New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

Week 2 Notes/ Chapter 16

by: Hayley Lecker

Week 2 Notes/ Chapter 16 BIOL 1306/1106

Hayley Lecker
GPA 3.42
Organismal Biology
Anthony Darrouzet-Nardi

Almost Ready


These notes were just uploaded, and will be ready to view shortly.

Purchase these notes here, or revisit this page.

Either way, we'll remind you when they're ready :)

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

These notes covers 16.1 to 16.4 of Chapter 16 in Principles of Life. As well as covering information provided during lecture, many of which is definitions.
Organismal Biology
Anthony Darrouzet-Nardi
Class Notes
Biology, Organismal Biology, general biology, University of Texas at El Paso, UTEP
25 ?




Popular in Organismal Biology

Popular in Biology

This 8 page Class Notes was uploaded by Hayley Lecker on Thursday September 3, 2015. The Class Notes belongs to BIOL 1306/1106 at University of Texas at El Paso taught by Anthony Darrouzet-Nardi in Fall 2015. Since its upload, it has received 28 views. For similar materials see Organismal Biology in Biology at University of Texas at El Paso.


Reviews for Week 2 Notes/ Chapter 16


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 09/03/15
Biology Week 2 Important Information Professor s Email aidarrouzetnardiutepedu or anthonvdnutepedu Chapter 16 reference pages 325342 Chapter 161 All of Life is connected through its Evolutionary History All life is related through a common ancestor m Phylogeny is the evolutionary history of these relationships A Phylogenetic tree is a diagrammatic reconstruction of that history As the example to the left A lineage is a series of ancestor and descendant population shown as a line drawn on a time axis The only problem with the example to the left is it doesn t have an x axis to represent the passage of time When a single lineage divides into two it is directed as a split or node The example to the left shows the ancestor lineage being 11 which spilt into 13 and 12 and so forth Each descendant population can give rise to a new lineage which continues to evolve The example phylogenetic tree shows that 12 gave rise to 15 and 16 A phylogenetic tree is not limited to one species it can depict all life forms major evolutionary groups small groups of closely related species individuals populations or genes The common ancestor of all organisms in the tree forms the root of the tree The splits can represents events where one lineage divides into two because of a speciation event for a tree of species a gene duplication event for a tree of genes and a transmission event for a tree of viral lineages through a host population Vertical distances between braches don t have any meaning and the order of the vertical branches is arbitrary Take 19 in the example above it gave rise to 10 and 9 those two numbers could be switched and the image would still have the same meaning Any group of species that we designate with a name is called a taxon A taxon that consists of all the evolutionary descendants of a common ancestor is called a clade A clade can be identified by choosing any point on a phylogenetic tree and tracing all the descendant Hneages Two species that are each other s closest relatives are called sister species Any two clades that are each other s closest relatives are called sister clades Before the 1980 s phylogenetic trees were mostly used in evolutionary biology and in systematics the study and classification of biodiversity Today phylogenetic trees are used in almost all fields of biology Evolutionary relationships among species form the basis for biological classification As new species are discovered phylogenetic analysis are viewed and revised this simply means that the tree is updated to reflect new insight The tree of life s evolutionary framework allows us to make predictions about the behavior ecology physiology genetics and morphology of species We can also make predictions about missing quotevolutionary links that sometimes haven t been discovered yet Any features shared by two or more species that have been inherited from a common ancestor are called homologous features They are not limited to just phenotypes but can be DNA sequences protein structures anatomical structures and even behavior Each character of an organism evolves from one condition the ancestral trait to another condition the derived trait An example of this is the vertebral column what we call our spines is a trait shared by vertebrates The ancestral trait of this was an undivided supporting rod Traits being developed it is not just between an ancestral tree sometimes unrelated groups can develop similar traits Convergent evolution is when superficially similar traits may evolve independently in different lineages In an evolutionary reversal a character may revert from a derived state back to an ancestral state An example of this is the whale whales are descendants of creatures who evolved into land walking creatures however through evolution whales became aquatic again it s key to remember that we all descendant of water creatures that eventually became land creatures thus reverting back to an ancestral state Similar traits generated by convergent evolution and evolutionary reversals are termed homoplastic traits or homoplasies Ok that was a lot of information but realize evolution is a long history and covers a lot So before going on take a break this is a lot to absorb Chapter 162 Phylogeny Can Be Reconstructed from Traits of Organisms Figure 163 Inferring a Phylogenetic Tree 39 The earliest branch in the tree represents the evolutionary split between the outgroup lamprey and the ingroup the remaining s cies of vertebrates De L V The lamprey is 17 quot designated as Lamprey l the outgroup outgroup biMA quot Cozttrrion amp ancestor Perch Derived traits are Les2 9 Salamander 2 indicated along lineages in which the evolved 7 Lun s g Lizard Keratinous scales 39 gt lngroup Claws Crocodile or nails Gizzard w Feathers u Pigeon Fur mammary glands Mouse Chimpanzee PRINCIPLES OF LIFE Figure 163 93 2012 Sinauer Associates Inc Throughout 162 we will refer back to this image so I took the liberty of including it as it is a great example to help explain The group of organisms of primary interest is called ingroup A species of group known to be closely related to but phylogenetically outside the group interest is called outgroup The Parsimony principle is used to provide explanation of observed data in the simplest way In phylogenies this entails minimizing the number of evolutionary changes that need to be assumed over all character in all group as an evolutionary change may occur multiple times the best hypothesis is the one that requires the fewest homoplasies Any trait that is genetically determined can be used in phylogenetic analysis An important source of phylogenetic information is morphology the presence size shape or other attributes of body parts If a species is extinct phylogenies depend on morphology Fossils provide evidence that helps distinguish between ancestral and derived trails the fossil record can also reveal when lineages diverged However morphology has some limitations such as 1 Some taxa see taxon for definitions in 161 show few porphological differences 2 It is difficult to compare distantly related species 3 Some morphological variation is caused by the environment When morphology cannot be depended upon we can look at development Similarities in developmental patterns may reveal evolutionary relationships Behavior some traits are cultural or learned and may not reflect evolutionary relationship example bird songs However other traits such as frog calls have a genetic basis and can be used in phylogenies Molecular data DNA sequences have become the most widely used data for constructing phylogenetic trees Nuclear chloroplast and mitochondrial DNA sequences are used however information on gene products amino acid sequences of proteins can be used as well Now we can use mathematical models to describe DNA changes over time These models can account for multiple changes at a given sequence position and different rates of change Maximum likelihood methods identify the tree that most likely produced the observed data Phylogenetic trees can be tested with computer simulations and experiments on living organisms Chapter 163 Phylogeny Makes Biology Comparative and Predictive Applications of phylogenetic trees Phylogeny can clarify the origin and evolution of traits this can help understand fundamental biological processes Figure 166 A Portion of the Leptosiphon Phylogeny L androszzceus Selfcompatibility I l L quotbquotco39orquot Common ancestor L mrw39 orus I quotutrfi39oi39ug L latiszx us outcross m 8 f00mg taxo39 nomists into class L fin ows Wing three 3003 310 speaes as L blCOIOf n Convergent floral morphology associated with selfcompatibility arose independently in three different Laptosphon lineages l ECOfor St 2m rig L narcularis l 1 1350th quot I ransom Selfcompatibility l quotbicolor quot PRINCIPLES OF LIFE Figure 166 201 2 Sinauer Associates inc The above image can be used to explain selfcompatibility Most flowering plants reproduce by mating with another individual this is called outcrossing Selfincompatible species have mechanisms to prevent selffertilization However other plants can be quotselfingquot which requires they be selfcompatible If you do not understand selfcompatible it means these flowers or plants can be reproduce with themselves Figure 167 Phylogenetic Tree of Immunode ciency Viruses Virus transferred from simian host to humans Q HIV1 humans Schpz chimpanzees SIVhoest L Hoest monkeys Sleun suntailed monkeys Slend mandrills Common ancestor SlVagm African green monkeys SIVsm sooty mangabeys Q HIV2 humans SIVsyk Sykes monkeys PRINCIPLES OF LIFE Figure 167 33 2012 Sinauer Associates Inc The image above can be used to explain zoonotic diseases These are caused by infectious organisms transmitted from an animal of a different species the example in the image is HIVAIDS Phylogenetic analysis helps determine when where and how a disease first entered a human population Figure 168 The Origin of a Sexually Selected Trait Evolution of male swordj V Sw0rdtail gt fishes J Platyfish Evolution of female 1 sensory bias J Platy sh O PRINCIPLES OF LIFE Figure 168 201 2 Sinauer Associates Inc Xiphophorus d Some adaptations relate to mating behavior and sexual selection which are complex traits The image above is example of this Phylogenetic analysis supports the sensory exploitation hypothesis this means female swordfishes have a preexisting bias for males with long tails When reconstructing ancestral traits morphology behavior and amino acids sequences or nucleotides are used for ancestral species The molecular clock hypothesis states that rates of molecular change are constant enough to predict the timing of lineage splits A molecular clock uses the average rate at which a given gene or protein accumulates changes to estimate the time of divergence A molecular clock was used to estimate the time when HIV first entered the human population from chimpanzees The estimated date of origin is about1930 Chapter 164 Phylogeny is the Basis of Biological Classification In the 1700 s a Swedish biologist Carolus Linnaeus created the biological classification system Binomial nomenclature gives every species a unique name consisting of two parts the genus to which it belongs and the species name Example Homo sapiens Species and genera are further grouped into a hierarchical system of higher categories such as family the taxon above genus Example The family hoinidae contains humans plus our recent fossil relatives the chimpanzees and gorillas Families are then grouped into orders Orders are grouped into classes Classes into phyla singular term is phylum Phyla are finally grouped into kingdoms Linnaeus developed this system before the thought of evolution was widespread Today we use biological classifications to express the evolutionary relationships of organisms Taxa are monophyletic meaning they contain an ancestor and all descendants of that ancestor and no other organisms However there is also polyphyletic which is a group that does not include its common ancestor and paraphyletic which is a group that does not include all the descendants of a common ancestor There are also codes to follow for biological nomenclature biologists around the word follow the rules for the use of scientific names however there name be many common names for one organism or a common name for several species but there is only one correct scientific name Example There are many species of cacti however we give them all the common name of cacticactus in reality they all have an individual unique name Lecture Notes from the Week Mostly Terms Some terms may be repeated from last weeks notes or from the chapter notes these are vocabulary the professor deems important Genetic variation the differences among individuals in the composition of their genes or other DNA segments variation in DNA sequences among organisms This makes evolution possible and variations endless however levels of similarity are surprisingly high Genetic polymorphism Genetic differences that are common among organisms of the same species Genetic divergence Genetic differences that accumulate between species Neutral variation Genetic variation that does not provide a selective advantage or disadvantage Population A group of individuals of the same species that live interact and reproduce together in a particular geographic area Microevolution Change in gene pool of a population from generation to generation Macroevolution Evolution of whole lineages speciation and extinction Gene pool The entire set of genetic information all the alleles of all genes within a population the set of alleles and their frequencies within a population for a specific gene locus Hardy Weinberg Equilibrium A condition in which allele and genotype frequencies remain constant through time in a population Gene flow Exchange of genes between populations through migration of individuals or movements of gametes Genetic drift Changes in gene frequencies from generation to generation as a result of random chance processes Founder effect Random changes in allele frequencies resulting from establishment of a population by a very small number of individuals Bottleneck effect a period during which only a few individuals of a normally large population survive Stabilizing selection Selection against extreme phenotypes Disruptive selection Selection for an extreme phenotype in one direction Directional selection Selection of phenotypes at both extremes Balanced polymorphism Two different versions of a gene are maintained in a population because individuals carrying both versions heterozygous are better able to survive than those who have two copies of either version alone lntersexual individuals from one sex choose mates from the other based on impressive features lntrasexual competition within same sex for mates Biological species concept A group of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups Morphological species concept A species distinguished from others only by its morphology Operational taxonomic unit An operational species definition using percent DNA sequences similarity typically from sequencing of conserved genes such as the ribosomal 16S gene A typical cutoff would be 97 Lineage species concept A branch on the tree of life which has a history that starts at a speciation event and ends either at extinction or another speciation event Reproductive isolation and reproductive barriers Prezygotic affects behavior prior to fertilization Barriers habitat isolation temporal isolation behavioral isolation mechanical isolation gamete isolation Postzygotic reduces survival or fertility of offspring Barriers zygote mortality hybrid sterility F2 sterility Allopatric A new species formed while geographically isolated from parent population Sympatric without geographical isolation a new species forming next to parent population Adaptive radiation A period of evolutionary change in which groups of organisms form many new species whose adaptations allow for them to fill different ecological roles in their communities The powerpoint from the teacher includes Darwin s finches as an example of this as well as cichlid fish It is estimated 99 of species are extinct and the average species lifespan is about 10 million years


Buy Material

Are you sure you want to buy this material for

25 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Bentley McCaw University of Florida

"I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"

Janice Dongeun University of Washington

"I used the money I made selling my notes & study guides to pay for spring break in Olympia, Washington...which was Sweet!"

Steve Martinelli UC Los Angeles

"There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."


"Their 'Elite Notetakers' are making over $1,200/month in sales by creating high quality content that helps their classmates in a time of need."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.