HUMAN BIOLOGY

prinCiples of evolution 455 hoW did life originate on earth? Various lines of research suggest that the organic molecules we as ...

456 Chapter 23 About 50,000 years ago humans began domesticating wild dogs. By about 14,000 years ago, people started to favor n ...

prinCiples of evolution 457 Explain the difference between a. divergence and gene flow b. homologous and analogous structures E ...

458 Chapter 23 Recently, paleoanthropologists announced the discovery in a South African cave of fossil remains of a new species ...

This chapter places your study of human biology in the broader context of the whole living world (1.3). You will gain a global p ...

Why learn about ecology and ecosystems? Humans and other organisms interact with one another in ecosystems. The general type of ...

prinCiples of eCology 461 Figure 24.2 Animals, plants, and other organisms interact in ecosystems. These photographs show some o ...

462 Chapter 24 consumers The organisms in an ecosystem that eat producers (plants and other photosynthesizers). food chain Linea ...

prinCiples of eCology 463 What is a food Web? A food web is a complex system of feeding relationships in an ecosystem. Producer ...

464 Chapter 24 hoW does energy floW through ecosystems? Energy enters ecosystems from outside—usually the sun. Energy leaves ec ...

prinCiples of eCology 465 What is a biogeochemical cycle? In a biogeochemical cycle, nutrients move from the environment to org ...

466 Chapter 24 carbon cycle Movement of carbon molecules from organisms and the Earth’s crust to the atmosphere and oceans, then ...

prinCiples of eCology 467 What is the global carbon cycle? In the global carbon cycle, carbon is released by the metabolic proc ...

468 Chapter 24 What is the nitrogen cycle? Nitrogen cycles from the atmosphere, through nitrogen-fixing organisms in soil and w ...

prinCiples of eCology 469 summary section 24.1 Ecology is the study of interactions of organisms with one another and with their ...

470 Chapter 24 Changes that are already occuring due to global warming include melting polar ice and rising sea levels in severa ...

Learning about human impacts on natural resources and biodiversity will draw on your understanding of ecosystems and biogeochemi ...

age structure The relative number of individuals of each age in a population. demographics A popula‑ tion’s vital statistics. po ...

hUMaN iMpaCts oN the Biosphere 473 Why has the human population groWn so fast? Advances in agriculture, industrialization, sani ...

474 Chapter 25 Why is there an upper limit to the number of humans the earth’s resources can support? Earth’s resources are not ...