Adaptation or Extinction!

1. Adaptation or Extinction! Mr. Hollander’s 8th Grade Science Class

2. What is Adaptation? • Adaptation is a characteristic usually caused by a gene mutation that helps an organism survive and reproduce in its environment • Adaptations can be physical and are known as an adaptive trait • Ex. 1: Bats have adapted hearing to hunt at night via sonic response • Ex. 2: Cacti have roots that spread laterally for quite a ways and activate growth only when wet • Adaptations can occur in behavior too • Ex. 1: Birds migrate during change in climate for breeding • Ex. 2: Bears hibernate in the winter in order to save energy during the months without food • Adaptations occur over a very long period of time (1000’s of years) and can be tracked using the fossil record of a species • If an organism is healthier…it can live longer…it can breed more…and pass down it’s genetic traits to offspring • Adaptations are often very specialized to specific environments and climates • Selective breeding is the human practice of breeding plants and animals for certain desirable traits and adaptations

3. It’s Survival of the fittest…Natural Selection • Natural selection is the process by which individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals • It was first thought of by Charles Darwin in 1859 • It has four parts: • Overpopulation – Lots of Offspring • Inherited Variation – Individual Combination of Genes/Traits • Struggle to Survive – Only Strong Live • Successful Reproduction – Reproduce

4. Inherited versus Learned behaviors • Inherited behaviors are behaviors in which an organism is inclined towards a particular behavior; like an instinct • Ex. 1: A sea turtle newly hatched will automatically move toward the ocean • Ex. 2 : A male stickleback fish will show aggression towards anything red during mating season • Learned behaviors are behaviors that are observed by an individual and that they find it to be beneficial to them in some way • Ex. 1: A child will not touch a hot stove a second time because they have been burned once • Ex. 2: A dog rolling over in order to receive a treat • Inherited behaviors are considered to be adaptations while learned behaviors are not • An inherited behavior is an adaptation because it is a trait that is passed down genetically to offspring in order to help it survive in its environment, however, a learned behavior is one that you decide to learn and can be either beneficial or harmful • Ex.: The ability to learn is an inherited behavior but learning to not eat poisonous mushrooms is not • Successful organisms often combine both behaviors together in order to benefit them and ensure their survival

5. Change drives change!!! • The Earth is estimated to be 4.6 billion years old and it has gone through a great deal of change over time • As the Earth’s environments have changed, the living organisms on the planet have adapted or died out • Species that cannot adapt to change or can no longer compete with new organisms will completely die out and become extinct • When scientists observe this change over time in the fossil record it is easy to recognize new species that have found success due to their ability to adapt and change • The process in which inherited characteristics within a population change over generations such that a new species is able to arise is known as evolution • In a nut shell…organisms either adapt and evolve to change or the go extinct

6. Using the Fossil Record to show Adaptations over time • The fossil record is a timeline showing a sequence of life indicated by fossils found in layers of the Earth’s crust • A fossil record organizes fossil by their estimated ages and physical similarities • The fossils found in the newest layers of the Earth’s crust tend to be closely related to present-day organisms while fossils from older layers are less similar and may not exist any longer • Scientist believe that all living species descended from common ancestors and evidence can be found in the shared physical traits and DNA • The fossil record is not perfect and the holes found between organisms are called missing links

7. Summing it All Up!!! • An adaptation is a physical or behavioral characteristic usually caused by a gene mutation that helps an organism survive and reproduce in its environment and occur over a very long period of time • Natural selection is nature’s way of deciding what adaptations are best suited for specific environments and determines the survival of the fittest • Inherited behaviors are instinctual adaptations and learned behaviors are observed in their environment • Environmental change drives changes in species; species either evolve and adapt or die off and turn extinct • The fossil record is used to piece together a sequence of life by using fossils found in the Earth’s crust

8. The End!!!