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There was fairly little mixing between European settlers and the first peoples in what is today USA and Canada. There was extensive mixing in what is today Mexico (modern day: 65% Mestizo, 17.5% Amerindian, 16.5% White, 1% Black, Asian, or other, source: wiki: Mexico. Argentina had very little mixing (modern day: 97% European, 3% Mestizo, source: wiki: Argentina ).
Are there existing theories, literature?
Here are my rough ideas, (disclaimer: not backed up with research!)
Gender balance of settler community
If a settler community was considered a family destination (like the USA), then European men and women moved and had children with each other. Settler communities that were composed primarily of men would mate with women from the first peoples.
Religious conversion and development of new national identity
Shared religion and integration into a shared national community would make mating more likely. There was large-scale conversion to Catholicism among first peoples in Mexico. There was not large-scale conversion to the varieties of Christianity among first peoples in USA/Canada. Co-religionists would make more feasible mating partners. What is more, co-religionists could be more likely to develop a shared sense of national identity (e.g., as "Mexicans") than a people following very different religions. Having different senses of national identity would make people less likely to mate (e.g., in Canada and USA).
I personally don't like this question because it gives credence to racial theories. Scientifically speaking, there is more variation from individual to individual than there is between peoples of different ethnic backgrounds.
Anyway, addressing your question: One theory I've heard is that King Phillip's war was the cause. The idea behind this theory is simple: When the pilgrims arrived at Plymouth Rock in 1620, the Native Americans aided them in establishing themselves, and helped them not to starve, by teaching the pilgrims, people who had lived as refugees in the Urban Netherlands for a generation, to learn farming and survival skills. They even celebrated the first thanksgiving together. In New England, generally speaking, the contact between the Europeans and Natives Americans were more than cordial - there was intermarriage, and conversion to Christianity, and peaceful coexistence. The primary difference between the two populations was more one of lifestyle than one of race.
By about 1670, the mixing of the two populations, combined with declining Native American populations and quality of life, set the stage for "King Phillips War" Supporting Source and Wikipedia links. The common narrative goes like this: Metacom, a Native American nicknamed "King Phillip" by the settlers, started attacking and slaughtering the colonial population. The English colonialist responded in kind, slaughtering the Native American population. Both sides killed whichever "enemy" they came across, including women and children. Persons of mixed heritage were victims of both sides. 5% of the settler and 40% of the Native American population died. The general slaughter led to well defined racial identities that didn't exist before the war, and set the stage for future separate ethnic trends in North America.
There is, of course, an opposing theory presented in this book that the war was not about race at all, but was instead a civil war intended to increase British control of the region, which used "divide and conquer" strategies, split what was a unified community to increase colonial power. One results of the increase British control was marginalization of the Native population, and a stronger racial identity for the settlers.
Traditional Chinese marriage
Traditional Chinese marriage (Chinese: 婚姻 pinyin: hūnyīn ) is a ceremonial ritual within Chinese societies that involves not only a union between spouses, but also a union between the two families of a man and a woman, sometimes established by pre-arrangement between families. Marriage and family are inextricably linked, which involves the interests of both families. Within Chinese culture, romantic love and monogamy was the norm for most citizens. Around the end of primitive society, traditional Chinese marriage rituals were formed, with deer skin betrothal in the Fuxi era, the appearance of the "meeting hall" during the Xia and Shang dynasties, and then in the Zhou dynasty, a complete set of marriage etiquette ("six rituals") gradually formed. The richness of this series of rituals proves the importance the ancients attached to marriage. In addition to the unique nature of the "three letters and six rituals", monogamy, remarriage and divorce in traditional Chinese marriage culture are also distinctive.
76 Reasons Why People Choose to Remain Single
Why do women prefer more masculine men during the fertile phase of their menstrual cycle? Why are men more distressed by a partner’s sexual infidelity than their emotional infidelity? And why do female dating profiles advertise beauty, while male dating profiles boast about wealth?
The relatively new field of evolutionary psychology has answered all of these questions, and more. By applying evolutionary theory to the study of human mating behavior, psychologists have revolutionized our understanding of attraction, jealousy, lust, and love.
But surely there’s one question that evolutionary psychology can never answer: Why does anyone stay single?
If natural selection favors individuals who are best able to survive and reproduce, what possible benefit might there be to bowing out of the mating market? For countless generations, our ancestors have successfully reproduced. If evolution has shaped human desire, the prospect of life as a singleton should be as terrifying and impossible as holding your breath for 20 minutes. And yet, for many, remaining single is a conscious lifestyle choice. Why?
76 Reasons to Stay Single
It’s a question that occurred to Menelaos Apostelou, an evolutionary psychologist at the University of Nicosia in Cyprus. To answer it, he gathered together 120 men and women for an in-depth discussion of the reasons why people might stay single. After discarding very similar answers, he had a list of 76 distinct reasons.
Next, Apostelou sent a team of research assistants onto the streets of Cyprus to ask the public how likely each of the 76 reasons might be to cause them to stay single. Some reasons tended to go with others: If someone said they were worried that nobody wanted to be with them, they were also likely to say that they couldn’t find the right person. If they said they didn’t want to lose their freedom, there was a good chance they would also say they like to have their own space. Through these surveys, Apostelou found that the 76 reasons clustered into 15 groups, which in turn clustered into three super-groups, or broad and distinct reasons people choose to stay single:
Super-group 1: freedom of choice included reasons that seemed to be about wanting to flirt, be free, not commit, avoid conflict and constraints, and feeling that one is already doing well without a partner, as well as having different priorities and simply enjoying being alone.
Super-group 2: constraints included reasons relating to sexual dysfunction and other factors that might hold a person back from starting a relationship, such as a health problem, being older, or having children from a previous relationship.
Super-group 3: difficulties with relationships included reasons to do with bad experiences in previous romantic encounters, a lack of trust in others, a fear of change, an unwillingness to compromise, difficulties starting a relationship, and a feeling that one would not be better off with a partner.
Although most people will identify with reasons in each of the three super-groups, people who chose a reason from within one super-group were more likely to choose other reasons from within that same group. This suggests that, at least among Apostelou’s Greek-Cypriot research volunteers, there are three broad reasons why people choose to stay single—because they like to be free to set other priorities, because they feel cannot successfully compete for a partner, and because they find relationships difficult.
An Evolutionary Account
So far, so good. But what does this have to do with evolution? Apostelou’s argument goes like this:
Evolution has selected for ways of thinking and behaving that enhance our reproductive success, or the number of offspring we produce. So we shouldn’t be surprised that humans are motivated to pursue relationships. However, it should be surprising if humans pursued relationships indiscriminately, regardless of the costs.
For example, men with a greater earning potential tend to be more attractive to women. This means it makes less sense for a man to settle down with his high-school sweetheart at 18 than to focus on his education and developing his career, so that he can be more competitive for mates later (although a man with fewer opportunities for advancement might do better to marry young). By the same token, a woman who decides to marry the first man she dates might be making a bad move, but after dating more men, she will be better placed to make an informed decision about the best partner for her.
In both cases, these people would be staying single to exercise freedom of choice, applying reasons from Apostelou’s first super-group, but in a manner that is consistent with evolutionary theory. Staying single can allow you to pursue short-term flings, gain experience evaluating potential matches, and develop yourself to better attract desired partners later.
Now imagine another set of possibilities: If you are ill, it might not be the best time to settle down. You may have a better chance of finding an attractive partner if you wait until your health improves. If you have young kids with an ex-partner, this might make you less attractive to a new partner. In this case, you might decide to invest your energy and resources in your children, instead of a romantic relationship. If you are older, or infertile, you may choose to invest in the children of relatives or in your own grandchildren.
All of these constraints could lead you to reason that it makes more sense to stay single, at least for the time being—and again, your behavior would make sense in light of evolutionary theory.
We’ve seen how reasons for staying single that fit within Apostelou’s first and second super-groups are not incompatible with natural selection. But what about the third super-group — difficulties with relationships? Here, Apostelou takes a different tack. He reasons that navigating romantic relationships is a modern phenomenon. For much of human history, men may have secured partnerships with women by simply out-competing other men in physical combat, gorilla-style. Meanwhile, women may have had less choice in their partners, with a loose system of marriages arranged by parents as the norm. Apostelou says:
"In ancestral human environments, individuals would get mates from their parents or by fighting other men, rather than by addressing opposite-sex partners directly. Thus, selection forces had not enough time to augment the capacity of individuals to approach and persuade other individuals to establish an intimate relationship with them."
In other words, those who stay single because they have trouble flirting, because they are too shy, or because they believe nobody wants to be with them are not operating a shrewd, long-term mating strategy. They are not unconsciously weighing the costs and benefits of settling down now rather than later. Instead, they are suffering the consequences of our species’ rapid development from hunter-gatherers to citizens of modern industrial economies in the (relative) blink of an eye.
In Apostelou’s view, natural selection "wants" these people to find a partner, but human circumstances have changed so quickly that evolution has yet to come up with a solution to these dating woes.
For an audio version of this story, see the 11 April 2017 episode of The Psychology of Attractiveness Podcast.
Support me at patreon.com/psychology and receive bonus podcasts and blogs.
Apostolou, M. (2017). Why people stay single: An evolutionary perspective. Personality and Individual Differences, 111, 263-271.
How Does Cloning Work?
Cloning may invoke an image of an army of identical cows or sheep churned out factory-style, but in actuality, the process is much more laborious.
The term "cloning" generally applies to a process more technically known as somatic cell nuclear transfer. What that means is that the DNA from the cell of an adult animal (take cows, for example), called the "donor," is extracted from the cell (usually a skin cell taken in a biopsy) and inserted into an egg cell from another cow. The egg cell has had its nucleus removed so that it will read and duplicate the DNA of the donor cell.
The newly created embryo is then zapped with electricity so that it starts multiplying, until it becomes a blastocyst (a small clump of cells that forms after an egg is fertilized), which is then implanted into a surrogate mother. The resulting newborn will be an identical genetic replica to the donor cow.
Cows have been cloned more than other animals because obtaining eggs from the cow is slightly easier than for swine, said geneticist Bill Muir of Purdue University, an author of a 2002 National Academy of Sciences report on the scientific concerns of animal biotechnology.
This process differs from other methods of artificial breeding, such as in vitro fertilization, in that it uses adult cells, instead of embryos.
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Some common doppelganger fic premises include:
- Two characters played by the same actor (a Same-Actor Crossover)
- A character + another version of that character from an alternate universe
- The same person at two different points in their personal timeline
- Clones, either canon or non-canon (aka clonecest) or an Evil Twin, or twincest
- Secret twins or twins separated at birth a-la Lottie and Lisa/Parent Trap
- "Artificial" doppelgangers, such as shapeshifters or robot or holographic duplicates
- A random doppelganger with no explanation whatsoever!
The Advantages of the Featherless Chicken
According to the research team that developed this breed, these featherless birds pose no danger to people’s heath when consumed. More or less, they taste the same and have equal nutritional value. Furthermore, they come with certain advantages, including:
- Faster growth
- Their meat is lower in fat
- They are energy efficient and require less food to produce the same amount of meat
- They can adapt better in hot climates
- The breed is more ecofriendly, as there is no need for plucking, a process that contaminates large quantities of water with feathers and fat tissues.
Truth be told, all the above sound quite logical, considering that these birds produce no feathers.
Before moving to the disadvantages, let&aposs see a video showing them in action. Jump to 1:40 if you are impatient.
Why Are Mules Sterile?
According to a friend of mine, mules are pretty much the best thing since sliced bread. He says they are smarter, more patient, and easier to work with than their horse mother and donkey father. After spending time around his beauties, I tend to agree. Unfortunately, I can’t just wait for his molly to foal – because she most likely never will. All male mules (johns) and most female mules (mollies) can’t reproduce. But why are mules sterile?
The key is in the chromosomes. Return with me now to junior high biology. Remember DNA, mitosis and meiosis? No? I didn’t either, so here’s a refresher: DNA (deoxyribonucleic acid – don’t worry, there won’t be a test) contains the genetic instructions for all living things. DNA is organized into chromosomes, the number of which varies from species to species (humans have 46 chromosomes an earthworm has 36 a goldfish, 100 to 104). You might notice all these numbers are even this is because chromosomes are usually organized in sets of homologous pairs (this will be important later). They are “homologous” because they contain the same genes in the same order. For example, humans have 23 pairs, and the gene for brown eyes is located on both chromosomes of pair 15.
For organisms with a cell nucleus, mitosis is the process of cell division needed to create new cells. In mitosis, the chromosomes are duplicated, the nuclear membrane dissolves, and then the cell splits in two, with each new cell getting half of the duplicate chromosomes. This is how organisms form and grow. Starting from a fertilized egg, cell division occurs, then happens again and again, until you have the trillions of cells that make up a dog, a goldfish or a human.
But it’s what happens before that first division that makes mollies babyless. For sexual reproduction, you need a cell from each parent that contains half of the necessary chromosomes (one from each homologous pair). These cells are created through a process of cell division called meiosis.
First, all the chromosomes are duplicated, then these duplicate duos align with their original homologous partner and its duplicate. While they are aligned, some crossover between the pairs occurs (you can have both your maternal grandfather’s eyes and your maternal grandmother’s smile). At this point the homologous chromosomes are separated, and the cell divides, giving the intermediate cells two versions of a chromosome from each homologous pair. Then these cells divide, separating the duplicates, and creating four cells with one chromosome from each original homologous pair.
But, what happens if the pairs aren’t so homologous? This is where the process breaks down in interspecies hybrids like the mule. The chances that two different species can form working homologous pairs are slim. Males of interspecies hybrids are usually sterile (their sperm doesn’t develop completely), and fertile females appear rarely.
Our molly mule has an extra strike against her because horses have 64 chromosomes (32 pairs), and donkeys have 62 chromosomes (31 pairs). When they mate, a mule receives 32 chromosomes from her mother and 31 from her father. This leaves a chromosome without a partner, and adds one more possibility for error. (Once in a great while, all the possible errors are avoided, and a molly foals.) Though even hybrids from species with the same number of chromosomes, like tigers and lions (whose offspring are called ligers or tigons), have trouble with fertility.
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Mitosis, a process of cell duplication, or reproduction, during which one cell gives rise to two genetically identical daughter cells. Strictly applied, the term mitosis is used to describe the duplication and distribution of chromosomes, the structures that carry the genetic information.
What is mitosis?
Mitosis is a process of cell duplication, in which one cell divides into two genetically identical daughter cells. In the various stages of mitosis, the cell’s chromosomes are copied and then distributed equally between the two new nuclei of the daughter cells.
How are mitosis and meiosis different?
Mitosis is the division of a cell into two daughter cells that are genetically identical to the parent cell. Meiosis is the division of a germ cell into four sex cells (e.g. egg or sperm), each with half the number of chromosomes of the parent cell. Mitosis is a means of asexual reproduction, whereas meiosis is necessary for sexual reproduction.
Why is mitosis important to organisms?
Mitosis is important to multicellular organisms because it provides new cells for growth and for replacement of worn-out cells, such as skin cells. Many single-celled organisms rely on mitosis as their primary means of asexual reproduction.
A brief treatment of mitosis follows. For a full treatment, see growth: In cells cell: Mitosis and cytokinesis.
Prior to the onset of mitosis, the chromosomes have replicated and the proteins that will form the mitotic spindle have been synthesized. Mitosis begins at prophase with the thickening and coiling of the chromosomes. The nucleolus, a rounded structure, shrinks and disappears. The end of prophase is marked by the beginning of the organization of a group of fibres to form a spindle and the disintegration of the nuclear membrane.
The chromosomes, each of which is a double structure consisting of duplicate chromatids, line up along the midline of the cell at metaphase. In anaphase each chromatid pair separates into two identical chromosomes that are pulled to opposite ends of the cell by the spindle fibres. During telophase, the chromosomes begin to decondense, the spindle breaks down, and the nuclear membranes and nucleoli re-form. The cytoplasm of the mother cell divides to form two daughter cells, each containing the same number and kind of chromosomes as the mother cell. The stage, or phase, after the completion of mitosis is called interphase.
Theoretical perspectives on ancestry and identity
That race and ethnicity are socially constructed is one of the axioms of contemporary social science (Omi 2001 Omi and Winant 1994). But how, exactly, are they constructed and by whom? At the individual level, intergenerational socialization is the primary mechanism for communicating group identities. Children and adolescents develop ethnic consciousness through interaction with parents, siblings, and other family members (Perry 2002). Nonverbal forms of socialization also take place through observation of family behavior, as well as informal interactions with friends and neighbors and in formal settings like schools, businesses, and institutions. These experiences foster a sense of the 𠇎thnic self” through which children learn who they are and, just as important, who they are not.
While childhood socialization is the crucible of racial and ethnic identity formation, the boundaries of racial and ethnic categories and the history underlying their creation are much less straightforward. One view is that racial and ethnic identities are imposed from above. Terms like “Hispanic” and 𠇊sian American” are unique to the United States and were created for data gathering and statistical tabulations by governmental agencies. But these categories also reflect the aims of panethnic coalitions and political advocacy groups, who played a direct role in the construction of racial and ethnic classifications adopted by government statistical authorities (Choldin 1986 Espiritu 1992: 99 Farley 2002). More importantly, individuals are free to report their racial and ethnic identity in the census, social surveys, and the vast majority of administrative forms that include a space for racial and ethnic identification. Respondents are instructed to mark the race or races they 𠇌onsider themselves to be” (see Figure 1 ), and those who refuse to identify with the listed categories can write in one of their own. The assumption is of widely shared understandings (folk meanings) of racial and ethnic categories and their boundaries.
As noted above, the administrative expectation, given the wording of the category definitions, is that folk understandings of race and ethnicity will be consistent with ancestry—the geographic origins of one's ancestors. For a number of reasons, however, responses to questions about race and ethnicity only partially reflect ancestral origins. Ancestry is a potentially objective characteristic—the countries or regions of birth of a respondent's parents, grandparents, great grandparents, and so on. Identities, by contrast, are subjective claims of affiliation with groups that are recognized in society. Identities overlap with ancestries, but they are also shaped by knowledge, socialization, physical appearance, and culture, among other factors. Birthplace does not vary by social context, whereas identities are contextual by definition. The birthplaces of recent ancestors are often passed down in family conversations (unless there are conscious reasons to suppress them), but for individuals whose Old World roots are distant or complex, there may be only a dim awareness of, and minimal interest in, ancestral origins. Some people with the same ancestry will respond differently to census questions about racial and ethnic identity.
The idea that humankind shares common ancestry through evolution and prehistoric migrations “out of Africa” is widely recognized (Diamond 1993 Oppenheimer 2003). Less well known is that all human beings alive today are likely to share at least one common ancestor born a few thousand years ago, and that everyone alive today is likely to be descended from the same mother and father who lived a few thousand years earlier (Rhode et al. 2004). These conclusions are derived from simulations that consider a range of probabilistic assumptions about the likelihood of mating between adjacent and isolated populations throughout history. In fact, if human mating were fully random, everyone alive today would share a common ancestor just 20 generations back, around 1500 ce assuming 25 years per generation.
Common ancestry does not mean that populations share the same genotype, however. Most genes have only a 50 percent chance of being passed on to the next generation, 5 so sporadic contact between isolated populations would not result in a large amount of genetic admixture. More importantly, even tiny differences in the genome, if differentially selected between populations, can account for variation in inherited physical features such as eye, skin, and hair color. These superficial differences, which arose in prehistory, probably resulted from natural selection in different climatic zones and can persist for many generations (Cavalli-Sforza and Cavalli-Sforza 1995).
Despite long stretches of relative isolation, there is evidence that geographically distant populations maintained some reproductive contact throughout history (Rhode et al. 2004), and the pace of contact and exchange has increased dramatically in the last one thousand years, and especially since 1500 (Davis 1974 Diamond 1997 Hoerder 2002 McNeill 1984). In addition to trade and warfare, long-distance contacts invariably led to intermarriage and other sexual relationships that produced offspring of mixed ancestry. Intermarriage and ethnic blending, in turn, diminished physical and cultural differentiation, a process nowhere more evident than in the New World where migrants from Europe, Africa, and Asia intermixed with indigenous peoples, creating entire continents of ethnically and racially mixed populations over the last few centuries (Harris 1964).
Figure 2 underscores the high probability of shared descent for most Americans: it plots the expected number of ancestors over the last 225 years for a person born in 2000 (time is shown along the horizontal axis). Because the number of ancestors doubles in each prior generation (2 parents, 4 grandparents, 8 great grandparents, etc.), the number of ancestors from any previous generation is equal to 2 x , where x is the number of prior generations. If the length of each generation is about 25 years, then a person born in 2000 would have had 512 ancestors in 1800 and 1,024 around the time of the American Revolution. Continued exponential extrapolation will of course predict an impossible number of ancestors—more persons than were alive𠅋y the close of the first millennium, a fallacy that results from double-counting persons who occupy multiple slots on a family tree. Most of our distant ancestors were related to one another, just as we are distantly related to most people alive today (Ohno 1996).