Why whites are divided into black haired whites, red haired whites, and blonde whites

Mainly there are more Spanish descent, Spain and Italy all belong to southern European countries, and people in southern European countries are all black haired, and the so-called blonde hair is all northern European.

People of Germanic descent will have blonde and red hair.

Most of those stars are Southern Europeans from Eastern Europe.

A lot of people are gypsies, Jews, those ethnic groups are dark-haired, and Southern Europeans are more good at acting, so a lot of the Hollywood stars are Southern Europeans.

The main thing is that North America was formerly a Spanish colony, and the Spaniards were all black-haired, and later became American soil, and people of Spanish ancestry, people of Italian ancestry, were integrated into American society, so there were a lot of people in the United States who were black-haired, and the main characteristics of southern Europeans Among European immigrants, people from southern European countries immigrated the most, so it is common for Americans to have more black hair, and Americans are mainly red-skinned.

Whites are divided into black-haired whites, red-haired whites, and blonde whites, mainly due to genetic factors and evolutionary processes. The difference in hair color is mainly due to the different types and proportions of pigments contained in the hair. The diversity of human hair color is the result of a combination of factors, including genetics, ethnicity, genetics, geography, and lifestyle.

1.Genetic factors: Human hair color is controlled by multiple genes that mutate and interact to cause different hair colors. For example, the allele MC1R can encode different hair colors, and other genes can also have an impact on hair color.

2.Racial heredity: Over the course of evolutionary periods, gene frequencies have also changed across races, which has led to differences in the distribution of hair color between different races.

For example, whites generally have genes for blonde, red, or white hair, while blacks typically have genes for black curly hair.

3.Environmental factors: Environmental factors can also affect the formation of hair color, for example, bad habits such as smoking and drinking alcohol during pregnancy in pregnant women may negatively affect fetal hair color.

In addition, diet can also have an impact on hair color, for example, consuming too much copper may cause hair to turn green.

4.Physiological factors: Some physiological factors can also affect hair color, such as age, hormone levels, diseases, etc. Hair may turn gray as we age, and this is because the pigment cells in the hair gradually decrease as we age.

In conclusion, human hair color is the result of a combination of factors, including genetics, ethnicity, genetics, environment, and physiological factors. It's the diversity of these factors that makes everyone's hair color unique.

ABC, the black and tan eyes of a person, the blonde and black hair of a person, the black and white of rabbit fur, are all different manifestations of the same trait, which are relative traits, and ABC is correct;

D. White flowers and smooth seeds are two traits auspicious, not relative, and D is incorrect

Therefore, the choice is d.