Evolution II - Biology II

What are the three main steps of fossilization?

1. An organism is buried in sediment. 2. Hard tissues (bones, etc.) mineralize. 3. Surrounding sediment hardens to rock.

What are six human examples of vestigial traits? (Alphabetical order)

1. Appendix. 2. Erector pili muscles and body hair. 3. Gill slits during embryonic development. 4. Male breasts and nipples. 5. Tailbone/coccyx. 6. Wisdom teeth.

What are three of the main characteristics of the modern horse family?

1. Fast runners. 2. Adapted to grasslands. 3. Long legs.

Which are three examples of anatomical features that provide evidence for evolution?

1. Homologous characteristics.

What are the 4 main types of preservation states fossils are found in?

1. Preserved in sedimentary rock. 2. Preserved in permafrost. 3. Preserved in amber. 4. Preserved in very dry caves.

The fossil record shows that early species of horses were generally ______ in size, but many lineages since about 30 million years ago exhibit substantial change toward ______ in size.

1. Small. 2. Increasing.

What two main roles to transitional fossils play in the study of evolution?

1. They help scientists fill in the gaps between two separate (but often genetically related) groups. 2. They help to illustrate how and why the major transitions in traits of an organism occur.

What are the two main reasons why island trees belong to plant families that typically do not have tree members (for example the sunflower family)?

1. Tree seeds rarely make it to isolated islands. 2. The tree niche is empty and so a flower can evolve through natural selection to be tree-like.

What was the cause of the adaptations observed in the evolutionary changes in the fossil records of the horse (Equidae) family?

Changes in the global climate.

Many fishes that inhabit the sub-freezing Arctic and Antarctic waters posses antifreeze proteins; we now know that there are at least five different kinds of antifreeze protein genes that have evolved independently in different species to perform the same function. This is an example of:

Convergent evolution.

What type of evolution happens when two species from different lineages independently evolve similar characteristics because they occupy similar environments?

Convergent evolution.

What is the name of fossils that contain characteristics from two different groups of organisms?

Fossils with characteristics from 2 different groups are called intermediate fossils.

Evolutionary changes in the horse family can be related to changes in their habitat in North America (where most of the horse evolution has occurred); in particular, horse evolution was related to the widespread appearance of...?

Grasslands.

What's the difference between homologous and analogous?

Homologous evolution is when species have similar structures due to *shared ancestry*. Analogous evolution is when species' have similar structures due to *convergent evolution through separate lineages*.

What are the three main anatomical points of evidence to support evolution?

Homologous structures, vestigial structures, and early embryonic similarities.

What is the best distinguishing difference between homologous and vestigial traits?

Homologous traits serve a current function, while vestigial traits are non-functional.

In the past 55 million years, the length of horses' limbs/legs have done what?

Increased (length in horse limbs).

What type of communities did Darwin note as missing plant and animal species typically found on continents?

Island communities.

How have horses feet evolved over time, from the original 4 toes (on front feet) and 3 toes (on hind feet) encased in fleshy pads to today?

Modern horses have a singular toe, encased in a bone-like hoof.

Typically, how are species on islands related to species on a nearby continent?

More closely related.

How many toes do modern horses have?

One toe per foot.

Since Darwin's time, how has rock and fossil dating changed?

Originally, relative dating was used starting in the early 18th century (when geology first emerged as a science); fossils and rocks were then dated using absolute dating methods, continuing to the current day.

As a result of convergent evolution, many marsupial mammals of Australia look similar to what type of mammals (that occupy a similar ecological niche)?

Placental mammals.

What is the other name for "fossil genes"?

Pseudogenes.

What is the term that refers to the coding of traits that are no longer present within the phenotype of a species?

Pseudogenes.

What is the term for dating a rock/fossil based off of its position in comparison to those around it?

Relative dating.

A lack in the production of the DNA ______ for ______ enzymes results in dairy intolerance.

Sequences; Lactase.

What was the size and complexity of early horses' (Hyracotherium) teeth?

Small and relatively simple.

Island species are usually most closely related to...?

Species on nearby continents.

What types of species are most likely to disperse to an island (three descriptive words)?

Species who can fly, float, or drift.

Fast swimming marine predators such as dolphins, sharks, and tuna, have what body type?

Streamlined.

What is the "best" studied example of evolutionary changes (official family name)? Donkeys and zebras are included in this family.

The Equidae family.

True or False: Pseudogenes are made inactive by mutation(s).

True, pseudogenes are made inactive by mutation(s).

True or false: Fossils have been found to connect all major vertebrate groups to their ancestors.

True.

What are pseudogenes?

Vestigial genetic structures that are carried along with functional DNA.

What type of habitat were the early species of horse (which had wide hooves and short legs) well-adapted to live in?

Wooded areas.

Best smart alleck response to someone being an ass?

"Oh? I didn't know you were an Equus africanus."

What are three of some of the most recently discovered intermediate fossils, and what were they intermediates between?

- A four legged aquatic mammal that links marine mammals to their terrestrial ancestors. - Tiktaalik, a species that is transitional between fish and amphibians. - A fossil snake with legs that links modern snakes to the lizards from which they descended.

The fossil record reveals that during the last 25 million years most of the lineages in the horse family have exhibited what type of change in size?

A rapid and substantial increase.

What is a vestigial structure?

A structure that doesn't have a function, but resembles that of a structure that used to have a purpose.

Structures that have evolved separately but look very similar exhibit what type of evolution (A.); while in contrast, structures that evolved through modification from a common ancestral trait exhibit what type of evolution (B.)?

A. Convergent. B. Homologous.

What is the term for determining the specific age of a rock/fossil by testing the isotopic composition?

Absolute dating.

Why is it that some organisms do not appear to be perfectly adapted to their environment?

Because natural selection can only work on the variation present in a population.

Why are giraffe's necks not perfectly adapted for their function?

Due to all mammals having only 7 vertebrae in their necks, giraffes have not been able to evolve more than 7, so they have limited mobility.

True or False: The muscles that wriggle the human ear is an example of convergent evolution.

False, the muscles that wriggle the human ear is an example of a vestigial trait.

Did the ability in Europeans and Africans to produce a significant enough amount of lactase develop separately, or were the populations related? What is that type of evolution called?

Lactase production in the European and African populations developed separately; convergent evolution.

What are the size and complexity of the teeth of the modern horse family?

Large, and with a complex pattern of ridges.

What are placental mammals?

Mammals which develop as embryos in the uterus of females and are nourished by placenta (in utero).

Early horses had four toes on the front feet and three toes on the hind feet, all encased in fleshy pads. What statement correctly describes how the toes have changed during the evolution of modern horses?

Modern horses have a single toe encased in a bony hoof.

What is lanugo?

The downy, soft hair that develops on fetuses during the fifth month of development (it also develops on those with anorexia nervosa).

What is one of the most direct pieces of evidence to support evolution?

The existence of fossils.

How have the fossil records changed since Darwin's time? (Improved, worsened, stayed the same)

The fossil records have improved since Darwin's time.

An opossum gives birth to tiny young that finish developing in the mother's pouch. A whale sustains its developing offspring in the uterus. What term(s) correctly identify the opossum and whale?

The opossum is marsupial, while the whale is placental.

What is a fossil?

The preserved remains of a now-dead organism.

What is a homologous structure?

The same structure, but with a different purpose/function.

What was the evolutionary advantage of early horses' short legs and broad feet?

They could easily graze through leaves, and evade predators by darting through small openings.

What is the point of having a streamlined body type?

To reduce drag in water.

Why are traits that develop and evolve through convergent evolution different that homologous traits?

Traits produced by convergent evolution have not evolved from a common ancestral trait, while homologies have.

What type of fossils act as evidence of major transformations in the portrayed life forms? (Two terms)

Transitional or Intermediate fossils.