Unit 1: Evolution - Adaptation, Variation and Mutation Flashcards
What are variations?
Structural, functional, or physiological differences between individuals
What do not all variations become?
NOT all variations become adaptations
What determines whether a variable has a positive/negative/no effect on an individuals ability to survive and reproduce?
Individuals possessing a helpful variation are more likely to survive and have a higher chance of passing this variation on to their offspring
What will happen to the variation?
It will become more frequent.
What happens when a variation becomes more frequent?
Becomes a CHARACTERISTIC or TRAIT of the population
Why do a litter of puppies or kittens do not usually all look the same?
They have inherited different parts of the DNA (called ALLELES) from their parents.
Where is this genetic information that the puppies and kittens inherit expressed?
Some of this genetic information is expressed in each kitten’s phenotype (physical appearance and behavior)
But much of it has no visible effect and remains part of each kitten’s genetic make-up and continues to be passed on to next generations
What is genetic variation?
In a population, results from the variety of genetic information in all individuals of the population
What are mutations?
Changes in the genetic material (DNA) of an organism
What are mutations the only source of?
New genetic variation when inherited
What do mutations do?
Continuously happening in DNA of all living organisms… happening to us right now!
How can mutations occur?
Spontaneously when DNA is copied
What can mutations be caused by?
Ultraviolet radiation (or other environmental agents)
What happens after a mutation?
-Cell could die
-Malfunction
-Multiply more than it should and form a tumor!
What can mutations drastically change? What can they be?
Mutations that drastically change the shape or structure of DNA can be harmful to an organism
Are all mutations harmful?
No
Where are mutations only passed on through?
Gametes (sexually reproducting cells), not somatic cells (which make up most of the cells of your body)
What is selective advantage?
A genetic advantage of one organism over its competitors
What does selective advantage cause?
Causes organism to be favoured in terms of survival and reproduction
What does selective advantage help?
Helps an organism survive changing environmental conditions and reproduce
How long does all of this take?
- It all depends on the organism!
What will happen to organisms that reproduce quickly and have short generations?
Will be seen to show the passing of traits more quickly. (This is why Darwin’s Finches adapted in just a few hundred years and why humans haven’t changed too much in a few thousand years!)
What are insects, bacteria and viruses?
All good examples of organisms that have very short life spans, reproduce and adapt quickly to changing environments
