Chapter 12: Evolution, Adaptation and Interdependence

• What is the definition of evolution?

  Change of inherited characteristics within a population over time through natural selection.
• What is natural selection?

  Only plants and animals most suited to their environment will survive to breed and pass on their characteristics.
• What does the theory of evolution propose?

  All species of living things have evolved from simple life forms over a period of time through natural selection.
• What did Lamarck believe about acquired characteristics?

  If an organism changes during life to adapt to its environment, those changes would be passed on to its offspring.
• What is the concept of use and disuse in Lamarck's theory?

  A characteristic used more becomes bigger and stronger, while one that is not used eventually disappears.
• What are the contradictions of Lamarck's theory?

  Simple organisms still exist, random mutations cause variations, and traits are not inherited by use and disuse.
• What is Darwin's theory of evolution also known as?

  Natural selection.
• What are the three main points of Darwin's theory of evolution?

  Variation exists within species, individuals best suited to their environment survive and breed, and these advantageous traits are passed to the next generation.
• What is the definition of natural selection?

  Process where organisms better adapted to an environment will survive and reproduce.
• How does genetic variation contribute to natural selection?

  Different organisms in a species show a wide range of variation due to differences in their genes and random mutations.
• What happens to alleles that produce successful characteristics in natural selection?

  They are passed on to the next generation, increasing the population.
• What is a mutation?

  Random changes in the DNA code that may lead to more rapid evolution.
• What is isolation in the context of evolution?

  Two populations of a species become separated.
• What is genetic variation?

  Each population has a wide range of alleles that control the characteristics.
• What is speciation?

  Populations are so different that interbreeding is no longer possible.
• How does isolation contribute to speciation?

  Isolation splits a population, leading to environmental changes and mutations that result in different traits.
• What is the role of natural selection in speciation?

  Natural selection favors individuals with advantageous genes, leading to the majority of the population having those genes.
• What happens if interbreeding occurs between isolated populations?

  It would produce infertile offspring.
• What is geographical isolation?

  When a population is separated by a geographical feature.
• What does the term endemic mean?

  When a species evolves in isolation and is only found in one place in the world.
• What is an evolutionary tree?

  It represents relationships between organisms and shows where speciation occurred.
• What are fossils?

  Remains of organisms from many years ago found in rocks.
• What does the fossil record show?

  Many species have become extinct since life on Earth began.
• What is adaptation?

  A special feature or behavior that makes an organism particularly suited to its habitat.
• What are selection pressures?

  External agents that affect an organism’s ability to survive in a given environment.
• What are the types of adaptations in organisms?

  • **Behavioral:** Responses that help survival/reproduction (e.g., bird migration).
  • **Physiological:** Body processes aiding survival (e.g., toxin production).
  • **Structural:** Physical features aiding survival (e.g., thorns on plants).
• What are extremophiles?

  Organisms that survive in inhospitable environments with highly specialized adaptations.
• What are hydrophytes?

  Plants that are either partially or completely submerged in water.
• What are the adaptations of hydrophytes?

  Thin/no waxy cuticle, many open stomata, wide flat leaves, aerenchyma tissue, and large surface area of stems and roots.
• What are xerophytes?

  Plants that live in areas where transpiration is greater than the volume of water taken up by roots.
• What are the adaptations of xerophytes?

  Thick waxy cuticle, sunken stomata, reduced surface area to volume ratio, hairs and spines, curled leaves, water storage, and extensive root systems.
• What is competition in ecology?

  When different organisms within a community or population seek the same limited resources.
• What are the types of competition?

  • **Intraspecific:** Competition among members of the same species.
  • **Interspecific:** Competition among members of different species.
• What do animals compete for?

  Food, territory, and mates.
• What do plants compete for?

  Light, water, nutrients, and space to grow.
• What are parasites?

  Organisms adapted for living in or on a host organism and feeding off it while it is still alive.
• What are the types of parasites?

  • **External (ecto):** Live on the outside of the host (e.g., fleas).
  • **Internal (endo):** Live inside the host (e.g., tapeworms).
• What are the adaptations of fleas?

  Sharp mouth parts, saliva with chemicals, flattened body, hard body, powerful hind legs, and long survival time.
• What are the adaptations of tapeworms?

  Covered in mucus, hooks and suckers, flattened segments, and no digestive system.
• What is malaria caused by?

  A single-celled parasite (Plasmodium Falciparum) with a complicated life cycle.