SBI3U – Unit 3: Evolution
Date: ____________________
7.1 Adaptation (Part 1)
Evolution involves two interrelated phenomena
– __________________: modifications of a species phenotype to help them
succeed in their environment
– __________________: the formation of a new species from a pre-existing species
Adaptations and Survival
Adaptation: a __________________, _________________, __________________________________
allowing an organism to survive and reproduce in its environment.
E.g. ___________________________________________ allows an organism to blend in its environment to
evade predators or sneak up on prey

_________________: type of structural adaptation
(p. 297 Fig.7.2)
- _______________ species resembles a _______________ species in
colouration or structure, therefore predators who avoid the harmful
species also avoid the harmless one
Development of Adaptations

Adaptations are the result of _____________, ___________________ changes that assist survival and
reproduction.

The small changes are the results of ____________, __________________________________ that
accumulate over many generations.
Section 7.1 p. 299 #1 – 3, p. 304 #1 – 3, 5, 9, 10
SBI3U – Unit 3: Evolution
Date: ____________________
7.1 Variation (Part 2)
All species show ____________________.
________________ - structural, functional, or physiological differences between individuals that may or may
not become _____________________.
Environment
Variations can have a positive, negative or no effect on an individual’s ability to survive or reproduce.
•
Individuals possessing a helpful variation are more likely to _______________.
•
These individuals pass this variation to the ___________________.
•
The variation becomes __________________.
The Peppered Moth
•
The English peppered moth (Biston betularia) has three __________________:
– Greyish white with black spots (pepper)
– Black (melanic)
– Intermediate colour (not shown)
Pollution
•
Peppered moths:
– Active at night
– During day, rest on leaves and tree trunks
– Lichen covered trees provide camouflage for pepper coloured moth
– Soot from factories ______________________, providing camouflage for
______________________________________
•
Frequency of _______________________ increased in population
•
Individual moths did not change from peppered to melanic
Source of Variation
•
From Unit 2:
– Crossing over
– Independent assortment
– Sexual reproduction
•
Mutations – changes in ________ sequences
– Can happen ______________________ when DNA is copied
– Can be caused by __________________________________ etc.
Mutations
•
In which ________ a mutation happens determines if it can be ________________________ to
subsequent generations.
Selective Advantage
•
Many mutations may ___________ an individual
•
Some may provide an _____________________
– _______ function
– _______________ function
•
A selective advantage is a __________________________ of one organism over its competitors.
Antibiotic Resistance
•
Organisms that ___________________________ can see a change in allele frequencies quickly
•
A gene that may have been rare, can become common in a short period of time if it provide a
significant advantage
•
Imagine a bacteria, exposed to an antibiotic for the first time…
Section 7.1 p. 299 #4 – 6, p. 304 #4, 6 – 8, 11-13