BIO 199 LECTURE EXAM 1

pseudogenes and example

(also called fossil genes) - traces of previously functional genes - example: hemoglobin gene in icefish (they have traces of the gene that produces Hb, but the gene has undergone mutation to make it nonfunctional, due to the high levels of O2 in the antarctic waters being so low in temperature)

homoplasty definition. what is this an example of? example.

- shared character state, not from a common ancestor - example of convergent evolution and evolutionary universal - moths in the industrial evolution (turned black in order to not be recognized by prey)

What is relative dating?how does this determine older/newer fossils?

- the method used to determine the age of rocks by comparing them with those in other layers - older rocks are buried under newly formed ones

vestigial structures and an example

- the remnant of a structure that may have had an important function in a species' ancestors, but has no clear function in the modern species. - example: muscle in the ears of humans, that we do not need, but other animals do for pinpointing sounds to detect predators

what happens if mutations occurs in relations to DNA?

- there is a lot of overlapping and can become an issue in terms of evolutionary variation. - if the mutation becomes too frequent, the variation of a species can become lost of very rare.

Which of the following provide evidence that natural selection occurs in peppered moths?

- Melanic moths become more abundant than light forms in polluted areas. -Light moths become more abundant than melanic forms when clean air legislation is implemented.

Which of the following is true about transitional fossils (choose all that apply)? They illustrate how major transitions in life occurred. -They illustrate how major transitions in life occurred. - They help to fill in the gap in the fossil record between two separate groups. - They are the most common type of fossil found in the fossil record. - They contain all characteristics of two separate groups.

- They illustrate how major transitions in life occurred. - They help to fill in the gap in the fossil record between two separate groups.

define the biological species concept and some issues with it

- a species is a population that can interbreed and make fertile offspring (BSC) - Can cause problems, what if they get separated, we can physically see the interbreeding - Fossils, very similar looking

define the phylogenetic species concept and some issues with it

- deals with cladistics - If you have the same characteristic as another organism, then you are the same species (characterized by one or more shared derived characteristics) (PSC)

define outgroup species? what is their purpose? what does it look like on a cladogram chart?

- has all 0s on the table - related, but not a member of, to the group under study - DOES NOT HAVE TO BE A PART OF THE GROUP -must be needed to see clarity of relation of the other organisms

monophyletic definition

- includes the common ancestor and all descendants (one big family)

systematics definition

- we want to organize the world around us (make sense of it) - looking at general characteristics * Since all organisms share the same basic components, we try to find things that they share and have uniquely

polyphyletic definition

- no common ancestor and descendants from the same ancestor but do not have to be closely related

what are the main issues with mutation? (2)

- not all genetic characters evolve at the same speed - you only have four options that DNA can be made with so there is more chance there is of a screw-up

what are the two BSC problems the PSC solves?

1. BSC cannot be applied to allopatric populations (looks to the past to see if they have been separated long enough to develop their own characteristics) 2. BSC can be applied only to sexual species (the ability to reproduce) PSC can be applied to both sexual and asexual species

theory of evolution depends on what three factors?

1. phenotypic variation must exist within a population 2. variation must lead to differences among individuals over a span of time (reproductive success) 3. phenotypic variation must be genetically transmittable to the next generation

examples of artificial selection?

Corn, bees, cows, horses, dogs, chickens, etc.

is an ancestor or derived characteristic more important in terms of biology? why?

DERIVED, because it shows that organisms have characteristics that are also applied to many other species. (share common traits)

_______ is sometimes better than ________ in terms of determining traits. WHY?

DNA, morphology - because DNA does not lie (due to their being only 4 nitrogenous bases possible) - characters can change over time

T or F: we should expect an intermediate form to be intermediate in every trait.

F

T or F: when a trait disappears, the gene vanishes from the genome. what happens?

F: the gene does NOT vanish from the genome, but some mutation renders it inactive, and once that occurs, other mutations can accumulate

T or F: Even though humans have used artificial selection for centuries, only animals have been significantly modified by our efforts.

False, even though humans have used this form of evolutionary growth for animals such as cows, dogs, etc. We also use these techniques or things such as crops, disease control, etc.

convergent evolution

Process by which unrelated organisms independently evolve similarities when adapting to similar environments

How has the fossil record changed since Darwin?

Today the fossil record is far more complete.

Define convergent evolution

Unrelated species begin to share similar traits. (when two different branches of species may have similar traits or characters, but necessarily the same function/purpose)

homologous structures

Structures in different species that are similar because of common ancestry. But have a different function and sometimes appearance.

What is a molecular clock?

The rate of change of mutation of a particular gene - estimated time of divergence - also helps with determining classifications

what are the three main types of systematic grouping?

monophyletic, polyphyletic, and paraphyletic

characteristics evolve at (the)_________ speeds. how does this relate to the theory of parsimony? How do we estimate it?

different speeds - this causes the theory to be misleading because sometimes the simper pathway might not be the way it happened - molecular clock

What type of evidence for evolution is provided by fossils?

direct (in fact the most direct)

what are examples of different phenotypes that can be used for cladistics?

morphology, physiology, DNA, and behavior (species' way of existing in nature)

why do we need systematics?

because even though we are familiar with the basic species that we are all aware of, how do we relate those with the rarest of species. where do they come from?

what are symplesiomorphies an issue?

because if we see shared ancestral traits in one area, then we can believe that they would be related -putting an ancestral trait where it should be (from distant ancestors)

what did Darwin believe in terms of evolution?

believed that every species come from a common ancestor - stated that evolution occurs through modification - depicted life as a tree (hence the design of the branching diagram)

what are the two main definition concepts of a species?

biological species concept (more leaning towards) and phylogenetic species concept

The observation that the relative frequencies of melanic to light peppered moths changes with the color of tree bark provides support for

natural selection

what are the nine classifications from largest to smallest?

domain, kingdom, phylum, sub-phylum, class, order, family, genus, species

Economically important organisms that have been modified significantly through artificial selection include (select all that apply) - cattle - fruit flies - corn -pigs

cattle, corn, pigs

what are the four things we generally see in all organisms

cell(s), metabolism, DNA, ATP

derived characterstics

characteristics shared only by a subset of a species (traits gathers further along in evolution) -example: mammals are the only species to have hair, so this means that hair is a derived trait which was only gained further along in evolution, meaning it is a derived trait

Genetic variation is necessary for ___________ change to occur.

evolutionary

In all cases when scientists have performed artificial selection experiments on fruit flies, a strong and predictable ________ response has been observed.

evolutionary

define phylogenetics.

evolutionary connections via roots (comparing structures in particular) Looking at homologous structures Similar ancestor source, the different purpose for that character Ex. the same anatomical structure of the arm, wing, fin, different functions

what is the most directive evidence of evolution?

fossils

does the finches example represent that evolution is based on natural selection (being genetically based) or the finches diet?

genetically based natural selection because they studied and found that when examining the beak size between parents and offspring over a period of time, their beak size was still similar no matter the environmental situation prevalent.

assuming that phenotypic differences are __________ __________, this directional selection should lead to evolutionary change, and it has.

genetically determined

Define species (most commonly used definition)

group of organisms that can interbreed and produce fertile offspring

two types of characteristics in cladistics

ancestor and derived

Plesiomorphic definition

ancestral states (things we do not see derived states)

In the laboratory setting, selection for a trait in fruit flies

has consistently lead to a strong, predictable evolutionary response

what percent of genes are shared with others?

around 60%, so you need to be careful which genes you choose.

The great variety of breeds of cats, dogs and other domestic animals have arisen through _______________ _____________.

artificial selection

In ___________ selection, humans choose the parents of the next generation, while in ___________ selection, organisms that survive and reproduce are those that pass their genes on.

artificial, natural

Natural selection can act as a complex system because...

at every stage of its evolution, the system functions. - parts that improve function are added and others may be modified or even lost - this is so that parts that were not essential when they first evolved become essential.

phylogenetic analysis determines _________.

homologies

The forelimbs of vertebrates are an example of___________________ structures, while the human appendix is an example of a __________ structure.

homologous, vestigial

One of the best studied examples of evolutionary change is that of the __________ family. This family includes zebras and donkeys, among other animals.

horse

The primary difference between natural and artificial selection is

how the parents are chosen (by humans or because of their reproductive success)

industrial melanism

darkening of populations of organisms come to predominate over lighter ones over time in response to industrial pollution

paraphyletic group

includes common ancestor and some descendants

Starting in 1850 when Europe become industrialized, the frequency of melanic forms of the peppered moth in populations ______ until they made up ______ of some population.

increased; almost 100%

In certain areas of the world, populations of moths have been shown to change over the years with dark forms becoming more abundant than light forms; this phenomenon is called

industrial melanism

The phenomenon, where dark forms of moths become more prevalent than light forms in industrialized areas, is known as

industrial melanism

The phenomenon, where dark forms of moths become more prevalent than light forms in industrialized areas, is known as ________ _________.

industrial melanism

Fossils that contain characteristics of two separate groups of organisms are called __________ __________.

intermediate fossils

J. W. Tutt proposed that__________ colored peppered moths were more visible to predators on trees without lichens.

light

Varieties of which of the following organisms are the result of the artificial selection? - Galapagos finches - pigeons -dogs -corn - oak trees - cats

pigeons, dogs, corn, cats

what systematic grouping is considered the worst?

polyphyletic grouping

what is the most common atom in organisms?

potassium

the fossilization process occurs _________. when does it usually occur?

rarely. usually in rocks that are inaccessible to scientists.

in terms of fossil rock dating, what is the difference between relative dating and absolute dating?

relative dating: Rocks are dated based on their position absolute: Rocks are dated based on changes in their isotopic composition

according to Kertwell's experiments established that.....

selection favors dark moths in polluted habitats and light moths in pristine (cleaner) habitats.

symplesiomorphies definition

shared ancestral states

synapomorphies definition and example

shared derived characteristics within the single clade (ex. hair and mammals, mammas=one synapomorphy)

In 1896, J. W. Tutt proposed that light colored moths were more visible to predators on

sooty trees that have lost their lichens due to pollution

what has artificial selection allowed us to infer?

that selection is an effective evolutionary process

due to pollution of the industrial revolution, the tree trunks were darkened with soot from pollution, leading to...

the decreased population of light-colored moths and the increase of melanic moths

what is the most direct evidence that evolution has occurred?

the fossil record

what is the theory of parsimony? why is this trusted in biology? is it always true?

the shorter and simpler the hypothesis (or the less amount of tick marks) is usually the correct or most accurate. - via counting various steps of characters - not always true. ALL HYPOTHESES HAVE THE SAME OUTCOME, but evolution is not always straightforward.

Prior to 1850, the melanic form of the peppered moth in Europe was:

very rare

The evolution of members of the horse family is

well-documented by the fossil record.

ancestor characteristics with example

when a trait some from a common ancestor (we look for traits that we got from prior generations) - example: lungs are ancestral because these are also found in mammals, amphibians, and reptiles, not just one species alone

what is the primary thing to note with picking character states for cladistics?

you need easily distinguishable (recognizable) traits - be careful to pick something that creates a clear line between opinion/assumption and fact (present and absent)

example of imperfect design in organisms?

the photoreceptors in the eye of vertebrates. - the photoreceptors face backwards towards the retina and not forward towards entering light. - therefore the nerve fibers run towards the the eye chamber, obscuring some light causing a blind spot in the retina

Why are giraffe necks not perfectly suited for their function?

Like all mammals, giraffes only have 7 vertebrae in their necks which limits their flexibility.

what are two things to take into consideration when thinking about the branch diagram?

1. you can have multiple hypotheses (forms of the same diagram) - this is because there are multiple ways that a group of species can be connected in terms of character states 2. even though two species can be closely related in terms of characteristics, thye do not necessarily have distinct evolutionary relationships

what are the two important variables in cladistic diagram tables?

1= trait/character present 0= trait absent

T or F greater the time since divergence of a species=more different two species are? WHY?

NO - Rates of evolution are always changing and the rate is also dependent on the species

is evolutionary unidirectional?

NO - evolution is not always divergent

the molecular studies of moths show that all black individual moths are descendents from a ___________ ___________.

single mutation

when princeton students studied the Galapagos finches, the finches with feed on ________ and _________ seeds during the wet years, and during the dry years, they fed on __________ and __________ seeds.

small tender seeds (wet), larger drier seeds (dry)

Natural vs. Artificial Selection

- Natural- real-world pressures causing its traits to have better odds. (dry weather would help animals reserve water. - Artificial selection is where humans select desirable traits and breed out non-desirable traits

biogeography. what does it show?

- definition: geographic distribution of species - shows that different areas in the world may have groups of organisms similar in appearance but may be distantly related

what is the point of polarizing characters? what does it do?

- determining if the characteristic is exhibited by the outgroup - if it is, the character is considered ancestral

T or F: artificial selection produces only minor changes. Why?

- false - if selection operating over a period of only a short period of time can still cause substantial changes

what are the steps of creating a cladogram?

1. select an outgroup 2. polarize the characteristics 3. make it into a tree

in what ways is PSC controversial?

1. slightly different=different species? NO 2. paraphyletic problem: different lineages can have similar derived characteristics

How has rock and fossil dating changed since Darwin's times?

Relative dating was used in the past; today we use absolute dating.

traits evolve at _________ rates and times.

different

homoplastic convergence and example

similar traits have evolved independently in different clades (groups) Example: flight, echolocation, opposable thumbs, eyes (have evolved independently multiple times)