BIOL150 Lecture Notes - Lecture 5: Divergent Evolution, Phenotypic Trait, Sympatric Speciation

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bronzehare94

7 Oct 2015

School

University of Waterloo

Department

Biology

Course

BIOL150

Professor

Heidi Swanson

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Document Summary

One of every four known species is a beetle. Adaptations: trait that enable an organism to exploit a particular resource or thrive in a given environment. Natural selection: the differential success (in survival and reproduction) of individuals that arises from their interactions with their environment. Natural selection has 2 conditions: (1) variation exists among individuals in a population in some heritable trait. (2) this variation causes individuals to differ in survival and reproduction. Individuals with more surviving offspring"s than others are considered more fit. Fitness is the proportionate contribution an individual makes to future generations. Individuals with traits that enable them to survive and reproduce and passing those traits to future generations are selected for. Natural selection leads to evolution: changed in the gene frequency of a population over generations. Change in gene frequencies from paternal to offspring"s reflects difference in the fitness ( survival and reproduction) of individuals in the parental generation.

Related Questions

What is NOT a requirement for evolution by natural selection to occur?

a) Traits must be inherited

b) Traits must influence reproductive success

c) Inherited traits must have variation within the population

d) Characteristics that are favored (fitness) relate to the immediate environment

e) Variations will appear that will allow the survival of the species in future, unforeseen, circumstances.

Charles Darwin...

a) ... arrived at the idea of natural selection in the GalÃ¡pagos Islands.

b) ... was the first scientist to suggest evolution.

c) ... claimed that only aggressive and strong individuals would survive and reproduce.

d) ... with Alfred Wallace, published a mechanism for adaptive change, natural selection, and proposed a "tree of life".

e) ... argued that chimpanzees and gorillas were progressively evolving into human beings.

Describe the theory of natural selection Which of thefollowing BEST describes the theory of natural selection? CHOOSEONE

	1 The genetic make-up of apopulation gradually changes from one generation to the next.
	2 Living organisms change overtime.
	3 Each species produces many moreoffspring than can survive long enough to reproduce. The offspringthat do survive contain genes that are inherited from theparents.
	4 There is variation among themembers of a species. Some of this variation is geneticallydetermined and so can be passed on to future generations.
	5 Some individuals have genes thatincrease their chances for survival and reproduction. Theseindividuals are more likely to reproduce and pass on their genes,causing their genes to become more common in the nextgeneration.
	6 There is a struggle for existenceamong the members of a population.

amberleopard326

Which statement about evolution by natural selection isfalse?

Natural selection allows organisms with higher fitness toreproduce more successfully.

Natural selection favors those traits that confer higherfitness in the environment.

Natural selection is a random change in characteristics of apopulation over generations.

Evolution by natural selection affects populations oforganisms, not individual organisms.

An organism's fitness depends on its _____.

ability to survive and reproduce

ability to swap genetic material with other organisms

physical size

ability to mutate

population

Consider the heavily armored stickleback fish population thatcolonized the lake. If all the individuals in that population weregenetically identical, what do you predict would happen when theycolonized the freshwater lake?

The population would increase, as it has increased foodresources.

The population would evolve through natural selection to bebetter adapted to its environment.

The population would decrease due to more juvenile fish beingeaten.

No answer text provided.

Which of the following are adaptations?

Thicker beaks on finches that allows them to eat large seeds,when large seeds are the most abundant.

Less armor on stickleback fish in freshwater that allows themto grow faster to avoid predation.

More armor on stickleback fish in the ocean that prevents themfrom being eaten by larger predators.

None of the above.

All of the above.