2- Clines (ch.8) Flashcards
Cline
incrementally or gradually changing distributions of traits over geographic regions, which are related to incrementally changing environmental pressures or challenges.
They are more useful because they have biological meaning.
It can also be related to population movements.
- they are represented in maps.
ex: frequency of yellow-brown hair in Australia.
ex: skin color cline
ex: ABO Allele Frequencies
Sexual Selection
There is cultural variation in what is considered attractive or not.
- the function might be cultural.
Lactase Hotspots
1/3 of people produce the lactase enzyme during adulthood, which enables them to drink milk.
- look at it in an evolutionary stance
- you can have cultural diffusion that can accompany people, or word of mouth and encounter these diffusions- such as the use of milk.
- domesticating herd animals arose at different tinmes.
Dermatoglyphic
Finger prints might be ore from genetic drift as to why they vary.
Non- Concordance of Clinal Traits
- Lactase Cline= NO
- B Allele Cline= NO
- Skin Color Cline= NO
When looking at these traits, you are looking at the percentage of people.
knowing 1 trait does not mean you can guess the other traits.
* this is the problem of not having many accordance clines.