Chapter 23 Bio

Chapter 23 Bio

phylogeny
The evolutionary history of a group of organisms is called a
monophyletic group
A taxon that includes a single common ancestor and all its descendants is a
Synapomorphies
Specific types of homologies used to develop phylogenies are shared derived characters or
Cladistics
Phylogenetic reconstruction based on shared derived characters is
Events that occur early in the fossil record are represented by branching events nearer to the root of the phylogenetic tree
How does the fossil record corroborate phylogenetic history?
fossils provide a record of extinct species
How do fossils provide evidence of evolutionary history?
dinosaurs, adaptive radiation
Extinction of ___ during the end-cretaceous mass extinction allowed mammals to diversify through the process of ______?
by exhibiting some features of ancestral organisms and some of derived organism
How can fossils provide evidence for macro-evolution processes such as the divergence of two species from a common ancestor?
by reducing competition among surviving organisms
How do mass extinction events influence subsequent species composition and diversity?
humans and gorillas are more related than orangutans and gorillas
this monkey phylogeny shows that
common ancestor from which the descendant species diverged.
In phylogenetic tree, a node represents
polyphyletic
A taxon that does not include the last common ancestor of all its members is
genetic basis, vary among taxa being analyzed
To be useful, phylogenetic reconstruction a taxonomic character must exhibit
homologous, analogous
Characters that are similar because descent come from common ancestor are___, similar due to convergent evolution are_______
reconstruct the evolutionary history of a group of organisms over millions of years.
track the spread of a pathogen, such as a fungus or virus, from place to place.
identify the origin of invasive pest species.
track shipments of endangered species or their products (such as elephant ivory or bushmeat).
All of the answer options are correct
With advent tools to incorporate molecular data, phylogenetic analysis can be used to
properties of organisms themselves and the environment in which they live
The probability that an ancient species will be represented in the fossil record is a function of?
marine life during initial diversification of animals in the Cambrian period 550 mill years ago
The burgess Shale preserves a remark fossil record of
oxygen levels in the deep oceans dropped.
global warming occurred as a result of volcanic eruptions.
oceans were acidified as a result of volcanic eruptions.
oxygen levels in the deep oceans dropped and oceans were acidified as a result of volcanic eruptions.
All of the answer options are correct.
During the end of Permian Mass extinction
moss group-fern-daisy
Fossils of these groups in order from oldest to youngest
probability of fossilization varies among species
What is a disadvantage of using fossils to reconstruct phylogenetic history?
clam
What organism is most likely to be fossilized
Not all organisms fossilize with equal probability
Why is the fossil record not a complete catalog of bio history?
cellular melanosomes that produce pigments
Recent discoveries of fossils that retain some coloration are result of preservation of?
Shallow lake bed
What kind of environment do fossils form in?
sedimentary
What type of rock are fossils found?
Two examples of a nested pattern of similarity among organisms are (1) a dog and a wolf are more similar to each other than either is to a cat, and (2) a dog, a wolf, and a cat are more similar to each other than they are to a turtle.
Give two examples of a nested pattern of similarity among organisms.
Monophyletic groups are groups in which all members share a single common ancestor not shared with any other species or group of species, like amphibians. Paraphyletic groups include some, but not all, of the descendants of a common ancestor, like birds being excluded from the “reptile” group even though there is evidence that they share a common ancestor. A polyphyletic group does not include the last common ancestor of all members, like putting bats and birds in a single “flying vertebrates” group.
Distinguish among monophyletic, paraphyletic, and polyphyletic groups, and give an example of each
The levels of classification are as follows: species, genus, family, order, class, phylum, kingdom, and domain.
List the levels of classification, from the least inclusive (species) to the most inclusive (domain).
A homologous trait is one that results from shared ancestry, such as an amniotic egg and lungs. An analogous trait is a similarity that results from convergent evolution, such as bird and bat wings or echolocation
Describe two traits that are homologous and two that are analogous
Synapomorphies, or shared derived characters between some members of a group, are useful in building phylogenetic trees because the homologies are shared by some but not all of the members of the group. If an entire group shared the same homologous trait, we would not be able to construct a meaningful phylogenetic tree.
Name a type of homology that is useful in building phylogenetic trees and explain why this kind of homology, and not others, is useful.
For an organism to be fossilized it must be buried and have features that resist decay after death. Not all organisms meet these two criteria, so they do not become fossils and lead to gaps in the fossil record.
Explain why there are gaps in the fossil record.
The relative timescale of past events can be determined by the location of the fossil in the Earth’s surface since a fossil’s age is related to how deep into the Earth’s layers the fossil is found. The absolute timescale can be determined by measuring isotope decay, since unstable isotopes decay at a particular, known rate. Carbon, uranium, and lead are all used to date fossils.
Explain how the fossil record can be used to determine both the relative and the absolute timescales of past events.
Mass extinctions have shaped the ecological landscape by removing the dominant species in an ecosystem and thereby changing the competitive landscape of the remaining organisms. The survivors of this altered ecosystem live and reproduce, thus introducing new mutations into the population.
Describe how mass extinctions have shaped the ecological landscape.
molecular data, fossil evidence and anatomical, physiological and developmental studies of extant species
What types of data can be used to construct phylogenies such as the one above?
I would branch the gorilla lineage and add the new species with the defining trait “upright stance”.
You discover a new species of ape that looks like a gorilla but walks upright. How would you change the phylogeny above?
is expected, because the fossil record is incomplete
You discover a new species of ape that looks like a gorilla but walks upright. After you have found a new species of ape, you spend 10 years in the field seeking a fossil of its ancestor. You fail. This lack of fossil data:
to calibrate the time scale of your phylogeny that is based on molecular/anatomical data
to reconstruct the environment, and possible selective pressures, on these lineages
to better understand anatomical changes that occurred during the evolution of this lineage
All of options 1, 2, and 3 are correct.
You discover a new species of ape that looks like a gorilla but walks upright. After you have found a new species of ape, you spend 10 years in the field seeking a fossil of its ancestor. You fail. Why would you have bothered to spend 10 years looking for a fossil ancestor of your new species?