33 FACTS OF EVOLUCTION [CHAPTER 1]
[1] Ultimately every living thing can trace its ancestry to a bacterium that lived billions of years ago.
[2] Bears, seals, and dogs are closely related carnivores but are on a different branch of the evolutionary tree than cats and hyenas.
[3] Some snakes have hipbones, which shows they once had four legs like lizards, their close cousins.
[4] Inside some whales and dolphins are small bones that show they once had back legs and that their ancestors walked on land. These occasionally reappear as tiny rear flippers.
[5] Birds evolved from dinosaurs and both are descended from reptiles. The closest living reptilian relation of a bird is the crocodile.
[6] Evolution rarely follows a straight line from species to species. Instead, it is more like a tree with many branches. Some branches lead to new branches, while others become dead ends.
[7] Most people had brown eyes until about 10,000 years ago when a single genetic mutation from the Black Sea switched the eyes from brown to blue. Approximately 8% of the world’s population now has blue eyes.
[8] An elephant’s trunk is an amazing example of evolutionary development. It is a combined nose and upper lip that lengthened as the elephant’s ancestors became taller and their tusks grew bigger. With its heavy head, it needed an easy way to reach the ground.
[9] Physically, the human body seems to have changed very little in the last 50,000 years. However improvements in diets, increased lifespan, and developments in biotechnology may start to speed up the evolutionary process.
[10] All humans develop a tail in the womb that eventually dissolves.
[11] The penises of human ancestors were covered in hard spines. Theorists believe these spines possibly helped a man’s sperm overtake that of his competitors. As humans became more monogamous, the spines became obsolete.
[12] Darwin (1809–1882) did not come up with the phrase “survival of the fittest” to summarize his theory. Rather, the philosopher Herbert Spencer (1820–1903) coined the phrase.
[13] Darwin did not argue that humans came from monkeys. Rather he wrote only that monkeys, apes, and humans have a common ancestor.
[14] Approximately 550 million years ago, humans had a common ancestor with a lancelet, a rod-like sea animal.
[15] A pair of parents would have to have 1,000,000,000,000,000 (a quadrillion) babies before they possibly might have a child with the same genes as any of their other children. This genetic variation between individuals is the key to how species have evolved.
[16] According to a Pew Research Center analysis, 6 in 10 Americans agree that humans and other animals have evolved over time. A third reject the idea of evolution.
[17] Approximately 43% of Republicans and 67% of Democrats believe in evolution.
[18] According to Pew Research, men are somewhat more inclined than women to say that humans and animals evolved over time. Younger adults are more likely than older generations to agree with evolution. Additionally, those with more years of formal education are more likely than those with less education to agree with evolution.
[19] Humans share about 31% of their genes with yeast, a single living cell that replicates every 90 minutes. They share about 50% of their genes with a banana.
[20] A descended larynx, which allows humans to speak, evolved roughly 350,000 year ago. Humans also possess a descended hyoid one, which allows humans to articulate words. In contrast, the larynx in a chimp, for example, sits higher in the throat than in a human.
[21] A hobbit-like species of human lived about 18,000 years ago. About the size of a 3-year-old, they lived with pygmy elephants and 10-foot-long lizards.
[22] The changes in a human pelvis that allow humans to walk upright also made bearing children unusually more dangerous than the rest of the animal kingdom. Additionally, the lumbar curve in the lower back, which helps humans maintain balance, is more vulnerable to pain and injury.
[23] A square inch of human skin on average has as much or more hair-producing follicles as other primates. The difference is that human hair is thinner, shorter, and lighter.
[24] While other primates have opposable thumbs, humans are unique because they can bring their thumbs across the hand to their ring and little fingers. Humans can also flex the ring and little fingers toward the base of the thumb. This allows humans to have a powerful grip and dexterity to hold and use tools.
[25] Charles Darwin did not come up with his theory of evolution while at the Galapagos Islands. His ideas came later, after his return from the voyage.
[26] The development of human clothes has influenced the evolution of other species. For example, unlike all other kinds of louse, the body louse clings to clothing not to hair.
[27] Evolutionary biologists hypothesize that species that cooperate rather than compete value sameness, which has led to right-hand dominance. Lefties constitute just 10% of the normal population; yet they make up 50% of elite athletes.
[28] Researchers suggest that the discovery of fire influenced human evolution. Fire allowed humans to cook their food, which made food easier to chew and digest—which, in turn, contributed to the reduction of human tooth and gut size.
[29] While most animals reproduce until they die, humans have evolved to survive long after the ability to reproduce. Scientists believe this has helped ensure the success of a woman’s family.
[30] The theory of evolution has three basic parts: 1) it is possible for an organism’s DNA to change or mutate; 2) the change is harmful, beneficial, or neutral; and 3) after a long period of time, the mutations cause new species to form.
[31] Mutations fuel evolution by providing new genes in the gene pool of a species. Many factors cause DNA mutation, including X-rays, cosmic rays, nuclear radiation, and random chemical reactions in a cell.
[32] In 1861, the fossil of a primitive bird named Archaeopteryx (“first bird”) was found in Germany. It has impressions of feathers and a long, bony tail. Scientist believe this fossil links birds and reptiles and was the first solid evidence to support Darwin’s theory of evolution.
[33] In the 1870s, Ernst Haeckel, a German biologist and naturalist, developed the idea of “evolution as progress,” which assumes that all nature is moving toward a final goal: human beings.
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