Biology of Life

Biochemistry, Physiology and Philosophy

Laurence A. Cole

• Publisher: Academic Press
• Year: 2016
• Print ISBN: 9780128096857
• eBook ISBN: 9780128096864
• Topic: Biological Sciences
• Subtopic: Biology
• Index: Biological Sciences

Biology of Life: Biochemistry, Physiology and Philosophy provides foundational coverage of the field of biochemistry for a different angle to the traditional biochemistry text by focusing on human biochemistry and incorporating related elements of evolution to help further contextualize this dynamic space. This unique approach includes sections on early human development, what constitutes human life, and what makes it special. Additional coverage on the differences between the biochemistry of prokaryotes and eukaryotes is also included. The center of life in prokaryotes is considered to be photosynthesis and sugar generation, while the center of life in eukaryotes is sugar use and oxidative phosphorylation. This unique reference will inform specialized biochemistry courses and researchers in their understanding of the role biochemistry has in human life. - Contextualizes the field of biochemistry and its role in human life - Includes dedicated sections on human reproduction and human brain development - Provides extensive coverage on biochemical energetics, oxidative phosphorylation, photosynthesis, and carbon monoxide-acetate pathways

Section IV

4.5 Billion Years of Evolution

Outline

Chapter 12. Evolution Timeline

Chapter 13. Evolution of Chemical, Prokaryotic, and Eukaryotic Life

Chapter 14. Animal Evolution, Small Brain and Advanced Brain

Chapter 15. The Evolution of Humans

Chapter 16. Human Development

Picture taken by Laurence Cole. Rough and tough street lass in Rawalpindi, Pakistan, 2001.

Chapter 12

Evolution Timeline

Abstract

Here we try and explain evolution in its full magnitude, from the start of chemical life through to humans. The evolution tree that results is massive covering eons of time. It is best covered with a massive table. The dating of the table is in accordance with the time periods laid down by scientists: the Hadean Eon, 4600–4000 million years ago (mya); the Archean Eon, 4000–3000 mya; the Proterozoic Eon, 3000–540 mya; the Paleozoic Era, 540–250 mya; the Mezozoic Era, 250–66 mya; and the Cenzoic Era 66 mya to present.

Keywords

Archean Eon; Cenzoic Era; Evolution; Hadean Eon; Mezozoic Era; Paleozoic Era; Proterozoic Eon

Here we try and explain evolution in its full magnitude, from the start of chemical life through to humans. The evolution tree that results is massive covering eons of time. It is best covered with a massive table. The dating of the table is in accordance with the time periods laid down by scientists: the Hadean Eon, 4600–4000 million years ago (MYA); the Archean Eon, 4000–3000 MYA; the Proterozoic Eon, 3000–540 MYA; the Paleozoic Era, 540–250 MYA; the Mezozoic Era, 250–66 MYA; and the Cenzoic Era 66 MYA to present (Table 12.1).

The following sources of information were sought and pooled for this table:

Timeline of the evolutionary history of life. https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_history_of_life

Exploring life’s origins. http://exploringorigins.org/timeline.html

Evolution and geological timelines http://www.talkorigins.org/origins/geo_timeline.html

Timeline: The evolution of life https://www.newscientist.com/article/dn17453-timeline-the-evolution-of-life/

Tree of life rewritten: Evolutionary timeline looks more like a giant lollipop - and reveals new species appear every 2 million years http://www.dailymail.co.uk/sciencetech/article-2982564/Tree-life-rewritten-Evolutionary-timeline-looks-like-giant-lollipop-reveals-new-species-appear-2-million-years

It is all very complicated. One massive tree stretches in multiple direction. The key events are:

Formation of planet Earth 4.54 billion years ago

for the last 3.6 billion years, simple cells (prokaryotes);

for the last 3.4 billion years, cyanobacteria performing photosynthesis;

for the last 2 billion years, complex cells (eukaryotes);

for the last 1.2 billion years, eukaryotes which sexually reproduce

for the last 1 billion years, multicellular life;

for the last 600 million years, simple animals;

for the last 550 million years, bilaterians, water life forms with a front and a back;

for the last 500 million years, fish and proto-amphibians;

for the last 475 million years, land plants;

Table 12.1

Evolution, Earth’s Creation–Present

Hadean Eon (4600–4000 MYA)
Date	Event
4567 MYA	The solar system is formed.
4540 MYA	Planet Earth forms from planetesimal deposits and solar debris.
4450 MYA	The Moon is made when planet Earth collides with smaller planets.
4450 MYA	Initial atmosphere is hydrogen and helium, this then escapes Earth’s gravity. A new atmosphere from volcanic emissions is carbon monoxide, carbon dioxide, water vapor, methane, hydrogen, and ammonia.
4280 MYA	Water lands on Earth from meteors and comets, and oceans are formed.
4000 MYA	Bombardment of Earth by meteors and comets stops.
Archean Eon (4000–3000 MYA)
3900 MYA	The Earth’s crust solidifies.
3800 MYA	Chemical life and RNA molecules appear.
3500 MYA	Cyanobacteria, blue-green algae, shown to have existed.
3200 MYA	Early acritarchs shown to have existed.
3000 MYA	Advanced photosynthesizing cyanobacteria shown to have existed; producing oxygen as a waste product. The oxygen in the atmosphere slowly rises.
Proterozoic Eon (3000–540 MYA)
2800 MYA	It was not until the Earth was 1.7–2.8 billion years old, that a new atmosphere, rich in oxygen, emerged.
2800 MYA	Land continents formed from raised plates known as the Precambrian shields.
2400 MYA	It was not until the Earth was 1.7–2.4 billion years old, that a new atmosphere, rich in oxygen, emerged. Oxygenation of the atmosphere was led by cyanobacteria’s oxygenic photosynthesis, causing the displacement of the carbon monoxide, carbon dioxide, water vapor, methane, and ammonia atmosphere.
2200 MYA	Organisms with mitochondria capable of aerobic respiration appeared.
2000 MYA	Diversification of acritarchs.
1850 MYA	Eukaryotic cells appeared. Eukaryotes contain membrane-bound organelles with diverse functions, probably derived from prokaryotes engulfing each other via phagocytosis. An oxygen atmosphere was an incentive to eukaryotic life.
1850 MYA	Complex ...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Introduction
• Section I. How Life Started
• Section II. DNA and RNA
• Section III. Energetics
• Section IV. 4.5 Billion Years of Evolution
• Section V. Human Development
• Index