EVOLUTION: CHANGE OVER TIME. In Biology…evolution refers to:. Changes in SPECIES over time A species is a group of similar organisms that can breed and produce fertile offspring. CHARLES DARWIN. Proposed the theory of evolution
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2. ORGANISMS COMPETE FOR LIMITED NATURAL RESOURCES
3. ORGANISMS PRODUCE MORE OFFSPRING THAN CAN SURVIVE
4. INDIVIDUALS WITH VARIATIONS SUITABLE FOR THEIR HABITAT SURVIVE AND REPRODUCE
1. Natural Selection
3. Gene flow
4. Genetic drift
5. Nonrandom mating
(relative to the larger population from which they have migrated)
GENE FLOW (MIGRATION)
Rhea (South America) frequency—there are 5 forces of
2. Analogous structures
3. Vestigial structures
IDENTIFY THE ORGANISMS
HOW ABOUT NOW?
Kids Prefer Cheese Over Fried Green Spinach
2. No Migration (No Gene Flow)
3. No Mutation
4. No Selection (No Differential Selection)
5. Random Mating (No Differential Reproduction)
All blue-eyed people can be traced back to one ancestor who lived 10,000 years ago near the Black SeaBy MICHAEL HANLON
Everyone with blue eyes can be traced back 10,000 years to the Black Sea region. Throughout history they have been the eyes that are prized. Frank Sinatra's were legendary, Paul Newman's melted a million hearts while Cameron Diaz's dazzle in modern Hollywood.But how - and why - blue eyes arose has always been something of a genetic mystery. Until now.According to a team of researchers from Copenhagen University, a single mutation which arose as recently as 6-10,000 years ago was responsible for all the blue-eyed people alive on Earth today.The team identified a single mutation in a gene called OCA2, which arose by chance somewhere around the northwest coasts of the Black Sea in one single individual, about 8,000 years ago.The gene does not "make" blue in the iris; rather, it turns off the mechanism which produces brown melanin pigment. "Originally, we all had brown eyes," says Dr Hans Eiberg, who led the team.And most people still do. The finding that a rare mutation, probably dispersed in the rapid wave of colonization that followed the end of the last ice age, highlights one of the great mysteries of human evolution: the oddness of Europeans. One theory is that Europe's cold weather and dark skies played a part. Fair skin is better at making Vitamin D from the 8 per cent of the world's population have blue eyes weak sunlight found in northern latitudes. Perhaps the most plausible theory is that blonde hair and blue eyes arose because of a mechanism called sex selection.This is where males and females choose as their mates those who have one unusual physical characteristic, not necessarily associated with "fitness" per se but simply something unusual.The gigantic (and otherwise useless) tail of the peacock is the best example.