Which Statement About Natural Selection On Early Earth Is Correct

Which statement about natural selection on early Earth is correct?

Natural selection could act on a population of proto-cells on early Earth, selecting for those that were stable and had self-replicating, catalytic RNA that allowed them to grow and divide to produce similar daughter proto-cells.

A paleontologist finds a new tyrannosaur in a site she is excavating, and wishes to date the fossil. What is the most likely method she will use?

She will infer the age of the fossil by dating layers of volcanic rock above and below the stratum containing the fossil.

The figure shows eyes found among living molluscs, ranging from a patch of pigmented cells in a limpet to a complex, image-forming eye in a squid. Is it possible that a structure as complex as an image-forming eye evolved by natural selection?

Yes, if the photoreceptor cells and simple eyes that preceded it were useful to the animals in which they arose.

The oldest fossils usually _____.

are found in the deepest strata

allows us to indirectly date fossils up to billions of years old based on minerals in surrounding volcanic strata

Which of the following organisms would be most likely to fossilize?

a common squirrel

Which of the following would be LEAST likely in the fossil record?

desert-dwelling species

If the half-life of carbon-14 is about 5730 years, then a fossil that has one-sixteenth the normal proportion of carbon-14 to carbon-12 should be about how many years old?

22,900

For many years scientists believed that almost all animal lineages burst into being during the Cambrian era (just after the end of the Precambrian super eon). However, there have been many recent findings of animal-like fossils and "trace fossils" (fossils of an animal-like organisms movement) from the late Precambrian. Which of the following best explains why it took so long to realize there was animal-like life in the Precambrian?

Animals from the late Precambrian had soft bodies.

Which listing of geological periods is in the correct order, from oldest to most recent?

Cambrian, Devonian, Permian, Cretaceous

An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to _____.

cause iron in ocean water and terrestrial rocks to rust (oxidize)

What is true of the Cambrian explosion?

There are fossils of animals in geological strata that are older than the Cambrian explosion.

How does continental drift affect living organisms?

It causes climate change, which puts selective pressure on organisms.
It causes changes in habitats, such as when large amounts of shallow marine habitat were lost in the formation of Pangaea.
It may cause an increase or decrease in competition among different species.
It happens so slowly that it does not affect living organisms.
All but one of these are correct.
Continental drift affects organisms by changing the current environment in all of these ways. Organisms may have to adapt, move, or go extinct.

Which factor most likely caused animals and plants in India to differ greatly from species in nearby southeast Asia?

India was a separate continent until forty-five million years ago.

Evolution works by _____.

"tinkering" with existing structures
Evolution, and in particular natural selection, can only select for the best available traits. Modifications to those traits are usually made in small, incremental steps, and new inventions are rare.

The oxygen revolution changed Earth's environment dramatically. Which of the following took advantage of the presence of free oxygen in the oceans and atmosphere?

the evolution of cellular respiration, which used oxygen to help harvest energy from organic molecules

Adaptive radiations can be a direct consequence of four of the following five factors. Select the exception.

genetic drift

evolutionary innovation
an adaptive radiation in a group of organisms (such as plants) that another group uses as food
vacant ecological niches
colonization of an isolated region that contains suitable habitat and few competitor species