An insect population lives along the edge of a north-south mountain range. The populations from the east and west slope eventually join in a low northern pass and interbreed, producing fertile offspring, but they do not circle around the southern edge because of a desert barrier. When glaciers move southward, the populations are pushed south of the northern pass and are isolated. While isolated, the two populations develop enough differences over time that when the glaciers retreat north and the insects again share the same pass, they no longer mate at the same time, nor can they produce fertile offspring. These insects
A. were originally two species and remain two species.
B. began as one species and therefore remain one species.
C. were originally one species but are now two species.
D. were originally two species but are now one species.
E. The number of species cannot be determined from the information given.
Answer: C
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Which of the following is/are true of most of the extreme thermophilic Archaea in the phylum of Crenarchaeota?
A. They are acidophiles B. Their cell walls contain lipoprotein and carbohydrate C. They are sulfur dependent D. Unlike most other Archaea, their membrane lipids are similar to those of the bacteria E. They are sulfur dependent, they are acidophiles, and their cell walls contain lipoprotein and carbohydrate
Sensory receptors in muscles and joints that detect ________ never adapt
Fill in the blank(s) with correct word
How do fossils support the theory of common descent?
A) They are a record of some intermediate types of organisms that document the process of evolution. B) They can be easily and precisely dated by comparing the rock layers where they are found. C) They are found equally all over the world, so they explain all our questions about biogeography. D) They contain complete DNA genomes, so they can be compared to modern organisms.
How does the phenomenon of horizontal gene transfer muddle the concept of monophyletic groups?
A. Monophyletic groups are based on the concept that members of a particular group of species are related to one another at a particular taxonomic rank. However, a species that undergoes horizontal gene transfer no longer belongs to that taxon and the group becomes paraphyletic. B. Monophyletic groups are based on the concept that members of a particular group of species are related to one another at a particular taxonomic rank. An unrelated species that undergoes horizontal gene transfer can become more closely related to members of a different group, making that group polyphyletic. C. Monophyletic groups are based on the concept that a particular group of species descended from a common ancestor. When horizontal gene transfer occurs, not all of the genes in a species were inherited from the common ancestor. D. Monophyletic groups are based on the concept that a particular group of species descended from a common ancestor. When horizontal gene transfer occurs in the common ancestor, any species to which it gives rise can no longer be considered descendent species.