i. ii. iii. iv. A. B. C. D.

TEST CORRECTIONS 1/3 pts back if done correctly1/3 pts back if done correctly Multiple choice:Multiple choice: –Write question –Look up answer in notes/book! –Clearly write letter for correct answer AND the answer itself –Be neat! Highlight, underline, indent, etc…

Short Answer Write questionWrite question Write # pts earned/#pts availableWrite # pts earned/#pts available –Example: “earned 2/8” Summarize your earned pts & incorporate new points into a complete, thorough answer.Summarize your earned pts & incorporate new points into a complete, thorough answer. –Underline or highlight the NEW points –Do NOT copy straight from the markscheme or you will not get pts –Make it MAKE SENSE, paragraphs, sentences!

5.4 Evolution 5.4 Evolution

REALLY cool site...

5.4.1 Define evolution cumulative change in the heritable characteristics of a population.cumulative change in the heritable characteristics of a population. –Small changes, upon small chgs, –Over many generations –Gene-controlled factors –NOT an individual!

Range of eye complexity in living mollusk species (left to right): a pigment spot, as in the limpet Patella; a pigment cup, as in the slit shell mollusk Pleurotomaria; the "pinhole-lens" eye of Nautilus; a primitive lensed eye, as in the marine snail Murex; and the complex eye—with iris, crystalline lens, and retina—of octopuses and squids.

5.4.1 Define evolution 5 “sub theories” –Evolution: all life is and has been perpetually changing –Common descent: if traced back far enough,  all life has common ancestor –Gradualism: evol change is slow & gradual –Multiplication of species: speciation leads to diversity of life; pops adapt to locations, become reproductively isolated from other pops –Natural selection: produce genetic variation & select for/against

Explain evolution of a species by natural selection in response to environmental change.Explain evolution of a species by natural selection in response to environmental change. (Total 7 marks)

species show variation; variation is inherited; species have the potential to produce more offspring than can survive; this leads to a struggle for existence / survival; resources are limited; those that are best adapted (on average) survive to reproduce; this leads to a population adapted to the environment; as the environment changes those that are best adapted will leave more offspring; this will cause the species to evolve to a new adaptation / change in gene frequencies;species show variation; variation is inherited; species have the potential to produce more offspring than can survive; this leads to a struggle for existence / survival; resources are limited; those that are best adapted (on average) survive to reproduce; this leads to a population adapted to the environment; as the environment changes those that are best adapted will leave more offspring; this will cause the species to evolve to a new adaptation / change in gene frequencies; [7][7]

5.4.2 Outline the evidence for evolution provided by the fossil record,...

PBS: Whales in the Making ibrary/03/4/quicktime/l_034_05.html ibrary/03/4/quicktime/l_034_05.html

5.4.2 Outline the evidence for evolution provided by the.. selective breeding... Selective Breeding: By Humans! (Art. Sel.) –Animals, plants selected for breeding b/c desirable traits  future generations w/higher freq of trait –Cows w/high milk yield –Dog breeds –Corn –Select for... –Select against...

5.4.2 Outline the evidence for evolution provided by... homologous structures. Analogous = not a recent common ancestor; convergent evo.

So, how does natural selection work?? ____________ & __________________

5.4.3 State that populations tend to produce more offspring than the environment can support.

More than needed to keep species around More than K can support, ltd resources Intraspecific competition –Some have competitive advantage (traits, behaviors, symbioses) More fit (competing for resources, fighting disease, etc.) = More likely to successfully reproduce Freq of these alleles higher in next generation

5.4.4 Explain that the consequence of the potential overproduction of offspring is a struggle for survival. Some individuals selected FOR, some selected AGAINST –Survivors (FOR) form new breeding population –Increases freq of advantageous alleles

5.4.5 State that the members of a species show variation. Populations show variation... differences in phenotypes! Varying forms of a trait... (flower color, teeth shape)

5.4.6 Explain how sexual reproduction promotes variation in a species.

MIXING IT UP w/MEIOSIS! Random asstmt of chromosomes in Metaphase I –2^n combinations of chroms in daughter cells –8,388,608 in humans!! Crossing-over in Prophase I –New combos of alleles on a chrom. Random fertilization  any gamete can fert any gamete from the other indiv

Other source of variation??Other source of variation?? MUTATIONSMUTATIONS