Use the following information and figure to answer the question below
In a review paper published in 2000, Adoutte et al. examined some animal phylogenies generated by comparing the ribosomal RNA (rRNA) of animals from many different phyla. They then integrated these independently created phylogenies into one phylogeny that best fit all the data.
The figure below compares a traditional phylogeny based on morphological characteristics (A) to the new molecular-based phylogeny described by Adoutte et al. (B).
Note that platyhelminthes, nemerteans, and entoprocts, which do not have coeloms and are classified as acoelomates in the morphological phylogeny, are reclassified as lophotrochozoans in the molecular phylogeny. Similarly, groups classified as pseudocoelomates in the morphological phylogeny are reclassified as either lophotrochozoans or ecdysozoans in the molecular phylogeny; other lophotrochozoans and ecdysozoans have coeloms. Copyright 2000 National Academy of Sciences, U.S.A. (A. Adoutte, G. Balavoine, N. Lartillot, O. Lespinet, B. Prud'homme, and R. de Rosa. 2000. The new animal phylogeny. Proceedings of the National Academy of Sciences USA 97(9):4453-56.)
What does this reclassification based on molecular data imply about the evolution of acoelomates, pseudocoelomates, and coelomates?
A) Pseudocoelomates can be seen as an intermediate stage between acoelomate and coelomate development.
B) Although acoelomates and pseudocoelomates evolved only once, coelomates evolved multiple times in different lineages.
C) Only the animals that evolved earliest are acoelomates.
D) Some pseudocoelomates and acoelomates have evolved from coelomates.
Answer: D
You might also like to view...
Ecosystem ecology is primarily concerned with
A. ecosystem stability. B. interactions among species. C. the synthesis of new forms of nutrients. D. patterns of species diversity. E. movement of energy and materials through organisms and their communities.
Flowering can be regulated by light, temperature, gibberellin levels, or internal factors. What do all of these different flowering pathways have in common?
A. All four pathways result in a decrease in LEAFY (LFY) expression, which induces flowering. B. All four pathways result in an increase in CONSTANS (CO) expression, which induces flowering. C. All four pathways result in an increase in LEAFY (LFY) expression, which induces flowering. D. All four pathways result in a decrease in CONSTANS (CO) expression, which induces flowering.
The greatest rate of extinction of all time is/was probably caused by ____
a. an ice age b. unknown reasons c. formation of Pangea d. human activity e. asteroid impact
When both glucose and lactose are available in the growth medium, the presence of which molecule is capable of inducing basal transcription of the lac operon?
What will be an ideal response?