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What is artificial selection? And some examples?
Occurs when phenotypes at each end of the spectrum are less suited to the environment that organisms in the middle of the phenotypic range.
Favors intermediate phenotypes.
Occurs when a single phenotype predominates in a particular environment.
Acts against individuals at one of the phenotypic extremes.
What is molecular biology? What can it tell us regarding the relationships of organisms?
Molecular biology is the comparisons of DNA and amino acid sequences between different organisms. It reveals evolutionary relationships. Where DNA is similar, they are closely related. Different more distantly related.
What is evolution? How does it relate to populations?
Evolution is change over time (in populations).
An entire group or species, to become more adapted (more FIT, reproduce and have more offspring) evolves to their environment.
Evolution is not individual.
What is sexual dimorphism?
Sexual Dimorphism: the distinction in appearance between males and females of a species
Can natural selection create perfect organisms? Why or why not?
How do insects and bacteria become resistant to insecticides and antibiotics, respectively?
Initial use of pesticides favors those few insects that have genes for resistance… Over time, the vulnerable ones die, and the only ones who mate are those with the resistance. Chromosome with allele conferring resistance to pesticide, also, additional applications are less effective.
We define species diversity by species richness and species abundance. What is species richness and species abundance.
Species Abundance – How many of these species are in the areaSpecies Richness – The number of different species within a community
Morphological species concept: Outward appearance. Sometimes a species can have so much variation, you might think you are looking at different species, but are in fact only looking at one. There is a lot of variation, which can be very problematic for this concept. There can also be different species that look identical.
If they look the same, then they are the same species.
Biological: Reproduction or breeding to tell if they are different species or the same. You cannot use biological to categorize fossils, you must be able to observe mating.
Can they breed and have healthy and viable offspringDefines a species as members of populations that actually or potentially interbreed in nature, not according to similarity of appearance. Although appearance is helpful in identifying species, it does not define species
Homeotic Genes: Control batteries of genes that shape anatomical parts such as antennae, legs and body segments. (Genes that control development).
Linnaeus' system: the branch of biology concerned with naming and classifying the diverse forms of life.
What is polyploidy?
Polyploidy: multiplication of the chromosome number due to errors in cell divison.
Plant species have evolved because of polyploidy.
Adaptive Radiation: may occur in new or newly vacated habitats; the evolution of new species may occur when mass extinctions or colonization produce organisms with new environments. (Many species come from one single ancestoral lineage… like the fish).
Diversifying Selection (Disruptive)
Typically occurs in a "patchy" environment, in which extremes of the phenotypic range do better than the middle range.
Favors individuals at both extremes of the phenotypic range.
the evolutionary history of a group
based on identifying homologous and molecular sequences that provide evidence of common ancestry
Reconstructed evolutionary history (the Tree of Life is a great big phylogeny)
What is variation? What contributes to variation in a population?
What types of evidence influenced Darwin’s thoughts on evolution?
What is a vestigial trait? Examples?
Tail bones in humans; we have no tail but we have remnant’s of a tail bone. Snakes have remnant’s of a pelvic bone and hind legs. Appendix in humans isn’t necessary anymore.
Acquired Characteristics: the organism was not born with it, but they acquire it over their lifetime… These are NOT heritable or passed down.
Homology-similarities of characteristics from shared ancestry
Anaology-similarity of structure between 2 species who aren’t related.
What is comparative anatomy? Comparative embryology?
Comparative Anatomy: The comparison of body structures in different species
Comparative embryology: Many vertebrates have common embryonic structures
What are fossils? What is the fossil record?
They strongly support the theory of evolution, they reveal that organisms have evolved over time.
What are transitional fossils? How did whales evolve? How do we know?
Transitional fossils help us date things and see how species have changed; link early extinct species to species living today.
Whales evolved through graduated evolution. We have fossils that show the transitional states they went through from a group of land mammals.
What is the definition of a population? Gene pool?
Population: a group of organisms of one species that interbreed and live in the same place at the same time.
Gene Pool: is the total collection of genes in a population at any one time.
What is fitness? How do we define fitness with regards to populations/evolution?
Fitness: the relative measure of reproductive success of an organism in passing its genes to the next generation
Regards to populations… the more offspring an organism can reproduce, the more ‘fit’ they are.
What is the difference between microevolution and macroevolution?
Microevolution: Small changes—Change in allele frequency from one generation to the next
Macroevolution: Big changes (shocker). A new species has evolved or a new novel trait arised. This could also be extinction.
What are gene flow and genetic drift?
Gene Flow: the movement of individuals or gametes between populations… Can alter allele frequencies in a population
Genetic Drift: the change in allele frequency due to chance – can be caused by bottleneck or founder effects
Bottleneck Event: a population is limited by a single or limited number of resources, and so the numbers slowly decline because of this.
Founder Effect: the reduced genetic diversity that results when a population is descended from a small number of colonizing ancestors
Why are populations with low genetic variability more likely to become endangered or extinct? What has happened to the Cheetah?
Low Genetic Variability: It almost ensures their extinction because there is no variant that can beat the new environmental challenge or obstacle.
Cheetah: several different bottlenecks that took the population down to near extinction… habitat loss. They lost almost all genetic variation.
What is sexual selection? What is Male competition?
Sexual selection: the determining of who mates with whom, which leads to the evolution of secondary sexual characteristics that may give individuals an advantage in mating.
Male Competition: A form of sexual selection; where males compete for the right to mate with all the females. (i.e. deer, fighting and butting heads… the loser cannot mate with any females)
What is speciation? How do we hypothesize that the 500 or so species of cichlid fish originated?
Speciation: the origin of new species
Originated: Habitat differentiation and sexual selection… Over “time” they developed different mouth parts. Also, females in different regions were mating with brightly colored males.
What is branching vs. linear evolution? Which one leads to increased biological diversity?
Branching evolution: A parent population breaks apart and forms two different species through enough ‘changes’
Linear evolution: A parent population completely changes altogether to become a new species, rather than branching off.
Biological diversity is found in Branching evolution, but not in linear, because it creates much more diversity.
Who is Carolus Linnaeus? What is a binomial system for naming organisms? How did Linnaeus classify species?
Carolus Linnaeus: a Swedish physician and botanist who used physical characteristics to distinguish species.
Binomial naming systems: Has two parts and classifies a species special characteristics.
However, similarities between some species and variation with that species can make defining them very difficult.
What is the difference between allopatric and sympatric speciation?
Allopatric Speciation: a population is geographically divided; such as the emergence of a mountain or subsidence of a lake.
Sympatric Speciation: new species can arise within the same geographic area as the parent species
A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding.
Reproductive barriers: They keep species separate, and serve to isolate a species’ gene pool and prevent interbreeding.
Prezygotic barrier: Prevent mating or fertilization between species
Postzygotic barrier: Barriers operate after hybrid zygotes are formed (prevents it from forming properly)
What is a geographical barrier? Is a geographical barrier alone enough to define 2 populations as distinct species?
A barrier that separates a certain species from the “parent” one; no, it is not enough to define two populations as distinct species.
What is punctuated equilibrium model of evolution? What is the graduated evolution? How did whales evolve (punctuated or graduated?).
Punctuated Equilibrium: Draws on the fossil record, where species change the most as they arise from an ancestral species, and then change relatively little for the rest of their existence
Graduated Evolution: New species evolve by the gradual accumulation of changes brought about by natural selection
Whales ‘evolved’ through graduated evolution.
How do evolutionary novelties arise? What is the definition of an exaptation?
They arise through many complex structures evolving in many stages from simper versions having the same basic function
Exaptation: The gradual adaptation of existing structures to new functions
What is evo-devo? Why are genes that control development so important in evolution?
Evo-devo: A field that combines evolutionary and developmental biology
Why: We see that the development genes of different species are the same… Embryos. The difference is how they are regulated between species.
What is convergent evolution? Divergent evolution?
Prokaryotes are very important to Eukaryotes. Why?
What does it mean to be gram positive or gram negative?
How can prokaryotes withstand harsh conditions?
Although prokaryotes are smaller than eukaryotes, their mass would significantly outweigh all the eukaryotes.
What does the term pathogenic mean?
What is an opportunistic pathogen?
What are the three morphologies of bacteria?
What are pili? Are they different from flagella and cilia?
What are archea? What types of extreme environments can the live in?
What are methanogens? Where can they be found and what is unique about their metabolism?
What type of bacteria carry out photosynthesis?
What are dead zones? What causes them and how do they develop?
1. High nutrition in the water (Nitrogen & Phosphorous) due to pollution
2. Cyanobacteria & algae (who feed on N & P) bloom in response to excess nutrients
3.Eventually use up nutrients & die and are decomposed by other bacteria/fungi
4.Decomposition depletes the oxygen b/c they carry out respiration
5.Creates hypoxic conditions which = dead zone
What are biofilms? Some infections are due to biofilm formation.
We get some of our antibiotics from bacteria.
Is there a difference between endotoxins and exotoxins? If so, what?
What prokaryotes are “hot topics” for biological weapons/warfare?
What is symbiosis? What is the endosymbiotic hypothesis?
Remember that two significant evolutionary events occurred with the protists, first, the evolution of eukaryotes, second, the evolution of multicellularity.
How do amoeba move?
Many human diseases are caused by Protists. What are protists? Do Protists fit nicely into one category? Are they Eukaryotes?
Protists can be classified based on their mode of nutrition. What are plant like protists? Fungus like protists? Animal like protists?
(i.e. not prokaryotic, not plants, not fungi, not animals)
-Eukaryotic, and mostly single celled
What are heterotrophs? Autotrophs?
Which protists are the most closely related to plants?
What are diatoms? What are dinoflagellates? Which lives inside the bodies of coral? Which are the cause of toxi red tides?
Be familiar with the following: Giardia, Volvox, Paramecium, Amoeba, Euglena, Trypansoma, Trichomonas and Trichonympha. What is Trichonympha’s relationship with termites?
How do we hypothesize that multicellular plants evolved? Which protist is the most closely related to land plants? What is chlamydomonas? Volvox? How do these plant like protists get their nutrition?
Be familiar with Water molds and slime molds. Are they fungus like protists? How do they get their nutrition?
What types of symbiotic relationships can fungi have with members of other species?
What are mycorrhizae? What do they do for plants?
What are lichens? Where do they grow and what role do they play in soil formation? Are they good indicators of air pollution?
What are hyphae? Mycelium?
How does a fungus acquire its nutrients? Is it a heterotroph?
Fungi are classified based on their reproductive structures. What are they?
What is the earliest branch of the fungal group? How do we know?
What are some important roles carried out by fungi in ecosystems?
What are some of the medically significant diseases caused by fungi? Plant infections caused by fungi?
How do leaf-cutter ants rely on fungi? Is this a symbiotic relationship?
What are mosses? Ferns? Gymnosperms? Angiosperms? What traits are seen in each of these groups that adapt them partly or fully to land? Which are only incompletely adapted to land? Why? Which are completely adapted to land? Why?
Be able to tell me the order in which groups of land plants evolved.
Which were dominant in forests of the carboniferous period? What happened when many of them died/became extinct?
Make sure you are familiar with male and female parts of the flower.
Why do gymnosperms make so much pollen?
To assure successful pollination. (wind probs)
Why do angiosperms (for the most part) make less pollen? Why do they make a showy flower?
Be familiar with pollinators of angiosperms and the fact that they have co-evolved with the plants they pollinate. How do angiosperms and animals depend/cooperate with each other?
What do humans depend on plants for? Food? Clothes? Building material? Medicines? Recreation?
What is the greatest threat to plant diversity today? How many years before the rainforests are destroyed if destruction continues at the current rate?
What is bioremediation?
Cleaning up a polluted site with microorganisms to break it down, like oil spills – When you use organisms to clean up pollution or waste for the environment – two examples we have talked about is cleaning up waste and oil spills