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

lecture 1

by: Jordyn

lecture 1 ISB 202

GPA 3.6
Appl Envir & Organismal Bio
Pamela Rasmussen

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

Appl Envir & Organismal Bio
Pamela Rasmussen
Class Notes
25 ?




Popular in Appl Envir & Organismal Bio

Popular in Department

This 9 page Class Notes was uploaded by Jordyn on Friday February 27, 2015. The Class Notes belongs to ISB 202 at Michigan State University taught by Pamela Rasmussen in Winter2015. Since its upload, it has received 40 views.


Reviews for lecture 1


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: 02/27/15
The Forces Of Evolution What s the evidence for change and ancient origins 0 Evidence for change through time 0 Fossil record total number of fossils found in rocks around the world and help understand past bones Process of studying fossils just beginning in Darwin s time Fossils are ant trace of organisms form the past 0 Most are skeletons or shells preserved in sedimentary rocks 0 Layers of sand or mud that eventually becomes rocks 0 Lower layers older than newer layers The fossil record 0 Still has gaps o Fossilization rare Most never found 0 Yet millions of fossils are in museums Provides clear evidence for progression of life forms Extinctions 0 Species were thought unchangeable Why would they then go extinct President Jefferson thought Lewis and Clark would nd living giant ground sloths If they occur as bones or fossils they must appear somewhere how could they just disappear off earth Cuvier showed they lrish elk extinct 0 Now known that far more species extinct than exist now Extinction natural for all species Transitional form is a fossil with traits intermediate between older and younger species 0 Ex whale fossils o Mammallike reptiles Horse evolution 0 Several transitional fossils show Increase in size length and complexity of teeth Decrease in number of toes through time Missing links 0 Ex archaeopteryx o Transitional between dinosaurs and modern birds 0 Reptilian features Toothed beak Long bony tail Clawed hand Pelvis shape 0 Bird feathers Feathers o Asymmetrical Numerous bone characters Environmental change 0 Most parts of earth s surface is very different than was previously Sea shells high mountains Grand Canyon Mountains have uplifted in pas several million years Eroded from Colorado river and wind Many shallow seas Marine reptiles sh in Kansas Continents move 0 Theory of plate tectonics Earths crust made up of plates that change position 0 Continental drift Conclusion earth and species ancient and have changed 0 From living species 0 Vestigial traits Reduced functionless structures clearly similar to functioning structures in other species 0 Human coccyx goose bumps Evidence of change Chimpanzees our closest relative use their erector Pilli muscles when they want to appear threatening to cause their hair stand on end and make them look larger What about humans We have hair on arms too when we get cold our erector Pilli muscles try to keep us warmer however don t make us look scarier or keep us warmer The cave sh has eyes but they are tint covered by skin and non functional lt lives in complete darkness so would not be able to see anyway lts relatives that live in streams all have excellent vision The eyes of the cave sh are an example of vestigial trait Ongoing observable documented evolution 0 Contemporary evolutionary events Evolution of resistance by insects to insecticides bacteria to antibiotics weeds to herbicides Change in front of our very eyes Always happening in millions of lineages Evolution of resistance to insecticides spray insecticide on crops and one insect happens to survive then they keep reproducing then causes a problem What s the evidence for relatedness of species 0 DNA code 0 Resemblances between different forms on islands Suggests that a single ancestral species colonized different islands and diverged in isolation o All species can be placed on a phylogeny family tree or organisms Phylogenetic tree branching diagram of relationships among organisms Similar to genealogy of humans Which is true of the manner in which pests evolve pesticide resistance a few insects survive and have many offspring which themselves can survive the toxin Structural homologies o Homology Similarity between organisms due to relationship In common ancestor Ex vertebrate forelimb is a homology 0 Analogy or convergence Independently evolved similarities Not common shared ancestor Ex bird creating the ability to use forelimb to y 0 Some homologous vertebrae forelimbs evolved into wigs Developmental homologies 0 Developing embryos Two levels of homology Similarities of embryos o All have same structures shape Fates of embryonic tissues 0 Ex heart develops from same embryotic tissues in any vertebrae Genetic homologies 0 Similar DNA sequences of genes from different species Similar DNA sequences result in similar development which determines similarity of structures Even very different structures may have genetic homology 0 Ex eyeless gene in fruit ies Aniridia in humans 0 Both code for eye structure even though y and human eyes are very different O O o Aniridia human and eyeless fruit y only have six different amino acids of the 60 The more similar organisms are morphologically the more similar their biochemistry Number of amino acids that differ form a human hemoglobin polypeptide total chain length146 amino acids Rhesus monkey 8 Mouse 27 Chicken 45 Frog 67 Snake 125 A turkey would differ from a human by more than 27 and fewer than 67 amino acids Summary of the pattern component of evolution 0 0 Data from many independent sources show species have changed and are related Descent with medication 0 Controversy among biologists long over No single observation Pattern of evolution consistent with data Process also observed directly Thousands of peerreviewed papers published annually support evolution The four steps of natural selection 1 2 3 4 Individuals in a population vary Traits with genetic basis passed on to offspring Only some offspring survive some produce more offspring that others Individuals that survive have certain traits that make them better t Naturally selected Outcome of natural selection is evolution 0 O Genetically based change in characteristics of population over time Traits that contribute to high reproductive success increase in frequency in population over time Successful individuals more r Darwin tness biological tness 0 Ability of individual to produce offspring relative to ability of other individuals in population Directly measurable Adaptation o A heritable trait that increases individuals tness in particular environment in relation to individuals lacking trait Increases tness Adaption in environmental context 0 An adaption to one environment may be maladaptive in any other Temporally and spatially o Organisms must have genetic variability to enable adaption to changing conditions The best t individual to a particular environment will be the one that produces the most surviving offspring Which is not true of natural selection individuals evolve 0 Evolution happens in a larger picture not on the scale of a single person Evolutionary processes and their consequences 0 Natural selection Increases frequency of alleles gene variants that improve tness 0 Only mechanism consistently leading to adaptation Sexual selection of special case 0 May favor nonadaptive changes Genetic drift 0 Change in allele frequencies due to random chance 0 Mostly in small populations Gene ow 0 Mixing of genes due to mating of individuals in same population lmmigrating individuals introduce new alleles 0 Immigration coming into population Alleles may be lost through emigration o Emigrating leaving population Mutation Ultimate cause of all heritable variation Continually introduces new alleles o Bene cial s harmful or neutral 0 Where entirely new alleles come from Mechanism of restoration and increase of diversity Mutations are mistakes in replication of DNA 0 If change in DNA that codes for protein change may result in protein with new amino acid sequence 0 Errors inevitable in all genes of all populations Random 0 Mutations in welladapted organisms frequently harmful to offspring lower tness Occasional bene cial mutations selected for Deleterious alleles lower tness 0 Too rare to be signi cant in changing allele frequencies of particular genes on their own without other evolutionary mechanisms 0 In combination with natural selection very important A frog sh is colored just like the coral on which its sits so neither its predators nor prey will see it What evolutionary mechanism is primarily responsible for this natural selection Which us NOT true of mutations they are a result of mistakes in copying DNA and chromosomes Models of natural or arti cial selection 0 Directional selection Changes the average value of a trait o Stabilizing selection Reduces the amount of variation in a trait Favors organisms in the middle organisms in the extreme weren t able to reproduce o Disruptive selection Increases the amount of individual variation in a trait Directional selection 0 Peccaries prefer cacti with fewer spines Cacti with more spines not eaten they pollinate most owers Leave most offspring o Fewspined cacti die out more spined cacti selected for 0 Change in population mean Stabilizing selection 0 Parasites prefer manyspined cacti 0 Together with peccaries selection against extremes 0 Variation reduced 0 Vulnerable to environmental change Disruptive selection 0 Population without peccaries or parasites 0 Near road tourists Prefer averagespined cacti Few and manyspined cacti survive Can result in speciation Sexual selection 0 Fundamental asymmetry of sex Eggs expensive sperm cheap 0 Females invest much in offspring than males Female s tness limited by resources for producing and rearing young Male s tness limited by number of females they can mate with o Predicts that females that invest in offspring should be choosy 0 And sexual selection should be much stronger Types of sexual selection 0 Two main types Female choice 0 Female orangutan like men with a bigger cheek bone Malemale competition 0 Consequences of sexual selection Affects only genes involved in competition for mates Produces change in allele and genotype frequencies 0 Ex a form of natural selection Often leads to sexual dimorphism 0 Female choice intersexual selection or mate choice 0 When members of one sex usually females choose among individuals of the other sex Males with certain features most attractive to females 0 These features may not be adaptive in other ways 0 May expose these individuals to extra risks 0 Expensive to produce 0 Often leads to extravagant noncombat features 0 Widowbird females like males with longer tails so they adapted to have longertaHs o Malemale competition intrasexual competition Direct competition among individuals of one sex usually males for mates of opposite sex 0 Direct physical battles between individuals 0 More often ritualized displays discourage lesser competitors amp determine dominance o Rattle snakes ght each other but just pretend because if actually would ght would both die 0 Can be competition for resources females need or for prime mating space Often leads to strength weapons Costs of extravagant features outweighed if they help individual get mating s When female chooses mate based on appearance or behavior she perpetuates alleles that caused her to make that choice 0 Her choice also perpetuated alleles of male with particular phenotype she chose 0 Features must have a genetic basis to be perpetuated Underlying basis of female choice probably assessment of general health 0 Males with infections or poor nutrition are likely to have duller disheveled less developed characteristics 0 Unlikely to win many females 0 Female that chooses a healthy mate has a greater probability of healthy offspring 0 Sexual selection may lead to secondary sex differences Sexes of a species often differ in secondary sexual characteristics 0 Not directly associated with reproduction Sexual dimorphism 0 Male vertebras usually larger showier 0 Over all animals females usually larger 0 Degree of dimorphism strongly correlated with degree of sexual promiscuity greater difference greater promiscuity o Sexes similar often monogamous especially in birds 0 Differential reproductive success Highly skewed in some species 0 Ex elephant seal 0 Over 90 of the male seals die without reproducing a few successful males father between 80100 offspring o Females 60 die without having offspring an the most successful females produce up tolO offspring Heredity vs environmental traits o Translocation studies show some geographic variation is the result of environmental differences Arti cial selection 0 Very like natural selection except People choose the mates 0 Select for certain traits Often results in traits not welladapted for life in nature Pigeon breeds Darwin used pigeons to represent arti cial selection 0 Arti cial selection birds don t survive as much as the Wild type Rock Dove because it well adapted to the real wild Wolf is the ancestor of all dog breeds The Jacobin pigeon below has a feathered hood that covers its eyes It is most likely to be a wild species or a domestic breed and why domestic because it could not survive well in the wild


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

Jim McGreen Ohio University

"Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."

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.