Which was Charles Darwin’s contribution to the study of biology?

He proposed that natural selection is the primary mechanism of evolution.

During a trip to the Galapagos Islands, which observation led Charles Darwin to suspect that organisms change over time?

Island finches resembled mainland finches, but were not the same species.

Charles Darwin observed a unique beak size and shape in the finch population of each of the Galapagos Islands that he visited.

Which is the most likely cause of the observed variation?

competition among individuals for available food sources

Veronica wrote Charles Darwin’s main points on the board, but she made a mistake in one point.

1. Since more offspring are produced than an environment can support, organisms within a population must compete for resources to survive.

2. Due to variations within the population, some competitors will be better equipped for survival than others.

3. The best-equipped organisms will survive and will produce well-equipped offspring.

4. Variations that help with survival will be passed on to future generations and will rapidly change the whole population.

point 4

Natural selection is a process by which organisms that are better adapted to their environment tend to

survive.

What is natural selection?

a process that selects variations that help with survival and that spreads the variations to more offspring

In terms of natural selection, what is the best description of an organism that is fit?

The organism is better able to survive and pass on traits to offspring than competing organisms.

According to the concept of “survival of the fittest," if a population of birds eats worms that they find deep under ground by using their beaks, which members of the bird population would be more fit?

birds that have longer beaks

Which statement would least likely be used to describe variation?

Variations that decrease reproductive success are more likely to be passed on.

In the African savanna, more wildebeests are born than the environment can support. Which is most likely to happen over a period of years as a result?

Individuals that are well suited to the environment reproduce, and those that are not well suited die before they reproduce.

Which of the gazelle’s naturally selected traits is shown in this picture to be an evolutionary advantage?

coat color for blending in with dry grass

Koalas are marsupials that are found in eastern Australia. Although their ancestors lived mostly on the ground, modern koalas spend most of their time in eucalyptus trees. This is possible because their hands and feet have strong claws and opposable digits.

What other adaptations could have helped koalas as they evolved from land dwellers to tree-dwellers?

fur color that closely matches the eucalyptus bark color

Which statement describes natural selection?

It is the primary mechanism for evolution.

Which best describes the relationship between evolution and natural selection?

Natural selection leads to evolution

Which would least likely be a cause of natural selection?

Evolution

Scientific investigations often lead to the formulation of new scientific questions. Charle’s Darwin reviewed his observations after he returned home from his voyage studying the selective breeding of pigeons. Which question would he be prompted to ask based on his voyage?

Can selection in nature also lead to a new species over time?

A frog has more offspring than can survive on available resources.
Which is this an example?

Overpopulation

The map shows the allele frequency of sickled hemoglobin (HbS) and malaria endemicity in Africa.

Which statement best explains the relationship between HbS allele frequency and malaria endemicity in Africa?

When an area is malaria free, the HbS allele frequency is between 0 and 4.04.

Which organism exhibits behavioral adaptation?

A possum playing dead to increase its chances of survival

A population of rabbits has individuals with fur coloring that ranges from white to brown. The population lives in a temperate deciduous forest where the summers are mild and average about 50°F. The winters are often below freezing.

If warmer temperatures last longer into the fall and the average temperature in the winter is getting warmer, what do you expect to happen to the population?

The percentage of the population with white fur will decrease.