Exam 16: The Evolution of Biodiversity

Many organisms decompose rapidly after death;some organisms have had soft bodies and some areas where organisms died have undergone massive geologic changes.For these reasons,the ____________________ record is incomplete.

Scientific advances in the study of evolutionary developmental biology (evo-devo)have demonstrated that another factor has had as much of an impact as specific alterations in the genes on the macroevolutionary changes in body plans that have been observed through time.This factor is _____________.

Which kind of organism makes up the oldest fossil found on Earth?

Among the first organisms to colonize land were descendants of ____________________.

A group of orders is called a(n)____________.

The first single-celled organisms arose 3.5 ____________________ years ago.

Large timescales have played a role in creating the diversity of life that has existed over billions of years on the planet Earth in combination with ______________.

The supercontinent Pangaea began to break up ___________.

Mammals branched out to evolve many new species after the extinction of the ___________________.

A trait that represents a reversion to an ancestral state is known as a(n)____________.

Recent research in developmental biology has shown that the body plans of organisms may be varied as a result of _____________.

The Cambrian explosion resulted in the evolution of more than 17,000 species of an animal known as the trilobite.The shear number of trilobite fossils found in modern times suggests that trilobites were very abundant,perhaps the rulers of the seas.Today,no living descendants of this group exist.What happened?

The first vertebrates to colonize land were ____________.

The first land plants ____________.

If the homeotic genes that control limb development in the fruit fly are expressed in the head region of the fly,instead of developing antennae,the fly builds __________.

Mass extinctions cause the loss of many species,no matter how well adapted those species were before the extinction.Why might previous adaptations NOT help a species survive a mass extinction?

The lowest level of classification in the Linnaean hierarchy is the __________.

Which of the following is NOT documented by the fossil record?

Which of the following methods would give the most accurate estimate of the age of a fossil?

Mass extinctions can often lead to adaptive radiation since they provide new ecological and evolutionary opportunities for groups of organisms that were previously important to only a minor degree.