Biology Chapter 6 Variation Flashcards
What is variation
Differences in appearance
What are the main types of variation
Genetic
Environmental
Mixture of both
Give examples of genetic variation
Blood group
eye colour
hair colour
hand dominance
tongue rolling
Give examples of environmental variation
length of hair
scars
accent
Give examples of variation caused by a mixture of genetics and environmental
weight
height
Variation can be grouped into continuous or discontinuous variation. what is continuous variation
Continuous variation is when you can measure a characteristic eg weight or height so have a range of values
continuous variation is caused by a mixture of genetics and environment
Type of graph is a histogram
Variation can be grouped into continuous or discontinuous variation. what is discontinuous variation
Discontinuous variation is when you have distinct groups
Tongue rolling, blood group are examples
Type of graph - Bar chart
What is natural selection
There is variation of feature within population eg wing length
Competition causes some to survive more than others
eg long wings can fly faster away from predator
They survive
Reproduce
Pass on genes for the next generation
eventually more off population have the genetic feature (long wings)
Who came up with the theory of evolution linked to natural selection
Charles Darwin
What did Charles Darwin theory of evolution suggest
The continuing process of natural selection would lead to gradual changes in the organism over time
this may result in the formation of a new species
What is meant by extinction
When a species has failed to adapt to changes in the environment and they have ALL died out
What is evidence of evolution
Fossils - remains of dead plants or animals found in the rocks
