BIOL10004 Chapter Notes - Chapter 34: Hemoglobin, Anemia, Sickle-Cell Disease

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jadebutterfly872

29 Jun 2018

School

University of Melbourne

Department

Biology

Course

BIOL10004

Professor

All

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ESSENTIAL READING: EVOLUTION (Chapter 34: 833–839)

What is evolution?

Biological evolution is change over time in genetic composition of a population

Change in genetic structure within populations of same species leads to genetic differences

-> new species

Natural selection --> heritable traits improve survival or reproduction of an organism

Over time this trait will increase percentage of this trait because it is favourable

Alleles responsible for this trait increase in population at expense of other alleles

Natural selection

1. Excess reproduction - More individuals produce in the generation than the amount

that will survive

2. Genetic Variation - Individuals in population exhibit variation in traits. Variation is

generated by mutation, and vary between individuals of a population

3. Different genetic variants have different fitness - Fitter individuals will survive the

environment with the favourable trait but also produce fertile offspring. If an individual does

not produce offspring but survives, they do not contribute to the gene pool. Over time alleles

will change so that populations adapt to the environment because of the success of the

favourable traits

Evidence for Evolution

Spread of the weed Impatiens glandulifera

The weed was introduced to the Czech republic from the Himalayas in the 1890s

Slowly spread over habitat in 100 years

However when introduced into Slovakia 100 years later

Growth of the weed was exponential at 10x greater speed

This was due to the similar climate between Slovakia and Czech Republic

Plants in Czech Republic that better survived and reproduced

Therefore the dominant trait weeds would reproduce more adapted to the similar climate in

Slovakia

Artificial Selection

Domestication of animals

Animals were selectively bred by stockbreeders

Artificial selection produces a wide variety of shapes in domestic animals

Choosing to allow certain extreme types to reproduce while others are prevented from

reproducing

Insecticide resistance

Insecticides applied to kill flies and mosquitoes

Insects can break down the poison and survive to reproduce

Certain individuals possess the resistance allele of a gene encoding esterase enzyme

Individuals that carry this allele breaks down poisons and reproduce

Increases offspring with this allele

Over time the population of insects will have an insecticide resistance genetic makeup

Eventually pesticide will be useless against the immune pest population

Natural selection in humans

Seen in humans

Genetic variants increase or decrease individual lifespans

Worse of better at surviving and reproducing

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Document Summary

Biological evolution is change over time in genetic composition of a population. Change in genetic structure within populations of same species leads to genetic differences. Natural selection --> heritable traits improve survival or reproduction of an organism. Over time this trait will increase percentage of this trait because it is favourable. Alleles responsible for this trait increase in population at expense of other alleles. Excess reproduction - more individuals produce in the generation than the amount. Genetic variation - individuals in population exhibit variation in traits. 2. generated by mutation, and vary between individuals of a population. Different genetic variants have different fitness - fitter individuals will survive the environment with the favourable trait but also produce fertile offspring. If an individual does not produce offspring but survives, they do not contribute to the gene pool. Over time alleles will change so that populations adapt to the environment because of the success of the favourable traits.

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

An adaptation or adaptive trait is a trait/characteristic that has evolved in a population of organisms which provides a functional advantage. Adaptations increase the biological fitness of a population. Fitness is defined as the ability to survive and pass genes on to subsequent generations. For the purposes of this assignment, you are to choose an adaptive trait common to more than one species. For example, birds and bats both have wings. Write a 2-3 page (500 â 750 words, 12 point font) paper including the following elements. Be sure to compose your work with your own words. Do not copy and paste from any source. Describe what makes this trait an adaptation. Briefly describe how the trait evolved; e.g., mutation, genetic drift, migration and/or natural selection. Be sure to support your answer with evidence. What is the difference between homologous and analogous traits? How does your trait of choice fit either of these descriptions? What is convergent and divergent evolution? Describe whether the trait is a result of convergent or divergent evolution. Use in-text citation and provide source references for at least 3 sources. The textbook can be one source. When citing articles or other types of documents, follow standard guidelines as introduced on "Citing references in scientific research papers".

BIOL10004 Chapter Notes - Chapter 34: Hemoglobin, Anemia, Sickle-Cell Disease

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