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UW / Biology / BIOL 180 / What is a subspecies?

What is a subspecies?

What is a subspecies?

Description

School: University of Washington
Department: Biology
Course: Introductory Biology
Professor: Scott freeman
Term: Summer 2015
Tags:
Cost: 50
Name: Biology180 Exam 3 Study Guide
Description: In preparation for exam 3, I've made an extensive, yet concise in terms of key topics and vocabulary to know, study guide that covers speciation, history of life, population growth, diversifications of animals, plants and chordates, as well as behavioral ecology. I've also included about a page and a half of study questions I've made myself that help cover concepts and make applications, which have
Uploaded: 11/15/2015
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Biology 180 Exam 3 Study Guide 


What is a subspecies?



Biology 180 ­ Dr. Freeman and Dr. Dooley ­ Exam 3 Study Guide

Highlight=Important Points Highlight=Important Concept Highlight=Key Term Main Ideas Covered in this Study Guide:

● Speciation

● History of Life:

○ Major innovations

○ Radiations and Extinctions

○ Rare Earth

● Plant Diversification

● Animal Diversification

● Chordate Diversification

● Sexual Selection

● Population Growth

● Human Population Growth/Life Histories

KEY VOCABULARY:

Note: Most, if not all, of the key vocabulary from these sections are compiled all together here. As a study method, practice defining each in your own words and then APPLY them­­figure out which topics they connect to and in what context they should be used.


What is allopatry?



➔ subspecies: ​​populations that live in distinct areas and have slightly different features but are not different enough to be completely separate species

➔ allopatry: ​(different homeland) when populations are geographically separated and leads to allopatric speciation We also discuss several other topics like david zuzga

➔ vicariance: ​when a habitat is physically split

➔ sister species: c​losest relative to a particular species

➔ sympatry: ​(together homeland) when populations or species live in the same area or close enough to inbreed and may lead to sympatric speciation

➔ niche: ​range of resources that a species uses and the conditions in the particular environment


What is vicariance?



➔ polyploidy:​error in meiosis/mitosis that doubles the chromosome number ➔ autopolyploidy:​individuals have doubled chromosome number and the chromosomes are all from the same species

➔ allopolyploidy:​an individual that has two sets of chromosomes from parents of two different species

Biology 180 Exam 3 Study Guide 

➔ transitional feature:​trait in a fossil species that is an intermediate between a trait in an extinct and extant (alive) species

➔ PreCambrian period:​era that includes the time between formation of the Earth and appearance of animal groups

➔ adaptive radiation ​: ​a single lineage produces many many descendant species with very different forms very rapidly We also discuss several other topics like usc gesm

➔ ecological opportunity​: ​availability of new types of resources ➔ morphological innovation: t​he evolution of key morphological traits that allowed species to exploit new resources in new ways and move in new ways ➔ Cambrian explosion:​rapid adaptive radiation event during the Cambrian period in which many different animal lineages diversified and many different traits evolved

➔ mass extinction ​: ​rapid extinction of at least 60% of species within 1 million years We also discuss several other topics like lesley ashmore pitt

➔ background extinction: l​ower average rate of extinction than mass extinction due to normal environmental changes, predation or disease If you want to learn more check out sona psychology ucla

➔ impact hypothesis: h​ypothesis for the extinction of dinosaurs that suggests an asteroid hit the Earth and killed 60­80% of species

➔ World Went to Hell hypothesis:​suggests extreme global climate change such as high CO2 levels and anoxic oceans

➔ Rare Earth Hypothesis:​complex multicellular life required rare astrological and geological events to occur at the right time on the planet

➔ nonvascular plants: ​plants that do not have vascular tissue ➔ vascular tissue: g​roups of cells that transport water and nutrients throughout the plant Don't forget about the age old question of ma 26500
We also discuss several other topics like What are the types of electromagnetic radiation?

➔ seed: ​plant embryo with tissue and package of nutrients surrounded in a protective layer

➔ angiosperm: ​a flowering plant that is part of the seeded vascular land plant group (“enclosed seeds”)

➔ spore: ​reproductive cells with no package of nutrients like the seed ➔ cuticle:​water tight waxy coating that acts as a barrier on the epidermis of plants to prevent water loss

➔ sporopollenin: w​axy material in land plants that encases spores and pollen to prevent the from drying out

➔ sporangia:​spore producing structures in plants

➔ gymnosperms: ​plants that are part of the seeded vascular plant group that makes seeds but does not produce flowers like the angiosperms (“naked seeds”) ➔ stomata:​opening/pore in a plant that is surrounded by guard cells that control the opening and closing of the pore and is responsible for gas and liquid exchange­­often found on underside of leaves in most of today’s plants ➔ lignin:​complex carbon polymer that provides strength in cell walls and allows plants to grow taller and upright

Biology 180 Exam 3 Study Guide 

➔ tracheids:​long thin cells with two cell walls and pits in the inner secondary wall at the ends of the tracheids to allow water to pass through

➔ gametangium: ​reproductive organs in plants that protect gametes from damage ➔ vessel elements:​wide short cells that have pores at the ends through both primary and secondary walls to allow for better water transport

➔ embryophytes: ​land plants that retain the embryo on its body to nourish it ➔ sporophyte​: m​ulticellular diploid stage of plant reproductive cycle and produce spores by meiosis

➔ gametophyte​multicellular haploid stage of plant reproductive cycle and produce gametes by mitosis

➔ pollen grain:​male gametophyte that has cells to produce male sperm surrounded by tough coating of sporopollenin

➔ stamen:​contains microsporangia where meiosis happens to make pollen ➔ carpel:​contains protective ovary where ovules are found (ovules are enclosed so this is in angiosperms not gymnosperms)

➔ pollination: ​pollen transferred from one stamen to another carpel ➔ bottleneck effect:​sudden reduction in number of alleles causing a change in frequencies when a large portion of a population is wiped out randomly ➔ heterospory:​production go two types of spores through different structures ➔ monocots:​plants with one cotyledon

➔ cotyledon:​“seed leaf” stores nutrients and gives them to developing embryos ➔ dicots:​plants with two cotyledons

➔ homology​: ​a similarities between species due to common ancestry ➔ eudicots​: ​true dicots­­monophyletic group that includes most dicots but not all ➔ species:​evolutionarily independent population or group of populations ➔ morphospecies concept:​lineages differ by size, shape or other physical features

➔ biological species concept:​identifies species based on reproductive isolation ➔ heterotrophs: ​animals that obtain compounds from other organisms (eat instead of absorb)

➔ phyla:​major lineage

➔ multicellularity​: differential gene expression; different cells have different structures and functions

➔ phylogenetic species concept:​identify species based on the history of populations and on ancestor/descendent relationships

➔ synapomorphy:​trait found in certain groups and a common ancestor, but is not found in more distant ancestors

➔ phylogenetic tree:​summary of ancestor/descendant relationships ➔ diploblast​:​two types of tissue­­ectoderm and endoderm

➔ homoplasy​:​(same form) similarities between species not derived from common ancestry; arose through different processes and ways (convergent evolution) ➔ convergent evolution:​​natural selection favors similar traits in different species (based on similar ways of life)

Biology 180 Exam 3 Study Guide 

➔ triploblast​:​three types of tissue: endoderm, ectoderm and mesoderm ➔ endoderm​: ​produces the digestive tract

➔ mesoderm​: ​tissue in between ectoderm and endoderm consisting of bone, tissue, circulatory system and some organs

➔ ectoderm​: ​produces covering of the animal on the outside

➔ radial symmetry​: ​spoke symmetry­­at least two planes of symmetry ➔ bilateral symmetry​: ​one plane of symmetry with long narrow bodies ➔ cephalization:​evolution of the head/face with regions for eating, sensing and processing

➔ coelom​: ​fluid filled cavity between inner and outer tubes in bodies and lined with mesoderm­­provides space for circulation of gases and nutrients ➔ hydrostatic skeleton:​​allows soft bodied animals to move without fins or limbs and is possible because of the coelom

➔ segmentation:​​presence of repeated body structures

➔ vertebrates​: m​onophyletic lineage with key feature of segmented backbone ➔ invertebrates:​​paraphyletic group with some segmentation in annelids and arthropods but do not have defining feature of backbone

➔ chordate:​​animals that have four key morphological features at some point in their lives

➔ pharyngeal gills:​​opening in throat (most basal)

➔ dorsal hollow nerve cord:​​composed of neurons that run length of body ➔ notochord:​​stiff and supportive, flexible rod that runs length of body ➔ cranium:​​made of bone, cartilage or fibers that encase the brain ➔ amniotic egg:​​egg with membranes surrounding a food supply, water supply and

area for waste­­present in amniotes and allows for larger offspring to develop ➔ grade​: ​sequence of lineages that are paraphyletic (like fish)

➔ anthropoids:​​human­like monkeys including new and old world monkeys, gibbons and great apes/hominins

➔ primates:​​have hands and feet that grab, flat nails, bigger brains, complex social behavior and color vision with eyes on front of face

➔ hominins: ​large body, no tail, long arms and short legs (chimps, gorillas, humans)

➔ Out­of­Africa Hypothesis:​​suggest Homo sapiens evolved distinct traits in Africa and then continued to spread throughout the world and no interbreeding occurred­­supported by fossil and some molecular evidence, but some molecular evidence rejects hypothesis because of suggested interbreeding

➔ sexual selection:​​natural selection that favors traits that increase individuals ability to mate

➔ intersexual selection:​​when an individual of one gender selects to mate with an individual of the other gender

➔ intrasexual selection:​​selection within a gender, usually in the form of competition for mates

Biology 180 Exam 3 Study Guide 

➔ theory of Fundamental Asymmetry of Sex:​​sexual selection acts on males much more strongly than females because the energy cost of creating a large egg is high while cost of sperm is low

➔ sexual dimorphism​: ​a difference in traits between male and female

➔ altruism​: ​self sacrificing behavior in which the actor is costing itself fitness but the individual whom the action was done for benefits in terms of fitness

➔ Hamilton’s Rule​: (​Br > C) altruistic behavior is likely when fitness benefits are high for recipient, low costs to actor and the altruist and recipient are closely related

➔ coefficient of relatedness:​​probability that the alleles in two individuals are identical by descent

➔ inclusive fitness​: ​combination of direct and indirect fitness

➔ direct fitness​: ​derived from individuals own offspring (parental care)­­parents increase fitness by helping their offspring

➔ indirect fitness​: ​derived from helping relatives increase their fitness than an individual could by itself

➔ kin selection​: ​selection that affects reproductive success of close relatives (shared alleles) increases relatives fitness at cost of individual fitness

➔ reciprocal altruism​: ​exchange of fitness benefits that are separated in time ➔ exponential population growth:​​when r does not change over time (does not depend on number of individuals in pop.)

➔ logistic population growth:​​growth is density dependent and occurs when pop. density gets high, then per capita death rate increases while birth rate decreases and r decreases

➔ carrying capacity​: ​maximum number of individuals in a population that can be supported by a habitat (limited by resources and space)

➔ metapopulation:​​a population made up of smaller isolated populations connected by migration

➔ population dynamics​: ​changes in populations through space and time ➔ population ecology​: ​study of how and why number of individuals in pop. change in time and space

➔ population density​: ​number of individuals per unit area

➔ demography​: ​study of factors that determine size and structure of populations ➔ fecundity​: ​number of female offspring produced by each female in population ➔ survivorship​: ​proportion of offspring produced that survive to certain age ➔ life history​: ​describes how individual uses resources for growth, reproduction, and activities and structures for survival

➔ fertility rate​:​average number of surviving children each woman has in lifetime Speciation

Biology 180 Exam 3 Study Guide 

★ speciation begins when gene flow is reduced or eliminated between populations which causes genetic isolation

★ allopatric speciation: occurs either by vicariance or by dispersal 

○ dispersal: genetic drift creates colonizing population (founder effect) and natural selection in new environment favors certain alleles independently of in other populations

○ vicariance: a new physical barrier separates a species into two or more populations and these populations may continue to diverge through natural selection, mutation and lack of gene flow

★ sympatric speciation occurs through outside events like disruptive selection or through mutation like polyploidization 

○ disruptive selection: species can become reproductively isolated by adapting to different niches through disruptive selection even if they live in the same area and populations further diverge through selection

○ mutation/polyploidization: errors in meiosis leads to doubling of chromosome number whether the chromosomes are from same species (autopolyploidy) or from parents of two different species (allopolyploidy)

■ if autopolyploid can self fertilize, reproduction can resume correctly, or if an error in mitosis occurs that doubles chromosomes again, meiosis can continue

■ speciation by polyploidy is common in plants and occurs VERY fast and is common

History of Life: 

★ Major Innovations: 

○ only the fossil record provides direct evidence about what extinct species look like, where they lived and when the lived

○ limitations of the fossil record: biases regarding habitat, taxonomies and tissue, temporal scale, and abundance of species

○ Life’s Timeline: PreCambrian (Earth formation to appearance of animals) → Phanerozoic Eon (end of Precambrian to present day→ appearance of most animal lineages/first diversifications, then extinction of dinosaurs and domination of plants, then abundance of mammals and angiosperms)

★ Radiations and Extinctions: includes Cambrian explosion and both mass and background extinctions 

○ adaptive radiation: either through ecological opportunity (availability of new resources) or morphological innovation (new traits to allow exploitation of resources in new ways/move differently)

○ Cambrian explosion: rapid adaptive radiation

○ only a few mass extinctions that occur relatively rapidly (most like genetic drift­­extreme bottlenecking); background extinctions occur much slower and occur when mass

extinctions are not occurring

○ impact hypothesis: extinction of dinosaurs via asteroid striking the Earth

○ World Went to Hell hypothesis: extreme global climate change over time (ie high CO2 levels)

★ Rare Earth hypothesis suggests multicellular life requires very rare, specific astrological and geological events to occur at very particular times 

○ suggests simple life may be common, but complex life require specific environments ○ requirements for complex life:

Biology 180 Exam 3 Study Guide 

■ right location in right galaxy

■ right planets surrounding it (a large outer planet like Jupiter for protection)

■ right orbit shape and distance­­stable

■ plate tectonics

■ large moon

■ right timeline of evolution (with right timing of all other environmental conditions) ○ criticism: this hypothesis is explanation for why life arose on this planet, not hypothesis for what could occur on other planets; current technology limits testing for right conditions ○ misconceptions: do not need same Earth conditions for life to arise elsewhere and lots of Earth­like planets have been found so our environmental occurrences are not that rare

Plant Diversification: 

★ land plants are divided into 3 main categories: nonvascular plants, seedless vascular plants and seeded vascular plants 

○ fossil record suggests: evolution green algae → nonvascular plants → seedless vascular plants → seeded vascular plants and each evolved to become less dependent on moist habitats

○ cuticle, stomata and vascular tissue are three key adaptations that allowed for plants to transition to land

○ green algae are paraphyletic, seedless vascular plants are paraphyletic group between nonvascular and seed plants and seed plants are a monophyletic group including gymnosperms and angiosperms

■ seed plants have two key synapomorphies: production of seeds and pollen

★ natural selection favored plants that protected from drying out/dying in 3 main ways: ○ preventing water loss (cuticle and stomata)

○ protection against UV radiation

○ vascular tissues that allowed plants to grow upright to transport water and avoid falling over ★ the evolution of embryophytes and the evolution of seeds, pollen grain and flowers were key to plant reproductive evolution 

○ in angiosperms, the evolution of double fertilization in the flower and evolution of the ovary (protection of female gametophytes) were key innovations

○ embryophyte evolution allowed for embryo to stay protected and nourished by parent plant instead of dropping off embryo immediately like many other organisms

○ flower and fruit production are key synapomorphies for angiosperms

○ directed pollination hypothesis:

■ natural selection favored structures like the ovary and flower to increase probability of pollination of flower (reproduction) as well as rewarding pollinators for carrying

pollen from flower to flower with food in form of nectar

○ in land plant reproduction: sporophytes produce spores by meiosis → spores germinate, divide by mitosis and create gametophytes → gametophytes produce gametes by mitosis → two gametes fuse to make zygote → zygote divides by mitosis into sporophyte

★ summary of land plant adaptation: vascular tissue, stomata and cuticle for growth in dry habitats → diversified traits that allowed sperm to efficiently reach eggs in flowers and help seeds disperse to new locations

Biology 180 Exam 3 Study Guide 

Animal Diversification: 

★ radiation of animals began during Cambrian explosion and animals all have key traits: ○ eukaryotes

○ multicellular and no cell walls

○ heterotrophs

○ move under own power

○ neurons that transmit electrical signals and muscle cells that change body shape ★ Animals evolved through the evolution of main synapomorphies of multicellularity → tissues → bilateral symmetry, cephalization and nervous system → coelom → segmentation ○ origin of multicellularity

■ animals are monophyletic; multicellularity evolved in sponge­like ancestor as

sponges are earliest animal in fossil record and sponges are paraphyletic group

■ root of animal tree is multicellularity

○ origin of tissues: animals are either diploblasts or triploblasts (number of types of tissue) except sponges

■ germ layer consists of ectoderm, endoderm (and mesoderm in triploblasts)

■ diploblasty appears to have originated after multicellularity but before triploblasty ○ origin of bilateral symmetry, cephalization and nervous system

■ body symmetry is KEY morphological aspect of animal body (either radial­­basal­­ or bilateral­­more derived)

■ bilateral symmetry evolution is closely related to cephalization/evolution of head ■ evolution of central nervous system also coincides with evolution of head (sponges have no nerves → the nerve nets → then central nervous system evolution)

○ origin of coelom: (basic bilateral body is tube within a tube design) and segmentation ■ coelom important because allowed for soft bodied animals to move with hydrostatic skeleton (without fins or limbs)

■ segmented backbone is key to defining vertebrates and is hypothesized to allow for specialization of bodies and appendages

Chordate Diversification: 

★ chordates are defined by 4 key morphological features at some point in their lives: pharyngeal gills, dorsal hollow nerve cord, notochord, muscular, post­anal tail (with muscles and goes past the anus) ○ key synapomorphies specifically for chordata: muscular tail, notochord and dorsal hollow nerve cord

★ 3 major lineages of chordates: cephalochordates, urochordates and vertebrates ○ 2 key synapomorphies of vertebrates are bony column of vertebrae along dorsal side of body to protect spinal cord and cranium made of bone, cartilage or fibers that encases brain ○ key innovation of vertebrate evolution: evolution of large 3 part brain protected by hard cranium

★ key innovations of vertebrates as the lineage diversified: 

○ bony exoskeleton, jaws, bony endoskeleton, amniotic egg (key synapomorphy of amniotes­­all tetrapods except amphibians)

★ summary of key synapomorphy evolution in chordates: 

○ pharyngeal gill slits

○ notochord, dorsal hollow nerve cord, muscular post anal tail

○ vertebrae, cranium

Biology 180 Exam 3 Study Guide 

○ jaws

○ lungs, internal bone

○ lobed fins

○ limbs

○ amniotic egg

○ scales with hard keratin

★ key synapomorphy of anthropoids: large brain

★ key synapomorphy of great apes: fist walking

★ bipedalism is key synapomorphy of hominins (monophyletic group of humans and 20 extinct relatives)

★ Out­of­Africa Hypothesis: suggest Homo sapiens evolved distinct traits in Africa then spread throughout the world and that Homo sapiens evolved separately from other Homo species, no interbreeding 

★ summary of key synapomorphy evolution of primates:

○ eyes in front of face, grasping hand

○ larger brain

○ long arms, short legs, no tail

○ fist walking

○ knuckle walking

○ bipedalism

Sexual Selection: 

★ sexual selection is natural selection that favors traits that increase individual’s ability to obtain mates­­(can be intrasexual OR intersexual) 

○ Fundamental Asymmetry of Sex:

■ Pattern: sexual selection acts on males more strongly on males­­traits that attract mates are more elaborate in males

■ Process: costs more energy to create large egg, while sperm takes less energy “eggs are expensive but sperm are cheap”

■ Predictions: females are more choosy about mates and mates should compete with each other more; thus sexual selection should act more strongly on males since

male fitness is limited by finding mates

★ Sexual dimorphism RESULTS from sexual selection→ not same thing

★ Hamilton’s Rule is a formula for predicting the probability that alleles in two individuals are the same as result of close relatedness; suggests altruistic behavior occurs when fitness benefits are high for recipient, costs are low for altruist and both altruist + recipient are close relatives

○ Significance: individuals can pass on their alleles to next generation (increase fitness) by producing own offspring AND helping close relatives (who likely share same alleles) produce their offspring

○ Br > C where r=coefficient of relatedness

★ kin selection and inclusive fitness:

○ kin selection INCREASES overall inclusive fitness (decreases direct fitness, yet increases indirect fitness)

Population Growth:

Biology 180 Exam 3 Study Guide 

★ population’s growth rate is function of birth rates, death rates, immigration rates and emigration rates 

○ difference between birth rate and death rate is the per capita rate of increase (symbolized by r)

★ Exponential population growth: when r does not change​(the RATE of increase is the same but number of individuals added is not) 

○ KEY: this type of growth is DENSITY INDEPENDENT because rate does not depend on number of individuals in population

○ common situations: few individuals in a new population in new habitat OR population is devastated by disaster and must begin regrowing with just a few survivors (this growth can not continue forever)

★ Logistic growth: growth is DENSITY DEPENDENT because as pop. density gets high, birth rate decreases and death rate increases therefore r decreases

○ logistic population growth are essentially changes in the rate of growth as function of pop. size

○ as population approaches carrying capacity​, growth rate slows

★ Populations are limited by both density dependent factors and density independent factors ★ there is a balance between extinction and recolonization in metapopulations​: there are a stable number of individuals in the overall population over time

Human Population Growth and Life Histories: 

★ More and more species are becoming metapopulations because human population is rapidly growing and reducing grasslands/forest habitats

○ range of populations (distributions) are dynamic and always changing as both biotic and abiotic factors change throughout time 

■ KEY: fitness trade offs are always occurring because each individual has restricted amount of time and energy

★ Life tables summarize probabilities that individuals survive and reproduce through lifetimes ○ 3 types of survivorship curves: (1: high survivorship through life; 2: steady curve of same chance of dying and living; 3) extremely high death rates that high survival rates later in life for survivors)

○ net reproductive rates determines whether a population is increasing or decreasing ○ life histories​are often shaped by natural selection so that fitness of individual is maximized

★ Human population growth has been dramatically increasing 

○ future of human population relies on fertility rates­­how many kids each woman decides to have

○ population growth usually only concerns women because number of males typically has no effect on population growth

○ consequences of overpopulation (reaching the carrying capacity of the planet): ■ primary cause of habitat loss and species extinction

■ shortages of resources, political instability, mass movements of people, decline in living standard

Biology 180 Exam 3 Study Guide 

STUDY QUESTIONS:

★ Compare and contrast tracheids and vessels. Which one evolved first and which is the better adaptation?

★ Name and describe the significance of the three key adaptations that occurred in plants and allowed for successful transition onto land.

★ Compare and contrast the zygote and spores in the plants reproductive cycle. (Refer to sections 580­588 and 592­599 in textbook for detail about plants’ reproductive cycles.) ★ Is the Out­of­Africa Hypothesis supported? What evidence suggests it is or it is not supported?

★ How did angiosperms diversify further beyond just the seeded vascular plants? ★ What is the significance of pollination? (Think directed pollination hypothesis) ★ What is the key synapomorphy of hominins? What separates us from other primates? ★ What are the four key morphological features in chordates? How are they present in

humans? What is the significance of the evolution of these features? In other words, what other traits may evolve due to these features?

★ What are the killing mechanisms and predictions for the impact hypothesis and the World Went to Hell hypothesis?

★ Why is the coelom important? Why is this a critical innovation for animals? ★ Why is bilateral symmetry a key morphological aspect of animals? What other innovations occurred as a result or in close association with the evolution of bilateral symmetry?

★ Describe a mechanism for each type of speciation: allopatric and sympatric. What are the consequences of speciation through these mechanisms?

★ Why do biologists believe that the animals most basal common ancestor is sponge­like? ★ What are some key traits specific to animals?

★ How can you tell if a specific trait found in more than one species is due to homology or homoplasy?

★ What are some causes for homoplasy?

★ Explain how natural selection, genetic drift, mutation and gene flow are in effect during speciation, or if they have any influence at all.

★ Describe some limitations of the fossil record. (Think biases.) What effects do these limitations have on what we know about organisms?

★ How do fossils form?

★ What two mechanisms lead to adaptive radiation? How do they occur? ★ What is the difference between a mass and background extinction? ★ Can you redraw the graphs from class showing what a mass extinction vs a background extinction would look like in terms of species present over time?

★ Which evolutionary process is mass extinction most similar to and why? ★ What does the Rare Earth hypothesis suggest are necessary requirements for complex life to arise and be sustained? What are some criticisms for this hypothesis? ★ Do proponents of the Rare Earth hypothesis believe in alien life? Why or why not?

Biology 180 Exam 3 Study Guide 

★ What is the ‘r’ value (coefficient of relatedness) between first cousins? Is this a high r value? Do you think these cousins are closely related enough to engage in altruistic behavior? ★ What is the difference between direct and indirect fitness? Inclusive fitness? Which increases and which decreases when an altruistic behavior occurs?

★ What is the difference between sexual selection and sexual dimorphism? How are they related?

★ Does sexual selection always act stronger on males? Why or why not? ★ Compare and contrast intrasexual selection and intersexual selection. ★ What are some consequences of overpopulation?

★ What is a key factor that the future of the human population size relies on? ★ What are some general trends in species with: a) high survivorship and b) high fecundity?

★ What are the consequences of the Theory of Fundamental Asymmetry of Sex? What predictions does this theory make?

★ Why do fitness trade offs occur?

★ Name and describe at least two types of survivorship curves.

★ What are some density dependent factors and density independent factors? What do the exponential and logistic growth patterns rely on?

★ Would alleles for altruistic behavior continue to be passed on or increase in frequency if there are cheater alleles present in population?

★ What is the importance of Hamilton’s Rule? What are the three criteria for this rule? ★ Describe the pattern and process components of the Fundamental Asymmetry of Sex.

Biology 180 Exam 3 Study Guide 

Biology 180 ­ Dr. Freeman and Dr. Dooley ­ Exam 3 Study Guide

Highlight=Important Points Highlight=Important Concept Highlight=Key Term Main Ideas Covered in this Study Guide:

● Speciation

● History of Life:

○ Major innovations

○ Radiations and Extinctions

○ Rare Earth

● Plant Diversification

● Animal Diversification

● Chordate Diversification

● Sexual Selection

● Population Growth

● Human Population Growth/Life Histories

KEY VOCABULARY:

Note: Most, if not all, of the key vocabulary from these sections are compiled all together here. As a study method, practice defining each in your own words and then APPLY them­­figure out which topics they connect to and in what context they should be used.

➔ subspecies: ​​populations that live in distinct areas and have slightly different features but are not different enough to be completely separate species

➔ allopatry: ​(different homeland) when populations are geographically separated and leads to allopatric speciation

➔ vicariance: ​when a habitat is physically split

➔ sister species: c​losest relative to a particular species

➔ sympatry: ​(together homeland) when populations or species live in the same area or close enough to inbreed and may lead to sympatric speciation

➔ niche: ​range of resources that a species uses and the conditions in the particular environment

➔ polyploidy:​error in meiosis/mitosis that doubles the chromosome number ➔ autopolyploidy:​individuals have doubled chromosome number and the chromosomes are all from the same species

➔ allopolyploidy:​an individual that has two sets of chromosomes from parents of two different species

Biology 180 Exam 3 Study Guide 

➔ transitional feature:​trait in a fossil species that is an intermediate between a trait in an extinct and extant (alive) species

➔ PreCambrian period:​era that includes the time between formation of the Earth and appearance of animal groups

➔ adaptive radiation ​: ​a single lineage produces many many descendant species with very different forms very rapidly

➔ ecological opportunity​: ​availability of new types of resources ➔ morphological innovation: t​he evolution of key morphological traits that allowed species to exploit new resources in new ways and move in new ways ➔ Cambrian explosion:​rapid adaptive radiation event during the Cambrian period in which many different animal lineages diversified and many different traits evolved

➔ mass extinction ​: ​rapid extinction of at least 60% of species within 1 million years

➔ background extinction: l​ower average rate of extinction than mass extinction due to normal environmental changes, predation or disease

➔ impact hypothesis: h​ypothesis for the extinction of dinosaurs that suggests an asteroid hit the Earth and killed 60­80% of species

➔ World Went to Hell hypothesis:​suggests extreme global climate change such as high CO2 levels and anoxic oceans

➔ Rare Earth Hypothesis:​complex multicellular life required rare astrological and geological events to occur at the right time on the planet

➔ nonvascular plants: ​plants that do not have vascular tissue ➔ vascular tissue: g​roups of cells that transport water and nutrients throughout the plant

➔ seed: ​plant embryo with tissue and package of nutrients surrounded in a protective layer

➔ angiosperm: ​a flowering plant that is part of the seeded vascular land plant group (“enclosed seeds”)

➔ spore: ​reproductive cells with no package of nutrients like the seed ➔ cuticle:​water tight waxy coating that acts as a barrier on the epidermis of plants to prevent water loss

➔ sporopollenin: w​axy material in land plants that encases spores and pollen to prevent the from drying out

➔ sporangia:​spore producing structures in plants

➔ gymnosperms: ​plants that are part of the seeded vascular plant group that makes seeds but does not produce flowers like the angiosperms (“naked seeds”) ➔ stomata:​opening/pore in a plant that is surrounded by guard cells that control the opening and closing of the pore and is responsible for gas and liquid exchange­­often found on underside of leaves in most of today’s plants ➔ lignin:​complex carbon polymer that provides strength in cell walls and allows plants to grow taller and upright

Biology 180 Exam 3 Study Guide 

➔ tracheids:​long thin cells with two cell walls and pits in the inner secondary wall at the ends of the tracheids to allow water to pass through

➔ gametangium: ​reproductive organs in plants that protect gametes from damage ➔ vessel elements:​wide short cells that have pores at the ends through both primary and secondary walls to allow for better water transport

➔ embryophytes: ​land plants that retain the embryo on its body to nourish it ➔ sporophyte​: m​ulticellular diploid stage of plant reproductive cycle and produce spores by meiosis

➔ gametophyte​multicellular haploid stage of plant reproductive cycle and produce gametes by mitosis

➔ pollen grain:​male gametophyte that has cells to produce male sperm surrounded by tough coating of sporopollenin

➔ stamen:​contains microsporangia where meiosis happens to make pollen ➔ carpel:​contains protective ovary where ovules are found (ovules are enclosed so this is in angiosperms not gymnosperms)

➔ pollination: ​pollen transferred from one stamen to another carpel ➔ bottleneck effect:​sudden reduction in number of alleles causing a change in frequencies when a large portion of a population is wiped out randomly ➔ heterospory:​production go two types of spores through different structures ➔ monocots:​plants with one cotyledon

➔ cotyledon:​“seed leaf” stores nutrients and gives them to developing embryos ➔ dicots:​plants with two cotyledons

➔ homology​: ​a similarities between species due to common ancestry ➔ eudicots​: ​true dicots­­monophyletic group that includes most dicots but not all ➔ species:​evolutionarily independent population or group of populations ➔ morphospecies concept:​lineages differ by size, shape or other physical features

➔ biological species concept:​identifies species based on reproductive isolation ➔ heterotrophs: ​animals that obtain compounds from other organisms (eat instead of absorb)

➔ phyla:​major lineage

➔ multicellularity​: differential gene expression; different cells have different structures and functions

➔ phylogenetic species concept:​identify species based on the history of populations and on ancestor/descendent relationships

➔ synapomorphy:​trait found in certain groups and a common ancestor, but is not found in more distant ancestors

➔ phylogenetic tree:​summary of ancestor/descendant relationships ➔ diploblast​:​two types of tissue­­ectoderm and endoderm

➔ homoplasy​:​(same form) similarities between species not derived from common ancestry; arose through different processes and ways (convergent evolution) ➔ convergent evolution:​​natural selection favors similar traits in different species (based on similar ways of life)

Biology 180 Exam 3 Study Guide 

➔ triploblast​:​three types of tissue: endoderm, ectoderm and mesoderm ➔ endoderm​: ​produces the digestive tract

➔ mesoderm​: ​tissue in between ectoderm and endoderm consisting of bone, tissue, circulatory system and some organs

➔ ectoderm​: ​produces covering of the animal on the outside

➔ radial symmetry​: ​spoke symmetry­­at least two planes of symmetry ➔ bilateral symmetry​: ​one plane of symmetry with long narrow bodies ➔ cephalization:​evolution of the head/face with regions for eating, sensing and processing

➔ coelom​: ​fluid filled cavity between inner and outer tubes in bodies and lined with mesoderm­­provides space for circulation of gases and nutrients ➔ hydrostatic skeleton:​​allows soft bodied animals to move without fins or limbs and is possible because of the coelom

➔ segmentation:​​presence of repeated body structures

➔ vertebrates​: m​onophyletic lineage with key feature of segmented backbone ➔ invertebrates:​​paraphyletic group with some segmentation in annelids and arthropods but do not have defining feature of backbone

➔ chordate:​​animals that have four key morphological features at some point in their lives

➔ pharyngeal gills:​​opening in throat (most basal)

➔ dorsal hollow nerve cord:​​composed of neurons that run length of body ➔ notochord:​​stiff and supportive, flexible rod that runs length of body ➔ cranium:​​made of bone, cartilage or fibers that encase the brain ➔ amniotic egg:​​egg with membranes surrounding a food supply, water supply and

area for waste­­present in amniotes and allows for larger offspring to develop ➔ grade​: ​sequence of lineages that are paraphyletic (like fish)

➔ anthropoids:​​human­like monkeys including new and old world monkeys, gibbons and great apes/hominins

➔ primates:​​have hands and feet that grab, flat nails, bigger brains, complex social behavior and color vision with eyes on front of face

➔ hominins: ​large body, no tail, long arms and short legs (chimps, gorillas, humans)

➔ Out­of­Africa Hypothesis:​​suggest Homo sapiens evolved distinct traits in Africa and then continued to spread throughout the world and no interbreeding occurred­­supported by fossil and some molecular evidence, but some molecular evidence rejects hypothesis because of suggested interbreeding

➔ sexual selection:​​natural selection that favors traits that increase individuals ability to mate

➔ intersexual selection:​​when an individual of one gender selects to mate with an individual of the other gender

➔ intrasexual selection:​​selection within a gender, usually in the form of competition for mates

Biology 180 Exam 3 Study Guide 

➔ theory of Fundamental Asymmetry of Sex:​​sexual selection acts on males much more strongly than females because the energy cost of creating a large egg is high while cost of sperm is low

➔ sexual dimorphism​: ​a difference in traits between male and female

➔ altruism​: ​self sacrificing behavior in which the actor is costing itself fitness but the individual whom the action was done for benefits in terms of fitness

➔ Hamilton’s Rule​: (​Br > C) altruistic behavior is likely when fitness benefits are high for recipient, low costs to actor and the altruist and recipient are closely related

➔ coefficient of relatedness:​​probability that the alleles in two individuals are identical by descent

➔ inclusive fitness​: ​combination of direct and indirect fitness

➔ direct fitness​: ​derived from individuals own offspring (parental care)­­parents increase fitness by helping their offspring

➔ indirect fitness​: ​derived from helping relatives increase their fitness than an individual could by itself

➔ kin selection​: ​selection that affects reproductive success of close relatives (shared alleles) increases relatives fitness at cost of individual fitness

➔ reciprocal altruism​: ​exchange of fitness benefits that are separated in time ➔ exponential population growth:​​when r does not change over time (does not depend on number of individuals in pop.)

➔ logistic population growth:​​growth is density dependent and occurs when pop. density gets high, then per capita death rate increases while birth rate decreases and r decreases

➔ carrying capacity​: ​maximum number of individuals in a population that can be supported by a habitat (limited by resources and space)

➔ metapopulation:​​a population made up of smaller isolated populations connected by migration

➔ population dynamics​: ​changes in populations through space and time ➔ population ecology​: ​study of how and why number of individuals in pop. change in time and space

➔ population density​: ​number of individuals per unit area

➔ demography​: ​study of factors that determine size and structure of populations ➔ fecundity​: ​number of female offspring produced by each female in population ➔ survivorship​: ​proportion of offspring produced that survive to certain age ➔ life history​: ​describes how individual uses resources for growth, reproduction, and activities and structures for survival

➔ fertility rate​:​average number of surviving children each woman has in lifetime Speciation

Biology 180 Exam 3 Study Guide 

★ speciation begins when gene flow is reduced or eliminated between populations which causes genetic isolation

★ allopatric speciation: occurs either by vicariance or by dispersal 

○ dispersal: genetic drift creates colonizing population (founder effect) and natural selection in new environment favors certain alleles independently of in other populations

○ vicariance: a new physical barrier separates a species into two or more populations and these populations may continue to diverge through natural selection, mutation and lack of gene flow

★ sympatric speciation occurs through outside events like disruptive selection or through mutation like polyploidization 

○ disruptive selection: species can become reproductively isolated by adapting to different niches through disruptive selection even if they live in the same area and populations further diverge through selection

○ mutation/polyploidization: errors in meiosis leads to doubling of chromosome number whether the chromosomes are from same species (autopolyploidy) or from parents of two different species (allopolyploidy)

■ if autopolyploid can self fertilize, reproduction can resume correctly, or if an error in mitosis occurs that doubles chromosomes again, meiosis can continue

■ speciation by polyploidy is common in plants and occurs VERY fast and is common

History of Life: 

★ Major Innovations: 

○ only the fossil record provides direct evidence about what extinct species look like, where they lived and when the lived

○ limitations of the fossil record: biases regarding habitat, taxonomies and tissue, temporal scale, and abundance of species

○ Life’s Timeline: PreCambrian (Earth formation to appearance of animals) → Phanerozoic Eon (end of Precambrian to present day→ appearance of most animal lineages/first diversifications, then extinction of dinosaurs and domination of plants, then abundance of mammals and angiosperms)

★ Radiations and Extinctions: includes Cambrian explosion and both mass and background extinctions 

○ adaptive radiation: either through ecological opportunity (availability of new resources) or morphological innovation (new traits to allow exploitation of resources in new ways/move differently)

○ Cambrian explosion: rapid adaptive radiation

○ only a few mass extinctions that occur relatively rapidly (most like genetic drift­­extreme bottlenecking); background extinctions occur much slower and occur when mass

extinctions are not occurring

○ impact hypothesis: extinction of dinosaurs via asteroid striking the Earth

○ World Went to Hell hypothesis: extreme global climate change over time (ie high CO2 levels)

★ Rare Earth hypothesis suggests multicellular life requires very rare, specific astrological and geological events to occur at very particular times 

○ suggests simple life may be common, but complex life require specific environments ○ requirements for complex life:

Biology 180 Exam 3 Study Guide 

■ right location in right galaxy

■ right planets surrounding it (a large outer planet like Jupiter for protection)

■ right orbit shape and distance­­stable

■ plate tectonics

■ large moon

■ right timeline of evolution (with right timing of all other environmental conditions) ○ criticism: this hypothesis is explanation for why life arose on this planet, not hypothesis for what could occur on other planets; current technology limits testing for right conditions ○ misconceptions: do not need same Earth conditions for life to arise elsewhere and lots of Earth­like planets have been found so our environmental occurrences are not that rare

Plant Diversification: 

★ land plants are divided into 3 main categories: nonvascular plants, seedless vascular plants and seeded vascular plants 

○ fossil record suggests: evolution green algae → nonvascular plants → seedless vascular plants → seeded vascular plants and each evolved to become less dependent on moist habitats

○ cuticle, stomata and vascular tissue are three key adaptations that allowed for plants to transition to land

○ green algae are paraphyletic, seedless vascular plants are paraphyletic group between nonvascular and seed plants and seed plants are a monophyletic group including gymnosperms and angiosperms

■ seed plants have two key synapomorphies: production of seeds and pollen

★ natural selection favored plants that protected from drying out/dying in 3 main ways: ○ preventing water loss (cuticle and stomata)

○ protection against UV radiation

○ vascular tissues that allowed plants to grow upright to transport water and avoid falling over ★ the evolution of embryophytes and the evolution of seeds, pollen grain and flowers were key to plant reproductive evolution 

○ in angiosperms, the evolution of double fertilization in the flower and evolution of the ovary (protection of female gametophytes) were key innovations

○ embryophyte evolution allowed for embryo to stay protected and nourished by parent plant instead of dropping off embryo immediately like many other organisms

○ flower and fruit production are key synapomorphies for angiosperms

○ directed pollination hypothesis:

■ natural selection favored structures like the ovary and flower to increase probability of pollination of flower (reproduction) as well as rewarding pollinators for carrying

pollen from flower to flower with food in form of nectar

○ in land plant reproduction: sporophytes produce spores by meiosis → spores germinate, divide by mitosis and create gametophytes → gametophytes produce gametes by mitosis → two gametes fuse to make zygote → zygote divides by mitosis into sporophyte

★ summary of land plant adaptation: vascular tissue, stomata and cuticle for growth in dry habitats → diversified traits that allowed sperm to efficiently reach eggs in flowers and help seeds disperse to new locations

Biology 180 Exam 3 Study Guide 

Animal Diversification: 

★ radiation of animals began during Cambrian explosion and animals all have key traits: ○ eukaryotes

○ multicellular and no cell walls

○ heterotrophs

○ move under own power

○ neurons that transmit electrical signals and muscle cells that change body shape ★ Animals evolved through the evolution of main synapomorphies of multicellularity → tissues → bilateral symmetry, cephalization and nervous system → coelom → segmentation ○ origin of multicellularity

■ animals are monophyletic; multicellularity evolved in sponge­like ancestor as

sponges are earliest animal in fossil record and sponges are paraphyletic group

■ root of animal tree is multicellularity

○ origin of tissues: animals are either diploblasts or triploblasts (number of types of tissue) except sponges

■ germ layer consists of ectoderm, endoderm (and mesoderm in triploblasts)

■ diploblasty appears to have originated after multicellularity but before triploblasty ○ origin of bilateral symmetry, cephalization and nervous system

■ body symmetry is KEY morphological aspect of animal body (either radial­­basal­­ or bilateral­­more derived)

■ bilateral symmetry evolution is closely related to cephalization/evolution of head ■ evolution of central nervous system also coincides with evolution of head (sponges have no nerves → the nerve nets → then central nervous system evolution)

○ origin of coelom: (basic bilateral body is tube within a tube design) and segmentation ■ coelom important because allowed for soft bodied animals to move with hydrostatic skeleton (without fins or limbs)

■ segmented backbone is key to defining vertebrates and is hypothesized to allow for specialization of bodies and appendages

Chordate Diversification: 

★ chordates are defined by 4 key morphological features at some point in their lives: pharyngeal gills, dorsal hollow nerve cord, notochord, muscular, post­anal tail (with muscles and goes past the anus) ○ key synapomorphies specifically for chordata: muscular tail, notochord and dorsal hollow nerve cord

★ 3 major lineages of chordates: cephalochordates, urochordates and vertebrates ○ 2 key synapomorphies of vertebrates are bony column of vertebrae along dorsal side of body to protect spinal cord and cranium made of bone, cartilage or fibers that encases brain ○ key innovation of vertebrate evolution: evolution of large 3 part brain protected by hard cranium

★ key innovations of vertebrates as the lineage diversified: 

○ bony exoskeleton, jaws, bony endoskeleton, amniotic egg (key synapomorphy of amniotes­­all tetrapods except amphibians)

★ summary of key synapomorphy evolution in chordates: 

○ pharyngeal gill slits

○ notochord, dorsal hollow nerve cord, muscular post anal tail

○ vertebrae, cranium

Biology 180 Exam 3 Study Guide 

○ jaws

○ lungs, internal bone

○ lobed fins

○ limbs

○ amniotic egg

○ scales with hard keratin

★ key synapomorphy of anthropoids: large brain

★ key synapomorphy of great apes: fist walking

★ bipedalism is key synapomorphy of hominins (monophyletic group of humans and 20 extinct relatives)

★ Out­of­Africa Hypothesis: suggest Homo sapiens evolved distinct traits in Africa then spread throughout the world and that Homo sapiens evolved separately from other Homo species, no interbreeding 

★ summary of key synapomorphy evolution of primates:

○ eyes in front of face, grasping hand

○ larger brain

○ long arms, short legs, no tail

○ fist walking

○ knuckle walking

○ bipedalism

Sexual Selection: 

★ sexual selection is natural selection that favors traits that increase individual’s ability to obtain mates­­(can be intrasexual OR intersexual) 

○ Fundamental Asymmetry of Sex:

■ Pattern: sexual selection acts on males more strongly on males­­traits that attract mates are more elaborate in males

■ Process: costs more energy to create large egg, while sperm takes less energy “eggs are expensive but sperm are cheap”

■ Predictions: females are more choosy about mates and mates should compete with each other more; thus sexual selection should act more strongly on males since

male fitness is limited by finding mates

★ Sexual dimorphism RESULTS from sexual selection→ not same thing

★ Hamilton’s Rule is a formula for predicting the probability that alleles in two individuals are the same as result of close relatedness; suggests altruistic behavior occurs when fitness benefits are high for recipient, costs are low for altruist and both altruist + recipient are close relatives

○ Significance: individuals can pass on their alleles to next generation (increase fitness) by producing own offspring AND helping close relatives (who likely share same alleles) produce their offspring

○ Br > C where r=coefficient of relatedness

★ kin selection and inclusive fitness:

○ kin selection INCREASES overall inclusive fitness (decreases direct fitness, yet increases indirect fitness)

Population Growth:

Biology 180 Exam 3 Study Guide 

★ population’s growth rate is function of birth rates, death rates, immigration rates and emigration rates 

○ difference between birth rate and death rate is the per capita rate of increase (symbolized by r)

★ Exponential population growth: when r does not change​(the RATE of increase is the same but number of individuals added is not) 

○ KEY: this type of growth is DENSITY INDEPENDENT because rate does not depend on number of individuals in population

○ common situations: few individuals in a new population in new habitat OR population is devastated by disaster and must begin regrowing with just a few survivors (this growth can not continue forever)

★ Logistic growth: growth is DENSITY DEPENDENT because as pop. density gets high, birth rate decreases and death rate increases therefore r decreases

○ logistic population growth are essentially changes in the rate of growth as function of pop. size

○ as population approaches carrying capacity​, growth rate slows

★ Populations are limited by both density dependent factors and density independent factors ★ there is a balance between extinction and recolonization in metapopulations​: there are a stable number of individuals in the overall population over time

Human Population Growth and Life Histories: 

★ More and more species are becoming metapopulations because human population is rapidly growing and reducing grasslands/forest habitats

○ range of populations (distributions) are dynamic and always changing as both biotic and abiotic factors change throughout time 

■ KEY: fitness trade offs are always occurring because each individual has restricted amount of time and energy

★ Life tables summarize probabilities that individuals survive and reproduce through lifetimes ○ 3 types of survivorship curves: (1: high survivorship through life; 2: steady curve of same chance of dying and living; 3) extremely high death rates that high survival rates later in life for survivors)

○ net reproductive rates determines whether a population is increasing or decreasing ○ life histories​are often shaped by natural selection so that fitness of individual is maximized

★ Human population growth has been dramatically increasing 

○ future of human population relies on fertility rates­­how many kids each woman decides to have

○ population growth usually only concerns women because number of males typically has no effect on population growth

○ consequences of overpopulation (reaching the carrying capacity of the planet): ■ primary cause of habitat loss and species extinction

■ shortages of resources, political instability, mass movements of people, decline in living standard

Biology 180 Exam 3 Study Guide 

STUDY QUESTIONS:

★ Compare and contrast tracheids and vessels. Which one evolved first and which is the better adaptation?

★ Name and describe the significance of the three key adaptations that occurred in plants and allowed for successful transition onto land.

★ Compare and contrast the zygote and spores in the plants reproductive cycle. (Refer to sections 580­588 and 592­599 in textbook for detail about plants’ reproductive cycles.) ★ Is the Out­of­Africa Hypothesis supported? What evidence suggests it is or it is not supported?

★ How did angiosperms diversify further beyond just the seeded vascular plants? ★ What is the significance of pollination? (Think directed pollination hypothesis) ★ What is the key synapomorphy of hominins? What separates us from other primates? ★ What are the four key morphological features in chordates? How are they present in

humans? What is the significance of the evolution of these features? In other words, what other traits may evolve due to these features?

★ What are the killing mechanisms and predictions for the impact hypothesis and the World Went to Hell hypothesis?

★ Why is the coelom important? Why is this a critical innovation for animals? ★ Why is bilateral symmetry a key morphological aspect of animals? What other innovations occurred as a result or in close association with the evolution of bilateral symmetry?

★ Describe a mechanism for each type of speciation: allopatric and sympatric. What are the consequences of speciation through these mechanisms?

★ Why do biologists believe that the animals most basal common ancestor is sponge­like? ★ What are some key traits specific to animals?

★ How can you tell if a specific trait found in more than one species is due to homology or homoplasy?

★ What are some causes for homoplasy?

★ Explain how natural selection, genetic drift, mutation and gene flow are in effect during speciation, or if they have any influence at all.

★ Describe some limitations of the fossil record. (Think biases.) What effects do these limitations have on what we know about organisms?

★ How do fossils form?

★ What two mechanisms lead to adaptive radiation? How do they occur? ★ What is the difference between a mass and background extinction? ★ Can you redraw the graphs from class showing what a mass extinction vs a background extinction would look like in terms of species present over time?

★ Which evolutionary process is mass extinction most similar to and why? ★ What does the Rare Earth hypothesis suggest are necessary requirements for complex life to arise and be sustained? What are some criticisms for this hypothesis? ★ Do proponents of the Rare Earth hypothesis believe in alien life? Why or why not?

Biology 180 Exam 3 Study Guide 

★ What is the ‘r’ value (coefficient of relatedness) between first cousins? Is this a high r value? Do you think these cousins are closely related enough to engage in altruistic behavior? ★ What is the difference between direct and indirect fitness? Inclusive fitness? Which increases and which decreases when an altruistic behavior occurs?

★ What is the difference between sexual selection and sexual dimorphism? How are they related?

★ Does sexual selection always act stronger on males? Why or why not? ★ Compare and contrast intrasexual selection and intersexual selection. ★ What are some consequences of overpopulation?

★ What is a key factor that the future of the human population size relies on? ★ What are some general trends in species with: a) high survivorship and b) high fecundity?

★ What are the consequences of the Theory of Fundamental Asymmetry of Sex? What predictions does this theory make?

★ Why do fitness trade offs occur?

★ Name and describe at least two types of survivorship curves.

★ What are some density dependent factors and density independent factors? What do the exponential and logistic growth patterns rely on?

★ Would alleles for altruistic behavior continue to be passed on or increase in frequency if there are cheater alleles present in population?

★ What is the importance of Hamilton’s Rule? What are the three criteria for this rule? ★ Describe the pattern and process components of the Fundamental Asymmetry of Sex.

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