magine a scientist finds the fossils of an extinct Ichthyosaur and finds this morphological
similarity of Ichthyosaurs and modern dolphins: bones indicating flippers and a tail for
swimming. The scientist guesses that Ichthyosaurs may form a monophyletic group with the
dolphins, based on this morphological similarity. What is one method or line of reasoning that
scientists could NOT use when testing the hypothesis that dolphins and Ichthyosaurs form a
monophyletic group? Take blood samples and use DNA evidence to determine a more complete
phylogenetic tree, because biologists have not successfully obtained DNA from Ichthyosaurs
Collect more data about the presence and absence of many more characters of both dolphins and
ichthyosaur bones Make sure that the flippers and tail in both Ichthyosaurs and dolphins are due
to homology, rather than analogy See if the living sister group to dolphins is more closely related
to dolphins than is the Ichthyosaur Use the principle of parsimony to decide which of several
trees is most parsimonious
Solution
Yes the similar characters bewteen ichthyosaur and dolphin is maily due to homology. They
share the following characters:
1. Muscular body
2. Dorsal fin to swim through the water
3. Good eye sight
4. Propulsive fins.
5. The internal structure of the pectoral-fin have five fingered limb which has evolved into a fin
in dolphin
They both have different evolutionary pathways , but they share common physical characters due
to the environmental same stress and selection they are subjected to.But in evolutionary tree they
are distinctly realted and are seperate species..
magine a scientist finds the fossils of an extinct Ichthyosaur and f.pdf
1. magine a scientist finds the fossils of an extinct Ichthyosaur and finds this morphological
similarity of Ichthyosaurs and modern dolphins: bones indicating flippers and a tail for
swimming. The scientist guesses that Ichthyosaurs may form a monophyletic group with the
dolphins, based on this morphological similarity. What is one method or line of reasoning that
scientists could NOT use when testing the hypothesis that dolphins and Ichthyosaurs form a
monophyletic group? Take blood samples and use DNA evidence to determine a more complete
phylogenetic tree, because biologists have not successfully obtained DNA from Ichthyosaurs
Collect more data about the presence and absence of many more characters of both dolphins and
ichthyosaur bones Make sure that the flippers and tail in both Ichthyosaurs and dolphins are due
to homology, rather than analogy See if the living sister group to dolphins is more closely related
to dolphins than is the Ichthyosaur Use the principle of parsimony to decide which of several
trees is most parsimonious
Solution
Yes the similar characters bewteen ichthyosaur and dolphin is maily due to homology. They
share the following characters:
1. Muscular body
2. Dorsal fin to swim through the water
3. Good eye sight
4. Propulsive fins.
5. The internal structure of the pectoral-fin have five fingered limb which has evolved into a fin
in dolphin
They both have different evolutionary pathways , but they share common physical characters due
to the environmental same stress and selection they are subjected to.But in evolutionary tree they
are distinctly realted and are seperate species.
