Evolution Flashcards
What was Charles Darwins theory about evolution?
- individuals in a species show a wide range of variation
- this variation is because of differences in their genes
- individuals with characteristics most suited to the environment are more likely to survive and reproduce
- the genes that allow these individuals to be successful are passed to their offspring.
What was Lamarks theory?
- A characteristic which is used more and more by an organism becomes bigger and stronger, and one that is not used eventually disappears
- Any feature of an organism that is improved through use is passed to its offspring.
How did peppered moths evolve?
Before the industrial revolution in Britain, most peppered moths were of the pale variety, meaning that they were camouflaged against the pale birch trees that they rest on. Moths with a mutant black colouring were easily spotted and eaten by birds. This gave the white variety an advantage and they were more likely to survive to reproduce.
Airborne pollution in industrial areas then blackened the birch tree bark with soot. This meant that the mutant black moths were now camouflaged, while the white variety became more vulnerable to predators. The black variety now had the advantage and were more likely to survive and reproduce. Over time, black peppered moths have become far more numerous in urban areas.
How has the Horse evolved?
Originally the Horse had multi-toed feet,that were adapted for walking across the forest floor. Now however the Horse has evolved into single-toed hooves more suited for running over open country.
