Evolution Chapter 15

Evolution What causes things to become different over time? Many changes can be traced to mutations that have occurred. Sexual reproduction causes variability. Mutations introduce new traits into the gene pool.

Evolution

Evolution Comes from the root word to evolve. To evolve, means to change. Things change over time. Ex. Human height Charles Darwin was the most famous person to study evolution. Darwin published a book , Origin of Species.

Evolution E:\Evolution_and_the_Success_or_Failure_of_Species.asf

Species A group of organisms that can mate and produce fertile offspring.

Lamarck’s Theory of Evolution Selective use or disuse of organs. Organisms acquired or lost certain traits during their lifetime, if they needed a trait they grew it, if they didn’t need a trait, they lost it. Traits gained or lost could be passed on to offspring Over time this change led to formation of new species.

Lamark cont. He also proposed that all organisms have a tendency to achieve perfection as a species, therefore they constantly change.

Charles Darwin Naturalist Studied plants and animals for differences Collected specimens from the areas that he visited for further study Talked to the local people about how plant and animal life had changed over time.

Charles Darwin Five year voyage on the H.M.S. Beagle a refitted warship. Traveled to the Galapagos Islands Studied nature; plants and animals.

Evolution E:\Charles_Darwin.asf

Evolution E:\The_Galapagos_Islands.asf

Charles Darwin’s Origin of Species Individual organisms in nature differ from one another. Some of this variation is inherited. Organisms in nature produce more offspring than can survive, and many of those that survive do not reproduce.

Charles Darwin’s Origin of Species Because more organisms are produced than can survive, members of each species must compete for limited resources. Because each organism is unique, each has different advantages and disadvantages in the struggle for existence.

Charles Darwin’s Origin of Species Individuals best suited to their environment survive and reproduce most successfully. The characteristics that make them best suited to survive their environment are passed to the offspring. Individuals whose characteristics are not well suited to their environment die or leave fewer offspring.

Charles Darwin’s Origin of Species Species change over time. Over long periods, natural selection causes changes in the characteristics of a species, such as in size and form. New species arise, and other species disappear.

Charles Darwin’s Origin of Species Species alive today have descended with modification from species that lived in the past. All organisms on Earth are united into a single tree of life by common descent.

Evolution E:\Agents_of_Evolution.asf

Evidence of Evolution Geographic distribution Fossil Record Homologous body structures Similarities in early development

Evolution E:\Fossils_and_the_Study_of_Evolution.asf

Evolution E:\The_Types_of_Fossils_and_How_They_Formed.asf

Artificial Selection VS. Natural Selection What causes certain characteristics to benefit an organism over others? Natural selection Speed Strength Intelligence Coloration

Natural Selection cont. Product production Amount of food produced each season

Evolution E:\Elephant_Evolution.asf

Artificial Selection Many times determined by Humans Selective breeding, most milk, more meat. More fruit, larger, stronger. Environmental change caused by humans Peppered moth

Interactions among Organisms E:\Introduction___Interactions_and_Relationships_Among_Organisms.asf

Predation E:\Predation.asf

Symbiosis E:\Symbiosis.asf

Endangered Species Species that is close to extinction because of environmental factors. Predation Habitat change Loss of food source

Speciation Formation of new species Reproductive isolation Geographic isolation Change in feeding habits or food availability.

Classification Putting large amounts of material into an order that allows easier identification. Library- Dewey Decimal System Phone book- Alphabetical order Textbook- Chapters that put similar information into easy to find order

Scientific Names Names assigned to organisms to help identify them. Aristotle was the first person to attempt a classification system He classified according to where an animal or plant lived. Air, land or water PROBLEMS???

Linnaeus’ System of Classification Developed binominal nomenclature Two word naming system Genus species Notice the Genus is capitalized the species is not Based on Latin descriptive language

Linnaeus’ System of Classification Genus is a verb Species is a noun Homo sapien Man-like

Classification E:\Basics_of_Biology__The__How_Living_Things_are_Classified.asf

Evolution E:\Endangered_Species.asf

Evolution E:\Protecting_Endangered_Species.asf

Evolution E:\Extinction__Gone_Forever.asf

Evolution E:\Increased_Rates_of_Extinction_in_the_Modern_World.asf