Natural Selection & Adaptations Ecology

Lamarke’s Theory of Acquired Traits Some thought that you would gain or lose features if you overused or didn't use them, and you could pass these new traits onto your offspring. This was known as the Inheritance of Acquired Characteristics A lizard that didn't use it legs would eventually not have legs and its offspring wouldn't have legs A giraffe stretched its neck to reach higher leaves, and this stretched neck would be a trait inherited by its offspring

Darwin’s Theory of Evolution by Natural Selection Darwin was a naturalist who observed many species. He is famous for his trips to the Galapagos Islands, his observations of the finches (and other animals) and the book he wrote: "The Origin of Species” 1. Variation exists among individuals in a species. 2. Individuals of species will compete for resources (food and space) 3. Some competition would lead to the death while others would survive 4. Individuals that had advantageous variations are more likely to survive and reproduce.

Natural Selection This process he describes came to be known as Natural Selection Process by which individuals that are better suited to their environment survive and reproduce most successfully; also called survival of the fittest.

Evolution Causes and Examples Carbon dating Fossil record Evidence from Living Organisms Homologous Structures Vestigial Organs Biochemistry and DNA Direct Observation of species change (wolves/dogs, peppered moths) Causes Genetic Mutations Genetic Flow Genetic Drift Natural Selection Fossil Evidence We have fossils of creatures that no longer exist but bear resemblance to creatures that do exist today. Examples

Example of Natural Selection Peppered Moth Prior to the industrial revolution the Biston betularia (peppered moth) in New England was a light gray color and blended in with the lichens that covered the trees. After the start of the industrial revolution the air was much more polluted which caused the lichens to die off the trees. Dark peppered moths were the result.

Adaptations Inherited characteristic that increases an organism’s chances for survival. Examples: Darwin’s Finches Mimicry Camouflage Hibernation Migration

Mimicry & Camouflage Mimicry is the similarity in appearance of one species to another that offers one or both protection. Examples: Butterflies, snakes, ants/spiders, etc. Camouflage allows an otherwise visible organism to remain hidden also known as cryptic coloration Examples Sand crabs, frogs, moths, etc.

Mimicry

Camouflage

Hibernation & Migration state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernation conserves energy, especially during winter. Can last several days to several weeks (depending on species). Migration Periodic movement and return of animals from one place to another.