EVOLUTION NATURAL SELCTION AND EVIDENCE OH MY! 100 100 100 100 100 200 200 200 200 200 300 300 300 300 300 400 400 400 400 400 500 500 500 500 500

What did Darwin observe about finches in the Galapagos Islands?

They had different beaks depending upon where they lived and what they ate.

Define evolution.

Evolution is the gradual change of a species over time.

What is a species? Is a mule a species?

A species is a group of similar organisms that can mate with one another and produce fertile offspring. A mule isn’t fertile. Members of a species by definition must be able to mate and have fertile offspring. That means their babies have to be able to have babies. Mules can’t do that, so mules aren’t a species.

What do genes have to do with evolution?

Only genetically inheritable traits are impacted by natural selection and they are also involved in the process of evolution.

Explain how a new species can arise from geographic isolation?

Geographic isolation can separate a group of individuals from the rest of the species. If the environment is different enough in the their new home range, the traits that are helpful to survival will be different than they were in the old location. So…these “new” traits will accumulate and eventually the group may be different enough so that they can no longer breed with the other group and produce fertile offspring… creating a new species. ***This is called allopatric speciation…in case you’re interested. Actually it’s called that even if you’re not interested.

Define extinct.

A species that no longer has any living members is considered extinct.

Choose an organism and a habit Choose an organism and a habit. Use the four mechanisms of natural selection to explain why these organisms don’t overpopulate their environment.

Butterfly Fish/Coral Reef Overproduction: more fish are born than can survive Variation: there are slight genetic differences among the individuals…some differences are beneficial to survival. Competition: The fish compete for resources (food, space, mates) Selection: Better adapted individuals survive and those traits that help them out are passed on to their offspring. These beneficial traits accumulate. Not all of the individuals can compete and this keeps the population in check.

What are four types/ pieces of information that scientists use to determine the evolutionary relationships among organisms?

-Fossils -Body structure -Early development morphology -DNA and protein structure

What is the difference between punctuated equilibria and gradualism?

Punctuated Equilibria:A type of evolution that occurs rapidly in short bursts of time. Gradualism: A type of evolution that occurs slowly over a long period of time.

What are homologous structures? Extra: What are analogous structures?

Homologous structures: Similar body parts (structures) that related species have inherited from a common ancestor. Like…a whale flipper, a bat wing, and your hand. Analogous Structures: Body parts that perform the same function but are not physiologically similar. Like…a fly wing, a bird wing, and a flying fish “wing.”

Why do evolutionary biologists think that related species have similar body structures and development patterns?

The organism has inherited many of the same genes from a common ancestor.

1. What does this branching tree (cladogram) show. 2 1.What does this branching tree (cladogram) show? 2. Are turtles more closely related to lamprey or salamanders? How do you know? 3. Name two common traits of wolves and grouper.

1. It shows how scientists think that groups of organisms are related 1.It shows how scientists think that groups of organisms are related. 2. Salamanders…they are closer together on the diagram thus they share more common traits. 3. Jawbones and a Vertebral Column.

Explain the process of Natural Selection?

The process by which organisms that are better adapted to their environment (having beneficial traits) are more likely to survive to reproduce. This means that these beneficial traits are more likely to accumulate in their offspring. By the same token, traits that are not helpful tend to disappear over time.

What is overproduction?

When a species produces more offspring than can survive.

Differences between members of the same species is called________

Variation

How does natural selection lead to evolution?

Some traits are helpful and give certain individuals a survival advantage. These beneficial traits accumulate because the members of a species that have these traits have a greater chance of successfully reproducing thus passing their genetic information to their offspring.

Describe the evidence that whales have evolved from land mammals.

Well one, THEY ARE MAMMALS, not fish. 2. Whales have hipbones. 3 Well one, THEY ARE MAMMALS, not fish! 2. Whales have hipbones! 3. Fossils, fossils, and more fossils!

What is an adaptation?

An adaptation is an inherited characteristic that improves an organisms chance for survival.

What are the four factors that effect natural selection?

1. Overproduction 2. Variation (genetic) 3 1. Overproduction 2. Variation (genetic) 3. Competition for limiting factors (food, water, space, mates, sunlight, etc.) 4. Selection (aka Successful Reproduction)

Can natural selection occur without variation (support your answer)?

No. Without genetic variation, all individuals within a species would have a equal chance of survival.

What is half-life and how do we use it to date rocks and fossils?

A radioisotope decays and changes to a different element at a constant rate (time). The rate is measured in a unit called the half-life. This is the length of time it takes for half of a given amount of the radioisotope to decay. For example: If a radio active element has a half-life of 4 days, it will take 4 days for half of that sample to decay. 8 days for ¾ of the sample to decay.

1. Most of what we know about extinct organisms is based upon________ 2. In which type of rock do you find fossils.

1.The fossil record. 2. Sedimentary

Explained what happened to the peppered moths in England.

Well…once upon a time in England during the industrial revolution, there a species of moths called peppered moths. These generally light-colored moths were camouflaged against the tree bark upon which they hung out. Because of genetic variation, some moths were lighter and some darker. The dark ones were usually eaten because they were easier to spot. Gradually, soot from the emerging industrial processes started to darken the tree bark. Moths that were lighter in color began to be more easily seen by predators, and the darker colored moths were now better camouflaged (it used to be the opposite). This illustrates how a once beneficial trait can become a detriment as the environment changes.

How do fossils form?

Mostly when an organism dies and becomes buried in sediment Mostly when an organism dies and becomes buried in sediment. *Less common ways: insects trapped in amber or woolly mammoths being frozen in ice

How do scientists determine the age of fossils?

1. Relative dating : scientists estimate the age of a fossil by its position in the sedimentary rock layers. 2. Absolute dating: scientists determine the actual age of a fossil using half-life.