Principles of Biology: Animal Systems: A Tutorial Study Guide (box set) E-Book

Nicoladie Tam

• Herausgeber: Nicoladie Tam, Ph.D.
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 953

Veröffentlichungsjahr: 2015

Beschreibung

“Principles of Biology: Animal Systems” is a part of the college-level Principles of Biology course series textbooks. It is a tutorial written in questions and answers format to describe the principles of anatomy and physiology in the biological systems, including evolution and the functions of each organ system.

It is a study guide with in-depth explanations. Each section is a modular unit that is self-contained for easy reading. The principles and concepts are introduced systematically so students can learn and retain the materials intuitively.

Leseprobe

Principles of Biology:

Animal Systems

A Tutorial Study Guide

Nicoladie Tam, Ph. D.

Copyright © 2015 by Nicoladie Tam, Ph.D.

ISBN 978-1-301-69173-9

All rights reserved, no part of this publication may be reproduced in any form, stored in a retrieval system, or transmitted in any form by any means without prior written permission of the author, except in the case of brief quotations in critical review articles.

Authored by: Nicoladie Tam, Ph.D.

Published by: Nicoladie Tam, Ph.D.

First Published: September 9, 2013

Revision Date: June 26, 2015

eBook ISBN: 9781301691739

Book statistics: 204,000 words

Keywords: biology, biological system, scientific methods, biological principles, origin of species, nervous system, neuron, action potential, synapse, reflex, neurotransmitter, sensory system, motor system, endocrine system, reproductive system, circulatory system, respiratory system, immune system, renal system, digestive system, study guide, tutorial

Produced in the United States of America

The printed version of this eBook is also available in PDF format in 651 pages.

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Preface

“Principles of Biology: Animal Systems” is a part of the college-level Principles of Biology course series textbooks. It is a tutorial written in questions and answers format to describe the principles of anatomy and physiology in the biological systems, including evolution and the functions of each organ system.

It is a study guide with in-depth explanations. Each section is a modular unit that is self-contained for easy reading. The principles and concepts are introduced systematically so students can learn and retain the materials intuitively.

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Textbooks by Nicoladie Tam, Ph.D., in the Principles of Biology course series:

Principles of Biology textbook in one volume:

Principles of Biology: Animal Systems

ISBN 9781301691739

Individual chapters of the Principles of Biology textbook series:

Biological System

ISBN 9781301003891

Scientific Methods

ISBN 9781301898688

Biological Principles

ISBN 9781310803666

Origin of Species

ISBN 9781301352456

Nervous System

ISBN 9781301053025

Neuron

ISBN 9781301119646

Action Potential

ISBN 9781301115372

Synapse

ISBN 9781301374120

Reflex

ISBN 9781301991266

Neurotransmitter

ISBN 9781301268610

Sensory System

ISBN 9781301660070

Motor System

ISBN 9781301500895

Endocrine System

ISBN 9781301642939

Reproductive System

ISBN 9781301424078

Circulatory System

ISBN 9781301262410

Respiratory System

ISBN 9781301805389

Immune System

ISBN 9781301452309

Renal System

ISBN 9781301927111

Digestive System

ISBN 9781301317097

Textbooks by Nicoladie Tam, Ph.D., in the Neuropsychopharmacology course series:

Neuropsychopharmacology textbook in one volume:

Neuropsychopharmacology

ISBN 9781311596178

Individual chapters of Neuropsychopharmacology textbook series:

Neuropsychopharmacology: An Introduction

ISBN 9781301482733

Scientific Methods

ISBN 9781301898688

Mind-Brain Connection

ISBN 9781301903405

Pharmacology: In Introduction

ISBN 9781301843534

Pharmacokinetics

ISBN 9781301010776

Dose-Response Curve

ISBN 9781301541812

Learning Mechanisms

ISBN 9781301729531

Cognitive Learning

ISBN 9781301966455

Experimental Methods in Neuropsychopharmacology

ISBN 9781301966455

Brain Imaging Techniques

ISBN 9781311863638

Nervous System

ISBN 9781301053025

Neuron

ISBN 9781301119646

Action Potential

ISBN 9781301115372

Synapse

ISBN 9781301374120

Reflex

ISBN 9781301991266

Neurotransmitter

ISBN 9781301268610

Neurotransmitter Pathways

ISBN 9781301696666

Cytoplasmic Release of Neurotransmitters

ISBN 9781311978615

Executive Functions

ISBN 9781301125968

ADHD: Attention Deficit Hyperactivity Disorder

ISBN 9781301318445

Schizophrenia

ISBN 9781301972692

Affective Disorders: Depression, Mania and Bipolar Disorder

ISBN 9781311988416

Anxiety Disorders

ISBN 9781311060419

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Table of Contents

Cover Page

Preface

Biological System

Organization of the Biological Systems

Life as a Process

Biological Systems

Levels of Organization of Biological Systems

Organization of Biological Studies

Functions of Animal's Organ Systems

Biological Systems: Review

Biological Principles

Evolution as a Process

Biological Principles: Review

Scientific MethodsScientific Methods

Objectives of Science

Logical Deduction and Induction

Scientific Process

Scientific Methodology

Hypothesis Testing

Experimental Methods

Theory Proving

Critical Thinking

Creative Thinking

Scientific Methods: Review

Origin of Species

History of Life on Earth

Origin of Species: Review

Nervous System

Evolution of the Nervous System

Organization of the Nervous System

Anatomy of Spinal Cord.

Functions of Spinal Cord

Brainstem

Cerebellum

Hypothalamus

Pituitary

Thalamus

Neocortex

Cortical Features

Somatosensory Cortex

Motor Cortex

Visual Cortex

Auditory Cortex

Frontal Cortex

Association Cortex

Topographical Representation of the Body

Language Processing

Olfactory Bulb

Limbic System

Amygdala

Hippocampus

Basal Ganglia

Autonomic Nervous System

Nervous System: Review

Neuron

Functions of neurons

Neural Processing and Neural Integration

Signal Transmission

Action Potential

Membrane Potentials

Ionic Channels

Na-K Pump

Mechanisms of Action Potentials

Action Potentials

Refractory Period

Conduction Velocity

Synapse

Synaptic Transmission

Electrical Synapse

Chemical Synapse

Synaptic Integration

Neurotransmitters

Drugs

Reflex

Knee-Jerk Reflex

Reflex Arc

Pain Withdrawal Reflex

Other Reflexes

Neurotransmitter

Classes of Neurotransmitters

Acetylcholine

Serotonin

Norepinephrine

Dopamine

Glutamate

GABA

Endorphins and Enkephalin

Substance P

Nitric Oxide

Anandamide

Drugs

Neurotransmitter: Review

Sensory System

Sensory Transduction

Sensory Receptor Cells

Sensory Encoding

Vision

Lensed Eyes

Optics

Retina

Color Vision

Sterovision

Phototransduction

Audition

Hearing

Echolocation

Balancing

Cutaneous Sense

Proprioception

Thermoreception

Baroreception

Olfaction

Chemoreception

Electroreception and Magnetoreception

Nociception

Synesthesia

Sensory System: Review

Motor System

Muscle Types

Myofilaments

Muscle Contraction

Motor pools and Motor units

Endocrine System

Evolution of Endocrine System

Hormones

First and Second Messengers

Endocrine Glands

Posterior Pituitary

Antidiuretic Hormone (ADH)

Oxytocin

Anterior Pituitary

Growth Hormone

Thyroid Stimulating Hormone (TSH)

Adrenocorticotropic Hormone (ACTH)

Prolactin

Follicle Stimulating Hormone (FSH)

Luteinizing Hormone (LH)

Melanocyte Stimulating Hormone (MSH)

Pineal Gland

Melatonin

Thyroid Glands

Thyroid Hormones

Calcitonin

Parathyroid Hormone (PTH)

Adrenal Glands

Glucocorticoid

Mineralcorticoid

Adrenaline

Pancreatic Hormones

Insulin

Glucagon

Thymus

Thymoxin

Reproductive Hormones

Androgens

Estrogens

Progestogens

Reproductive System

Menstrual Cycle

Sexual Response Cycle

Birth Control

Evolution of the Reproductive System

Circulatory System

Function and Structure of Circulatory System

Heart Chambers

Blood Pressure

Electrical Activity of the Heart

Cardiac Action Potentials

Electrocardiogram

Cardiac Disorders

Cardiac Output

Regulation of Heart Rate and Blood Volume

Evolution of the Circulatory System

Respiratory System

Function of Respiratory System

Principles of Gas Diffusion

Principle of Partial Pressure of Gases

Principles of Gas Exchange

Principles of External Respiration and Internal Respiration

Regulation of Respiration

Mechanisms of Ventilation in Lungs

Chemo-Regulation of Respiration

Neural Control of Respiration

Principle of Counter-Current Exchange System

Principles of Oxygen Carrier: Hemoglobin

Hemoglobin Oxygen Dissociation Curve

Immune System

Functions of Immune System

First Line of Defense

Second Line of Defense

Third Line of Defense

Immune System Disorders

Immune System: Review

Renal System

Functions of Renal System

Anatomy of Renal System

Functions of Nephron

Counter-Current Exchange Systems

Passive vs. Active Reabsorption

Regulation of Fluid Balance

Kidney Failure and Dialysis

Urine Test

Nitrogen Waste

Digestive System

Functions of Digestive System

Digestive Steps

Digestive Enzymes

Digestive Hormones

Essential Nutrients

Digestive System: Review

About the Author

Other Books Published by the Author

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1.Biological System

Objectives

Understand the different levels of organization in the biological system

Concepts to Learn

Understand life as a dynamical process

Understand system phenomena

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1.1.Organization of the Biological System

Objectives

Understand the different levels of organization in the biological system

Concepts to Learn

Understand life as a dynamical process

Understand how a system can be formed by the interactions of its components

Understand how complex phenomena can be created in a system

Understand how life is formed as a system

Understand the evolutionary process

Understand how life can be formed using an evolutionary process without intelligent design

Understand different levels of organization in the biological systems

Understand different levels of description in sub-disciplines of biological studies

Understand the interplay between these different levels of description from physics and chemistry to physiology and ecology

Biology is a study of life. The study can be examined at different levels — from organism level to organ level or cellular level, or any level we want to define. Each level of description can reveal different embedded systems. Each of these systems can be interpreted as functioning at different levels. Collectively, they produce the behavior we observe in the life forms we know on earth. These systems improve gradually in the evolutionary process driven by random variations in microscopic scales, yet the resulting end-products are gradual adaptation to the environment that may increase their survivability. This process results in the variations in species that exhibits as diversity in the biological system.

Life is an emergent property that exhibits as a result of the functional interactions of its components. Life is formed by a system. A system is a collection of interaction parts that can produce functions that its components may not exhibit.

For instance, the biological system is composed of plants and animals. An ecosystem is created as a result of the interactions of the plants and animals. A circulatory system is created from the pumping of blood by the heart into the blood vessels. A heart is a system of muscle fibers arranged in a spherical shell configuration such that when the cardiac muscles contract synchronously, it will produce pumping action. The pumping action of the heart cannot be found in the muscle fiber itself. Thus, the pumping function is an emergent property of the system. Similarly, the circulatory function cannot be found in either the heart or the vessels by themselves; thus, the circulatory function is an emergent property of the circulatory system.

The biological system can be considered as composed of many different levels of organization, from higher-levels (such as the ecological level and organismal level) to lower-levels (such as the organ level and cellular level). There are different sub-disciplines of biology that study the system at these specific levels (with different levels of description). For instance, ecology describes the system at the ecosystem level, physiology and anatomy describe the system at the organism and organ level, cell biology describes the system at the cellular level, etc.

Evolution is an iterative process of elimination in which the solution is explored by a random trial-and-error process. It goes through a fitness test in each of its iterations in which successful trials are retained while failed trials are eliminated. The successful trials are accumulated and pass onto the next generation for iteration again. Thus, by this process of elimination, successful solutions are arrived at eventually even though the trial-and-error process is randomly executed without any prediction of results. Design process is similar to evolutionary process using a trial-and-error method, except that the prediction of possible results based on theory and models reduces the number of random trials in the process of elimination.

Summary

Life is a process that requires dynamical interactions of its components to produce the desired functions. It is formed by a system of interacting parts. Life, as we known on earth, is an evolutionary process that performs trial-and-error by mutation of genes, which then undergoes the survival test in the process of elimination of the successful trials, which are then passed onto the next generation by accumulating the successful trials either by genetic traits or by acquired traits.

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1.2.Life as a Process

Concepts to Learn

Understand life as a process

Objectives

Understand the definition of life as an autonomous self-regulating process

Understand life is a dynamical process rather than a static entity

Biology is a study of life using the scientific methodology. Life is a dynamical process in which the interaction of components results in the emergent property of life. When the interacting parts are functioning, the system is alive. When the interacting parts are not functioning properly, the system is sick. When the interacting parts are non-functional, it is dead.

One of the characteristics of life is that it usually is a self-contained entity, which is autonomously functioning in its environment. Autonomous is the ability to function by itself as an independent entity. It regulates and controls by itself. It may be inter-dependent on each other because most systems rely on other systems to function properly, but it can at least function autonomously.

A dynamical process is a process that changes over time rather than static (fixed). Life is a dynamical process because life only exists when the system is functioning. Life is not a static entity, i.e., it exists as a result of the interactions of the components, which produce the working functions of an organism.

Life on earth is an emergent property resulted from the dynamical interactions of the biological system which functions with the environment to produce its action. A system is composed of interacting parts whose emergent properties may not be found at the constituent level. The collective functions resulting from the cooperation of its parts will exhibit as the behavior of the system. Each of these systems can be decomposed into different level of description and organization. These levels of description can be expressed at the cellular level, organ level, organism level or ecological level. Each species evolves slightly differently in the process such that the end-products as we observe now at these levels are slightly different for each species. The evolutionary process shows gradual changes over time that are cumulative of its predecessors, which can branch off into many different directions. Random variation is the driving force in the evolutionary process even though the end-products of evolution are very systematic and progressively improving in its survival success due to the natural selection process. Without the cumulative process in successive generations, life would not have evolved, as we know it today.

Summary

Life is a dynamical process resulted from the interactions of the components that produce the working function of an organism. The one of characteristics of life is that it functions autonomously as an independent entity, although most organisms inter-depend on each other for survival.

Q&A

What is biology?

Biology is the study of life, as we know it on this planet earth. In other word, it studies the life forms that are specific to those evolved in this earth (in this biosphere). It usually excludes the life forms of other planets or from other parts of the universe.

What is life?

Life is a phenomenon that emerges from the interactions of the components of a system operating autonomously.

Although there are many definitions of life depending on the particular perspectives, the commonalities among all these definitions is the fact the autonomous self-sustaining functions that interact with the environment. That is, it is the functioning that defines life; thus, life is a process rather than a static physical entity. A biological organism is an autonomous being that has the ability to sustain its own functions by itself.

Simply put, if an autonomous being is able to function by itself, it is alive. If it is not functioning properly, it is dysfunctional, or sick. If it is not able to function completely, it is dead.

In fact, it is easier to define death in the sense that if it is not functioning at all, it is dead. The same principle can be applied to other inanimate objects, such as a dead battery or a dead car, when it is not able to function at all. Thus, living or dead is defined by the dynamical process of functioning rather than by the static, physical attributes.

What are the characteristics of life?

The characteristics are self-sustaining and functioning in an environment.

Reproduction is not necessarily required in life since there are many examples of sterile animals that don’t reproduce, such as worker ants and worker bees, and are definitely living animals.

The ability to self-sustain and functioning in an environment is one of the common features of life forms, although most life forms are not entirely independent of each other because they are all interdependent. Yet it is the ability to self-sustain and function that characterizes the individual as being alive. When the individual life form ceases functioning, it is generally considered as dead, or at least dysfunctional.

What is autonomous?

Autonomous is the ability to function by itself.

Autonomous is not necessarily functioning independently, but rather it can function interdependently. That is to say, an animal has to rely on food to function, so even though it can function autonomously, it is not independent of other factors. Autonomous means that it can operate on its own and it is controlled by its own self-regulation, rather than controlled externally.

A colony of plants and animals is an example of autonomous and yet functioning interdependently. We will explore the concept of systems phenomenon in the next section to explain how interdependence occurs in a system that forms the foundation of biological systems.

Review Questions

What is life?

What is a dynamical process?

What is an autonomous being?

Critical Thinking Questions

Why is life not a static entity?

What happens to life when an organism dies?

Why is reproduction not necessarily essential to life?

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1.3.Biological Systems

Objectives

Understand what a system is and how it is formed

Concepts to Learn

System as a dynamical process

Life as a system

Emergent properties

Multicellular vs. unicellular organisms

A system is composed of a collection of many interaction parts, yet the resulting interactions produce some properties that the individual components do not have. Thus, a system is more than the sum of its parts put together. For instance, the circulatory system is composed of the heart, blood, and the blood vessels. The ability to circulate materials in the body relies on the interactions of the heart, blood and blood vessels. Yet circulatory motion is not found in either the heart, the blood or the vessels, although the heart performs the pumping, the blood provides the medium for materials to flow through and the vessels provides the network for transport. Together they form a system that operates in concert for the system to function properly. If any of the components are not operating properly, it leads to the dysfunction of the system. It is sick in terms of the organism. If the entire system stops functioning, then it is dead.

Life is composed of a system, in fact, multiple systems put together — in animals, it includes the nervous system, sensory system, motor system, endocrine system, reproductive system, circulatory system, respiratory system, renal system, digestive system, immune system, etc. The result of the interaction of these systems produce yet another emergent property that becomes what is known as life. Because we often cannot find the properties of the system in the components themselves, so is life — life exists as an entity in the system at the organism level but life does not exist in the components themselves, i.e., it does not exist in the organ level or in the tissue or cellular level.

Emergent property is the property that exhibits at the system level as a result of the interaction of its components. The emergent property cannot usually be found at the component level. For instance, thinking and learning is an emergent property of the brain (as a system), but thinking and learning cannot be found at the neuron level. The interactions of the neurons will result in thinking and learning.

The advantage of a multicellular organism over unicellular organism is that it operates as a system in which the system as a whole can survive even though the components are missing, such as missing a limb. It is because an organism relies on the “interactions” of the components to survive rather than relying on the individual “components” per se to survive. That is the dynamical property, which we found in life or in an autonomously functioning organism.

Summary

System is composed of many interacting parts that work together to produce some functions that cannot be found in each of its components. The resulting phenomenon from the interactions of its parts produces the emergent properties that are not exhibited at the component level. Thus, life is a phenomenon exhibited at the system level, which is resulted from the interactions of its parts to produce the desired functions. Multi-cell organisms have the advantage of a system in which even if it components failed, the organism as a system can still survive compared to a unicellular organism.

Q&A

What is a system?

A system is a collection of interacting components that exhibits collective properties that individual components do not have. A system is more than its parts put together.

That is, a system is bigger than the sum of its parts put together. In fact, when you put the parts together, something new can come out of it that the parts do not have.

For example, the circulatory system is a system that is composed of the heart and the blood vessels. By putting the pumping heart and vessels together, then it produces a system of circulation that delivers materials to the body. The circulating ability is emerged from the system that neither the heart nor the vessels can do by itself.

By the same token, the heart is also a system that is made of cardiac cells. The pumping ability is an emergent property of the system that none of the elongated cardiac cell can perform. It is the arrangement of the cardiac muscles in a spherical shell that provide pumping action when they contract. If the cardiac cell is contracting by itself alone, it cannot produce pumping action. That is why a system, as a whole, can perform functions that its individual components cannot. The function of the system is produced by the interactions of its parts. In this example, the pumping action is produced only when the cardiac muscles are contracting synchronously. If they are contracting randomly, no pumping action can result. That is why the precise function is determined by how they interact.

Biological system is an example of a system that is composed of many components, such as plants and animals. The ecosystem is a system that is composed of the interaction and interdependence of plants, animals and the environment of the living things called the biosphere in this earth.

Another example of a system is the social system, which is composed of people interacting with each other. We call such social system a society. Note that society exists only when there are interactions among people. However, you cannot find society in the people itself. Thus, society is not a physical entity, but a dynamical property that only exists when people are interacting. When people are not interacting, the society disappears. Similarly, physical systems are composed of physical objects.

All these systems are resulted from the interactions of the components. Without the interactions, the systems phenomenon would not be exhibited. In other words, if the plants and animals were not interacting, then there would not be an ecosystem; in which case, the system is “dead.”

What is life as a system?

Life is essentially a system phenomenon in which the components are interacting with each other to produce the functioning system.

In other words, life is composed of interacting components that are functioning, which is essentially a system. When the components are not interacting or if they are not interacting properly, the system malfunctions. Life only exists when the system is functioning, i.e., the components are operating properly.

Life is a specific system in which it is self-sustaining and is autonomous, i.e., it has the ability to interact with the environment for self-sustaining. The autonomy is what characterizes the life entity.

Life can be defined at many different levels, from elemental component, such as living cell, to an organism, which is composed of a collection of cells.

At the level of a living cell, it is a life form on its own and self-sustaining. Although it also depends on other cells for its function collectively (the interdependence is universal to all life forms), it can sustain on its own in its self-regulation function.

At the level of an organism, it is a life form on its own and self-sustaining. Again, although it also depends on other organisms for its function collectively, it can sustain on its own in its self-regulating function. In other words, the autonomous function is what defines the life entity.

What is emergent property?

Emergent property is the phenomenon that is exhibited at the systems level but not at the component level. That is, the property emerged from the interaction of the components is something that cannot be found in the components themselves.

For example, molecules are composed of atoms interacting with each other. The property of a molecule, such as water (H2O), is very different from the property of the components — hydrogen (H) atom and oxygen (O) atom. Water is very dissimilar to hydrogen or oxygen. Thus, the property of water is an emergent property of hydrogen and water interacting together.

Furthermore, water is really a system of hydrogen and oxygen. In other words, molecules are systems of atoms.

Similarly, life and living properties are emergent properties of a collection of living cells; and living cell’s properties are emergent properties of cellular components. Thus, the properties of life cannot be necessarily found at the lower level of its components. That is, you cannot necessarily find life in molecules of a cell, but collectively when they are functioning and interacting with each other to produce the necessary process for cellular functions, then it becomes a living cell. When the components fail to function properly, the cell is “sick.” When the components cease to function, the cell is “dead.” Thus, living, sick, and dead are emergent properties of a system; in this case, it is the emergent property of a biological system.

What is a systems phenomenon?

It is the phenomenon, which is exhibited at the systems level but not at the component level.

Emergent property is an example of a systems phenomenon. Life and intelligence are examples of emergent properties at the systems level (i.e., organism) even though you don’t necessarily find the same at the component level (i.e., in the cells or in the organelles).

What is the advantage of multicellular organism over unicellular organism?

The advantage is the “fault-tolerant” principle — i.e., if parts of the system fail, the system as a whole, can still survive (function properly).

In other words, if some of the cells die, the organism can still be living. Therefore, multi-cell organism can survive better than a single-cell organism because it is more fault-tolerant.

For instance, most of the living things on earth are multicellular organisms because even if one of the limbs is removed, the organism (as a whole) can still survive. Thus, some of the cells in the body can die, yet the organism as a whole can still live. That is the advantage of using a system for functioning because part of the system can be malfunctioning (i.e., sick or dead); yet, the whole system can still be living. It is only when too many parts fail, and the system cannot sustain its functioning then will it die.

This is precisely when an organism gets old, and the parts started to fail (unable to repair completely), and when enough parts fail (such as organ failure), then the organism dies.

Review Questions

What is a system?

What are the characteristics of a system?

What is emergent property?

What is a dynamical phenomenon?

Critical Thinking Questions

What is the advantage of a system over its component?

Why can’t you find properties in the components that you find at the system level?

How can you explain the properties exhibited in life that cannot be found at the organ or cellular level?

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1.4.Levels of Organization of Biological Systems

Objectives

Understand the organization of the biological system from higher-level systems to lower-level systems

Concepts to Learn

Ecosystems

Organisms

Organ systems

Tissues

Cells

Organelles

Macromolecules

Simple molecules

Atoms

Subatomic particles

The biological system can be considered as organized in multiple levels in a systematic way — from high-level organization to low-level organization. At the top level is the ecosystem, which is composed of the interactions of organisms (plants and animals). Organisms are composed of organ systems interacting with each other. Organ systems are composed of tissues; tissues are composed of cells, cells are composed of organelles. Organelles are composed of macromolecules (which are large molecules, such as DNA, RNA, lipid molecules, etc.). Macromolecules are composed of simple molecules, such as NaCl, amino acids, etc. Molecules are composed of atoms; atoms are composed of subatomic particles, such as protons, electrons, neutrons, etc.

Because biological system is a system, many of its properties at the higher-level are not found at the lower level, as explained before. Nonetheless, the biological system is based on the lower-level substrates, such as the molecules and atoms, even though most of the emergent properties of organisms are not found at the molecular or atomic level.

Summary

Biological system is a system composed of ecosystem, organisms, organ systems, tissues, cells, organelles, macromolecules, simple molecules, atoms and subatomic particles.

Q&A

How can the biological system be organized in a systematic way?

It can be organized based on the level of structure, i.e., from high-level organization to low-level organization.

At the highest level, the most general level or top level is the biosphere, and each level can be described based on the next lower level of organization. This can be systematically organized such that the biological system can be studied at different level of details. Each level of description can be described by its constituting parts that form a system at that level, yet they all have individual characteristics that are not found at a lower level.

By separating the biological system into different levels, we can understand how each level of description can be explained by a lower level of building blocks. That is, everything can be derived from its constituents, and the interactions of these constituents will form new functions that cannot be seen at the lower level. This helps us understand how complexity can be created from the interactions of simple parts.

That is to say, biology is rather simple if we understand all the basic building blocks, and how they are put together to form the complexity. There is no mystery if we understand these fundamental concepts of what the biological system is built upon.

What is the highest level of organization in the biological system on earth?

The top level of organization is the ecosystem in the biosphere.

The biosphere contains the earth and its organisms that live in it. It contains the interactions among these living organisms to form a system. The biosphere is a system that is formed by its constituents of both living organisms and non-living (abiotic) things. The dynamical interactions among these living and non-living things forms the ever-changing biosphere. Thus, the biosphere is not a static entity, but a dynamical system.

What is an ecosystem comprised of?

An ecosystem is comprised of the interactions among plants, animals and microorganisms.

An ecosystem is a system that changes depending on the interactions among plants, animals and microorganisms. These interactions create the dynamical ebb and flow of changes in the population and the composition of these constituents.

What is an organism comprised of in the animal kingdom?

It is composed of organ systems.

Typical examples of organ systems are: nervous system, circulatory system, respiratory system, reproductive system, endocrine system, immune system, muscular system, skeletal system, digestive system, renal system, etc.

Organ system is a system of specialized cells that perform similar functions. For example, circulatory system contains the heart and blood vessels, and both are involved in producing fluid circulatory function, even though the heart is involved in pumping and the vessels are involved in providing the aqueduct for delivery of circulatory materials. They all work together in different ways to provide the system with the overall function for delivery of materials to the target sites.

What is an organ system comprised of?

It is composed of organs.

Examples of organs are: heart, lungs, brain, stomach, kidney, uterus, etc.

Organs are made up of specialized cells to form similar function. For instance, the heart is made up of cardiac muscle cells for contraction, Purkinje fibers for conducting electricity, and other coronary vessels for delivering blood to the heart. These constituents all work together in different aspects to provide the overall function in the system.

What is an organ comprised of?

It is composed of tissues.

Examples of tissues are: muscle tissues, nerve tissues, etc.

Tissues are special classes of cell type that function similarly. For instance, muscle tissue can contain many different types of muscle cells, yet they all provide the same function of contraction. Thus, similar cell types fall into the same class of tissue because they function similarly.

What is a tissue comprised of?

It is composed of cells.

Examples of cells are: muscle cells, nerve cells, etc.

Cells are individual basic units in biological system that often can function independently. Most organisms are made up of these basic units called cells. In biological systems, cells are often formed by a membrane enclosing its inside constituents. The membrane allows the cell to form a single unit on its own. Even though some cells may rely on other cells for survival, it is a basic unit, which sets them apart from each other.

What is a cell comprised of?

It is composed of organelles.

Examples of organelles are: mitochondria, nucleus, etc.

Organelles are basic structures inside a cell that function similarly. For instance, the cell nucleus contains the genetic materials for gene expression. They form a single unit with specialized function, and work together as a system.

What is an organelle comprised of?

It is composed of macromolecules.

Examples of macromolecules are: DNA molecules, RNA molecules, lipid molecules, etc.

Macromolecules are large complex molecules that function as a unit for special function, such as lipid molecule collectively forms the membrane of the cell, and DNA molecules collectively encode the genetic traits of the organism. These are specialized molecules produced by organisms specifically for special cellular functions.

What is a macromolecule comprised of?

It is composed of simple molecules.

Examples of simple molecules are: amino acid, water, oxygen, etc.

Simple molecules are often the inorganic molecules found in nature that organisms utilize for creating their own macromolecules. They are the building blocks.

What is a simple molecule comprised of?

It is composed of atoms.

Examples of atoms are: hydrogen, oxygen, carbon, sodium, potassium, chloride, etc.

Atoms are individual units that form molecules by the chemical bonds. Some molecules are made up of single atoms, while others are made up of two atoms, and some are made up of hundreds of atoms, such as macromolecules. By combining different atoms together with chemical bond, it forms a system called molecule.

What does an atom comprise of?

It is composed of subatomic particles.

Examples of subatomic particles are: electrons, protons, neutrons, etc.

The subatomic particles are the basic units that form an atom. Most atoms have protons and electrons that are opposite in electric charge while neutrons are not electrically charged. In fact, different atoms are merely different combinations in the number of protons, electrons and neutrons. Adding more protons or more neutrons to the unit will create a different atom, and an atom is unique in its total number of protons, electrons and neutrons. When the subatomic particles are put together, they form a system called atom.

Does this mean that biological functions can be derived from how molecules work?

Yes, all biological phenomena can be derived from how the molecules function. This includes intelligence, belief system, emotions, mental ability, psychological functions, reproduction, and other abstract phenomena.

Because the constituents of the biological system are molecules and atoms, the resulting functions can be traced to the molecules and atoms. These phenomena are more than just molecular interactions. That is because a system as a whole always exhibits emergent properties that are not found at the lower level of its constituents. Nonetheless, they can be derived from the building blocks.

For instance, the ability to transport fluid in the circulatory system can always be derived from its constituents of the heart and the blood vessels, even though the heart or the vessels by themselves cannot produce circulation without each other. Thus, circulation and transport are abstract quantities that are not found in their constituents, yet they can be derived from them.

Similarly, higher-cognitive functions such as mental ability, intelligence, and emotions can also be derived from the basic building blocks such as molecules, even though they are far more abstract than their own constituents are. Nonetheless, psychiatric medicine (which is merely a drug molecule) can profoundly alter mental conditions and change emotional states. That is why these mental functions can be traced to how molecules work in the brain, and how these molecules alter the biological functions. We will explain how this work in the Nervous System chapter.

Review Questions

What is biological system composed of?

What is ecosystem composed of?

What is organism composed of?

What is organ system composed of?

What is tissue composed of?

What is cell composed of?

What is macromolecule composed of?

What is simple molecule composed of?

What is atom composed of?

Analytical Thinking Questions

How can the phenomenon found at the higher-level be explained by the lower-level components?

Critical Thinking Questions

Why is it important to understand each level of organization in the biological system before we can fully understand how the entire system works?

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1.5.Organization of Biological Studies

Objectives

Understand the subdisciplines of biology that correspond to the different level of organization of the biological system

Concepts to Learn

Ecology

Physiology

Anatomy

Cell biology

Biochemistry

Chemistry

Physics

The study of biological system (biology) can be subdivided based on the level of organization of the subsystems in the biological kingdom. At the highest level, ecology studies the interactions of the ecosystems. Physiology studies the function of the system. Anatomy studies the structure of the system. Cell biology studies the cells. Biochemistry studies the interactions of biochemicals. Chemistry studies the molecular interactions. Physics studies the atomic interactions.

Many other subdisciplines can be subdivided in the study of specific systems, such as neuroscience studies the central nervous system, endocrinology studies the endocrine system, cardiology studies the circulatory system, etc.

Summary

The subdisciplines of biology can be divided based on the study of the subsystem (or organization of the subsystems).

Q&A

Why are there different sub-disciplines of biological studies?

There are different sub-disciplines because there are different levels of description at each system level — from ecology to biochemistry.

Each of these different levels of organization provides different sub-disciplines for studying the system at that level. For instance, ecology studies the interactions among plants and animals at a higher level than biochemistry, which studies at the molecular level of description. Because each level of description describes different phenomena not exhibited at other levels, subdividing them can help reduce the complexity at that level.

What is ecology?

It is the study of the interaction of plants and animals within an environment.

The environment in which the plants and animals interacting in is called the ecosystem. That is, ecology is a study of the ecosystem.

What is physiology?

It is the study of the function of an organism or its components.

Physiology deals with the function of an organism, whether it is a plant or an animal. Physiology is a study of how things work in an organism, i.e., the study of the functions. These functions can be studied at different levels — i.e., at the organism level (whole plant or whole animal level), at the organ level or at the cellular level.

What is anatomy?

It is the study of the structure of an organism or its components.

Anatomy deals with the physical structure of an organism, as opposed to the function.

In reality, structure and function are often interrelated to each other. In other words, anatomy can affect physiology, and physiology can affect anatomy.

For instance, the location of a limb and the number of joints can affect how the muscles need to contract to make the appropriate movements. Contracting the biceps will flex an arm while contracting the triceps will extend an arm. Therefore, the location of the attachment of the muscle (anatomy) can alter the physiology (flexion or extension).

What is cell biology?

It is the study of cells.

It is the study at the cellular level of individual cells rather than multicellular organisms as a whole.

What is biochemistry?

It is the study of the chemical reactions of biological molecules in biological systems.

It studies mainly the chemical systems found in the biological systems. It studies organic chemicals that are produced by biological systems as opposed to the study of inorganic compounds.

What is chemistry?

It is the study of the molecules in chemical systems.

It studies the chemical reactions of molecules, and how atoms interact with each other to form molecules. It includes chemical reactions of both organic and inorganic molecules.

What is physics?

It is the study of the atoms and the interactions of atoms in physical systems.

It studies the interactions and natural laws governing the physical world that are based on atomic interactions and subatomic particles. These are the fundamental physical laws that form the basis of all other phenomena, such as molecules and biological substrates.

Why is it important to understand physics and chemistry in biology?

It’s because biology is based on physics and chemistry. Biological functions are all derived from physical principles and chemical principles.

Nature’s physics laws and chemical laws are all applicable in biology. In fact, biological functions cannot defy physical laws of gravity, electromagnetic interactions and atomic bonds. All cellular functions are based on laws of physics and laws of chemistry. Physiological functions and anatomical structures of plants and animals are based on physics law of gravity and chemical bonds. Thus, everything in biology is derivable from physics and chemistry, even though the properties and phenomena exhibited at the biological level are systems phenomena that may not exhibit at the lower level. Nonetheless, they are derivable from the fundamental building blocks, even though more quantities that are abstract can emerge at the higher systems level.

Review Questions

What does ecology study?

What does physiology study?

What does anatomy study?

What does cell biology study?

What does biochemistry study?

What does chemistry study?

What does physics study?

Critical Thinking Questions

Why do we subdivide biology into so many different subdisciplines?

Can the phenomena in one subdiscipline be explained by another subdiscipline at another level?

For example, can ecology be explained by biochemistry?

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1.6.Functions of Animal’s Organ Systems

Objectives

Understand the function of each of the organ system

Concepts to Learn

Functions of nervous system

Functions of sensory system

Functions of motor system

Functions of muscular system

Functions of skeletal system

Functions of endocrine system

Functions of reproductive system

Functions of circulatory system

Functions of respiratory system

Functions of digestive system

Functions of renal system

Functions of immune system

Functions of integumentary system

The function of the nervous system is to control and regulate both the internal and external environment of the organism. It also performs other higher-level cognitive functions, such as thinking, emotions, reasoning, processing information, etc. It uses electrical and electrochemical signals to process its information. The sensory system is used to sense the stimuli from the environment for the nervous system to process. The motor system is used to move the animal in the environment. The motor system can be subdivided into the muscular system (which provides the muscle contractions), and the skeletal system (which provides the structural support for the animal).

The endocrine system is the hormonal system that uses hormones, which are the chemical messengers to regulate the internal environment of the animal. The reproductive system provides a means to allow the organism to continue its species by passing on the inherited traits to the next generations. The circulatory system provides a means to delivery materials through the organism. The respiratory system provides a means for gas exchange. The digestive system breaks down the materials to obtain the nutrients for synthesis and maintenance, and eliminate solid wastes. The renal system maintains the fluid homeostatic balance and eliminates fluid waste. The immune system serves as a defense from foreign invasion. The integumentary system is the skin that serves to protect the organism from dehydration and serves as a physical barrier to protect organism.

Summary

Each of the organ systems provides distinct and unique function for the organism. The cooperation of the organs provides the necessary functions for the entire organism to function and survive.

Q&A

Why are there different organ systems evolved in higher animals?

Different organ systems were evolved to perform specialized functions when the multicellular organism becomes more complex. These functions as a whole would provide the animals with the necessary functionalities for survival.

Simple animals often do not have specialized organ systems because these functions can be performed by individual cells. As organism evolves from single cell organism to multi-cell organism, it specialization of functions provides a more efficient way to manage than a distributed organization.

This is similar to building a house, if the house is a simple single-roomed house, the room can be used for everything. However, as the house becomes bigger, and contains multi-room, then it is more efficient to organize the room with special functions, such as a bathroom, a bedroom and a living room, etc. Thus, the specialization of a subsystem is merely an outgrowth of the complexity of the system.

For a simple shack, there is no need for subdividing the function, and everything can be accomplished in one room. However, for a mansion, subdividing the function in different rooms provides better efficiency to facilitate the integration of each component. That does not mean that a mansion has to have a bedroom, bathroom or a living room, and if all the rooms do exactly the same thing without specialization, it is perfectly functioning too. It is a matter of efficiency and convenience that the rooms are specialized the way it is.

The same principle applies to animal’s organ systems. That is why not all animals have the same organ systems, but in general, most higher-animals do have most of the organ systems similar to each other because those functions naturally group together in the most efficient ways as filtered by the natural selection process in evolution.

What are the functions of the nervous system?

It processes information in order to regulate, to control and to interact with the internal and external environment of an animal using both electrical and chemical signals (including electrochemical signals).

The nervous system uses both electrical and chemical signals to accomplish the controlling functions to regulate and interact with both the external and internal world.

The nervous system senses the external world, processes the information received from the external and internal world, integrates this information, forms an internal model of these environments, and produces output (actuates) to interact with these environments, such as moving or regulating internal temperature, etc.

The nervous system uses both electrical signals (action potentials) and chemical signals (neurotransmitters) to communicate and process information within the nervous systems. We will discuss why electrical signals are used to process information, and how chemical signals are used in the nervous system too.

What is the function of the sensory system?

It receives sensory stimuli from the environment.

The sensory system is the interface between the organism and the environment. It provides the means of sensing the environment by detecting the stimuli and transmitting the detected signal to the central nervous system to process.

What is the function of the motor system?

It provides the motor output of the organism so that it can move in the environment.

The motor system includes the muscular system and the skeletal system. Together they form the motor system that allows the animal to move in the environment.

What is the function of the muscular system?

It provides a means for movement and articulation for an animal.

The ability to move is one of the distinguishing characteristics of animals from plants, in which animals have the ability to move and move away from an environment for adaptation much easier than plants. The muscular system provides the propulsion system for the animal, even though muscles were evolved to contract only rather than extend. Yet, with the help of arrangement with the skeletal system, propulsion is possible even with contraction rather than extension.

What is the function of the skeletal system?

It provides physical rigid structure and support as well as protects the animals physically by the rigid structure.

The exoskeleton serves both in structure and protection while the endoskeleton often provides structural support with the flexibility to move and grow. The skeletal system does not need to be bone structures per se, but it can be a hydro-skeletal system, in which a rigid system is produced by hydrostatic pressure in aquatic animals.

The skeletal system can function both as a structural system and as a support and protection system, which protects an animal from either predation or from physical injury.

What are the functions of the endocrine system?

It regulates the internal environment of the body using chemical signals (hormones).

Regulation of the internal environment of an organism is as important as interacting with the external environment. The ability to regulate the internal environment allows an animal to survive autonomously without relying on external control.

Animals use the endocrine system to regulate a variety of internal environment, of which homeostasis is one of the common goals, such as maintaining constant temperature for warm-blooded animals, maintaining a constant fluid, electrolyte and osmotic balance, etc. Even regulation of food intake is one of the homeostatic regulation in which the body weight and energy reserve is maintained at a constant state. If any of these states are out of equilibrium, then it leads to pathological conditions and dysfunctional state we often called disease state.

What is the function of the reproductive system?

It allows the species to continue and maintains it traits in the evolutionary process from the previous generation.

Reproduction allows the species to pass on its traits from the previous generation to the next generation. Asexual (without sex) reproduction essentially maintains the same traits, whereas sexual reproduction recombines different traits (half from the male and half from the female) and passes these recombined traits into the next generation.

What is the function of the circulatory system?

It provides a transportation system for the body to deliver materials from the source to its target.

It transports bodily fluid, such as blood, oxygen, carbon dioxide, nutrients, hormones, or anything found within the circulatory system, such as toxins or drugs. It transports what it needs as well as what it does not need for elimination.

The circulatory system is really a forced circulatory system, i.e., it requires active energy to transport material rather than a passive transport system as found in plants. The heart is essentially the pump that pushes the materials through the system of blood vessels.

What is the function of the respiratory system?

It provides gas exchange in the body.

Respiratory system is important for aerobic animals only, since oxidative metabolism requires oxygen for its reaction, and produces carbon dioxide as a byproduct. Thus, gas exchange between the external and internal environments is essential for these chemical reactions to occur. Since each of the cells in the body produces its own set of chemical reactions to survive, and they are far removed from the outside environment inside the body, it relies on the exchange of gases between the external and internal environment and delivers these gases internally by the circulatory system.

What is the function of the digestive system?

It provides a way to break down the nutrients or energy source into their elementary component molecules for the body to utilize, and excretes the unwanted solid and fluid wastes.

The body basically rebuilds everything from scratch using the components rather than borrowing someone’s cells or incorporating someone’s cells as its own. The digestive system makes this breakdown process happen.

One of the reasons why animals build everything from scratch rather than using existing cells from other animals is that if they do use someone else’s cell, then they would incorporate someone’s DNA and genetic materials. This means that animal would inherit some other animals genetic information, and alters its own genetic traits completely. Thus, it is essential to break everything down first, and re-build everything from its component molecules, even though it may seem more efficient to use someone else’s cell as is.

What is the function of the renal (urinary) system?

It maintains the homeostatic condition of the bodily fluid and concentration, while excreting the excess fluid, ions, soluble molecules or other unwanted substances.

Since bodily functions essentially depend on the chemical reactions, the maintenance of the appropriate concentration of each chemical substrate in the body is important. The renal system regulates the balances of these chemicals in the body. This fluid and electrolyte balance is important to maintain the chemical reactions. In aquatic animals, the maintenance of osmotic balance is vital. Otherwise, they can either shrink or swell depending on their osmotic pressure with respect to the external fluid.

Since the renal system is maintaining the fluid balance, it also provides a fluid substrate for elimination of unwanted chemical byproducts, such as excess nitrogen from the breakdown of amino acids and proteins. These nitrogen wastes are often excreted via the renal system as urine, urea or uric acid, thus it is sometimes called urinary system (for eliminating urine).

What is the function of the immune system?

It provides protection of the body from foreign invasion.

The immune system is essential to identify self vs. others in the cellular level, and attacks any cells that are considered as non-self, i.e., foreign. It is a good strategy to protect itself by assuming anything foreign as potential threat, and destroy them. Mistaken identity of its own cells as foreign is often one of the causes of autoimmune disorders.

The immune system is evolved over time to act as the defense system for the body, and the defense is similar to war between the host and foreign invader, each producing strategies to kill each other, i.e., the immune system’s role is to kill the foreign invaders while the foreign invader creates strategies to kill the host. As this co-evolution process continues, both the pathogens and immune system evolve more and more sophisticatedly into the complex dynamics between the host and invaders.

Philosophically, it seems that the pathogens evolved to disrupt the host organisms, but, in reality, it is merely a dynamical process of co-evolution, in which the dual processes are destructive to each other. In some cases, it can be benign, such as allergy reaction in which the immune system is responding to harmless foreign substances, such as pollen.

What is the function of the integumentary system?

It is essentially the skin, which provides protection of the body from dehydration and provides a physical barrier for the body.

The integumentary system is the skin that forms the protective layer for the body to protect it from dehydration and from foreign invasion using a physical barrier method. Entry of substance to the body requires penetrating this physical barrier. In fact, most infections are entered through openings in the skin. As animals evolved from aquatic environment to terrestrial environment, protection from dehydration is also important, since water is the main medium in which the chemical reactions in cells can occur. It also has other functions since it provides the surface for an animal, such as changing color to provide camouflage for an animal to evade predation

Review Questions

What are the functions of the nervous system?

What are the functions of the sensory system?

What are the functions of the motor system?

What are the functions of the muscular system?

What are the functions of the skeletal system?

What are the functions of the endocrine system?

What are the functions of the reproductive system?

What are the functions of the circulatory system?

What are the functions of the respiratory system?

What are the functions of the digestive system?

What are the functions of the renal system?

What are the functions of the immune system?

What are the functions of the integumentary system?

Analytical Thinking Questions

Why are there so many organ systems?

Critical Thinking Questions

Can the function of one organ system be replaced by another organ system?

Are all the organ systems necessary for survival?

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1.7.Biological Systems: Review

Review Questions

What are the components of life?

What are the characteristics of life?

What is a system?

What is the difference between a system and its components?

How can biology be explained by chemistry and physics?

How can biology be studied under the subdiscipline of either physiology or anatomy?

What are the functions of each organ system?

Critical Thinking Questions

If parts of a living thing (such as a leg) dies, does it mean that the individual is dead too?

Does transplanting organs mean a dead person is living in another person?

Can life be re-incarnated or re-cycled?

How can life be created by the evolutionary process?

If life were created by an intelligent designer, then who created the designer? How could such a designer be created?

If life evolved in another planet, would life be anything like what we know on earth or would it be different? Could it use a silicon computer chip instead of DNA as the building block?

Are we earth-bounded by our dependence on oxygen as much as fish are water-bounded by their dependence on water?

Does life need to have a purpose, or did we make it up to satisfy our justification for its existence? Can life exist without a purpose?

Creative Thinking Questions

How can you create life in the laboratory?

Is cloning creating life?

Is reproducing creating life?

Big Picture Questions

What defines the living entity?

What is life?

Is life an abstract quantity or a physical quantity?

What are the constituents of life, or are there any components?

How can “life” be defined at different levels, such as a living cell and a living person?

How does the organization at different levels of the biological system integrate the various disciplines of science?

How can the studies of biological systems be subdivided in so many different levels of descriptions?

How are these subdisciplines interrelated to one another?

How does an organism’s function interrelate to the different levels — from organismal level to the cellular level?

What are the functions of different organ systems with respect to each other to produce the cooperative, interdependent nature in the organism (the system as a whole)?

Application of Knowledge

Can we re-grow lost limbs? Why or Why not?

How can genetic engineering improve or demote quality of life?

Small Group Discussion

If an animal does not have a brain, such as insects, can they think, feel or sleep?

Does the brain need to be in the head? If the brain were located in the spine, would it work the same too?

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2.Biological Principles

Objectives

Understand the basic biological principles

Concepts to Learn

Understand the basic biological principles

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2.1.Evolution as a Process

Objectives

Understand the evolutionary process and the necessary steps in evolution

Concepts to Learn

Evolutionary process

Process of elimination

Trial-and-error process

Fitness test

Survival test

Accumulation of previous trial results

Iterative process

Design process

Predictive process

Evolution is a process of trial-and-error to explore different solutions to produce an outcome that works best by elimination through the fitness test. It is usually a random process in the trial-and-error to try out different solutions. In biological evolution, this trial-and-error process often occurs as mutation of the gene. After trying out the new solution, it goes through the fitness test process, which is the survival test in biological evolution. The survival-of-the-fittest is essentially a fitness test of the solution to test out if the explored solution works or not. If it survived the fitness test, the trial result is accumulated so that this new result is used as the starting point rather than starting from scratch again. In biological evolution, the successful trials are retained in the gene (and pass onto the next generation) so that the next iteration would not need to start from scratch again. If it fails the survival test, it is automatically eliminated. Because the starting point of the next trial already contains the information of successful trials, this evolutionary method can accelerate as more and more information is accumulated from the previous generations.

Thus, evolution is essentially a process of elimination in the random trial process. If it works, it keeps it, and continues to try further along the same line. If it fails, it is automatically eliminated when it did not survive. Therefore, this iterative process is automatic without any design or prediction of what the outcome would be. It is merely a random trial process.

The design process is also very similar to the evolutionary process – it involves trial-and-error, and testing it out by using the fitness test method. If it works, continue along the similar design and change it a bit further. If it doesn’t work, then throw out the design and try something else. The only difference between design and evolution is that design reduces the number of random trials by making a prediction of what the likely success or failure would be. In contrast, for evolution, there is no prediction of the outcome in its iterative search method.

Because there is no prediction in the evolutionary process, it usually takes much longer time and more trials than design to arrive at the same solution. This is why it takes centuries for species to evolve, and we don’t often see species evolve in our life span, whereas we see significant changes in the design process. In either case, random trial is essential in both design and evolution. Otherwise, if the trials were the same, there would not be any variations. If there were no variations, there would not be any new design or new evolution. Thus, random variations are essential in both the evolutionary and design process. This also shows that intelligence is not needed in the evolutionary process because it is merely a process of elimination by trial-and-error method, with or without design prediction or intelligence.

Natural selection is merely the process of elimination in the “survival of the fitness test” in evolution. If the trial succeeds, it survives. If it does not, it dies. Then it is eliminated automatically. Thus, this is the survival-of-the-fittest phenomenon in biological evolution.

Summary

Evolution is a process of elimination method to arrive at a solution by random trial-and-error approach. The process of elimination in evolution is a result of going through a fitness test, or a survival test in biological evolution. The random variations allow exploration of different new solutions to the problem, such that one of those solutions may work better than others. The result of this process is that if it works, keeps it; if it doesn’t, throw it out. By accumulating the previous trial results (often passing on to the next generation), this trial-and-error method of evolution can accelerate as more and more information about previous trials are accumulated in each generation.