Nat Geo Notes for: How do Living Things Survive and Change? I. Physical characteristics of living things A. Animal Adaptations 1. adaptations are characteristics that help organisms survive or reproduce 2. they are inherited characteristics that are passed from parent to offspring a. teeth some animals have sharp teeth used to pierce other animals, while some animals have flat teeth that are used to grind tough grasses, stems and leaves. Teeth can also be used for self defense b. feet some animals have feet that help them find food or escape from predators c. shape of fins, tails, head d. inside organs B. Animal senses animals have special characteristics that help them survive 1. sight use eyes to spot prey or predators 2. smell use smell to find food in the soil or underground 3. hearing find food by listening for prey or help an animal know that a predator is near C. Plant adaptations plants have adaptations that help them survive 1. traps food (carnivorous plants) 2. flowers that attract pollinators (birds, bees, insects) a. plants need these pollinators to reproduce D. Behaviors that help animals survive behaviors are ways that an animal interacts with its environment protect itself, find food, make homes, find mates, raise young 1. instinct an inherited behavior that an animal can do without ever having learned how to do it. If the environment changes, an instinctive behavior may no longer work a. always performed the same way hunting
2. learning a change in behavior that comes about through experience. Learned behaviors are more flexible if the environment changes, a new behavior can be learned a. dog learns to go to the door when it wants to go out b. learning is more important in animals with bigger brains c. young animals learn behavior mainly from parents 3. How Behaviors Help Animals Survive Protection Shelter and Raising Young Migration Communication Opposum playing dead Most animals do not take care of their young but birds and mammals do Move to a different place when the season changes Lets animals share information Moth scares away predators by opening its wings Protect their young until they are old enough to do it themselves Instinctive behavior Can communicate to attract mates Squid releases a dark, inky substance into the water Some animals live together in groups and work for the good of the group (colonies, herds) Birds fly south in the winter to find enough food to survive Can communicate to protect themselves from predators Chipmunk runs away Instinctive behaviors Some use the position of the sun or landmarks like rivers and mountains to guide them Can communicate with sounds, movements, smells Use sharp claws, teeth, antlers to stand their ground and defend themselves Some animals sense the magnetic north pole to guide them (like a compass) Make themselves look large and fierce - cats II. Life Cycle Adaptations A. Plant Life Cycles 1. Dry conditions plants go through their life cycle very quickly right after it rains a. in just a few short weeks, seeds germinate, stems and leaves grow, flowers bloom, and seeds form. These seeds can survive dry conditions for months or even years until it rains again
2. Cold conditions In North America, plants usually only grow for 3 months spring, summer, fall flowering plants die when the weather turns cold, then new plants grow from seeds each spring 3. Some plants live for many years they may go dormant each winter, lose their leaves, and start growing again in the spring Some plants survive the winter by storing food in underground bulbs B. Animal Life Cycle 1. Insects have four stages egg, larva, pupa, and adult 2. In each stage, the animal has different needs a. larva need a lot of energy to grow and change eat constantly, day and night eat through leaf after leaf, so they must go through their larva stage when there are plenty of leaves b. If insects live in cold climates, must have adaptations that protect them from freezing might spend the winter as eggs c. insects that spend the winter as pupa are protected by a cocoon or chrysalis d. some insects migrate to a warmer climate III. When Environments Change A. Differences among individuals 1. Individual members of all species differ in many ways (horses, dogs, cats are different colors) 2. Some of these differences affect their ability to survive a. wild horses that can run faster may be better able to escape from predators b. plants can also show variation in their characteristics more colorful flowers can attract more pollinators and therefore have a better chance of surviving
B. Changes in population 1. When some individuals of a population are better adapted than others, their characteristics can be passed on to the next generation 2. Over time, these characteristics become more common in the population 3. When environments change, differences among individuals may allow some organisms to survive while others die Example: in the Galapagos Islands, some finches eat seeds which they crack open with their beaks Birds with bigger beaks can crack open bigger seeds During several years, seeds were scarce, so birds with smaller beaks had difficulty finding seeds The bigger-beaked birds could crack and eat more seeds, so they survived and reproduced. Now, most of the finches have larger beaks 4. Some organisms survive by moving to a new location may be too hot, or not enough rainfall, so they must move to where there needs are met C. How environments change (can change in many ways) when an environment changes, plants and animals either have to adapt, move away, or they will die 1. habitat may get smaller a. new roads, buildings, farms are built 1. Florida panther needs more room to hunt and find prey. Now their only habitat is the southern part of Florida and there are fewer than 100 panthers living in Florida 2. new organism may move into the habitat can change the number of predator and prey, which will affect the population of animals that live there 3. disease a. sometimes a few plants or animals have characteristics that are resistant to the disease and they grow and reproduce, but many others cannot survive
4. a new species can upset the balance of an ecosystem a. a new species can be introduced to an ecosystem with the hope of it helping, but it often hurts the ecosystem 1. a new species can have no predators, so their population increases as another decreases the ecosystem can be overrun with the new species 5. pollution a. harmful chemicals, trash can affect the way plants and animals live and survive b. animals that eat contaminated food will affect the food chain that eats them, which will affect the ecosystem 6. extinction a. when environments change, organisms that cannot adapt may go extinct 1. As many as 99% of all species that have ever lived on earth have gone extinct! 2. Read how this happens: a. people sprayed poison on marshes to kill mosquitoes b. the birds were poisoned when they ate the insects c. to solve the problem, people drained the marshes d. they destroyed the bird s habitat e. the dusky seaside sparrows were declared extinct b. plants can also become extinct c. if a species can t adapt, and can t move to a new location, they can become extinct!