Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
On the Origin of Species wikipedia , lookup
Sexual selection wikipedia , lookup
Hologenome theory of evolution wikipedia , lookup
Evolutionary mismatch wikipedia , lookup
Theistic evolution wikipedia , lookup
Population genetics wikipedia , lookup
Saltation (biology) wikipedia , lookup
The Descent of Man, and Selection in Relation to Sex wikipedia , lookup
Natural selection wikipedia , lookup
Cardinal Notes RIGHT Topic/Objective: Evolution by Natural Selection Name: Class: Biology Date: Essential Question(s): 1. What conditions need to be present for natural selection to occur? (underline in red) 2. How does natural selection lead to a population changing over time? (underline in blue) Evolution by Natural Selection Questions/Connections: Evolution: process of change over time Natural Selection: mechanism of how evolution occurs: the process in which organisms better adapted to their environment tend to survive and produce more offspring Charles Darwin ● First to propose how evolution works, by natural selection ● At 22, Darwin went on a five year trip around the world on the ship, the HMS Beagle (began in Britain) ○ As the ship’s naturalist, he made observations of organisms in South America and the Galapagos Islands. Fun fact: the main mission of the HMS Beagle was to chart the South American coastline. Right Page 1 "It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change." - Charles Darwin Right page 2 ● On the voyage they stopped at the Galapagos Islands. ○ Darwin found 14 different species of finches on the different islands. Darwin believed they evolved from a common ancestor because there is only one type of finch on the mainland. ○ The differences between the species of finch were associated with the different food they ate. ○ Darwin concluded that the variation in the beaks of the original population allowed for natural selection to occur on the different islands (the finches that were most fit for a particular island were more likely to survive and reproduce). ○ Over many generations, the finches separated into different species of finch. Each species adapted to the particular environment of the island. ● Darwin wrote the book, “Origin of the Species” Conditions that need to be present for natural selection to occur: 1. Genetic Variation: Variation within genes (traits) that can be passed from parent to offspring. Ex: some beetles are dark and some are light. 2. Competition: Not all organisms can survive because of limited food, predators, disease, shelter, hunting, etc. Ex: dark beetles are more likely to get eaten by bird. a. The factor that has a negative impact on the population of a species is called a stressor. In the picture to the right the stressor would be the bird (predator) 3. Fitness: Organisms with the most beneficial trait are more likely to survive and reproduce. By reproducing the beneficial trait will be passed on to the offspring through genes. Fitness depends upon the environment. a. In the picture to the right, the light beetles were more fit for the environment because they were better able to blend in and therefore not get eaten by the bird. End Result The more beneficial trait will make the organism more likely to survive. An organism that survives is more likely to reproduce and pass on the beneficial trait. If this process continues, eventually, all the organisms in a population will have the same adaptation. Right page 3 Survival of the fittest. NOTE: Fitness does not mean the fastest, strongest, or biggest. NOTE: For natural selection to happen, genetic variation has to already EXIST in the population. (variation occurs from random mutations or from meiosis) Summary: __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ Right page 4