The covariation of hair form and skin color are an exception to the pattern of clinal discordance. Hair on the head varies, and for a biological reason—spiral and wooly hair insulates the head from ultraviolet radiation.
What are examples of clinal distribution?
One easily visible example of a clinal distribution seen worldwide is the patterning of human variation in skin color. Whether in southern Asia, sub-Saharan Africa, or Australia, dark brown skin is found.
What is concordant variation?
HUMAN BIOLOGICAL VARIATION. … They noted that if traits are largely concordant, then the study of the variation in one trait will reveal the pattern in the other. However, if the opposite is true, and traits are discordant or nonconcordant, then population variation must be studied one trait at a time.
What are some common human variations?
| Type of Variation | Example |
|---|---|
| Sex | Klinefelter syndrome Turner syndrome Female Male |
| Skin Color | Human skin color Albinism |
| Eye Color | Eye color Martin scale |
| Hair Color | Human hair color Hair coloring |
What is a Cline and how does it help explain human variation?
Clines are gradations in biological features over geographic space. They refer to continuous degrees of difference in either phenotype or genotype across or within human populations. A given cline consists of the gradient in frequency of a single trait over space.
What is the meaning of clinal?
(klīn) A gradual change in a character or feature across the distributional range of a species or population, usually correlated with an environmental or geographic transition. [From Greek klīnein, to lean, see klei- in Indo-European roots.] clin′al (klī′nəl) adj.
Why is skin color a Cline?
The most easily perceived trait that has a clinal distribution is skin color. … The transition of pigmentation from the tropics to northern parts of the globe follows an unbroken gradation, making the distribution of skin color a true cline. The substance that accounts for pigment in the skin is called melanin.
What is Clinal distribution?
Genetically inherited traits often have a clinal distribution. That is to say there is a continuous, progressive gradation moving from one geographic region to another. … Such patterns can result when selective pressures differ from one region to another and when people mate mostly with their immediate neighbors.
What is non concordant?
Filters. Discordant, inharmonious, disconsonant, not in keeping with, not agreeable with, disagreeing. The patient’s left leg symptoms were nonconcordant with the right leg symptoms. adjective.
What is example of concordance?
The definition of concordance is an agreement, or an alphabetical list of primary words used by an author. An example of a concordance is two friends agreeing to go into business in a certain way. An example of a concordance is a list showing how many times the word Jesus shows up in the Bible and in what passages.
Why do humans vary in size?
About 80 per cent of the normal variation in human height is the result of inherited genetic differences between people, with the rest of the height difference being due to environmental influences, such as diet or upbringing.
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What are the three types of genetic variation?
Genetic variation occurs mainly through DNA mutation, gene flow (movement of genes from one population to another), and sexual reproduction.
What are examples of variations?
For example, humans have different coloured eyes, and dogs have different length tails. This means that no two members of a species are identical. The differences between the individuals in a species is called variation.
What is an example of a cline?
A cline is the specific set of traits in a population of a given species that have been influenced by the local environment. For example, a population of warm-blooded animals that lived in a cooler climate closer to the North Pole would have larger bodies, allowing them to better conserve heat.
What external factors might produce a cline?
What external factors might produce a cline? A cline is a graded change in a character along a geographic axis. Some clines are produced by a gradation in an environmental variable, as illustrated by the impact of temperature on the frequency of a cold-adaptive allele in mummichog fish.
What is cline in taxonomy?
In biology, a cline (from the Greek κλίνειν klinein, meaning “to lean”) is a measurable gradient in a single character (or biological trait) of a species across its geographical range. …