Critter/Evolution Test Review

The Four Factors That Allow for Natural Selection to Occur All species have great potential to increase in number. Most populations are stable due to competition for limited resources and predation. Variations of traits within a population due to genetic variation of individuals in a species. This variation is due to mutation and sexual reproduction. Nature selects traits of populations that are better suited for their environment. Those traits are passed down to offspring. If there are not enough favorable traits it can lead to

Factor 1 All species have great potential to increase in number.

Factor 2 Most populations are stable due to competition for limited resources and predation.

Factor 3 Variations of traits within a population due to genetic variation of individuals in a species. This variation is due to mutation and sexual reproduction.

Factor 4 Nature selects traits of populations that are better suited for their environment. Those traits are passed down to offspring. If there are not enough favorable traits it can lead to extinction.

Choose an environmental challenge from the new environment that was not present in the original environment and explain how your critter was able to adapt to this challenge so that it could survive in the new environment

Where do variations in a population come from Where do variations in a population come from? Explain what would happen to your Critters Population over time if the original population does not get/have the variations necessary for survival in the new environment Variations are the result of mutations in the Critter’s DNA which codes for its traits. A Critter population with little variation is less likely to have the adaptations (traits) necessary for survival in the new environment

Paleontology Evidence for change across time Fossil record shows gradual change over time of a large number of species Higher Rock levels Younger Fossils found here. Fossils are similar to modern species Lower Rock levels Older fossils found Fossils are much different from modern species

Evidence of Change Similarity of early stages of development indicate common ancestor

Evidence for change The presence of DNA in ALL living organisms is evidence that all living things evolved from a common ancestor.

Percentage of DNA that is the same as human DNA Evidence of change The similarity of DNA sequencing is evidence of that these organisms share common ancestors. Animal Percentage of DNA that is the same as human DNA Fruit Fly 60% Chicken Domestic cat 90% Monkey (an old world primate) 93% Gibbon (a lesser ape) 95% Chimpanzee (a great ape) 98%

Evolutionary Biologists Homologous Structures- Characteristics that are similar among different organisms because they evolved from a common ancestor. Vestigial Structures- Structures that seemingly serve no purpose in some animals that are functional in other animals.

Homologous Structures Evidence for common ancestor Structures evolved and changed across time

Vestigial Structures The Pelvic Girdle was functional in the ancestors of the modern Whale. The structure no longer serves a purpose but is still present

Specifically describe the changes that occurred to your organism’s original population that resulted in the evolution of your species. Species- A group of organisms that share common characteristics and are capable of producing fertile offspring. Include a selection pressure like climate change, predation or geographic isolation Recognize extinction occurs to species that cannot adapt.