Exam 11: Evidence Of Evolution

The time it takes for half of the atoms in a radioisotope sample to decay is called the ____.

The study of the body structures of the ostrich,emu and rhea shown here is an example of  ____.

Based on the structural similarity of vertebrate limbs,we can conclude that these structures are examples of ____.

Hind leg bones in whales are an example of ____ structures.

These statements ask about elements and isotopes that have been important in learning about earth's history and the age of organisms.For each one, select the best choice from the five isotopes or elements below. -wells up at oceanic ridges and drives the movement of tectonic plates

The discovery of immense ridges and trenches stretching thousands of kilometers across the seafloor in the 1950's led to acceptance of the theory of ____.

Scientists have determined that this crater was created by a(n)____.

The accumulating data from biogeography,comparative morphology,and fossil discoveries led early naturalists to propose that species ____.

In geological terms,a sudden,violent application of extreme pressure can be detected by the presence of ____.

Finding an abundance of iridium in the K-Pg boundary sequence worldwide pointed to evidence that this layer was of ____ origin.

These statements ask about a perception or line of thought associated with various researchers throughout history.For each description, select the best choice from the following naturalists. -Cuvier

If the 14C to 12C ratio present in a fossil is 25% of that in living organism,how many years have passed since this fossilized organism died?  

All vertebrate embryos have _____ at some point during embryonic development,indicating a common evolutionary ancestor.

Lyell's ideas that gradual,everyday geologic processes had shaped Earth challenged the prevailing estimate of Earth's age at ____,because ____.

Missing links in the fossil record prevent scientists from determining evolutionary lineages until _____ are discovered.

These statements ask about the various theories that were presented in an attempt to explain the new information discovered during the 19th century.Match the theory with the description. -Unique catastrophic geological events altered the face of the Earth in the past.

Which event occurred first?  

14C is a radioisotope of carbon that decays into ____.

Individuals with adaptive traits tend to survive longer and produce more offspring,leading to ___ of the species.

The radioactive decay of an isotope can be best compared to a ____.