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Natural Selection and Adaptations

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Presentation on theme: "Natural Selection and Adaptations"— Presentation transcript:

1 Natural Selection and Adaptations

2 What are Adaptation’s https://www.youtube.com/watch?v=9XC PK5Jy8yA
Any physical, physiological, or behavioural trait’s that are inheritable and improve chances of survival success for an organism. PK5Jy8yA

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4 The Peppered Moth

5 The Peppered Moth Peppered Moths have two colour variations:
(I) greyish-white with black flecks (ii) black

6 originally black was very rare
(approx 2% in 1850) - a black individual was 1st caught in 1848 in Manchester, England

7 50 years later -->95% of moths were black in Manchester --> in rural areas black moths were still rare

8 Peppered Moth Study by Bernard Kettlewell

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12 Peppered Moth Study by Bernard Kettlewell
1. Release-Recapture experiments - mark & release moths; recovered more melanic moths in polluted areas, light in clean areas 2. Direct Observation and filming - observed birds eating moths off trees 3. Camouflage - visually ranked effectiveness of moths on different backgrounds 4. Geographic Distribution - more light coloured moths in clean areas; more melanic in polluted area

13 Release and Capture Experiment
light moth dark moth non-industrial woods 14.6 % 4.7 % industrial woods 13 % 27.5 %

14 Conclusions of his work!
• behaviour & the genetic make up of moths along with environment pressures are important - during day rest on trees where at risk of predation by birds - prior to 1850 light-coloured moths were camouflaged on light coloured lichens on trees (dark were easily seen by birds) industrial revolution hit England--->pollution killed lichen--->soot blackened trees dark moths now camouflaged

15 What effects did clean air measure do?
1950’s clean-air legislation enacted---> lichen began to grow back 1959 : 9/10 black 1985: 5/10 black 1989: 3/10 black [2000-->estimated to be very rare]

16 What is Natural Selection?
The process in which organisms best adapted to their environment tend to survive and transmit their genetic characteristics to future offspring.

17 Artificial Selection occurs when people artificially select organisms for particular traits that they want to see in future generations

18 some results are: -disease resistant plants -cows that produce more milk -racehorses that run faster -roses with strong scents

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