CHAPTER 13 How Populations Evolve Modules 13.1 – 13.3

Clown, Fool, or Simply Well Adapted? All organisms have evolutionary adaptations Inherited characteristics that enhance their ability to survive and reproduce The blue-footed booby of the Galápagos Islands has features that help it succeed in its environment Large, webbed feet help propel the bird through water at high speeds

A streamlined shape, large tail, and nostrils that close are useful for diving Specialized salt-secreting glands manage salt intake while at sea

13.1 A sea voyage helped Darwin frame his theory of evolution EVIDENCE OF EVOLUTION 13.1 A sea voyage helped Darwin frame his theory of evolution Aristotle and the Judeo-Christian culture believed that species are fixed Fossils suggested that life forms change This idea was embraced by Lamarck in the early 1800s

While on the voyage of the HMS Beagle in the 1830s, Charles Darwin observed similarities between living and fossil organisms the diversity of life on the Galápagos Islands, such as blue-footed boobies and giant tortoises Figure 13.1A

The voyage of the Beagle Great Britain Europe North America Pacific Ocean Atlantic Ocean Africa Galápagos Islands Equator South America Australia Andes Cape of Good Hope Tasmania Cape Horn New Zealand Tierra del Fuego Figure 13.1B

Darwin became convinced that the Earth was old and continually changing He concluded that living things also change, or evolve over generations He also stated that living species descended from earlier life-forms: descent with modification

13.2 The study of fossils provides strong evidence for evolution Fossils and the fossil record strongly support the theory of evolution Hominid skull Petrified trees Figure 13.2A, B

Fossilized organic matter in a leaf Ammonite casts Fossilized organic matter in a leaf Figure 13.2C, D

Scorpion in amber “Ice Man” Figure 13.2E, F

Many fossils link early extinct species with species living today The fossil record shows that organisms have appeared in a historical sequence Many fossils link early extinct species with species living today These fossilized hind leg bones link living whales with their land-dwelling ancestors Figure 13.2G, H

13.3 A mass of evidence validates the evolutionary view of life Other evidence for evolution comes from Biogeography Comparative anatomy Comparative embryology Human Cat Whale Bat Figure 13.3A

Molecular biology Human Rhesus monkey Mouse Chicken Frog Lamprey Last common ancestor lived 26 million years ago (MYA), based on fossil evidence 80 MYA 275 MYA 330 MYA 450 MYA Figure 13.3B