Our Animal Connection

What Sapiens Can Learn from Other Species

Michael Hehenberger, Zhi Xia

• Publisher: Jenny Stanford Publishing
• Year: 2020
• ISBN:
  9781000292145
• Edition: 2
• Topic: Medicine
• Subtopic: Biotechnology in Medicine

This book covers the many ways humans benefit from interactions with other living species. By studying animals of all kinds and sizes, from microbial organisms to elephants and whales, we can learn about their adaptations to extreme conditions on the planet Earth, about the evolutionary development of specialized capabilities, and about their ways to defend themselves against predators and diseases. The authors discuss the strengths and weaknesses of Homo sapiens, and how the study of animals can make us stronger and healthier. To deepen our knowledge of genetics, molecular and cell biology, physiology and medicine, we need to study model organisms. To cure human disease, we can learn from animals how they have evolved ways to protect themselves. To improve human performance, we can study the animal kingdom's top performers and learn from their successes. Considering these important pointers, the authors review genetic engineering techniques that can translate our existing and future animal connections into benefits for human health and performance. Finally, they discuss the challenges associated with our animal connection: the history of pandemics caused by bacterial and viral pathogens demonstrates that there is a risk for transmission of diseases that can disrupt human societies. The recent COVID-19 outbreak is covered in detail as an example.

Chapter 1

Introduction

About 2600 years ago, the Greek storyteller Aesop started collecting “fables” where animals were used to project human qualities, and to teach moral values. Thanks to Aesop and his followers—in particular the French fabulist Jean de la Fontaine—we are convinced that owls are wise, foxes are smart, ants are diligent, and crickets happy, but lazy. We also tell fairytales to our children that teach them to be afraid of the “big bad wolf.”

In this book we intend to explore another side of our human interest in animals. We will focus on benefits to human health and well-being that can possibly be derived from a deeper understanding of their evolutionary characteristics.

Considering the diversity of living organisms around us, and the role we humans are playing on top of the animal “food chain,” it may be tempting to dismiss the notion that animals could teach us things we do not already know.

However, while enjoying a superior brain, humans don’t necessarily excel in all other areas of physical ability: When examining how we use our five senses—vision, hearing, taste, smell, touch—we can easily find animals that outperform us in each category. Actually, we had to use our creative brain throughout human history to compensate for our shortcomings, to invent and develop ever more sophisticated devices and technologies, designed to first emulate and then often surpass specialized animal capabilities. For example, human visual perception can be greatly enhanced by microscopes, by binoculars and by advanced telescopes built to explore the universe. Without those devices, we could not compete with birds of prey, or even certain insects.

Although we are proud of our athletic abilities—we can run, we can jump, we can swim, we can climb mountains—our best Olympic performances are often lagging behind potential animal competitors! Our resistance to diseases and our ability to recover from injuries are other areas where our performance is not always impressive.

In this book we ask ourselves the question whether human physiology and medicine could benefit from a closer study of highly specialized and well-functioning animal capabilities. There is nothing new about a focus on biology, zoology and animal health, but what connects animals to humans may not always have been studied in sufficient detail. In particular, as we are finding surprising similarities in the genetic makeup of humans and other living organisms, there may be emerging opportunities to benefit even more from the study of species other than homo sapiens. Those possible benefits could be relevant for both human wellness and disease.

During millions of years, evolution has transformed many species into highly specialized and capable living organisms. We humans have only recently started evolving along with them, and today gained a dominating position. As we are trying to overcome our many weaknesses, we should accept with gratitude what evolution can teach us about “best practices.”

Before introducing homo sapiens, we will review life on Earth, as it evolved on our planet for about 4 billion years. We will also cover a few examples of special adaptations made by living species to extreme conditions on the planet Earth. The sapiens’ connections to other species will then be grouped into the following categories:

  (i) model organisms that help us to increase our understanding of genetics, molecular biology, cellular biology, perception, neuroscience, physiology and medicine;

 (ii) animal species that can teach us lessons related to our understanding and our attempts to cure human disease;

(iii) animals with advanced capabilities that could potentially extend and “improve” human performance in areas sometimes referred to as “bionic.”

After that, we will review genetic engineering technologies that are already in current use or hold the promise of future transfer of capabilities from animals to humans.

Finally, a word of warning to readers based in the USA: We have chosen to use the metric system when discussing distances (measured in meters, kilometers, centimeters, etc.), volumes (liters), weights (grams, kilograms, etc.), speeds (meters per second, kilometers per hour, etc.), and temperatures (centigrades or Celsius degrees). We just felt that our international readers would not appreciate lengthy conversions into miles, yards, inches, ounces, etc., whenever a metric number is mentioned. However, a discussion of both systems is included as an appendix.

A book about our animal connection would not be complete without a chapter covering diseases that are transmitted from animals to humans. Most infectious diseases (including pandemics such as COVID-19) fall into that category.

Chapter 2

Evolution of Life on Earth

What is Life?

It took centuries of biological, chemical and geological research to get close to answering this fundamental question. Although we have learned a lot, we are still not quite sure how life started on the planet Earth. In the late Hadean period, more than 4 billion years ago, the atmosphere consisted largely of water vapor, nitrogen, and carbon dioxide, and smaller amounts of carbon monoxide, hydrogen, and sulfur compounds. There were oceans, but they were very hot, with temperatures about 100°C. The Earth was a water world with a still nonexistent continental crust, an extremely turbulent atmosphere, and a hydrosphere that was exposed to intense ultraviolet (UV) light. It was a chemical laboratory environment, almost impossible to replicate today.

What scientists seem to agree upon is that the first primitive life forms existed without access to oxygen, that there were no enzymes present to facilitate chemical reactions, and that there was no DNA available to create proteins. Organic molecules were synthesized from what we would today characterize a hostile, inorganic environment. But somehow it did happen, and there is now speculation that something similar to our definition of life started with RNA synthesis. The process further required encapsulation and the generation of replicates. The next step was to create a cell within a lipid wall, with DNA and the first ribosome-like mechanism to produce the 20 basic amino acids.

Before going any further, let’s review a few fundamental facts about life, as shared by all species alive today. We need to understand life “from the ground up,” starting with DNA, proteins, and cells.

While DNA provides the blueprint for living organisms, it’s the proteins that do the heavy lifting. In the human body, there are around 25,000 genes encoded in the DNA, but the total number of proteins is much larger, perhaps 500,000, or maybe even a million.

Each DNA molecule contains a large number of nucleotides, composed of one of four nitrogen-containing nucleobases, either cytosine (C), guanine (G), adenine (A), or thymine (T); a sugar called deoxyribose; and a phosphate group. DNA stands for “deoxyribonucleic acid.”

We promise not to dive much deeper into the details of molecular biology, but if the reader wants to learn more, we recommend the Nobel Foundation’s website (www.nobelprize.org) as a treasure trove of firsthand discovery stories, told by the Nobel Laureates themselves. It has been a Swedish tradition to never allow Nobel Prize winners to leave Stockholm without lecturing about their respective breakthroughs, thereby stimulating generations of curious students. We will provide numerous links to this site. In addition, if the reader feels an urge to explore the intricate chemistry of atoms, molecules, and proteins, please feel free to check out a recent book by one of the authors.¹

For our current purpose, we just need to remember that the two separate polynucleotide strands are bound together such that A is always connected with T, and C is connected with G, to form “double-stranded” DNA. Because of its unique double-helical structure (see Fig. 2.1), DNA can easily replicate and break up to initiate the transcription of “genes” into “proteins.”

The DNA of an organism is divided into a “coding” part, containing the genes that can produce proteins, and a “noncoding” part, which performs less obvious tasks. The role of genes goes beyond their association with proteins. They are often referred to as “units of heredity.” They typically form a region of DNA that influences a particular characteristic in an organism. The collection of all genes in a given organism is called its “genome,” and its study is called “genomics.”

Figure 2.1 The DNA double helix with its A-T and C-G connections (source: Wikipedia).

In most living organisms, DNA is physically divided into “chromosomes,”² packaged and organized structures among which DNA is distributed.

Genetics is the study of genes, genetic variation, and heredity in living organisms. As first observed in the 1850’s by Gregor Mendel, who studied flower colors of pea plants, inheritance in organisms occurs by passing discrete heritable units (genes) from parents to offspring. Mendel spent years carefully observing his peas and found that the flowers of pea plants were either purple or white—but never a shade of color in between.

Instead of peas, Thomas Hunt Morgan later studied fruit flies at his Columbia University lab in New York. Between 1910 and 1915 he discovered that each gene resides at a specific site on the chromosomes and that chromosomes are paired, one coming from the mother and the other from the father. The offspring of fruit flies (Drosophila melanogaster), and of other higher organisms, receives one copy of each gene from each of its two parents. Different and discrete versions of the same gene are called alleles and the set of alleles for a given organism is called its genotype. On the other hand, the openly observable features of the organism are called its phenotype.

In the 1920s the world of physics was revolutionized by quantum theory, by the realization that atomic energy levels are not continuous but quantized, that particles are discrete packets of energy with wavelike properties. One of the pioneers in this field was Erwin Schrödinger, and it is no surprise that he developed similar deep ideas when, after his emigration in 1940 to Dublin, Ireland, he turned his attention to biology. In his book What Is Life,³ he observed that it is the difference in their genes that distinguish one animal species from another. He wrote that “genes endow organisms with their distinctive features. They code biological information in a stable form so that it can be copied and transmitted from generation to generation. The storing and passing on of biological information are carried out through the replication of chromosomes and the expression of genes.”

Schrödinger’s ideas helped extend biochemistry from a discipline concerned with the role of enzymes in production and utilization of energy within a cell, to a discipline concerned with copying, transmission, and editing of information.

In 1944, scientists at the Rockefeller Institute in New York discovered that genes are not proteins but that they are made of DNA.

Watson and Crick’s discovery of the double helical structure of DNA then put Schrödinger’s ideas into a molecular framework and confirmed that an essential role of genes is replication: at the end of their famous paper⁴ they stated that ...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Dedication
• Table of Contents
• Foreword: Learn from Others
• About BGI and Prof. Yang
• Acknowledgments
• 1. Introduction
• 2. Evolution of Life on Earth
• 3. Adaptation of Life to Extreme Conditions
• 4. Homo Sapiens (“Us”): Strengths and Weaknesses
• 5. The Human Microbiome: How Our Health is Impacted by Microorganisms
• 6. Animals with Connection to Human Knowledge, Health, and Performance
• 7. Current Use and Future Promise of Genetic Engineering
• 8. Animal Connection Challenges
• Conclusion
• Appendix: Metric or US “Customary Units” System?
• References
• Index