bio

Darwin drew ideas for his theory from observations of organisms on

The Galápagos Islands

Superficially similar features molded by natural selection in very different species are classified as

analogous

Which term best describes the structures shown below

analogous

Mimicry

One species evolves to resemble another species. (Want to be seen).

Camouflage

allows an organism to blend in with its environment.

What type of adaptation is a walking stick bug using?

camouflage

Inbreeding in a population leads to individuals that are _____________________ for many traits.

homozygous

Punctuated equilibrium and gradualism are two models that describe the _______ of speciation.

rate

A population diverges and becomes reproductively isolated. This decribes the phenomenon __________.

speciation

Allopatric speciation

A physical barrier divides one population into two or more populations.

Sympatric speciation

A species evolves into a new species without a physical barrier. And The ancestor species and the new species live side by side during the speciation process but cannot reproduce.

Evidence that evolution occurs includes all of the following except

Acquired characteristics during an organism's life.

Populations of the same species living in different places

Become different as each population becomes adapted to its own environment.

What does evolution mean in biology?

Change in species over time

What pair is an example of convergent evolution?

Dolphins & Fish

Analogous structures indicate a shared ancestry, while homologous structures do not.

False

Gradualism and punctuated equilibrium are similar models of evolution.

False

The process of directed breeding to produce offspring with desirable traits is natural selection.

False

There is an involvement of natural disasters in Founders Effect

False

Fossil

Fossils have been found, such as of Archaeopteryx, that show an intermediate step between previous species and ones found on Earth today.

Which of the following is biochemical evidence for evolution?

Human hemoglobin is more similar to chimp hemoglobin than mouse hemoglobin.

Which of the following is most likely a vestigial structure?

Human's wisdom teeth

What are the four basic principles required for natural selection to happen?

Individuals in a population show variations Variations can be inherited Organisms have more offspring than can survive on available resources Variations that increase reproductive success will have a greater chance of being passed on.

Explain LaMarck's earlier view on evolution and why this is not accepted as valid anymore.

LaMarck believed that organisms obtained desirable characteristics during their life and then passed these on to their offspring. For example, he believed a short necked giraffe would stretch its neck to get higher up leaves, giving it a longer neck. Then, that giraffe's offspring would be born with longer necks too.

Which of the following is a correct statement about the relationship between natural selection and evolution?

Natural selection is one mechanism of evolution.

Explain natural selection and how it is a mechanism for evolution.

Natural selection is the idea that organisms best adapted for their environment will outcompete others and be the ones to survive and pass on their genes. As new adaptations take place in a population, and those adaptations get passed from one generation to the next, eventually new species can evolve.

The data obtained from our hand lab showed what kind of selection:

Stabilizing Selection

Distinguish between the three types of selection we discussed (Stabilizing, Directional and Disruptive)

Stabilizing Selection selects for more average traits than the extremes. For example, robins tend to lay an average number of eggs, around 4 or 5. If they laid too few, there is a chance none of the offspring would survive to reproduce themselves. If they laid too many, there wouldn't be enough resources to support all the baby robins. Directional Selection selects for one extreme form of a trait over another. The case of the black pepper moths in Europe during the industrial revolution shows this. Originally white moths were more common because the trees they lived on were lighter colored and they could camouflage. But as the trees turned darker because of pollution from industry, the dark colored moths became more common Disruptive selection selects for both extremes of a trait and selects against the average form.

Speciation

The development of new species through evolution.

List and explain each of the five different supports to the theory of evolution we discussed in class (fossil record etc.)

The fossil record shows how species that lived long ago are similar to species found on Earth today. Fossils have been found, such as of Archaeopteryx, that show an intermediate step between previous species and ones found on Earth today. Comparative Anatomy allows us to look at the anatomy and structures that make up different species and find similarities. These similarities can point to a common ancestor. Comparative Embryology shows us that early stage embryos of many different vertebrates are very similar, even though the adult forms are very different from each other. Early similarities in their development show evidence of common ancestors. Comparative Biochemistry looks at the DNA and amino acid sequence make up of different species. If there are a lot of similarities, it can point to a common ancestor. Geographic Distribution shows us that many animals fill similar niches in very different parts of the world. Even though these animals have similar diets and roles in their environments, they usually do not share many physical similarities, but instead look more like other animals found in their own geographic location.

Co-evolution

The relationship between two species might be so close that the evolution of one species affects the evolution of the other species.

A vestigial structure in one organism can be defined as a reduced form of a functional structure in another organism.

True

Biogeography is the study of why certain species live in certain areas.

True

Convergent evolution

Unrelated species evolve similar traits even though they live in different parts of the world.

Distinguish between vestigial, homologous and analogous structures

Vestigial Structures are organs or other structures in an organism that used to have a function in an ancestral species but now have limited or no function. Examples are the human appendix and tailbone. Homologous structures are anatomically similar in an organism inherited from a common ancestor. For example, even thought they serve very different functions, the bones that make up a human arm, bat wing, cat foot and whale fin are very similar. Analogous structures are structures in completely unrelated species that are similar and carry out a similar purpose. For example, both an Eagle and a fly have wings, but they are not at all related to each, they just both evolved a similar structure to help them survive and thrive.

Occurs when a population declines to a very low number and then rebounds

bottleneck

Evolution

cumulative changes in groups of organisms through time.

Any change in the allelic frequencies in a population that is due to chance is called:

genetic drift

A mutation is a random change in

genetic material

Adaptation

is a trait shaped by natural selection that increases an organism's reproductive success.

Which combination of characteristics in a population would provide the greatest potential for evolutionary change?

small population, many mutations

The process that occurs when a species evolves into a new species without a physical barrier separating populations?

sympatric speciation