BIO120H1 Lecture : lecture note

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turquoisekangaroo317

10 Jan 2011

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Blue and green curves eventually damp down, where as the red curve, goes on forever (violent ups and downs not good). S03- so far, we have assumed that all individuals are the same. When you think about age structure, you consider that not all individuals have the same capabilities. Childhood is the period where organisms are collecting resources, time of accumulation and producing a body that can reproduce. Number of individuals decreases as we move onto higher age groups. Through out age groups, number of individuals decrease, and biological functions change as well. Men are ignored in these age structures, because they do not produce babies. different species have different survivorship curves ( some have constant deaths through life, and some have higher death rate at the end of life) if death is constant through life, it is exponential decay (type 2)

Related Questions

Which of the following is most likely as a population goes through a bottleneck?

Heterozygosity decreases because genetic distance increases.

Genetic diversity increases because mutation rate increases while the population is going through the bottleneck

. Genetic diversity decreases because some alleles can be lost as the number of individuals dwindles

. The proportion of individuals that are heterozygous increases because there are fewer individuals.

2)What is meant when it says that genetic drift produces "non-adaptive" evolution?

Sometimes natural selection can favor a trait that is good for the current conditions, but when conditions change it is no longer helpful.

Evolution is just a genetic change in a population. If genes are lost from a population due to chance (i.e. genetic drift), that may not be adaptive, meaning the remaining organisms are no more fit.

Evolution isn't perfect, and sometimes it makes mistakes.

whitekoala529

In a large population of an annual wild pea species, height is controlled by a single locus; DD and Dd individuals are tall, while dd individuals are short. Because the local environment is very windy, tall plants tend to get broken and survive to reproduce only half as well as well as do short plants. Mating is random with respect to height and there is no immigration or emigration. In a population of 21,000 (large enough to be considered infinite for the purposed of the Hardy-Weinberg equilibrium and natural selection models; assume this population size remains constant through the generations described in this question) adult pea plants that successfully reproduce after natural selection through differential survival has occurred, there are 7,000 DD individuals, 7,000 Dd individuals, and 7,000 dd individuals.

a) What will be the frequency of the D allele in the gametes (sperm, in pollen, and ovules) that will unite to make up the next generation?

b) What will be the genotype frequencies of DD, Dd, and dd in the seeds that are formed to start the next generation? How many seeds will there be with each genotype?

c) What will be the genotype frequencies of DD, Dd, and dd in the adults that develop from these seeds and survive to reproduce? How many adults will there be with each genotype?

d) Over a long period of time, what do you expect to happen to the D and d alleles in this population? Why?

1. Traits don't necessarily have to be passed on from parent to offspring for natural selection to act on them; traits that are environmentally acquired during the life time of an individual (such as practicing to become very strong or very fast) can also be acted upon by natural selection. Select one: True or False

2.Within the same species and even within the same population, not all individuals are the same. They vary in size, shape or other traits.

Select one:

True

False

3.Differential reproductive success means that some individuals in a population leave more offspring that survive and reproduce relative to other individuals in a population.

Select one:

True

False

coraldolphin670

BIO120H1 Lecture : lecture note

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