1. Adaptation & Variation

2. Extinction To completely disappear from Earth
Results when species either lack diversity and/or the ability to change within their environment
Eg. Dodo bird, etc.

3. Adaptations Helps an organism survive & reproduce
Can be structural, behavioural or a physiological process

4. Adaptations Structural Too many to name
Owls (talons, eyesight); sharks (sensory organs, teeth, graceful swimmers); bats (sonar); humans (brain, bipedal, thumbs), etc.
Includes camouflage (stick insect, octopus…)

5. Mimicry A special structural adaptation
Harmless creatures posing as harmful species in either colour or structure
Tricks predators into believing the critter is untasty
Eg. Viceroy butterfly, king snake

6. Mimics

8. Adaptations Behavioural Things that animals do, not what they have
Eg. Meerkats standing, bird calls, migration,

9. Killer hornets

10. Japanese honey bee adaptation

11. Adaptations Physiological Hibernation Tanning
Bears can overwinter when food is scarce; ground squirrels can avoid harsh winters
Tanning
Lactic Acid fermentation (low O2)

12. How do Adaptations Develop?
Gradual, accumulative changes over generations
Random, heritable mutations in DNA
Variations → differences between individuals (structural or physiological)
Not all variations become adaptations

13. Interactions with Environment
Very important to adaptation & variation
Climates change; floods, droughts and famines occur
Human activities – deforestation, agriculture change landscapes
Unimportant characteristics may eventually become crucial for survival if things change

14. Saguaro cactus Fleshy stem holds water
Most roots < 15cm deep but cover huge area
Can absorb 750 L of water in a single storm
Leaves reduced to spines to reduce transpiration rate
Spines also ↓ predation
Stomata only open at night

15. Variation to Adaptation
The English Peppered Moth
Light peppered colour and black
Historically black was rare – lichen on trees in England was light coloured and moths were easy targets for birds
Industrial Revolution killed lichen and put soot on trees; 50 years later 95% of Manchester moths were black

16. English Peppered Moth Pre-industrial revolution
Post-industrial revolution

17. Green & orange bug game

18. Questions
Sharks have an excellent sense of smell. Is this a variation or an adaptation?
A black and yellow insect buzzes around you, causing you to freak out. When it lands you see that it is only a fly. What is the fly’s adaptation and explain the advantage.
When could genetic variation have no significant effect on a species’ survival?

19. Mutations Changes in genetic material (DNA)
New alleles = genetic variation
Eg. Your DNA has about 175 mutations compared to your parents’ (you freak)
Could be harmful or beneficial
In somatic cells → tumour
In gametic cells → may be passed on

20. Selective advantage
A genetic advantage of one organism over its competitors
Helps it to survive changing environmental conditions
Eg. Water flea surviving in warmer water temperatures

21. Antibiotic Resistance
Staphylococcus aureus (bacteria) can reproduce every 30 minutes
Adaptation can occur very quickly
Treatment of Staph. Infections can be inhibited by the adaptive bacteria
Populations of bacteria with the new allele can create antibiotic resistance

22. “Superbugs”