ENV 1101 Chapter 3: Chapter 3.docx

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skytoad178

16 Mar 2012

School

University of Ottawa

Department

Environmental Studies

Course

ENV 1101

Professor

Sonia Wesche

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Document Summary

Because organisms produce excess young, individuals vary in their traits, and many traits are inherited, some individuals will prove better at surviving and reproducing. Their genes will come more prominent in future generations. Mutations and recombination provide the genetic variation for natural selection. We have produced our pets, farm animals, and crop plants through natural selection. Natural selection can act as a diversifying force as organisms adapt to their environment in myriad ways. Speciation (by geographic isolation and other means) produces new species. Once they have diverged, lineages continue diverging, a process represented in a phylogenetic tree. Extinction often occur when species that are highly specialized or that have small populations encounter rapid environmental change. Earths life has experienced five known episodes of mass extinction, because of an asteroid impact and possible volcanism and other factors. Ecologists study phenomena on the organismal population, community, and ecosystem levels and increasingly, on the biosphere level.

Related Questions

Which of the following best describes the principle of evolution by natural selection?

A. Individuals within a population are genetically identical and natural selection occurs randomly

B. Individuals within a population exhibit genetic variation and those that are best adapted to their environment survive

C. Individuals within a population exhibit genetic variation and those that are least adapted to their environment survive

D. Individuals within a population undergo genetic mutation and natural selection occurs randomly

E. Individuals within a population exhibit genetic variation and natural selection occurs randomly

Which of the following states does NOT describe a requirement of natural selection? Question 4 options: Changes in the environment are what prompt organisms to adapt (through natural selection). Only variation in parents' sex cells are passed to their children. Individual organisms adapt to environmental changes via natural selection, not an entire species. Each organism decides what traits are favorable in a given environment.

Question 5

Which of the following is FALSE:

Natural selection has foresight, and can mold organisms in accordance with environments in the far future. This is why organisms have a good "fit" to their environments long after they have arisen through speciation.

Selection is an undirected process that can only ever work with the materials at hand.

Human beings have foresight because they possess brains that can think about possible outcomes and the consequences of actions. This is different to a process like natural selection.

The fact that natural selection has no foresight does not mean that it is incapable of producing beings that have foresight.

Question 6

The wings of bats, birds and flying insects are examples of:

Convergently evolved traits (at least in terms of their basic functionality).

Homologous traits.

Plesiomorphies.

None of the above.