About This Chapter
Evolution & Natural Selection - Chapter Summary
Use the following review lessons to learn about the different types of natural selection and the theory of evolution. Our video lessons cover the following materials:
- Postzygotic and prezygotic barriers
- Sympatric and allopatric speciation
- Phylogenetic trees and cladograms
- Theories for the origin of life
This chapter also helps you understand parallel, divergent and convergent evolution. Learn about these concepts by watching our short video lessons that are easy to understand. Coupled with our video lessons are quizzes that provide you with immediate feedback. Your quiz results help you identify your strengths, weaknesses and preparedness to answer evolution and natural selection questions on the MCAT's biological sciences section.
Evolution & Natural Selection Objectives
MCAT evolution and natural selection section objectives indicate that you should know concepts that include:
- Comparative anatomy
- Outbreeding and inbreeding
- Parasitism, mutualism and commensalism
- Phylogeny and ontogeny relationships
The MCAT's biological sciences section requires you to answer 52 multiple-choice questions. These questions are divided in to 13 independent questions and seven sets of questions based on passages. Each passage has four to seven corresponding questions. You will be allotted up to 70 minutes to complete the biological sciences section. In addition to the biological sciences section and an optional trial section, the MCAT also features sections focusing on physical sciences and verbal reasoning.
1. Natural Selection & Adaptation: Definition, Theory & Examples
How does natural selection help shape the amazing types of animals we witness around us? In this lesson, we'll explore adaptations and what they can tell us about a species' past evolution.
2. Natural Selection: Definition, Types & Examples
We'll take a look at the types of natural selection that can occur. From flying hamsters to moths, you'll start to grasp the different paths organisms can take as they respond to their changing environments over time.
3. Speciation: Allopatric and Sympatric Speciation
Discover the definition of a species and learn more about how species split. Find out common terms related to the splitting of species and study what role polyploidy plays in the development of a species.
4. Prezygotic Reproductive Barriers & Speciation: Definition & Examples
We may take for granted why animals choose to mate with other animals of similar appearance, but it's not that simple. There are actually biological barriers to reproduction that can prevent even seemingly closely related species from reproducing. This lesson looks at one such category of hindrances, prezygotic barriers, which make fertilization impossible.
5. Postzygotic Reproductive Barriers: Definition & Examples
Do flying hamsters represent a separate species from your run-of-the-mill hamsters? We'll get to the bottom of this by performing crosses between the two hamster types. You'll explore postzygotic reproductive barriers and their possibly tragic consequences.
6. Theories of Evolution: Lamarck vs. Darwin
We'll look at the interplay between population genetics and environment. Are traits individually acquired or do entire populations evolve? The flying hamsters and a few other notable experiments will provide the answers.
7. Ecosystems, Habitats and Ecological Niches
Check out this video lesson to understand the many complex aspects of an ecosystem. See how animals live in habitats and survive amongst their surroundings.
8. Symbiotic Relationships: Mutualism, Commensalism & Parasitism
If your cat or dog has ever had fleas, you've witnessed symbiosis in action. In this lesson, learn the many types of symbiosis in biology, and how these relationships can have a positive, negative, or neutral effect on the individual species.
9. Interspecific Competition, Competitive Exclusion & Niche Differentiation
What happens when two similar species that consume the same resources occupy the same space? Interspecific competition, that's what! Watch our video lesson to learn about the outcomes of this ecological battle.
10. Carrying Capacity, Migration & Dispersion
Have you ever wondered why some types of birds fly south in the winter or why some animals form territories? Watch this video to learn about a species' maximum growth capabilities, the way its members group themselves and why they might migrate to new locations every year.
11. Populations: Density, Survivorship and Life Histories
Have you ever wondered how biologists determine the populations of animals in a particular geographic area? Watch this video lesson to find out, and discover how scientists look at the survivorship and life histories of many different species.
12. Cladograms and Phylogenetic Trees: Evolution Classifications
Family trees help show how people are related to each other. Similarly, scientists use cladograms and phylogenetic trees to study the relationships between organisms.
13. The Origin of Life on Earth: Theories and Explanations
Ever wonder how living things came from non-living things? We will explore what conditions on early Earth may have created life from non-living items.
14. Evolutionary Change: Definition and Forms
You've probably heard of Charles Darwin and evolution. We know that evolution is change over time, but here we will look at how these changes may have occurred during Earth's history.
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Other chapters within the MCAT Test: Practice and Study Guide course
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- The Transcription and Translation Process
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- Developmental Mechanisms
- Mendelian Concepts
- Genetic Variability & Mutation
- Analytic Methods in Genetics
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- Thermochemistry & Thermodynamics
- Glycolysis, Gluconeogenesis & Metabolic Regulation
- Kinetics and Equilibrium
- Cell Structure, Functions & Processes
- Virus Structure & Life Cycle
- Prokaryotic Cells
- Cell Biology & Cell Cycle
- Nerve, Muscle & Specialized Cell Types
- Endocrine System: Hormones & Mechanisms of Hormone Action
- Nervous System: Structure, Function & Sensory Reception
- Circulatory System Overview
- Lymphatic System
- Immune System: Innate and Adaptive Systems
- Digestive System Functions & Organs
- Urinary Systems & Structures
- Muscle and Skeletal Systems
- Respiratory System
- Skin System
- Human Reproductive Systems
- Reproductive Sequence
- Translational Motion
- Force, Motion & Gravitation
- Equilibrium and Momentum
- Work and Energy
- Principles of Fluids
- Gas Laws
- Electrostatics & Magnetism
- Electronic Circuit Elements
- Light & Geometrical Optics
- Atomic Structure and Components
- Atomic Nucleus
- Electronic Structure
- Trends of the Periodic Table
- Stoichiometric Calculations
- Acids and Bases Overview
- Solution Chemistry
- Molecular Bonding
- Phase Equilibria
- Basic Molecular Biology Laboratory Techniques
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- Human Senses
- Human Attention & Cognition
- States of Human Consciousness
- Characterizing Language Development
- Genetics, Evolution & Environmental Influences on Behavior
- Prenatal Development & Birth
- Principles of Motor Development, Learning & Control
- Development in the Adolescence Years
- Personality Components & Assessment
- Psychological Health & Disorders
- Motivation Types and Sources
- Attitude Types and Theories
- Types of Social Groups & Organizations
- Theories of Deviance & Social Control
- Learning and Conditioning
- Understanding the Self
- Prejudice & Discrimination
- Social Behavior
- Social Structure
- Families, Religions & Schools as Social Institutions
- Political & Economic Systems
- Health and Medicine
- Culture, Socialization & Social Interaction
- Population and Migration
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- Social Status
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- Scientific Basics & Theories
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