of Hasan-Jalalians controlled provinces of Artsakh and Utik as the Kingdom of Artsakh.
What is the answer to this question: When did the Seljuk Empire experience it's decline?
****
So... early 12th century

The problem: Answer a question about this article:
Perhaps the most famous raid by Oeselian pirates occurred in 1187, with the attack on the Swedish town of Sigtuna by Finnic raiders from Couronia and Oesel. Among the casualties of this raid was the Swedish archbishop Johannes. The city remained occupied for some time, contributing to its decline as a center of commerce in the 13th century and the rise of Uppsala, Visby, Kalmar and Stockholm. The Livonian Chronicle describes the Oeselians as using two kinds of ships, the piratica and the liburna. The former was a warship, the latter mainly a merchant ship. A piratica could carry approximately 30 men and had a high prow shaped like a dragon or a snakehead and a rectangular sail. Viking-age treasures from Estonia mostly contain silver coins and bars. Saaremaa has the richest finds of Viking treasures after Gotland in Sweden. This strongly suggests that Estonia was an important transit country during the Viking era.
What type of ship was the liburna?
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The answer: merchant ship

Problem: Please answer a question about the following article about USB:
Sleep-and-charge USB ports can be used to charge electronic devices even when the computer is switched off. Normally, when a computer is powered off the USB ports are powered down, preventing phones and other devices from charging. Sleep-and-charge USB ports remain powered even when the computer is off. On laptops, charging devices from the USB port when it is not being powered from AC drains the laptop battery faster; most laptops have a facility to stop charging if their own battery charge level gets too low.
What is normally powered off whenever the computer is off?
A: USB ports

Question: Read this and answer the question

I Love New York (stylized I ❤️ NY) is both a logo and a song that are the basis of an advertising campaign and have been used since 1977 to promote tourism in New York City, and later to promote New York State as well. The trademarked logo, owned by New York State Empire State Development, appears in souvenir shops and brochures throughout the city and state, some licensed, many not. The song is the state song of New York.

I Love New York was established as advertising in what year?
Answer:
1977