Evolution+and+Biodiversity

=**//Evolution and Biodiversity//**=

//Topics://

//Evolutionary Biology (8%)//
 * 1) //Early evolution of life//
 * 2) //Evidence for evolution//
 * 3) //Mechanisms of evolution//

//Diversity of Organisms (8%)//

 * 1) //Evolutionary patterns//
 * 2) //__Survey__ of the diversity of life//
 * 3) //Phylogenetic classification//
 * 4) //Evolutionary relationships//

JFMcL. Lynn Margulis endosymbiotic theory is widely used to explain the evolution of eukaryotic cells. Click on the link below to watch a short tutorial on endosymbiosis. As you watch, write down 4 different pieces of evidence which support this theory.

[|http://highered.mcgraw-hill.com/sites/9834092339/student_view0/chapter4/animation_-_endosymbiosis.htm][|l]

RP. When studying evolution and evidence for it, scientists will often __study__ the structures of various organisms. Two differents kinds of structures that are easily mixed up are homologous structures and analogous structures. **Homologous structures** are anatomical signs of evolution that show a common ancestor. An example being the __bones__ in the human hand are similar to those in the wing of a bat or the flipper of a whale.


 * Analogous structures** show convergent evolution, or different species evolving and having similar traits. An example could be the wing of a fly and the wing of a bird. Although both are capable of flight, their structures are very different.

LJ: After taking the __diagnostic test__, I realized that I completely forgot how to do Hardy-Weinberg Equations Requires:
 * Hardy-Weinberg Law**
 * A large population
 * Random mating
 * No natural selection
 * No mutations
 * No movement in/out of population

P + Q = 1

P= dominant allele frequency Q= recessive allele frequency

P2 + 2pq + Q2 =1

P2 = Frequency of homozygous dominant 2pq= Frequency of heterozygous Q2 =Frequency of homozygous recessive

(Typically, you are given the Q2 value, to solve take its square root (q) and plug it into P + Q = 1 and find the P value. Then, plug these values into the second formula) here is a website with some practice problems [] JFMcL. You weren't the only one! Good __topic__ for review! That's the purpose of those diagnostic tests.

I had a lot of trouble remembering each phylum of animals for evolution. I found this website, which gives a short and concise summary of each phylum. []
 * KGT **

LJ: This helps explain phylogenetic trees.

JM:

How Does Genetic Variation Occur in a Population?
Genetic variation occurs through sexual reproduction. Due to the fact that environments are unstable, populations that are genetically variable will be able to adapt to changing situations better than those that do not contain genetic variations. Sexual reproduction allows for genetic variations to occur through genetic recombination. Recombination occurs during meiosis and provides a way for producing new combinations of alleles on a single chromosome. Independent assortment during meiosis allows for an indefinite number of combinations of genes Sexual reproduction makes it possible to assemble favorable gene combinations in a population or to remove unfavorable gene combinations from a population. Populations with more favorable genetic combinations will survive in their environment and reproduce more offspring than those with less favorable genetic combinations

BEG The following site helped to explain the different types of isolation such as reproductive and geographic. []

JM:

BEG //I had trouble distinguishing between stabalizing, directional, and disruptive selection and this page explains the differences.// []

This site goes over fossils and carbon __dating__. []
 * BEG**
 * Evidence for Evolution**

SRF

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"Genetic drift is the unpredictable fluctuation in allelic frequencies from one generation to the next." This can be found on page 157 of the review book. Two important types of genetic drift that can seem somewhat confusing are the founder and the bottleneck effects.
 * EGR**

The founder effect occurs when a few individuals become isolated from their larger population: The bottleneck effect is caused by a sudden change in the environment, due to some sort of catastrophe: Since the surviving individuals above were primarily blue, the next generation will primarily have this trait as well. [|http://biology200.gsu.edu/houghton/2107%20'12/lecture4.html] []

In class, I have found that I do not completely understand the concepts of the coelom.
 * EGR**

The main functions of the coelom, as found on page 188 of the review book, are: 1. Act as a cushion for organs suspended within the body 2. Act as a hydrostatic skeleton 3. Allow organs to move independently within the body, as well as growing

The organisms can have either be coelomates, pseudocoelomates, or aceolomates.

This section confused me because there are so many terms and so much information but I made this chart so hopefully it is a little simpler all written out here in a chart :) created by yours truly with info from the review book!
 * CCA**
 * **Phylum:** || **Description:** ||
 * Porifera (sponges) || Lack true tissues; have choanocytes (collar cells-unique flagellated cells that ingest bacteria and tiny food particles) ||
 * Cnidaria (hydras, jellies, sea anemones, corals) || Unique stinging structure (cnidae), each housed in a specialized cell (cnidocyte); gastrovascular cavity (digestive compartment with a single opening) ||
 * Platyhelmithes (flatworms) || Dorsoventrally flattened, unsegmented acoelomates; gastrovascular cavity, or no digestive tract ||
 * Rotifera (rotifers) || Pseudocoelomates with alimentary canal (digestive tube with mouth and anus); jaw (trophy) in pharynx; head with ciliated crown ||
 * Lophophorates: Ectoprocta, phoronida, brachiopoda || Coelomates with lophophores (feeding structures bearing ciliated tentacles) ||
 * Nemertea (proboscis worms) || Unique anterior proboscis surrounded by a fluid filled sac; alimentary canal; closed circulatory system ||
 * Mollusca (clams, snails, squids) || Coelomates with three main body parts (muscular foot, visceral mass, mantle); coelom reduced; most have hard shell made of calcium carbonate ||
 * Annelida (segmented worms) || Coelomates with body wall and internal organs (except digestive tract) segmented ||
 * Nematoda (roundworms) || Cylindrical, unsegmented pseudocoelomates with tapered ends; no circulatory system ||
 * Anthropoda (crustaceans, insects, spiders) || Coelomates with segmented body, jointed appendages, and exoskeleton made of protein and chitin ||
 * Echnodermata (sea stars, sea urchins) || Coelomates with secondary radial anatomy (larvae bilateral; adults radial); unique water vascular system; endoskeleto ||
 * Chordata (lancelets, tunicates, vertebrates) || Coelomates with notochord; dorsal, hollow nerve cord; pharyngeal slits; muscular, post-anal tail ||

ABM Thought this would be a good addition, seeing that we sort of skimmed over chordate evolution

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RAM There are a few different ways in which natural selection is expressed in a population 1. Directional selection is a type of natural selection in which individuals that express a certain trait are favored over those who do not. An example would be mice with darker colored fur being selected over those with lighter fur, leading to an increase in mice with dark fur in a population 2. Disruptive Selection is a type of selection that favors individuals with variants at polar ends of the spectrum. An example would be mice with very light fur and very dark fur being selected over mice with medium colored fur. This results in an increase in both darker and lighter colored mice, with medium colored mice populations decreasing. 3. Stabilizing selection is the last type of selection, in which organisms that do not fall on either end of a trait's spectrum are selected over the extremes. In this case, mice with medium fur would be selected over more light or dark mice, providing an increase in medium colored mice populations, and seeing a reduction in the number of lighter or darker colored mice.

ABM Something that confused me was the difference between prezygotic and postzygotic barriers

A **Prezygotic barrier** is a barrier that prevents mating or hinders fertilization, and include A **Postzygotic barrier** prevents a fertilized egg from developing into a fertile adult, and include -review book
 * Habitat Isolation- although two species might live in the same area, the habitat prevents them from mating
 * Bahavioral- A species uses specific signs or signals to attract mates
 * Temporal- Species may breed at different time like the time of day, different seasons, or years
 * Mechanical- Species can't reproduce
 * Gametic- Even if the gametes of two species meet, they might be unable to form a zygote
 * Reduced hybrid viability- when a zygote is formed, the genetic incompatability may cause development to stop
 * Reduced hybrid fertility- even if two species produce an offspring to adulthood, reporductive isloation still occurs if the offspring can't reproduce (like a donkey)
 * Hybrid breakdown- two species may produce fertile hybrids, but when the hybrids mate, the offspring might be weak or sterile

ELB I think this picture does a good job of illustrating the difference between Darwin's idea of gradualism and Gould's idea of punctuated equilibrium. Fossil records show that organisms evolve relatively quickly in short periods of time, separated by longer periods of little to no change.

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ELB I always mixed up allopatric and sympatric speciation, but this picture provides a simple explanation. A is showing allopatric speciation, where there is a geographical barrier. In B, sympatric speciation, the change occurs while in the same area. []

Here's a power point on allopactric vs. sympatric speciation! I thought I could use the review and see what the difference is between the two. @http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&ved=0CJMBEBYwBg&url=http%3A%2F%2Fchittkalab.sbcs.qmul.ac.uk%2Fchittkalab%2FTeaching%2FEvolutionary%2520Genetics%2Fevol_gen2_speciation2.ppt&ei=rASrT-quKu-16AGKj4GwBA&usg=AFQjCNHy85ZY6dF_YHpm8Yt-4DKpRWrInA
 * EJG **

Although classification is not a huge component of the AP test, you never know when part of an essay may be about it. It is important to just know the basics. The domains of bacteria and archara contain prokaryotic organisms, and eukarya contains eukaryotic organisms. http://www.nicerweb.com/bio1151b/Locked/media/ch27/27_T02DomainComparison-L.jpg
 * WJH **

SMM. When I was writing the evolution essays last night, I realized that I did not remember all of the evidence for evolution. I feel that evolution is a topic that is often dismissed as easy, but it actually is somewhat complicated. Though it doesn't seem as though there are many evolution questions on the diagnostic tests, I thought the evidence was worthwhile to review.

Evidence for Evolution Summarized from review book.
 * 1) Direct Observations of Evolutionary Change: evolution of drug-resistant viruses and antibiotic-resistant bacteria
 * 2) Fossil Record: fossils show evolutionary changes that have occurred over time, and when new organisms originated
 * 3) Homology: characteristics in related species can have an underlying similarity even though they carry out different functions. Example of homologous structures: forelimbs of mammals
 * 4) Convergent Evolution: explains why distantly related species can resemble one another. 2 organisms develop ANALOGOUS structures: two different organisms end up with similar solutions to a similar problem. Example of analogous structures: the torpedo shapes of a penguin, dolphin & shark are a solution to moving quickly through an aqueous environment. These organisms are distantly related, and these structures evolved independently in each species to solve a similar problem faced.

I think that someone has posted about this somewhere else, but it applies here too. __The Endosymbiotic theory:__ -proposes that mitochondria and plastids(chloroplasts) were formerly small prokaryotes that began living within larger cells __Evidence for this includes:__ - both organelles have enzymes and transprt sytems homologous to those found in the plasma membranes of living prokaryotes -both replicate by a splitting process similar to prokaryotes -both contain a single, circular DNA molecule, not associated with histone proteins -both has their own ribosomes which can translate their DNA into proteins (Prokaryotes are the earliest living organisms, eukaryotes appeared 2.1 billion years ago, multicellular eukaryotes evolved 1.2 billion years ago)
 * RMG**

TWK Ancestral vs. Derived characteristics -- Ancestral characteristics are characteristics that were present in an ancestral species while derived characteristics were not. Below is a picture that describes / shows the difference

VBG Advantages of phylogenetic classification Phylogenetic classification has two main advantages over the Linnaean system. First, phylogenetic classification tells you something important about the organism: its evolutionary history. Second, phylogenetic classification does not attempt to "rank" organisms. Linnaean classification "ranks" groups of organisms artificially into kingdoms, phyla, orders, etc. This can be misleading as it seems to suggest that different groupings with the same rank are equivalent. For example, the cats (Felidae) and the orchids (Orchidaceae) are both family level groups in Linnaean classification. However, the two groups are not comparable: There is just no reason to think that any two identically ranked groups are comparable and by suggesting that they are, the Linnaean system is misleading. So it seems that there are many good reasons to switch to phylogenetic classification. However, organisms have been named using the Linnaean system for many hundreds of years. How are biologists making the transition to phylogenetic classification? []
 * One has a longer history than the other. The first representatives of the cat family Felidae probably lived about 30 million years ago, while the first orchids may have lived more than 100 million years ago.
 * The have different levels of diversity. There are about 35 cat species and 20,000 orchid species.
 * They have different degrees of biological differentiation. Many orchids belonging to different genera are able tohybridize. But the same is not true of cats — house cats (belonging to the genus //Felis//) and lions (belonging to the genus //Panthera//) cannot form hybrids.
 * Orchids of these two different genera hybridize... || [[image:http://evolution.berkeley.edu/evolibrary/images/dot_clear.gif width="30" height="1"]] |||||| ...but cats of these two different genera do not. ||
 * [[image:http://evolution.berkeley.edu/evolibrary/images/evo/laelia_purpurata.jpg width="100" height="160" caption="Laelia purpurata"]] || [[image:http://evolution.berkeley.edu/evolibrary/images/evo/hybridize.gif width="30" height="32" caption="crosses with"]] || [[image:http://evolution.berkeley.edu/evolibrary/images/evo/cattleya_mossiae.jpg width="100" height="160" caption="Cattleya mossiae"]] ||^  || [[image:http://evolution.berkeley.edu/evolibrary/images/evo/housecat.jpg width="100" height="160" caption="House cat"]] || [[image:http://evolution.berkeley.edu/evolibrary/images/evo/nothybridize.gif width="30" height="32"]] || [[image:http://evolution.berkeley.edu/evolibrary/images/evo/lion.jpg width="100" height="160" caption="Lion"]] ||
 * //Laelia// ||  || //Cattleya// ||^   || //Felis// ||   || //Panthera// ||

RMG [|http://bcs.whfreeman.com/thelifewire9e/default.asp#542578__591183]__ This website has an interactive video thing of the Miller and URey experiment testing the hypothesis or Oparin and Haldane. In summary: Oparin and Haldane hypothesized that the early atmosphere was thick with water vapor, nitrogen, carbon dioxide methane, ammonia, hydrogen, and hydrogen sulfide. This combination provided with energy from lightning and UV radiation could have formed organic compounds, a primitive "soup" from which life arose. The experiment itself was done in a jar with such gases and an electrical charge imitating the lightning and produced a variety of amino acids which are building blocks. This is a picture of the overall experiment, more information on this link []

VBG Fossils are evidence that evolution is occurring or has occurred. ** The Fossil Record ** evolutionary sequence of fossils || Remains of animals and plants found in sedimentary rock deposits give us an indisputable record of past changes through vast periods of time. This evidence attests to the fact that there has been a tremendous variety of living things. Some extinct species had traits that were transitional between major groups of organisms. Their existence confirms that species are not fixed but can evolve into other species over time. The evidence also shows that what have appeared to be gaps in the fossil record are due to incomplete data collection. The more that we learn about the evolution of specific species lines, the more that these so-called gaps or "missing links in the chain of evolution" are filled with transitional fossil specimens. One of the first of these gaps to be filled was between small bipedal dinosaurs and birds. Just two years after Darwin published //On the Origin of Species//, a 150-145 million year old fossil of //Archaeopteryx// was found in southern Germany. It had jaws with teeth and a long bony tail like dinosaurs, broad wings and feathers like birds, and skeletal features of both. This discovery verified the assumption that birds had reptilian ancestors.
 * || [[image:http://anthro.palomar.edu/evolve/images/strata.gif width="182" height="202" caption="illustration of geological strata containing an evolutionary sequence of fossils from 570 to 2 million years ago"]] ||
 * ^  || Geological strata containing an

Since the discovery of //Archaeopteryx//, there have been many other crucial evolutionary gaps filled in the fossil record. Perhaps, the most important one, from our human perspective, was that between apes and our own species. Since the 1920's, there have been literally hundreds of well-dated intermediate fossils found in Africa that were transitional species leading from apes to humans over the last 6-7 million years. This evidence is presented in the last 3 tutorials of this series.
 * [[image:http://anthro.palomar.edu/evolve/images/Archaeoptryx_1.jpg width="175" height="133"]] ||  || [[image:http://anthro.palomar.edu/evolve/images/Archaeoptryx_2.jpg width="175" height="133"]] ||   || [[image:http://anthro.palomar.edu/evolve/images/Archaeoptryx_3.gif width="193" height="133"]] ||
 * //Archaeopteryx// fossil ||  || //Archaeopteryx// recreation ||   || //Archaeopteryx t//ail feathers ||

The fossil record also provides abundant evidence that the complex animals and plants of today were preceded by earlier simple ones. In addition, it shows that multicelled organisms evolved only after the first single-celled ones. This fits the predictions of evolutionary theory.

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RAM On the Biology SAT 2's I had a few questions about taxonomy that got me a little confused Taxonomy is the ordered division of organisms into categories based on a set of characteristics used to assess similarities and differences. [] This image really helped me to review the order of descent of taxonomy, and the book provided me with a mnemonic device just in case. King Phillip climbed over the fence and got shot. Hope this helps if anyone else gets confused with it.

When trying to understand pedigree charts, I always get confused on what the different symbols mean towards the individual. This chart gives a clear explanation for what each symbol means. I also attached a diagram of a basic pedigree chart. [] []
 * SAL**

YC I don't think we've reviewed asexual reproduction for a long time. Here is a refresher [] Some forms of asexual reproduction are budding, internal buds, fragmentation, regeneration, and parthenogenesis

One of the topics I have the most trouble with is categorizing animals into the different phylum. This chart shows the differences between protostomes and deuterstomes. A) Cleavage- In general, protostome development begins with spiral, determinate cleavage. Deuterostome development is characterized by radial, indeterminate cleavage B) Coelom formation- coelom formation begins in the gastrula stage. In protostome development, the coelom forms from splits in the mesoderm. In the deuterostome development, the coelom forms from mesodermal outpocketings of the archenteron. C) Fate of the blastospore- in protostome development, the mouth forms from the blastospore. In deuterostome development, the mouth forms from a secondary opening []
 * WJH **

CCB A few times in our evolution unit, Hox genes came into discussion. I never knew what those were or why they were significant, so I thought I would make a post about it. //Hox//genes are a group of regulatory genes that control the timing and route of development and contribute to body segmentation. This information might me extraneous, but it is extremely interesting, and if you happen to have an essay about evidence for evolution I bet it would be impressibe to mention these genes! Also, this essay does an excellent job with simplifying and clarifying the information, so definitely check it out: [] Also, this picture is a good representation of Hox genes. It shows how similar genes control the segmentation of different organisms and end up with different products, like a human torso and fly wings.

KEY TERMS OF EVOLUTION I believe that these terms are extremely important to know, as they are mainframe vocabulary for the section. Here are the key terms of evolution in summary. You can quiz yourself on the below listed terms and play games with the terms at: QuizLet Evolution Review

Happy Studying!media type="custom" key="17525930" -WMWoods environment. ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Evolution ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] all of the changes that have transformed life over an immense time. ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Adaption ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] an inherited characteristic that improves an organisms ability to survive and reproduce in a particular
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Beagle ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] the name of the ship that Charles Darwin sailed on in the 1830's ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Descent With Modification ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] the theory of Darwin that all of the species living on earth today descended from earlier species. ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Natural Selection ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] the process by which individuals with inherited characteristics well suited to the environment leave more offspring on average than do other individuals. ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Fossils ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] preserved remains of organisms that lived in the past ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Fossil Record ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] the collection of fossils recorded in rock layers over time ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Extinct ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] species that no longer exist ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Homologous Stucture ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] similar structures among related species ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Vestigial Structure ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] homologous structures that have a major function in one species but not in a related species ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Population ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] A group of individuals of the same species living in a particular area at the same time ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Variation ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] differences among members of the same species ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Artificial Selection ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] selective breeding of plants and animals to produce offspring with traits that humans value ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Gene Pool ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] consists of all the alleles [different forms of genes] in all the individuals of a population ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Microevolution ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] a generation-to-generation change in the frequencies of alleles withen a population ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Hardy Weinberg Equilibrium ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] populations that do not undergo change to their gene pools[not evolving] ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Genetic Drift ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] change in a gene pool due to chance ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Gene Flow ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] the exchange of genes with another population ||
 * < [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] Fitness ||< [[image:http://b.quizlet.com/a/i/spacer.MzUH.gif]] the contribution an individual makes to the gene pool of the next generation compared to the contribution of other individuals ||