This passage comes from a book titled Finding Your Inner Fish by Neil Shubin (© 2008 Neil Shubin).
- That a column of rocks has a
- progression of fossil species
- probably comes as no surprise. Less
- obvious is that we can make detailed
- predictions about what the species in
- each layer might actually look like by
- comparing them with the species of
- animals that are alive today; this
- information helps us to predict the
- kinds of fossils we will find in ancient
- rock layers. In fact, the fossil
- sequences in the world’s rocks can
- be predicted by comparing ourselves
- with the animals at our local zoo
- or aquarium.
- How can a walk through the zoo help
- us predict where we should look in
- the rocks to find important fossils?
- A zoo offers a great variety of
- creatures that are all distinct in many
- ways. To pull off our prediction,
- we need to focus on what creatures
- share. We can then use the features
- common to all species to identify
- groups of creatures with similar
- traits. All the living things can be
- organized and arranged like a set
- of Russian nesting dolls, with smaller
- groups of animals comprised in
- bigger groups of animals. When we
- do this, we discover something
- very fundamental about nature.
- Every species in the zoo and the
- aquarium has a head and two eyes.
- Call these species “Everythings.”
- A subset of the creatures with a
- head and two eyes has limbs. Call
- the limbed species “Everythings
- with limbs.” A subset of these
- headed and limbed creatures has
- a huge brain, walks on two feet,
- and speaks. That subset is us,
- humans. We could, of course,
- use this way of categorizing
- things to make many more
- subsets, but even this threefold
- division has predictive power.
- The fossils inside the rocks of the
- world generally follow this order,
- and we can put it to use in designed
- new expeditions. To use the
- example above, the first member of
- the group “Everythings,” a creature
- with a head and two eyes, is found in
- the fossil record well before
- “Everythings with limbs.” More
- precisely, the first fish
- (a card-carrying member of the
- “Everythings”) appears before the
- first amphibian (an “Everything with
- limbs”). Obviously, we refine this by
- looking at more kinds of animals and
- many more characteristics that
- groups of them share, as well as by
- assessing the actual age of the
- rocks themselves.
- Besides helping us refine the
- groupings of life, hundreds of years
- of fossil collection have produced a
- vast library, or catalogue, of the ages
- of the earth and the life on it. We can
- now identify general time periods
- when major changes occurred.
- Interested in the origin of mammals?
- Go to rocks from the period called
- the Early Mesozoic; geochemistry
- tells us that these rocks are likely
- about 210 million years old.
- Interested in the origin of primates?
- Go higher in the rock column, to the
- Cretaceous period, where rocks are
- about 80 million years old.
- The order of fossils in the world’s
- rocks is powerful evidence of our
- connections to the rest of life.
- If, digging in 600-million-
- year-old rocks, we found the
- earliest jellyfish lying next to the
- skeleton of a woodchuck, then we
- would have to rewrite our texts.
- That woodchuck would have
- appeared earlier in the fossil record
- than the first mammal, reptile, or
- even fish – before even the first
- worm. Moreover, our ancient
- woodchuck would tell us that much
- of what we think we know about the
- history of the earth and life on it is
- wrong. Despite more than 150 years
- of people looking for fossils—on
- every continent of earth and in
- virtually every rock layer that is
- accessible—this observation has
- never been made.
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Which of the following findings, if true, would most WEAKEN the idea that mammals appeared on earth before primates did?CorrectIncorrect
When the author states that “all living things can be organized and arranged like a set of Russian nesting dolls” (lines 26-28), he most likely means that organisms can be classified:CorrectIncorrect
The main purpose of the fourth paragraph (lines 48-66) is to relate:CorrectIncorrect
It can be reasonably inferred from the passage that people began hunting for fossils:CorrectIncorrect
The author’s purpose in writing this passage is most likely to:CorrectIncorrect
It can be reasonably inferred from the passage that given two ancient species, the one more similar to the modern version of the species will be found:CorrectIncorrect
In context of the passage as a whole, the discovery of a woodchuck skeleton next to that of the earliest jellyfish (lines 86-90) would most likely force scientists to rewrite their texts because:CorrectIncorrect
The word expedition in line 51 most nearly means:CorrectIncorrect
According to the passage, worms appeared on earth:CorrectIncorrect
The passage states that it is possible to predict where a creature will appear in the fossil record by paying attention to:CorrectIncorrect