* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Natural selection
Survey
Document related concepts
Sexual selection wikipedia , lookup
Evidence of common descent wikipedia , lookup
The Descent of Man, and Selection in Relation to Sex wikipedia , lookup
Evolving digital ecological networks wikipedia , lookup
Natural selection wikipedia , lookup
Evolutionary history of life wikipedia , lookup
Organisms at high altitude wikipedia , lookup
Theistic evolution wikipedia , lookup
Saltation (biology) wikipedia , lookup
Hologenome theory of evolution wikipedia , lookup
Inclusive fitness wikipedia , lookup
Transcript
HAPPY TUESDAY Bellwork: Write down only the bolded red portion and your answer. Two species of mice live in a field in the middle of East Texas. One mouse species is WHITE with BLACK spotting. The other is BROWN with WHITE spotting. After a year, the population of white mice has dramatically decreased, while the population of the brown mice has slightly increased. Why would this be happening? Standard: (7E)Analyze and evaluate relationship of natural selection to adaptation. Essential Question: What is Evolution? Evolution: change in heritable traits of a population across generations (over time). Charles Darwin: contributed more to our understanding of evolution than anyone else. • Darwin traveled, made observations and collected evidence that led him to propose his revolutionary process in a book called Origin of the Species. Population size is limited by environmental resources Fitness: the ability of an organism to survive and reproduce. • Fitness is the result of adaptations. Adaptation: any inherited characteristic that increases an organism’s chance of survival. Successful adaptations: - enable organisms to become better suited to their environment - increase an individual’s ability to survive and reproduce. Humans have thousands of adaptations: large brain, opposable thumbs, excellent sensory organs, light, strong skeleton, etc. The Primary Mechanism of Evolution: Natural Selection Natural selection: the process by which individuals with characteristics that are not well suited to their environment either die or leave few offspring. 1. Also referred to as survival of the fittest. 2. It is not seen directly, but only observed as changes in a population over a long time. Summary of Darwin’s Theory: Individual organisms differ and some of these variations are heritable (passed on) Organisms produce more offspring than can survive and many that do survive do not reproduce Because more organisms are produce than can survive, they must compete for limited resources (food, shelter, etc) Each unique organism has different advantages (good) and disadvantages (bad) Individuals best suited to their environment survive and reproduce successfully These organisms that survive pass their heritable traits to their offspring Summary of Darwin’s Theory cont’d: Other individuals that are not suited for their environment die or leave few offspring This process called natural selection causes species to change over time Species alive today are descended with modification from ancestral species (their ancestors) This process by which diverse species evolved from a common ancestor unites all organisms on Earth into a single tree of life Examples of natural selection Bunny Simulation If only one species is considered the "fittest", why do we still have so many variations among species. Why do some birds have very long pointy beaks, while other birds have short flat beaks?