Animal Pictures Archive accessed Evolution

D. Modern Evolution D. Modern Evolution zastavki.com accessed A. Evolution A. Evolution B. Natural Selection B. Natural Selection C. Evidence of Evolution C. Evidence of Evolution

A. Evolution 1. Evolution is the cumulative change in the heritable characteristics of a population_ bomega.com accessed

B. Natural Selection 1. Variation- the members of a species show variation a. sexual reproduction promotes variation in a species_ 2. Overproduction- populations tend to produce more offspring than the environment can support Bakka-Deliviano accessed Open

3. Struggle for existence- the consequence of the potential overproduction of offspring is a struggle for survival a. summary of Darwin’s observations and deductions_ National Geographic accessed

3. Struggle for existence- the consequence of the potential overproduction of offspring is a struggle for survival a. summary of Darwin’s observations and deductions_ National Geographic accessed Allott and Mindorff (p 187) Biology Course Companion Oxford University Press 2007 Allott and Mindorff (p 187) Biology Course Companion Oxford University Press 2007 Click

4. Survival of the fittest- a. as an environment changes, not all organisms are suited for survival in the new conditions b. certain variations provide for a greater chance of survival, these variations are called adaptations_ Cornell University accessed

Web c. individuals with these heritable variations that are favourable have an increased reproductive success d. as the surviving individuals reproduce, they pass on genes for the advantageous traits to their offspring e. over time, this leads to change in the characteristics of a population_ buanda accessed Open

C. Evidence of Evolution 1. Evolution is supported by evidence including: a. the fossil record b. selective breeding of domesticated animals c. homologous structures_ Earth History accessed

2. The fossil record a. sequence of fossils appearance matches the logical expectations of evolution 1) bacteria - protists  fungi – animals 2) vertebrates: fish  mammals b. sequence fits ecologically 1) plants  animals 2) insect pollinate-able  insect pollinators _ living the Scientific Life accessed

c. sequence of fossils known linking organisms with their likely ancestors 1) horse and rhinoceros linked by Hyracotherium (horse/rhinoceros- like)_ Oslo og Akershus Fjordhestlag accessed Link

3. Selective breeding of domesticated animals a. humans have been selectively breeding for thousands of years b. repeatedly selecting and breeding individuals most suited to human uses (artificial selection) c. comparisons between modern breeds and wild species show vast differences d. tremendous variation between breeds_ Dicts.info accessed

4. Homologous structures a. some structures are superficial (whale fin and fish fin), and perform similar functions- analogous structures b. some structures look very different superficially (human arm and bat wing), but perform different functions- homologous structures 1) pentadactyl limb- same bones in the same relative positions_ Through a Mirror Dimly accessed Play

c. some structures are reduced (thigh bones in snakes), and have no function- vestigial structures 1) functioned in ancestors and are being lost gradually (appendix in humans)_ Sinlung accessed

D. Modern Evolution 1. There are many examples of evolution in response to environmental change including: a. the changes in size and shape of the beaks of Galapagos finches b. antibiotic resistance in bacteria c. pesticide resistance d. industrial melanism e. heavy-metal tolerance in plants_ National Geographic accessed

2. Finches of the Galapagos islands have had changes in size and shape of the beaks a. there are preexisting variations among members of the population of finches b. the conditions of the island change (dry year) and all the small easy to eat seeds have been eaten leaving only larger seeds c. birds with smaller beaks have a difficult time finding food of a suitable size and die_ RIT accessed Play

d. the birds with the larger beaks have no problem finding food, as their beaks are capable of cracking large seeds e. these birds with the favourable trait (large beak) survive and reproduce, passing on their genes to the next generation f. offspring vary, but posses the larger beak size in proportion_ Nature accessed

3. Antibiotic resistance in bacteria a. bacteria vary in the ability to resist antibiotics (contain plasmids for resistance) b. as the population is exposed to an antibiotic, those containing the gene for resistance will be able to tolerate the antibiotic and survive c. bacteria that are not resistant will be killed by the antibiotic_ Adrian College accessed

d. survivors will live to pass on the gene for resistance to the next generation e. most of the offspring will contain the gene for resistance and will continue to survive_ Sanger Institute accessed Play