Circles of latitude are often used as boundaries between countries or regions. The five major circles of latitude are, starting from the North Pole and finishing at the South Pole; the Arctic Circle, the Tropic of Cancer, the Equator, the Tropic of Capricorn and the Antarctic Circle.

Four special parallels of latitude mark a specific area on the planet that has a unique relationship with the sun. In addition, these four lines mark the geographic boundaries of the frigid and torrid zones, which were first coined by Greek philosopher Aristotle.

The four important parallels of latitude besides the Equator are:

• The Tropic of Cancer at 23 ½° N in the northern hemisphere.
• The Tropic of Capricorn at 23 ½° S in the southern hemisphere.
• The Arctic circle at 66 ½° north of the Equator, and.
• The Antarctic circle at 66 ½° South of the Equator.

• artic circle.
• tropic of cancer.
• equator.
• tropic of Capricorn.
• Antarctic circle.

English

The prehistoric humans revealed by this find were called Cro-Magnon and have since been considered, along with Neanderthals (H. neanderthalensis), to be representative of prehistoric humans. Modern studies suggest that Cro-Magnons emerged even earlier, perhaps as early as 45,000 years ago.

In Eurasia, interbreeding between Neanderthals and Denisovans with modern humans took place several times. The introgression events into modern humans are estimated to have happened about 47,000–65,000 years ago with Neanderthals and about 44,000–54,000 years ago with Denisovans.

The upshot is that the Cro-Magnon mtDNA matches that of modern humans and does not contain patterns found in Neandertal mtDNA, the team reports online today in PLoS ONE. That result argues against the inbreeding hypothesis, says Barbujani.

Assortative mating. Human mating is inherently non-random.

Our human evolutionary lineage includes many species and relatives, including Neanderthals and Denisovans. Scientists already knew that modern humans interbred with Neanderthals and Denisovans 40,000 to 60,000 years ago. It’s the earliest known example of mating between different human populations.

2. Sex Between Cousins May Be Illegal Incest. Many states define their incest laws in parallel with their marriage laws, meaning if you cannot get married in that state because of familial relation, you also cannot legally have sex.

Current Alabama law requires permission from both parents, judicial approval, and does not allow a pregnancy exception, which is a law that means a girl younger than 16 years old can marry if she is pregnant.

Cousin marriage, or “consanguinity” (marriages among couples who are related as second cousins or closer), is allowed and often encouraged throughout the Middle East, and in Muslim countries such as Pakistan. As of 2003, an average of 45% of married couples were related in the Arab world.

The reason is, some families fear their daughters will be looked down upon, or treated badly, by a family of a higher caste. So the daughters marry someone who is in the same caste as them. And because there might not be many people in each caste, they often end up marrying their cousin.

Royal intermarriage is the practice of members of ruling dynasties marrying into other reigning families. Alternatively, kinship by marriage could secure an alliance between two dynasties which sought to reduce the sense of threat from or to initiate aggression against the realm of a third dynasty.

Summary

Children of first-cousin marriages have an increased risk of autosomal recessive genetic disorders, and this risk is higher in populations that are already highly ethnically similar. Children of more distantly related cousins have less risk of these disorders, though still higher than the average population.

It is against the law to marry your parent, grandparent, child, grandchild, brother, sister, half-brother or half-sister. If you are already married, you cannot marry another person. It is against the law in Canada to have more than one spouse.

four wives