Chapter 4 Evolution and Biodiversity

Chapter 4
Evolution and Biodiversity
4 TH H O U R
APRIL 14, 2011
1. Artificial selection- Process by which humans select
one or more desirable genetic traits in the population
of a plant or animal species and then use selective
breeding to produce populations containing many
individuals with the desired traits. Compare genetic
engineering, natural selection.
2. Background extinction- Normal extinction of various
species as a result of changes in local environmental
3. Biological evolution- Change in the genetic makeup
of a population of a species in successive generations.
If continued long enough, it can lead to the formation
of a new species. Note that populations not
individuals evolve. See also adaptation, differential
reproduction, natural selection, theory of evolution.
4. Biopharming- Use of genetically engineered
animals to act as biofactories for producing drugs,
vaccines, antibodies, hormones, industrial
chemicals such as plastics and detergents, and
human body organs.
5. Chemical evolution- Formation of the earth and
its early crust and atmosphere, evolution of the
biological molecules necessary for life, and
evolution of systems of chemical reactions needed to
produce the first living cells. These processes are
believed to have occurred about 1 billion years
before biological evolution. Compare biological
6. Coevolution- Evolution in which two or more
species interact and exert selective pressures on
each other that can lead each species to undergo
various adaptations. See evolution, natural
7. Differential reproduction-Phenomenon in
which individuals with adaptive genetic traits
produce more living offspring than do
individuals without such traits. See natural
8. Domesticated species- Wild species tamed or
genetically altered by crossbreeding for use by
humans for food (cattle, sheep, and food crops),
pets (dogs and cats), or enjoyment (animals in
zoos and plants in gardens). Compare wild
9. Ecological niche- Total way of life or role of a
species in an ecosystem. It includes all physical,
chemical, and biological conditions a species
needs to live and reproduce in an ecosystem.
See fundamental niche, realized niche.
10. Endemic species- Species that is found in only one area.
Such species are especially vulnerable to extinction.
11. Extinction- Complete disappearance of a species from the
earth. This happens when a species cannot adapt and
successfully reproduce under new environmental conditions
or when it evolves into one or more new species. Compare
speciation. See also endangered species, mass depletion,
mass extinction, threatened species.
12. Fossils- Skeletons, bones, shells, body parts, leaves,
seeds, or impressions of such items that provide
recognizable evidence of organisms that lived long ago.
13. Fundamental niche- The full potential range of the
physical, chemical, and biological factors a species can use if
there is no competition from other species. See ecological
14. Gene pool- The sum total of all genes found in the
individuals of the population of a particular species.
15. Generalist species- Species with a broad ecological niche.
They can live in many different places, eat a variety of foods,
and tolerate a wide range of environmental conditions.
Examples are flies, cockroaches, mice, rats, and human
16. Genetic adaptation- Changes in the genetic makeup of
organisms of a species that allow the species to reproduce and
gain a competitive advantage under changed environmental
conditions. See differential reproduction, evolution, mutation,
natural selection.
17. Genetic engineering- Insertion of an alien gene into an
organism to give it a beneficial genetic trait. Compare
artificial selection, natural selection.
18. Genetically modified organism (GMO)- Organism
whose genetic makeup has been modified by genetic
19. Geographic isolation- Separation of populations of
a species for long times into different areas.
20. Invertebrates- Animals that have no backbones.
21. Macroevolution- Long-term, large-scale
evolutionary changes among groups of species.
Compare microevolution.
22. Mass depletion- Widespread, often global period
during which extinction rates are higher than normal
but not high enough to classify as a mass extinction.
Compare background extinction, mass extinction.
23. Mass extinction- A catastrophic, widespread, often global
event in which major groups of species are wiped out over a short
time compared with normal (background) extinctions.
24. Microevolution- The small genetic changes a population
25. Mutation- Random change in DNA molecules making up
genes that can alter anatomy, physiology, or behavior in
26. Natural selection- Process by which a particular beneficial
gene (or set of genes) is reproduced in succeeding generations
more than other genes. The result of natural selection is a
population that contains a greater proportion of organisms better
adapted to certain environmental conditions. See adaptation,
biological evolution, differential reproduction, mutation.
27. Realized niche- Parts of the fundamental niche of a species
that are actually used by that species. See ecological niche,
fundamental niche.
28. Recombinant DNA- DNA that has been altered to contain
genes or portions of genes from organisms of different species.
29. Theory of evolution- Widely accepted scientific
idea that all life forms developed from earlier life
forms. Although this theory conflicts with the
creation stories of many religions, it is the way
biologists explain how life has changed over the
past 3.6-3.8 billion years and why it is so diverse
30. Vertebrates- Animals that have backbones.
Compare invertebrates.
31. Wild species- Species found in the natural
environment. Compare domesticated species.
32.Adaptation- Any genetically controlled
structural, physiological, or behavioral
characteristic that helps an organism survive
and reproduce under a given set of
environmental conditions. It usually results
from a beneficial mutation. See biological
evolution, differential reproduction, mutation,
natural selection.
33.Adaptive radiation- Process in which
numerous new species evolve to fill vacant and
new ecological niches in changed
environments, usually after a mass extinction.
Typically, this takes millions of years.
How do scientists account for the development of
life on earth?
 Scientific evidence indicates that the earth’s life is
the result of about 1 billion years of chemical change
to form the first cells, followed by about 3.7 billion
years of biological change to produce the variety of
species we find on the earth today.
What is biological evolution by natural selection, and how can
it account for the diversity of organisms on the earth?
 Biological evolution by natural selection involves the
change in a population’s genetic makeup through
successive generations. Note that populations- not
individuals- evolve by becoming genetically different.
How can geologic processes, climate change, and
catastrophes affect biological evolution?
 The very slow movement of huge solid plates making up the earth’s
surface, volcanic eruptions, and earthquakes can wipe out existing
species and help form new ones.
The locations of continents and oceanic basins greatly influence the
earth’s climate and thus help determine where plants and animals
cam live.
The movement of continents has allowed species to move, adapt to
new environments, and form new species through natural selection.
The changes in climate throughout the earth’s history have shifted
where plants and animals can live.
Asteroids and meteorites hitting the earth and large upheavals of
the earth’s crust from geological processes have wiped out large
numbers of species and created opportunities for the evolution by
natural selection of new species.
What is an ecological niche, and how does it help a population
adapt to changing environmental conditions?
 It is a species way of life or role in a community or
ecosystem and includes everything that affects its
survival and reproduction.
 The species will always know their role, so when the
environment is changing they will be able to adapt to
the new way of life.
How do extinction of species and formation
of new species affect biodiversity?
 A new species can arise when members of a
population are isolated from other members for so
long that changes in their genetic makeup prevent
them from producing fertile offspring if they get
together again.
 If the environment is changing then then some
species may not be able to handle and they may die
off, while others will adapt and change to fit the
What is the future of evolution, and what role
should humans play in this future?
 We selectively breed members of populations to produce
offspring with certain genetic traits and use genetic
engineering to transfer genes from one species to
 Biologists are learning to rebuild organisms from their
cell components and to make identical copies or clones
or organisms.
 Genetic engineering has great promise for improving the
human condition, but it is an unpredictable process and
raises a number of privacy, ethical, legal, and
environmental issues.
 There are arguments over how much we should regulate
genetic engineering research and development.
How did we become such a powerful species in a
short time?
 We have thrives as a species mostly because of our
strong opposable thumbs, ability to walk upright,
and complex brains. Like many other species, we
have certain traits that allow us to adapt to and
modify the environment to increase our survival

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