Bio Exam 2

The diagram shows undisturbed sedimentary strata at the bottom of the ocean. The fossils found in layer B resemble the fossils found in layer A. This similarity suggests that...

modern forms of life may have evolved from earlier forms of life

Why were fractal animals an evolutionary dead end?

their body plan was based upon branching- thus they never develop a mouth, symmetry, or mobility

What do natural selection and sexual selection have in common?

they both operate by some individuals passing on more genes to the next generation

Which species gave Darwin his first ideas about evolution?

mockingbirds of South America and Galapagos

Which of the following is geologic evidence for Snowball Earth?

drop stones

Which of the following processes will ruin your chances at becoming a fossil?

erosion, scavenging, and plate tectonics (sedimentation will not)

Tiktaalik is a fossil that fills the gap between...

fishes and tetrapods

When looking for fossils in amber, it's best to look near the site of a prehistoric _________

forrest

Evolution can be defined as a change in the ______________ over time. What are the two conditions required for evolution in a population?

gene pool of a population 1) Must be genetic variation 2) Must be pressure from the environment that favors one combination of DNA over others

Chris Shneider and his colleagues traveled to Ecuador to study ________ and determine how a new species may arise

hummingbirds

Natural selection ______________________, while sexual selection _____________________.

is about surviving and gathering resources, is about mating opportunities

A specialized bill that helps a particular group of birds access a rich new food resource...

likely evolved by natural selection

If you could travel back 400 million years ago, which of the following organisms would you NOT see on land?

mammals

The first organisms to evolve on earth...

did not have a nucleus

Charles Darwin

- English naturalist - 1809-1882 - Sailed on HMS Beagle for 5 years - Developed idea of natural selection

Basic Concept of Natural Selection

- Environment selects which genes are passed onto next generation - Environmental pressures favors some variation over others - Influences which individuals successfully survive and reproduce

These are all possible reasons why feathers might have evolved before flight:

- attracting mates - hiding from predators - insulating eggs - retaining body heat **NOT preventing sunburn

All of these are reptilian characteristics of Archaeopteryx:

- bony jaws with teeth - claws on the tips of wings - long bony tail - reptilian head **NOT wings with feathers

Choose the characteristics of this image (dirt colored, cracked bread top looking)

- earliest animal fossil - embryos - found in China

Darwin's Role in Evolutionary Biology

- evolution had already been proposed - geologic and fossil evidence supported idea that life changed over time - he provided a mechanism to explain how evolution works over time...making it testable

On the Origin of Species (1859)

- starts with agriculture - then discusses the idea that nature does the same thing, only not intentionally

What series of events led to the discovery of Lucy?

- the right conditions for fossilization had to occur - uplifting of buried sediment had to bring the fossil remains close to the surface - erosion of remaining layers of sediments had to expose the bones to the service

Mineralization occurs when...

- tissues dissolve away leaving a space to be filled with harder material - the weight of water or mud leaches out internal body parts to be replaced with minerals

List the 4 components of natural selection and give an example of each using the hummingbird

1. Genetic variation: if two parents mate and both parents have long bills, their offspring will have long bills 2. Overproduction of offspring: hummingbirds produce dozens of offspring but only one or two of those individuals are likely to survive 3. Struggle for existence: Excess of individuals creates competition, evolution will favor hummingbirds more efficient at getting to nectar 4. Differential survival and reproduction: for hummingbirds, small differences in length of peak affect its ability to adapt and survive

Darwin is best known for (2 answers)

1. writing the book the Origin of Species 2. Proposing that species evolve through the process of natural selection

A rock formed with 1000 atoms of radioactive atoms, but only contains 250 atoms today. The half-life of the rock is 1,000,000 yeas, how old is the rock?

2,000,000

You know that the half-life of a radioactive isotope is 10,000 years. If a rock layer starts out with 100,000 atoms of this radioactive isotope, how many atoms will be left after 10,000 years?

50,000

When did the Cambrian explosion take place?

535-525 million years ago

What do the rocks of the Permian and Triasic era tell us?

???

In this type of dating, radioactive isotopes are used to estimate how long ago rocks or fossils were formed. These radioactive isotopes include 14C and 238U

Absolute

How was Acanthostega different from Tiktaalik?

Acanthostega had fingers but Tiktaalik did not

What kinds of organisms can be genetically manipulated through AS?

All are correct - domesticated - plants - first generation organisms caught out of the wild

In Darwin's time, people were already practicing artificial selection on domesticated species. Why was AS important to Darwin's ideas of evolution?

All are correct - he could now extend the idea of selection per se to the natural world versus just the domesticated world - b/c the church believed that AS showed that new species could be created by someone other than god - b/c farmers saw that their livestock, like cows, could change over time in order to produce milk

Most scientists agree that the first definite fossil bird from 145 million years ago is _________.

Archaeopteryx

____ is the selection by humans for breeding of useful traits from the natural variation among different organisms.

Artificial selection

Darwin spent 5 years aboard the ____ studying fossils, plants and animals in the Galapagos islands

Beagle

Which of these radioactive elements would be more appropriate to date Yuka, a Siberian mammoth found in permafrost that is thought to be 10,000 years old?

Carbon-14

Why did Darwin take so long to publish the Origin of Species?

Darwin was concerned about the reaction of others to the implications of his theory b/c

The hair of this animal is modified into spines for protection.

Echidna

Struggle for Existence

Excess of individuals creates competition, compete for limited resources

Which of the following is NOT a type of "built in bias" when we look at the fossil record

Fossils found in older rocks mineralize faster than younger sites (FALSE) TRUE: - most fossils form best in aquatic environments - shells and bone decompose slowly, unlike soft bodied organisms

These animals had modular bodies, with 20 highly branched identical elements on either side. They were very thin.

Fractofusus

What are the two main characteristics that distinguish mammals from all other animals?

Hair and mammary glands

Differential survival and reproduction

Individuals with traits that are best suited to that environment have greater survival and more offspring

The platypus is one of the many strange Australian mammals. How does it locate its food?

It feeds underwater by touch, using its sensitive bill

Which animal is a monotreme?

Kangaroo

Which bird character from our story will be the most likely to pass on more genes to the next generation?

Longbill

Another name for a pouched mammal is a ___________.

Marsupial

The primary way that evolution occurs is through _________ when populations change in response to ________ and become adapted to new conditions.

Natural selection, the evironment

Bug Simulation: Is the simulation artificial or natural selection?

Natural, because the environment determines which bugs survive???

If there's no variation, or source of variation in a population, can evolution occur?

No B/C???

Would a dry cave be a good place for permineralization?

No, because permineralization requires flowing water

Opossums and koalas are members of which group of mammals?

Placental mammals

Which mammal gives birth to the most developed offspring?

Placentals

Some of the earliest traces of life on Earth are fossilized mats formed by colonies of bacteria. Scientists think that these mound-like structures were formed as sediments and mud accumulated on top of the bacteria. More bacteria grew on the top layer, which was subsequently covered by more sediments. The process repeated many times, forming a series of thin layers. Similar mounds are formed today in this manner by living bacteria. These structures, both living and fossilized, are known as....

Stromatolites

Which are unique to birds?

TWO OF THE ABOVE - feathers - fused arm bones - allantois membranes

When looked at in sequence, what do the fossils of Eusthenopteron, Tiktaalik, and Acanthostega reveal?

The evolution of tetrapods from fish

Based on the fossil record, feather first appeared in ________.

dinosaurs

Which of the following traits had NO observable variation in Darwin's mocking birds?

They all had observable traits: - beak lengths - beak size - feather coloration

Which statement below is FALSE about stromatolites?

They are commonly found on the shores of all continents TRUES: - they can grow into large mounds b/c there are no predators due to salty water - they consist of blue green algae also known as cyanobacteria - they were the first organisms to release oxygen into the air

How do baby platypuses get milk?

They lap up milk secreted onto the mother's fur.

In an ecosystem, some giraffes have long necks and others have short ones. If something caused low-lying shrubs to die out, the giraffes with short necks would not get enough food. After a few generations, all giraffes would have long necks.

This is natural selection

An example of a monotreme is a duck billed platypus...T/F

True

Mammary glands evolved from sweat glands...T/F

True

Which of these radioactive elements has the longest half-life and would be more appropriate to use to date very old rocks that are thought to be 4.0 billion years old?

Uranium 238

Which statement describes marsupials?

Young are born at an early age and finish development inside a pouch

Which of the following fossils is an example of permineralization?

a fossilized dinosaur bone

Which type of fossil dating uses radioactive isotopes?

absolute

Which of these is not an advantage of mobility?

absorb nutrients from the water True Advantages: - avoid overcrowding - escape danger - search for food

Define gene pool

all of the collective DNA of the population

Overproduction of Offspring

all species produce more offspring than needed to replace the parents

Which appeared first?

bangiomorpha

All of these are fish-like characteristics of Tiktaalik except __________.

crocodile-shaped head

Which of the following is a male characteristic associated in our story with sexual selection by male-male competition but NOT female choice?

defense of a resource-rich territory

The function of the placenta is to...

deliver food and oxygen while removing wastes

The stromatolites of Western Australia were formed by...

photosynthesizing bacteria

The only egg laying mammals are the ________ and _________.

platypus and echinid

Collagen is...

the protein used as "sticky tape" to hold sponge cells together

The best place to die if you wish to become a fossil is....

shallow ocean

This image represents...(round shelled milipede, look like insects)

the Cambrian age

Why do the offspring of individuals who survive and reproduce have an evolutionary advantage?

the offspring are more likely to have inherited the beneficial traits from their parents

Evidence shows that modern dogs are direct descendants of ___

wolves