Presentation is loading. Please wait.

Presentation is loading. Please wait.

UNIT 4 – Evolution A BRIEF REVIEW OF SUBTOPICS. Adaptation & Variation Extinction Adaptations:  Structural  Behavioural  Physiological Variations 

Similar presentations


Presentation on theme: "UNIT 4 – Evolution A BRIEF REVIEW OF SUBTOPICS. Adaptation & Variation Extinction Adaptations:  Structural  Behavioural  Physiological Variations "— Presentation transcript:

1 UNIT 4 – Evolution A BRIEF REVIEW OF SUBTOPICS

2 Adaptation & Variation Extinction Adaptations:  Structural  Behavioural  Physiological Variations  How do variations develop?  How do variations become adaptations?

3 Adaptation & Variation (con’t) Mutations Selective advantage Eg. Antibiotic resistance in staph. bacteria

4 Darwin & Natural Selection General info about Darwin General info about voyage of Beagle, research and observations in Galapagos Eg: Turtles & Finches Origin of Species Controversy surrounding Darwin

5 Darwin & Natural Selection (con’t) Natural Selection Process of change in populations over many generations Individuals with certain traits survive local environmental conditions Pass on favourable alleles to offspring Environment exerts ‘selective pressure’ Assumptions of Natural Selection Variation Competition Fitness Adaptation

6 Darwin & Natural Selection (con’t) Concepts: Natural Selection Fitness Selective pressure “Descent with Modification” Artificial selection

7 Mechanisms of Evolution Factors that Change Allele Frequencies: Mutation Gene Flow (Migration) Non-Random Mating Genetic Drift Natural Selection

8 Mechanisms of Evolution (con’t) “The Bottleneck Effect” “The Founder Effect”

9 RECALL: Result of the environment selecting for individuals with certain traits that make them better suited to survive and reproduce Over many generations, frequency of alleles of many different genes may change, resulting in significant changes Types of Natural Selection

10 Types of Natural Selection (con’t) 1. Stabilizing Selection 2. Directional Selection 3. Disruptive Selection 4. Sexual Selection

11 Types of Natural Selection (con’t) Long Term Evolution: Gradualism Punctuated Equilibrium

12 Evidence of Evolution Topics Discussed: Fossil record Radiometric Dating Transitional forms Biogeography

13 Evidence of Evolution (con’t) Topics Discussed: Embryonic development Homologous structures Vestigial structures Atavisms Micro-evolution happening today

14 Evolution of Humans Early primates Brain development (cranial capacities) Transition to 2 bipedal and life out of trees and onto plains Eg: Ardi

15 THE END … Questions? “Hey, quit Following me!”


Download ppt "UNIT 4 – Evolution A BRIEF REVIEW OF SUBTOPICS. Adaptation & Variation Extinction Adaptations:  Structural  Behavioural  Physiological Variations "

Similar presentations


Ads by Google