Ecology Exam #2

· In the recorded lecture, we reviewed allopatric speciation. How could the temperature fluctuations of the last 400,000 years+ contribute to evolution of salamander diversity in the Appalachians? How does this relate to allopatric speciation?

Going to the base of the tree, to where it all started we see a small deviation. Some 298 million years ago, in the late Carboniferous period an animal was born with the beginning mutations to split away from the lobe finned fishes of the time. From here the animal split into more species, one of which would eventually make the migration from the water to the land, leading to what we now call amphibians. These new land dwellers continued to split for a time just as the continents did. Pangea broke apart and new lands rose from the ocean, while others sank into the sea. Over this course of time the continent of North America was formed. In this new continent there was an area of shallow seas and marshes known as the Appalachian floodplain. However, in the cenozoic era roughly 66 mya this lowland was violently pushed upwards by a great contest between two tectonic plates. The water flowed downhill, the swamps were lifted and we were left with a familiar sight, the Appalachian Mountains. By this time, the amphibians had diverged enough to create the vital Salamander family known as Plethodontidae, the lungless salamanders. With the mountainous stage set, and the players present, this area would become host to one of the most fantastic examples of rapid evolution and speciation seen in the world, as this family of salamanders split into many wonderful unique species. Born from Fire and Ice For centuries salamanders have been misattributed to fire. In the middle ages people assumed that salamanders were born from fire, to be made out of the element itself as they emerged from burning logs. The years went by, and people learned that the salamanders were merely trying to escape from the fire as the logs they hid in were thrown into the flames, however, in a way the salamanders in the Appalachians were born from a certain element; ice. As the basal plethodontid moved into the North American continent it found a vast stretch of virgin habitat, created by the shifting of the plates. Here in the newly formed mountain terrain, the family began to split. Some individuals mutated for more terrestrial woodland habitats, some went into streams, some went to cliffs and others into caves. In the Appalachians the group split into two main subfamilies, Hemidactyliinae and Plethodontinae, or the stream salamanders and the woodland salamander respectively. We well go in depth into these two groups soon, but first, we need to look at what factors lead to the great number of species we see today. Though there is still debate on the issue, the prominent theory for why we see so many salamanders in the mountains today is the growth and decline of glaciers. Before the industrial revolution the planet experienced an endless cyclical dance of hot and cold. The planet would cool and warm, and the glaciers at each pole would advance and retreat throughout these periods. It was this cycle that lead to the diversity of salamanders in this area. Before all this in a time of heavy glaciation in each area there were only a few salamanders. They were generalist, and would inhabit wide ranges. However, when a warm period hit the planet the glaciers receded, and this generalist species had to move to cooler climes. Sometimes this meant moving north, however in a mountain range it often meant moving higher into elevation. And so the salamanders would move higher as the valleys became less habitable. Because of this populations of salamanders would become stranded on tops of mountains, with their relatives stuck on some adjacent mountain top, unable to reach each other. Each of these mountains had different habitats and different needs, and so the salamanders evolved to these habitats in their isolation. Sometimes the salamanders would be isolated on a single hilltop, sometimes isolated to a specific range, however the result was the same. When the world cooled and the glaciers advanced again the salamanders came back together only to find that they could no longer interbreed. This happened time and time again until the mountains were full of new distinct species, all different in their niches and ecology. In some places species inhabited an entire mountain range, while others were restricted to very small, and very specific habitats within the range as a whole. Both the climate and the topography of the region came together to form the perfect backdrop for rapid speciation.

· You should be able to able to think about and offer suggestions for costs/benefits as they relate to life history characteristics - what factors might select for early or late maturation, life span patterns, parental investment

Early Maturation - Benefits Reduced chance of dying before reproduction Shorter generation time Early Maturation - Costs Less energy for growth & long-term survivorship Less investment in individual offspring

· Why are they concerned about species that have environmental determination with climate change?

Climate change is causing the earth and oceans to heat up. There are less places in the world with colder temperatures. In some sea turtles colder temperatures cause eggs to become male. If the temperature doesn't get cold enough to produce males then most of the population will be female. Eventually the species will go extinct because it will be unable to reproduce without the presence of males. Having so few males will lead to inbreeding and expression of negative traits. GENERALLY 50/50 SEX RATIO typical for most species (unless sex environmentally determined)

· What is a species range? What determines a range? How could global climate change impact a species range?

Species Range - region where species found (determined by environmental conditions and presence/absence of other species.)

· Characteristics of lotic freshwater systems (flowing)?

Three main types of freshwater ecosystems 1) Lotic 2) Lentic 3) Freshwater wetlands - lotic: flowing freshwater (streams rivers) characteristic: Drain the landscape, unidirectional flow, continuously changing, lots of microhabitats with diverse organisms specialized for environment.

Define a species and population. Why is variation in a species important?

population: A population is a subset of individuals of one species that occupies a particular geographic area and, in sexually reproducing species, interbreeds. The geographic boundaries of a population are easy to establish for some species but more difficult for others. - species: A biological species is a group of organisms that can reproduce with one another in nature and produce fertile offspring. (defining what makes a species a species is more complex than that. Gray area)

Define chromosomes

- Chromosomes are threadlike structures made of protein and a single molecule of DNA that serve to carry the genomic information from cell to cell. In plants and animals (including humans), chromosomes reside in the nucleus of cells.

· Your reading highlights 4 common misperceptions of evolution - you need to know these and not make these same misperceptions.

- 1. It's just a theory Yes, scientists call it the "theory of evolution", but this is in recognition of its well accepted scientific standing. The term "theory" is being used in the same way that gravitational theory explains why, when an apple falls from your hand, it goes towards the ground. There is no uncertainty that the apple will fall to the ground, in the same way that there is no uncertainty that bugs resistant to antibiotics will continue to evolve if we do not curb our general use of antibiotics. Although people use "theory" in everyday conversation to mean a not necessarily proven hypothesis, this is not the case in scientific terms. A scientific theory typically means a well substantiated explanation of some aspect of the natural world that sits above laws, inferences, and tested hypotheses. - 2. Humans are descended from monkeys What would Darwin make of the fact that people are still misunderstanding his theory?Herbert Rose Barraud (1845-1896), CC BY-SA No, your great-great-great-ancestor was not a monkey. Evolution theory indicates that we have common ancestors with monkeys and apes - among the existing species, they are our closest relatives. Humans and chimpanzees share more than 90% of their genetic sequence. But this common ancestor, which roamed the earth approximately 7m years ago was neither a monkey nor a human, but an ape-like creature that recent research suggests had traits that favoured the use of tools. - Natural selection is purposeful There are many organisms that are not perfectly adapted to their environment. For example, sharks don't have a gas bladder to control their buoyancy (which bony fish typically use). Does this refute the theory of evolution? No, not at all. Natural selection can only randomly favour the best of what is available, it does not purposefully turn all living organisms into one super creature. It would be really convenient if humans could photosynthesise; hunger could be immediately cured by standing in the sun (and the much-sought miracle diet would have been found: stay inside). But alas, the genetic ability to photosynthesise has not appeared in animals. Still, selection of the best option possible has led to an amazing diversity of forms remarkably well adapted to their environments, even if not perfect. - 4. Evolution can't explain complex organs The eye seems to have evolved from primitive, light-sensing organs. TobiasD/pixabay A common argument in favour of creationism is the evolution of the eye. A half developed eye would serve no function, so how can natural selection slowly create a functional eye in a step-wise manner? Darwin himself suggested that the eye could have had its origins in organs with different functions. Organs that allow detection of light could then have been favoured by natural selection, even if it did not provide full vision. These ideas have been proven correct many years later by researchers studying primitive light-sensing organs in animals. In molluscs like snails and segmented worms, light-sense cells spread across the body surface can tell the difference between light and dark. - Religion is incompatible with evolution It is important to make it clear that evolution is not a theory about the origin of life. It is a theory to explain how species change over time. Contrary to what many people think, there is also little conflict between evolution and most common religions. Pope Francis recently reiterated that a belief in evolution isn't incompatible with the Catholic faith. Going further, the reverend Malcom Brown from the Church of England stated that "natural selection, as a way of understanding physical evolutionary processes over thousands of years, makes sense." He added: "Good religion needs to work constructively with good science" and vice-versa. I fully agree.

· We discussed the Trinidadian guppy experiment (figure shown in class) which demonstrated evolutionary change in the life history traits of this species in just 11 years. What were the patterns shown in the populations and what are some possible explanations for why those patterns exist?

- 1. the presence of predators causes the male guppy size to be smaller, the offspring volume to be larger, the offspring number to be relatively large and the embryo mass to be quite small. 2. High predation will cause the weight mass of the adults and embryos to be less, because they will mature faster and will need to conserve the amount of energy required to grow. The number of offspring will be higher in an area of high predation because not all the offspring will survive to maturity so there needs to be a larger number so a least some survive. 3. Tradeoffs helps the population of guppies survive and reproduce successfully. - High predation risk causes the guppies to have a higher density of offspring, but the offspring and embryos are smaller. Low predation risk causes them to have fewer offspring and embryos, but they are larger. This makes sense because larger offspring with longer maturation require more parental care. With a high predation risk, it makes sense to have more offspring so that there is a greater chance of some of them surviving to maturity, which allows them to produce offspring of their own.

What is the founders' effect? Know examples and impacts.

- A founder effect, as related to genetics, refers to the reduction in genomic variability that occurs when a small group of individuals becomes separated from a larger population. - A smaller group being separated permanently from a larger population is a classic example of the founder effect. These 500 members likely have far less genetic diversity than the larger population, so the subsequent population that develops will only contain alleles found in these 500 members. One trait that common in this population might not be common in the original population. - The founder effect (extreme example of drift) • When a small group of individuals breaks off from a larger population to establish a new colony • Can lead to inbreeding depression -

· What is a theory? Why do you think evolution via natural selection is ranked among the top ten scientific theories of science?

- A theory is a carefully thought-out explanation for observations of the natural world that has been constructed using the scientific method, and which brings together many facts and hypotheses. A theory never becomes a fact. It is an explanation of one or more facts. A well-supported evidence-based theory becomes acceptable until disproved. It never evolves to a fact, and that's a fact. - Theory of Evolution - foundational to Biology: supported by the facts of natural history and molecular biology genetics, testable by observation and experiment - many experiments have been run that explore the theory of evolution and they all point to the same conclusion. That populations evolve. When a theory is tested over and over it became accepted as based in science/noteworthy.

define alleles

- Allele" is the word that we use to describe the alternative form or versions of a gene. People inherit one allele for each autosomal gene from each parent, and we tend to lump the alleles into categories. Typically, we call them either normal or wild-type alleles, or abnormal, or mutant alleles.

What is allopatric speciation - why is it easier for species to emerge in this way than through sympatric speciation? How can polyploidy result in sympatric speciation?

- Allopatric speciation:

· Why are estuaries so rich, biologically?

- An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments and are an example of an ecotone. - Many different types of plant and animal communities call estuaries home because their waters are typically brackish — a mixture of fresh water draining from the land and salty seawater. This unique combination of salty and fresh water creates a variety of habitats. - The salinity gradient and the changes in tides, fresh water and accompanying flux in nutrients within estuaries create a variety of habitats that support a diverse food web. The differences in concentrations of other nutrients in both fresh and seawater also play an important part in creating gradients and encouraging biodiversity in estuaries.

What is anisogamy and how does it relate to the fact that males are often showier, larger and non-selective in mate choice.

- Anisogamy - differences in gamete size lead to differences in number of offspring that can be produced

What did we learn from Archaeopteryx? Tiktaalik?

- Archaeopteryx: transitional fossil for birds - We have evidence that some dinosaurs had feathers. Feathers evolved before the ability of flight. Early function of feathers could have been for insulation or mating displays/communication. Eventually feathers became modified for flight (co-opted) - Co-option: feathers played different roles at first, and then were modified for flight. The modification of an existing structure for a new use. Bird wings are modified forelimbs once used of grabbing and feeding. - Tiktaalik is technically a fish, complete with scales and gills — but it has the flattened head of a crocodile and unusual fins Its fins helped it swim, but also have sturdy interior bones that would have allowed Tiktaalik to prop itself up in shallow water Has a combination of features that show the evolutionary transition between swimming fish and their descendants, the four-legged vertebrates. All tetrapods have the same bone fracture in their limbs. (the person who discovered the tiktaalik wrote a book called The Inner Fish.)

· The video lecture by Renee focuses in on the evidence that Darwin (and Wallace) were exposed to in their travels (fossils, biogeography - eg patterns on Galapagos), in their readings (Lyell's geology, Malthus's treatise on populations) and in their experiences as people interested in biology (artificial selection and breeding, anatomical and embryological patterns of vertebrates) and how these led Darwin (and Wallace) to conclude that evolution via natural selection was a better way to explain patterns of life on earth. You need to understand these observations, facts, readings and how they pointed in the direction of evolution via natural selection.

- Both believe in Creationism as the force that explains species origins. BUT travels and reading compel them towards the theory of evolution via natural selection Charles Darwin and Alfred Russel Wallace were both investing the processes we later associate with the theory of evolution. - Darwin is remembered as the person who came up with evolution, Darwin and Wallace independently and simultaneously came up with the theory of evolution. Darwin is remembered over Wallace because Darwin came from a wealthy family and Wallace came from a poor family. (Evidence they observed) - Fossils: Pattern: extinct species resemble living species in the same region - Transitional fossils such as Archaeopteryx and Tiktaalik - biogeography: distribution of living species. Biogeography, the study of the geographical distribution of organisms, provides information about how and when species may have evolved. Fossils provide evidence of long-term evolutionary changes, documenting the past existence of species that are now extinct. Today, the camel family includes different types of camels (Figure 9.3.69.3.6). All of today's camels are descended from the same camel ancestors. These ancestors lived in North America about a million years ago. Early North American camels migrated to other places. Some went to East Asia via a land bridge during the last ice age. A few of them made it all the way to Africa. Others went to South America by crossing the Isthmus of Panama. Once camels reached these different places, they evolved independently. They evolved adaptations that suited them for the particular environment where they lived. Through natural selection, descendants of the original camel ancestors evolved the diversity they have today. (Llamas are related to camel species) - patterns on the Galapagos: Darwins fiches. In Darwin's finches, those that have short beaks turned out to be an adaptation that made them more suited into poking holes in the ground and feed on grubs. 3. Darwin's finches are an example of how natural selection caused variation of beaks among finches. During a storm a small population of fiches were blown out to the islands from the mainland. over time that population grew and evolved into separate species. There are 18 species of Darwin finches and they all evolved from a single species of finch from the mainland. Also Galapagos tortoises also show something similar. - selective breeding: Darwin's pigeons. - similar bone/body structures. Think of your arm. (digits, lost a small wrist bones, two bones, one bone) - Lyell was fundamental in establishing the popularity and credibility of geology as a science in the nineteenth century. He was the author of the book 'Principles of Geology', which was published in three volumes between 1830 and 1833 (and multiple revised editions thereafter). Believed the earth formed millions, billions of years ago through version and weathering. - A key portion of the book was dedicated to what is now known as the Malthusian Law of Population. The theory claims that growing population rates contribute to a rising supply of labour and inevitably lowers wages. In essence, Malthus feared that continued population growth lends itself to poverty. Malthus specifically stated that the human population increases geometrically, while food production increases arithmetically. Under this paradigm, humans would eventually be unable to produce enough food to sustain themselves. He hated poor people. His beliefs are reminiscent of Eugenics movement ideology.

How is genetic drift related to inbreeding? What is an inbreeding depression?

- Bottleneck Effect (extreme type of genetic drift) Only a few individuals from a population survive to have offspring after an event What has happened to the gene pool available within the remaining population? Are they as genetically diverse? If their environmental conditions (food supply, climate, predators, etc.) change, are they going to be able to adapt? - Can lead to Inbreeding depression• Genetic variation is reduced within a breeding population Close relatives produce offspring which results in reduced success/fitness of offspring Increases likelihood of negative recessive traits being expressed

· What is convergent evolution? - why is this a pattern between organisms found in the same biome in different regions of the world?

- Convergent evolution is the process by which two species develop similar features despite not sharing a recent common ancestor. Evolutionary biologists explain these similar characteristics as the product of natural selection. By sharing similar ecological niches, the two unrelated species benefit from developing the same functional characteristics. Convergent evolution occurs in all biological kingdoms, and it is particularly noticeable in plant species and animal species. The only requirement is that two species, lacking a common ancestor, undergo independent evolution that results in similar body forms or similar useful traits. - Flying animals: Birds, bats, and insects all developed wings via different evolutionary paths. For example, hummingbird hawk moths (a type of insect) strongly resemble hummingbirds and have wings that allow them to hover while collecting nectar from flowers. While both species are distinct, their wings shapes converged on a similar evolutionary trajectory.

· What is coral? Who makes it? What is the symbiotic relationship that sustains this biome? What is coral bleaching and WHY is occurring? What impact could coral loss have on the earths ecosystems?

- Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and secrete calcium carbonate to form a hard skeleton. - Coral reefs are built by coral polyps as they secrete layers of calcium carbonate beneath their bodies. The corals that build reefs are known as "hard" or "reef-building" corals. Soft corals, such as sea fans and sea whips, do not produce reefs. A coral polyp is an invertebrate that can be no bigger than a pinhead to up to a foot in diameter. Each polyp has a saclike body and a mouth that is encircled by stinging tentacles. The polyp uses calcium carbonate (limestone) from seawater to build a hard, cup-shaped skeleton. - The relationship between coral and zooxanthellae (algae), is one of the most important mutualistic relationships within the coral reef ecosystem. Zooxanthellae are microscopic, photosynthetic algae that reside inside the coral. The hard coral provides protection, as well as compounds needed for photosynthesis to occur. The corals and algae have a mutualistic relationship. The coral provides the algae with a protected environment and compounds they need for photosynthesis. In return, the algae produce oxygen and help the coral to remove wastes. - When water is too warm, corals will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white. This is called coral bleaching. When a coral bleaches, it is not dead. Corals can survive a bleaching event, but they are under more stress and are subject to mortality. Bleaching leaves corals vulnerable to disease, stunts their growth, affects their reproduction, and can impact other species that depend on the coral communities. Severe bleaching kills them. The average temperature of tropical oceans has increased by 0.1˚ C over the past century. - Coral reefs are known as "the rainforests of the sea" and provide a quarter of marine species with habitat and food. If coral reefs disappeared, essential food, shelter and spawning grounds for fish and other marine organisms would cease to exist, and biodiversity would greatly suffer as a consequence

General characteristics of Deserts

- Deserts are areas that receive very little precipitation. People often use the adjectives "hot," "dry," and "empty" to describe deserts, but these words do not tell the whole story. Although some deserts are very hot, with daytime temperatures as high as 54°C (130°F), other deserts have cold winters or are cold year-round. And most deserts, far from being empty and lifeless, are home to a variety of plants, animals, and other organisms. People have adapted to life in the desert for thousands of years.One thing all deserts have in common is that they are arid, or dry. Most experts agree that a desert is an area of land that receives no more than 25 centimeters (10 inches) of precipitationa year. The amount of evaporation in a desert often greatly exceeds the annual rainfall. In all deserts, there is little water available for plants and other organisms.Deserts are found on every continent and cover about one-fifth of Earth's land area. They are home to around 1 billion people—one-sixth of the Earth's population.Although the word "desert" may bring to mind a sea of shifting sand, dunes cover only about 10 percent of the world's deserts. Some deserts are mountainous. Others are dry expanses of rock, sand, or salt flats. - They are mainly found around 30 to 50 degrees latitude, called the mid-latitudes. These areas are about halfway between the equator and the north and south poles. Remember that moist, hot air always rises from the equator. As this air climbs higher in the sky, it cools. Geographically speaking, most deserts are found on the western sides of continents

define dominant and recessive traits

- Dominant refers to the relationship between two versions of a gene. Individuals receive two versions of each gene, known as alleles, from each parent. If the alleles of a gene are different, one allele will be expressed; it is the dominant gene. The effect of the other allele, called recessive, is masked. - Individuals inherit two versions of each gene, known as alleles, from each parent. In the case of a recessive trait, the alleles of the trait-causing gene are the same, and both (recessive) alleles must be present to express the trait. A recessive allele does not produce a trait at all when only one copy is present. - Think of Punnett squares.

· Ash trees are dying on our campus - because of the emerald ash borer - you should know the story. What is the range of the EAB? Why has it been so problematic? What impact has it had on Fraxinus (ash) trees in NA?

- EAB larvae kill ash trees by tunneling under the bark and feeding on the part of the tree that moves water and sugars up and down the trunk. And it's really good at the job. In fact, millions of ash trees both in Canada and the United States have been completely decimated. - Range of EAB: https://entnemdept.ufl.edu/creatures/TREES/BEETLES/emerald_ash_borer.htm - The EAB is problematic because its killing Ash trees at a rate in which they cannot recover from and their population size is growing at an alarming rate because they have no natural predators here. - Less Ash trees are surviving and reproducing offspring.

Be sure to watch the linked evolution of birds video - What were original functions of feathers and what organisms had them?

- Feathers were used for isolation in cold temperatures and as a communication method during mating rituals. - Theropods are the type of dinosaurs that birds are descended from.

How can Handicap Principle, Sexy son hypothesis, Parasite Mediated Sexual Selection explain the evolution of bright colors and extreme traits (like super long tail in a peacock?)

- Handicap Principle: Males with extreme traits have survivorship deficit. Thus the males must have good genes. An example of this is the male peacock. It has bright feathers, which decease its change of survival but indicate it is healthy and has enough nutrients to produce beautiful feathers. - Parasite mediated sexual selection: males that look good must have fewer external parasites and a better immune system. If the birds are health, their bodies have the resources to make beautiful feathers. - sexy son hypothesis: females son will have higher reproductive success. if her mate has nice feathers he will have a higher reproductive success. If the son inherits these good genes that produce nice feather he too will have a higher reproductive success.

· How do dispersal patterns influence populations' geographic range and ability to colonize new habitats (if introduced)? How does dispersal relate to wildlife corridors?

- Important characteristics of population distributions Geographic Range Dispersal Ability Dispersion - spacing of individuals in population Population density 1. Geographic Range 2. DispersalAbility 3. Dispersion - spacing of individuals in population dictated by species biology influences density estimates There are three types of population distributions shaped by dispersion: - clustered - evenly spaced - random - Wildlife corridors are defined as narrow strips of land that differs, usually in terms of dominant vegetation, from the surrounding area. They serve as traveling avenues for wildlife species between two similar yet fragmented habitat areas, and provide important sources of food and cover for many species. - TODAY: Humans fragment ranges by altering landscape....small populations isolated and inbreeding can occur Habitat corridors - enhance Dispersal of some populations

· Catch per unit effort is used in fisheries - how does it work? Why are improvements in technology so problematic for this estimate of populations?

- In fisheries and conservation biology, the catch per unit effort (CPUE) is an indirect measure of the abundanceof a target species. Changes in the catch per unit effort are inferred to signify changes to the target species' true abundance. A decreasing CPUE indicates overexploitation, while an unchanging CPUE indicates sustainable harvesting.[1] - CPUE is calculated by dividing the catch of each fishing trip by the number of hours fished during that trip. This gives CPUE in units of kilograms per hour.

What is intersexual selection? What does the choosy sex (often females) gain from being choosy? What is mate guarding? Sperm competition?

- Intersexual selection - selection for qualities that make one sex (usually male) attractive to the choosier sex (usually female) • Males are often colorful, perform displays, give gifts, may build structures or nests to attract females - What do females gain by being choosy? 1. Material resources - territory, food 2. Good genes for offspring - Mate Guarding: Mate guarding — a male staying near a female for a while after mating — has traditionally been interpreted in the context of sexual conflict. New observations of wild field crickets suggest instead that guarding males provide protection from predators, enhancing female fitness. the Males goal is to prevent other males from mating with her. Mate guarding is generally performed when females are at their most fertile (Birkhead, 1998b) and experimentally removing males from their mate during this period results in the female engaging in more extra-pair copulations with rival males, which in turn results in increased rates of extra-pair paternity. - Sperm competition: This about northern right whales. As a population northern right whales are all very similar genetically. Low genetic diversity. A female will mate with many males and the sperm will compete to reach the egg in her uterus. The sperm selected for is one what has some good genes/some genetic variation. Northern Right Whales use sperm completion to increase gene diversity in their population. -Sperm competition occurs whenever females mate multiply and ejaculates from different males overlap and compete for fertilization, and is virtually ubiquitous throughout the animal kingdom. Transfer of many sperm is advantageous in sperm competition, but the cost of sperm production favors male ejaculate tailoring.

· Why are introduced species from the same biome particularly problematic?

- Invasive species from same biome particularly devastating!Population Growth & Invasive species. - The direct threats of invasive species include preying on native species, outcompeting native species for food or other resources, causing or carrying disease, and preventing native species from reproducing or killing a native species' young. - Because they are adapted to that type of environment but do not have any natural predators to keep them in check in that new location.

· Generally, where are the biomes located? WHY are they located in these regions - can you tie that back into your understanding of factors that set up major global climate patterns (tilt, differential heating, proximity to oceans, landmass size, etc.)

- Latitude, humidity, and biodiversityRecall that relative humidity is a measure of how much water vapor an air mass contains relative to how much it can contain. From the poles to the equator, humidity, and the biodiversity of plants and animals increase. Biodiversity refers to the measure of the variety and number of organisms that live in an area.Sunlight at the equator vs. high latitudesEarth is hottest near the equator where the Sun is closest to being directly overhead year round. At the north and south poles, temperatures are much colder. This effect is related to the fact that light travels in straight parallel lines. To demonstrate what is happening, imagine shining a flashlight on a sheet of paper (Figure 6.19). The light makes a bright, small spot. By tilting the paper, you can make the light spot bigger and less intense. Latitude and solar radiationAt the equator, sunlight is direct and intense. Earth's north and south poles are tilted away from or toward the Sun depending on the time of year. The locations of the poles relative to the Sun and Earth's spherical surface mean that sunlight reaching these areas is spread out and less intense (Figure 6.19). As a result, the average yearly temperature at the equator is 27 °C (80 °F), while at the North Pole it is -18 °C (0 °F). Generally, as latitude (or distance from the equator) increases, the amount of incoming solar radiation decreases. - Temperatures in inland regions Have you ever wondered why cities near the ocean don't get as hot in the summer or as cold in the winter as inland cities at the same latitude? Portland, Oregon and Minneapolis, Minnesota are two cities near the same latitude (Figure 6.20). Look at Table 6.1 below to see the average daily temperature ranges for these cities. -Water helps regulate temperature The differences in temperature between the two cities have to do with water. Because of its higher specific heat, water warms up and cools down slowly. In contrast, land warms up and cools down quickly because of its lower specific heat. Therefore, regions near water—like Portland—do not have extremely hot or cold weather. Elevation Latitude is an important factor in defining a biome. However, elevation is also a factor. Elevation is the height or distance of an object or area from sea level. The range of biomes that exist on Earth from the equator to the poles also exists if one goes from the bottom of a mountain to the top of a mountain

What are life history characteristics -- Age and size at maturity, # of offspring (fecundity), life span (longevity), sex ratio, care, parity

- Life History Traits Schedule of individuals growth, development, reproduction, and survival, Age and size at maturity (reproduction) Fecundity (number of offspring produced) Parity (number of reproductive episodes) Parental investment Longevity (life span) Sex ratio (number of males and female)

define macroevolution and microevolution

- Macroevolution - change at higher taxonomic levels - Macroevolution refers to evolution of groups larger than an individual. Macroevolution encompasses the grandest trends and transformations in evolution, such as the origin of mammals and the radiation of flowering plants. Ex: birds evolving from dinosaurs. - Microevolution: Change at the population scale. Microevolution is defined as changes in the frequency of a gene in a population. These are subtle changes that can occur in very short periods of time, and may not be visible to a casual observer. - Ex: microevolution: Some examples of microevolution through the process of natural selection are herbicide resistance, pesticide resistance, antibiotic resistance and so on. Few other generally noticeable evolutionary instances of microevolution are the bacterial strains incorporating the property of resistance to antibiotics.

· Some species have environmental determination of sex - be able to interpret figures that show how patterns of sex relate to ambient temperature.

- Many species of reptiles (and fish) rely on environmental factors to determine the sex of embryos. Temperature is by far the most common environmental characteristic that determines sex in certain species of reptiles, but recent research has also shown that other factors (e.g., egg size) can influence sex ratios. - One of the best-studied reptiles is the European pond turtle, Emys obicularis. In laboratory studies, incubating Emys eggs at temperatures above 30°C (86F) produces all females, while temperatures below 25°C (77F) produce all-male broods. The threshold temperature (at which the sex ratio is even) is 28.5°C (83.3F)

define mutation

- Mutations are changes in an organism's DNA code and are the original source of genetic diversity • Mutations create different versions of genes called alleles - Example: Dog breeds being different sizes. The original dog genome had to have different versions of genes for size/body type in oder for different phenotypes to be possible. - Mutations are essential to evolution. Every genetic feature in every organism was, initially, the result of a mutation. The new genetic variant (allele) spreads via reproduction, and differential reproduction is a defining aspect of evolution.

What role does sexual reproduction play in generating variation in a population?

- Sexual reproduction has the potential to produce tremendous genetic variation in offspring. This variation is due to independent assortment and crossing-over during meiosis, and random union of gametes during fertilization. - your getting genes from two sources. not just one. - understand meiosis and mitosis.

· What is the difference between social monogamy and genetic monogamy? What are the costs and benefits of extra pair copulations?

- Social monogamy: Social monogamy in mammals is defined as a long term or sequential living arrangement between an adult male and an adult female (heterogeneous pair). This is used to parental care of offspring. Increase offsprings chances of survival. It should not be confused with genetic monogamy, which refers to two individuals who only reproduce with one another. - Genetic monogamy: Genetic monogamy refers to a mating system in which fidelity of the bonding pair is exhibited. Though individual pairs may be genetically monogamous, no one species has been identified as fully genetically monogamous. - Extra pair copulations: Extra-pair copulation is a mating behaviour in monogamous species. Monogamy is the practice of having only one sexual partner at any one time, forming a long-term bond and combining efforts to raise offspring together; mating outside this pairing is extra-pair copulation. Extra-pair copulations = mating with someone other than the social partnerBenefits: enables males to sire more offspring, creates more genetic variability in population. Createsmoregeneticvariation Neighboringmalesmayhave better genes than her mate - see the figure Maybe social partner is better at parenting but neighbor has better genes for immunity, other health benefits. Costs: Costs of extra-pair copulations for females potentially involve a decrease in paternal care, since the number of own offspring and therefore the reproductive value of a brood decreases for cuckolded males. Females, on the other hand, have to invest a lot more in their offspring; extra-pair copulations produce a greater cost because they put the resources that their mate can offer at risk by copulating outside the relationship

define polyploidy

- Speciation event arising from problems with meiosis (formation of gametes). - during meiosis, homologous chromosomes may fail to separate, resulting in a polyploidy event - offspring can't mate with the original population, so its a different species. - Triploid organisms are sterile unless they reproduce asexually - clones. - Ex: Polyploidy also occurs commonly in amphibians; for example the biomedically important genus Xenopus contains many different species with as many as 12 sets of chromosomes (dodecaploid).[43] Polyploid lizards are also quite common. Most are sterile and reproduce by parthenogenesis;[citation needed]others, like Liolaemus chiliensis, maintain sexual reproduction. Polyploid mole salamanders (mostly triploids) are all female and reproduce by kleptogenesis,[44] "stealing" spermatophores from diploid males of related species to trigger egg development but not incorporating the males' DNA into the offspring.

define speciation, sympatric speciation, allopatric speciation

- Speciation: Speciation occurs when a group within a species separates from other members of its species and develops its own unique characteristics. The demands of a different environment or the characteristics of the members of the new group will differentiate the new species from their ancestors. - Sympatric speciation - species formation without geographic barrier. EXAMPLE: African cichlids -speciation because of microhabitat preferences Over time, different groups of cichlids became isolated, even though they shared a body of water Eventually stopped interbreeding and became separate species - Allopatric speciation: evolution of a species in geographic isolation. ex: When Arizona's Grand Canyon formed, squirrels and other small mammals that had once been part of a single population could no longer contact and reproduce with each other across this new geographic barrier. They could no longer interbreed. The squirrel population underwent allopatric speciation.

Know stabilizing, directional and disruptive selection

- Stabilizing selection is the opposite of disruptive selection. Instead of favoring individuals with extreme phenotypes, it favors the intermediate variants. Stabilizing selection tends to remove the more severe phenotypes, resulting in the reproductive success of the norm or average phenotypes. Classic examples of traits that resulted from stabilizing selection include human birth weight, number of offspring, camouflage coat color, and cactus spine density. - Directional selection occurs when individuals with traits on one side of the mean in their population survive better or reproduce more than those on the other. It has been demonstrated many times in natural populations, using both observational and experimental approaches. An example of directional selection is fossil records that show that the size of the black bears in Europe decreased during interglacial periods of the ice ages, but increased during each glacial period. Another example is the beak size in a population of finches. - Disruptive selection, also called diversifying selection, describes changes in population genetics in which extreme values for a trait are favored over intermediate values. In this case, the variance of the trait increases and the population is divided into two distinct groups. For example, if both short and tall organisms, but not medium height organisms were favored this would be disruptive selection in action.

· What is turnover? How does it happen and WHY does it happen in temperate (and sometimes polar) lakes but not in tropical lakes? How does turnover impact life in these bodies of water?

- Stratification — the condition of a lake or pond when the warmer, less dense surface water floats on the cooler, denser water below. - What you are experiencing is thermal stratification—when lakes "divide" into different layers of density due to differing temperatures. When spring turns to summer, most Canadian lakes, including those at IISD Experimental Lakes Area, experience both thermal stratification and lake turnover. These phenomena are very important for many aquatic organisms and allow for lake ecosystems to thrive. - Spring to Summer: Lakes begin to stratify due to differences in temperature Thermal stratification occurs when the water in a lake forms distinct layers through heating from the sun. When the ice has melted in the spring, solar radiation warms the water at the surface of the lake much faster than in deeper waters. In fact, sunlight often only penetrates a few metres into the lake, directly warming just the top few metres. As the water warms, it becomes less dense and remains at the surface, floating in a layer above the cooler, denser water below. - Lake turnover is a phenomenon whereby the entire volume of water in a lake is mixed by wind. This can only happen when the entire lake is the same temperature (and density!), which in northwestern Ontario (home to IISD-ELA) generally occurs two times per year—once in the spring after the ice melts, and once in the fall before ice forms. - Lake turnover is extremely important in freshwater lakes, as it is the event that is responsible for replenishing dissolved oxygen levels in the deepest lake waters. When the lakes are a uniform temperature and density, it takes relatively little wind energy to mix water deep into the lake. Wind moves highly oxygenated surface water to the lake bottom, forcing low oxygen water from the lake bottom up to the surface where it becomes saturated with oxygen. This is critical for aquatic organisms, as once the lakes freeze over for the winter, no new oxygen gets mixed into the lake from the atmosphere, and what is in the lake must last until ice goes off in the spring. Spring turnover is important for the same reason. Once thermal stratification sets up, hypolimnetic waters do not get mixed to the surface and whatever dissolved oxygen exists in the deepest parts of the lake is all that is available until lake turnover in the fall. - Tropical lakes don't freeze, so they don't undergo spring turnover in the same way temperate lakes do.

· What are survivorship curves? What do they show? You should be able to interpret curves and make predictions about fecundity and maturation patterns (from recorded lecture)

- Survivorship curves are graphs that show what fraction of a population survives from one age to the next. - here are three types of survivorship curves. Type I curves depict individuals that have a high probability of surviving to adulthood. Type II curves depict individuals whose chance of survival is independent of age. Type III curves depict individuals that mostly die in the early stages of their life. - Ecologists use survivorship curves to visualize how the number of individuals in a population drops off with time. In order to measure a population, ecologists identify a cohort, which is a group of individuals of the same species, in the same population, born at the same time. - Fecundity: # offspring (fecundity). Fecundity is the ability to produce offspring. It can also describe the reproductive rate of an individual organism. Fecundity can be influenced by the availability of resources and the presence of potential mates. - Maturation patterns: Animals that mature slowly are bigger and reproduce less offspring. The size of their embryo/egg/child tend to be large as well. They usually also invest a lot of time into parental care. Maturation patterns that look like this happen when there is less pressure to survive. (less predation) Animals that mature faster happen to be smaller and produce many offspring. The size of their embryo/egg/child smaller too. They usually invest less time into parental care. This type of maturation occurs in environments with high predation.

General characteristics of Temperate Deciduous Forests

- Temperate deciduous forests are located in the mid-latitude areas which means that they are found between the polar regions and the tropics. The deciduous forest regions are exposed to warm and cold air masses, which cause this area to have four seasons. The temperature varies widely from season to season with cold winters and hot, wet summers. The average yearly temperature is about 10°C. The areas in which deciduous forests are located get about 750 to 1,500 mm of precipitation spread fairly evenly throughout the year. During the fall, trees change color and then lose their leaves. This is in preparation for the winter season. Because it gets so cold, the trees have adapted to the winter by going into a period of dormancy or sleep. They also have thick bark to protect them from the cold weather. Trees flower and grow during the spring and summer growing season. Many different kinds of trees, shrubs, and herbs grow in deciduous forests. Most of the trees are broadleaf trees such as oak, maple, beech, hickory and chestnut. There are also several different kinds of plants like mountain laurel, azaleas and mosses that live on the shady forest floor where only small amounts of sunlight get through.

General characteristics of Temperate Grasslands (cold deserts)

- Temperate grasslands are found throughout central North America, where they are also known lands have pronounced annual fluctuations in temperature with hot summers and cold winters. as prairies, and in Eurasia, where they are known as steppes (Figure 8 below). Temperate grass‐ The annual temperature variation produces specific growing seasons for plants. Plant growth is summer, and fall.possible when temperatures are warm enough to sustain plant growth, which occurs in the spring, Annual precipitation ranges from 25.4 cm to 88.9 cm (10-35 in). Temperate grasslands have few consist of grasses. The treeless condition is maintained by low precipitation, frequent fires, and trees except for those found growing along rivers or streams. The dominant vegetation tends to packed with the roots and rhizomes (underground stems) of these grasses. The roots and rhizomes grazing. The vegetation is very dense and the soils are fertile because the subsurface of the soil is act to anchor plants into the ground and replenish the organic material (humus) in the soil when they die and decay. Fires, which are a natural disturbance in temperate grasslands, can be ignited by light‐ ning strikes. It also appears that in North American grasslands the lightning-caused fire regime was enhanced by intentional burning by humans. When fire is suppressed in temperate grasslands, the vegetation eventually converts to scrub and dense forests. Often, the restoration or management of temperate grasslands growth of trees and maintain the grasses. requires the use of controlled burns to suppress the growth of trees and maintain the grasses.

What is the Red Queen Hypothesis? Why do we see higher rates of sexual reproduction in populations that are experiencing high rates of parasitism and/or pathogens?

- The Red Queen hypothesis was coined in evolutionary biology to explain that a species must adapt and evolve not just for reproductive advantage, but also for survival because competing organisms also are evolving. - sexual reproduction is a way for a population to stay one step ahead of the fast evolving parasites/pathogens that target them.

General characteristics of Boreal Forests

- The boreal forest, also known as the taiga, covers about 11% of the land mass of this planet. This makes it the world's largest terrestrial biome! It is located in the northern hemisphere, approximately between the latitudes of 50° N - 65° N. The term "boreal forest" tends to mean the more southern part of the biome, while the term "taiga" tends to mean the more northerly part of the biome where it transitions to the tundra. Description This biome is known for its coniferous (cone-bearing evergreen) forests and many freshwater bodies in the form of rivers, lakes, bogs, fens and marshes. Overall, the soil has relatively low fertility, which means that it is not good for growing plants. Most of the nutrients occur in the upper layer of the soil where organic matter is found. The soil also tends to be slightlyacidicacidic because of the breakdown of evergreen needles when they fall to the ground and decompose. The boreal forest has cold winters and relatively warm summers. Typical temperatures range from 21 °C in summer down to -54 °C in winter. Precipitation is moderate, averaging around 200-600 mm per year, and droughts are relatively rare.

General characteristics of Scrub forests/Woodlands (aka Chaparral - Mediterranean woodlands)

- The chaparral is also called scrub forest and is found in California, along the Mediterranean Sea, and along the southern coast of Australia (Figure 7 below). The annual rainfall in this biome ranges from 65 cm to 75 cm (25.6-29.5 in) and the majority of the rain falls in the winter.arral vegetation is dominated by shrubs and is adapted to periodic fires, with some plants produc‐ Summers are very dry and many chaparral plants are dormant during the summertime. The chap‐ing seeds that germinate only after a hot fire. The ashes left behind after a fire are rich in nutrients nance of this biome.like nitrogen and fertilize the soil, promoting plant regrowth. Fire is a natural part of the maintenance of this biome. - Chaparrals can be found from 30° to 50° N and 30° to 40° S latitudes. The chaparral climate occurs in central and southern coast of California; the coast areas of the Mediterranean Sea; coastal western and southern Australia; the Chilean coast in South America, and the Cape Town region of South Africa.

What is the cost of meiosis?

- The loss of half an animal's genetic material when it produces haploid gametes - the female that uses asexual reproduction contributes eight copies of her genes (b) In contrast, the female that uses sexual reproduction only contributes four copies of her genes - An asexual mother transmits her entire genome to her offspring; a sexual mother transmits on average only one-half of her genetic material to her sons and daugh- ters, the other half being provided by her mate. This cost has been called the cost of meiosis (Williams 1975) or the cost of ge- nome dilution (Lewis 1987).

· What is population density? How does this impact our ability to estimate density?What is the relationship between animal size and density?

- The number of individuals living within that specific location determines the population density, or the number of individuals divided by the size of the area. Population density can be used to describe the location, growth, and migration of many organisms. On average, large-bodied species live at lower densities than small-bodied ones. Early studies suggested that population densities might scale so that the energy use of a population is independent of body size. Density - # individuals/unit area -

What are transitional fossils? How do they relate to our understanding of Macroevolution?

- Transitional fossils: A transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group.[1]This is especially important where the descendant group is sharply differentiated by gross anatomy and mode of living from the ancestral group. These fossils serve as a reminder that taxonomic divisions are human constructs that have been imposed in hindsight on a continuum of variation. Because of the incompleteness of the fossil record, there is usually no way to know exactly how close a transitional fossil is to the point of divergence. Therefore, it cannot be assumed that transitional fossils are direct ancestors of more recent groups, though they are frequently used as models for such ancestors. - Transitional fossils are remnants of an organism that came in between a known version of a species and the current species. Allegedly, transitional fossils would be evidence for evolution because it would show intermediate forms of a species and they changed and accumulated adaptations at a slow pace.

· What species would be good to use quadrat and linear sampling for population density estimates?

- Tree populations in a forest. - Sampling of plants or slowly moving animals (such as snails)can be done using a sampling square called a quadrat. A suitable size of a quadrat depends on the size of the organisms being sampled. For example, to count plants growing on a school field, one could use a quadrat with sides 0.5 or 1 metre in length.

general characteristics of Tropical rainforests

- Tropical wet forests are also referred to as tropical rainforests. This biome is found in equatorial regions. The vegetation is characterized by plants with broad leaves that fall and are replaced throughout the year. Unlike the trees of deciduous forests, the trees in this biome do not have a seasonal loss of leaves associated with variations in temperature and sunlight; these forests are "evergreen" year-round. The temperature and sunlight profiles of tropical wet forests are very stable in comparison to that of other terrestrial biomes, with the temperatures ranging from 20 °C to 34 °C (68 °F to 93 °F). When one compares the annual temperature variation of tropical wet forests with that of other forest biomes, the lack of seasonal temperature variation in the tropical wet forest becomes apparent. This lack of seasonality leads to year-round plant growth, rather than the seasonal (spring, summer, and fall) growth seen in other more temperate biomes. In contrast to other ecosystems, tropical ecosystems do not have long days and short days during the yearly cycle. Instead, a constant daily amount of sunlight (11-12 hrs per day) provides more solar radiation, thereby, a longer period of time for plant growth. The annual rainfall in tropical wet forests ranges from 125 cm to 660 cm (50-200 in) with some monthly variation. While sunlight and temperature remain fairly consistent, annual rainfall is highly variable. Tropical wet forests typically have wet months in which there can be more than 30 cm (11-12 in) of precipitation, as well as dry months in which there are fewer than 10 cm (3.5 in) of rainfall. However, the driest month of a tropical wet forest still exceeds the annual rainfall of some other biomes, such as deserts.

General characteristics of Tundra

- Tundra is the coldest of all the biomes. Tundra comes from the Finnish word tunturi, meaning treeless plain. It is noted for its frost-molded landscapes, extremely low temperatures, little precipitation, poor nutrients, and short growing seasons. Dead organic material functions as a nutrient pool. The two major nutrients are nitrogen and phosphorus. Nitrogen is created by biological fixation, and phosphorus is created by precipitation. Characteristics of tundra include: Extremely cold climate Low biotic diversity Simple vegetation structure Limitation of drainage Short season of growth and reproduction Energy and nutrients in the form of dead organic material Large population oscillations Tundra is separated into two types: Arctic tundra Alpine tundra - Arctic tundra is located in the northern hemisphere, encircling the north pole and extending south to the coniferous forests of the taiga. The arctic is known for its cold, desert-like conditions. The growing season ranges from 50 to 60 days. The average winter temperature is -34° C (-30° F), but the average summer temperature is 3-12° C (37-54° F) which enables this biome to sustain life. Rainfall may vary in different regions of the arctic. Yearly precipitation, including melting snow, is 15 to 25 cm (6 to 10 inches). Soil is formed slowly. A layer of permanently frozen subsoil called permafrostexists, consisting mostly of gravel and finer material. When water saturates the upper surface, bogs and ponds may form, providing moisture for plants. There are no deep root systems in the vegetation of the arctic tundra, however, there are still a wide variety of plants that are able to resist the cold climate.

· The reading includes life history tables - what is included in a life history table?

- While population size and density describe a population at one particular point in time, scientists must use demography to study the dynamics of a population. Demography is the statistical study of population changes over time: birth rates, death rates, and life expectancies. Each of these measures, especially birth rates, may be affected by the population characteristics described above. - Life tables provide important information about the life history of an organism. Life tables divide the population into age groups and often sexes, and show how long a member of that group is likely to live. They are modeled after actuarial tables used by the insurance industry for estimating human life expectancy. Life tables may include the probability of individuals dying before their next birthday (i.e., their mortality rate), the percentage of surviving individuals dying at a particular age interval, and their life expectancy at each interval. An example of a life table is shown in Table from a study of Dall mountain sheep, a species native to northwestern North America. Notice that the population is divided into age intervals (column A). The mortality rate (per 1000), shown in column D, is based on the number of individuals dying during the age interval (column B) divided by the number of individuals surviving at the beginning of the interval (Column C), multiplied by 1000. - mortality rate = number of individuals dyingnumber of individuals surviving x 1000mortality rate = number of individuals dyingnumber of individuals surviving x 1000

define gene pool

- all the genes in a population - A gene pool refers to the combination of all the genes (including alleles) present in a reproducing population or species. A large gene pool has extensive genomic diversity and is better able to withstand environmental challenges.

· What are depth, salinity and flow characteristics of the freshwater streams, rivers, lakes, ponds....

- aquatic biomes are categorized by flow, depth and salinity. - Lakes and ponds can range in area from a few square meters to thousands of square kilometers. Temperature is an important abiotic factor affecting living things found in lakes and ponds. In the summer, thermal stratification of lakes and ponds occurs when the upper layer of water is warmed by the sun and does not mix with deeper, cooler water. Light can penetrate within the photic zone of the lake or pond. Phytoplankton (algae and cyanobacteria) are found here and carry out photosynthesis, providing the base of the food web of lakes and ponds. Zooplankton, such as rotifers and small crustaceans, consume these phytoplankton. At the bottom of lakes and ponds, bacteria in the aphotic zone break down dead organisms that sink to the bottom. Nitrogen and phosphorus are important limiting nutrients in lakes and ponds. Because of this, they are determining factors in the amount of phytoplankton growth in lakes and ponds. When there is a large input of nitrogen and phosphorus (from sewage and runoff from fertilized lawns and farms, for example), the growth of algae skyrockets, resulting in a large accumulation of algae called an algal bloom. Algal blooms (Figure) can become so extensive that they reduce light penetration in water. As a result, the lake or pond becomes aphotic and photosynthetic plants cannot survive. When the algae die and decompose, severe oxygen depletion of the water occurs. Fishes and other organisms that require oxygen are then more likely to die, and resulting dead zones are found across the globe. Lake Erie and the Gulf of Mexico represent freshwater and marine habitats where phosphorus control and storm water runoff pose significant environmental challenges. - Rivers and streams are continuously moving bodies of water that carry large amounts of water from the source, or headwater, to a lake or ocean. The largest rivers include the Nile River in Africa, the Amazon River in South America, and the Mississippi River in North America. Abiotic features of rivers and streams vary along the length of the river or stream. Streams begin at a point of origin referred to as source water. The source water is usually cold, low in nutrients, and clear. The channel (the width of the river or stream) is narrower than at any other place along the length of the river or stream. Because of this, the current is often faster here than at any other point of the river or stream. The fast-moving water results in minimal silt accumulation at the bottom of the river or stream; therefore, the water is clear. Photosynthesis here is mostly attributed to algae that are growing on rocks; the swift current inhibits the growth of phytoplankton. An additional input of energy can come from leaves or other organic material that falls into the river or stream from trees and other plants that border the water. When the leaves decompose, the organic material and nutrients in the leaves are returned to the water. Plants and animals have adapted to this fast-moving water. For instance, leeches (phylum Annelida) have elongated bodies and suckers on both ends. These suckers attach to the substrate, keeping the leech anchored in place. Freshwater trout species (phylum Chordata) are an important predator in these fast-moving rivers and streams. As the river or stream flows away from the source, the width of the channel gradually widens and the current slows. This slow-moving water, caused by the gradient decrease and the volume increase as tributaries unite, has more sedimentation. Phytoplankton can also be suspended in slow-moving water. Therefore, the water will not be as clear as it is near the source. The water is also warmer. Worms (phylum Annelida) and insects (phylum Arthropoda) can be found burrowing into the mud. The higher order predator vertebrates (phylum Chordata) include waterfowl, frogs, and fishes. These predators must find food in these slow moving, sometimes murky, waters and, unlike the trout in the waters at the source, these vertebrates may not be able to use vision as their primary sense to find food. Instead, they are more likely to use taste or chemical cues to find prey.

General characteristics of Seasonal Tropical Forests (aka Dry Tropical Forests)

- centered on the Tropic of Cancer and and 30o north and south latitude and are Subtropical deserts exist between 15o 6 below). Deserts are frequently located the Tropic of Capricorn (Figure on the downwind or lee side of moun‐ tain ranges, which create a rain shadow content on the mountains. This is typi‐ after prevailing winds drop their water as the Mohave and Sonoran deserts.cal of the North American deserts, such Sahara Desert in northern Africa or the Deserts in other regions, such as the Namib Desert in southwestern Africa are dry because of the high-pressure, dry air descending at those latitudes. Subtropical deserts are very dry; evaporation typically ex‐ ceeds precipitation. Subtropical hot deserts can have daytime soil surface temperatures above acterized by low annual precipitation of fewer than 30 cm (12 in) with little monthly variation and 60oC (140oF) and nighttime temperatures approaching 0oC (32oF). Subtropical deserts are charreceive more. In some cases, the annual rainfall can be as low as 2 cm (0.8 in) in subtropical deserts located in central Australia ("the Outback") and northern Africa. - Subtropical deserts are caused by the circulation patterns of air masses. They are found along the Tropic of Cancer, between 15 and 30 degrees north of the Equator, or along the Tropic of Capricorn, between 15 and 30 degrees south of the Equator.Hot, moist air rises into the atmosphere near the Equator. As the air rises, it cools and drops its moisture as heavy tropical rains. The resulting cooler, drier air mass moves away from the Equator. As it approaches the tropics, the air descends and warms up again. The descending air hinders the formation of clouds, so very little rain falls on the land below.The world's largest hot desert, the Sahara, is a subtropical desertin northern Africa. The Sahara Desert is almost the size of the entire continental United States. Other subtropical desertsinclude the Kalahari Desert in southern Africa and the Tanami Desert in northern Australia.

· Your reading mentions important terms you should know: convergent evolution, divergent evolution, adaptation.

- convergent evolution: convergent evolution occurs when species occupy similar ecological niches and adapt in similar ways in response to similar selective pressures. Traits that arise through convergent evolution are referred to as 'analogous structures'. They are contrasted with 'homologous structures', which have a common origin. - divergent evolution: Definition. Divergent evolution represents the evolutionary pattern in which species sharing a common ancestry become more distinct due to differential selection pressure which gradually leads to speciation over an evolutionary time period. (think of Darwin's finches) - adaptation: In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the population during that process. Thirdly, it is a phenotypic trait or adaptive trait, with a functional role in each individual organism, that is maintained and has evolved through natural selection.

Define DNA

- deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information. - DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person's body has the same DNA. - carrier of genetic information.

· What is dispersion? What factors may be linked to a species showing a particular dispersion pattern? How does dispersion pattern influence the reliability of methods employed to estimate density?

-Dispersal: Dispersal - the movement of an individual or multiple individuals away from the population in which they were born to another location, or population, where they will settle and reproduce. Global climate change and plant dispersal - barriers.

How is genetic drift different from natural selection?

- genetic drift: Occurs when a random event changes the frequency of allele within a population (non-selective) • One allele may be reduced due to chance, not due to any adaptive advantage • Genetic drift can have a particularly significant effect in a small population • Examples include catastrophic events Can allow neutral or harmful alleles to persist, even if they lower fitness - Genetic drift is change in allele frequencies in a population from generation to generation that occurs due to chance events. To be more exact, genetic drift is change due to "sampling error" in selecting the alleles for the next generation from the gene pool of the current generation. - Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. - Summary. Unlike natural selection, genetic drift does not depend on an allele's beneficial or harmful effects. Instead, drift changes allele frequencies purely by chance, as random subsets of individuals (and the gametes of those individuals) are sampled to produce the next generation.

· How will regions of lentic freshwater systems (still) vary from littoral & profundal zones?

- lentic: Standing freshwater systems are known as lentic systems. While these can take a wide variety of forms from swamps and bogs to lakes and lagoons, here in the mountains our lentic waters are limited to man-made waters and beaver ponds - Littoral Zone This zone is the shore area of the lake or pond. It consists of the area from dry land that slopes into the open water and can be very narrow or very wide. Typically, oligotrophic, or young, bodies of water have narrow Littoral Zones due to their steep sides. Conversely, eutrophic, or old, bodies of water have wide Littoral Zones because of their gentle sloping shoreline and sides. The Littoral Zone is shallow and gets a lot of nutrients from runoff and non-point source pollution. Therefore, it typically has an abundance of aquatic plant and algae growth. Some other common inhabitants of the Littoral Zone are cattails, reeds, crawfish, snails, insects, zooplankton, and small fish. - Limnetic Zone The Limnetic Zone is generally classified as the open water area of the lake or pond. This is a much larger section of water in oligotrophic ponds and lakes than it is in eutrophic bodies of water. Within this zone are two separate sections: the Euphotic Zone and the Profundal Zone. - Euphotic Zone The Euphotic Zone or Epilimnion (warm water region) is the upper portion of the Limnetic Zone near the surface of the water. This is the portion of water that receives sunlight. The zone ends where the sunlight fails to penetrate the water. The Euphotic Zone is where algae and other aquatic plants thrive in addition to the Littoral Zone. Typically, this area has a dense fish population because oxygen levels are usually higher due to contact with the air. - Profundal Zone The Profundal Zone or Hypolimnion (cold water region) can be found below the Euphotic Zone. This zone is located under the thermocline where the sunlight does not penetrate the water. Again, the size of this zone depends on the age and water clarity of the pond or lake. The Profundal Zone typically has a low population of fish because of the lack of oxygen during many parts of the year. - Benthic Zone The Benthic Zone is the bottom of the pond or lake and consists of organic sediments and soil. As the body of water ages, this zone will increase. It is considered the pond or lake's digestive system. This zone is where bacteria decompose organic matter from dead algae, aquatic plants, and fish and animal waste. The more organic matter there is in the body of water, the more decomposition takes place. Decomposition can take place either aerobically (in the presence of oxygen) or anaerobically (without oxygen). It is much better to have aerobic decomposition because it is a faster process, and the byproducts are easier to handle.

· What are the trade-offs in offspring number and parental investment? How does that relate to Lack's Clutch Size hypothesis?

- less offspring, more parental care. - more offspring less parental care. - Lack Clutch Size Hypothesis - natural selection has selected for individuals that produce the optimal clutch size (max # eggs that can fledge) Life history characteristics will vary with environment - different pressures different patterns Clutch size matches food availability • Each species has its own curve (optimal clutch size for that species) - Spieces that mature faster lay more eggs. They lay more than one egg because if some do not make it, there are enough that a least a few will most likely survive to adulthood. If there are too little eggs this decreases survival rate, because it doesn't make up for the fact that some of the chick will die before adulthood. I there are too many eggs though this also decreases survival rate because the parent can't keep up with all those mouths to feed and care for and this then effect how well all the chicks are cared for. -Lack's principle, proposed by the British ornithologist David Lack in 1954, states that "the clutch size of each species of bird has been adapted by natural selection to correspond with the largest number of young for which the parents can, on average, provide enough food".[1]As a biological rule, the principle can be formalised and generalised to apply to reproducing organisms in general, including animals and plants. Work based on Lack's principle by George C. Williams and others has led to an improved mathematical understanding of population biology. Principle[edit] Further information: Natural selection Lack's principle implies that birds that happen to lay more eggs than the optimum will most likely have fewer fledglings (young that successfully fly from the nest) because the parent birds will be unable to collect enough food for them all.[1] Evolutionary biologist George C. Williams notes that the argument applies also to organisms other than birds, both animals and plants, giving the example of the production of ovules by seed plants as an equivalent case. Williams formalised the argument to create a mathematical theory of evolutionary decision-making, based on the framework outlined in 1930 by R. A. Fisher, namely that the effort spent on reproduction must be worth the cost, compared to the long-term reproductive fitness of the individual.[2] Williams noted that this would contribute to the discussion on whether (as Lack argued) an organism's reproductive processes are tuned to serve its own reproductive interest (natural selection), or as V.C. Wynne-Edwards proposed,[3] to increase the chances of survival of the species to which the individual belonged (group selection). The zoologist J.L. Cloudsley-Thompson argued that a large bird would be able to produce more young than a small bird.[4] Williams replied that this would be a bad reproductive strategy, as large birds have lower mortality and therefore a higher residual reproductive value over their whole lives (so taking a large short-term risk is unjustified).[5] Williams' reply "is one of the most cited papers in life history evolution because it ... made it conceptually possible to find the optimal life history strategies in age-structured populations".[6] - Birds lay only as many eggs as they will be able to provide for. - If there are too many mouths to feed, fewer young will survive, reducing the parents' reproductive fitness.

What is original source of genetic variation?

- mutation This view of evolution held that variation in populations was the result of random genetic mutation and recombination, and as a result, proposed that populations evolve by changes in gene frequencies due to genetic drift, gene flow, and natural selection. - Sexual reproduction - shuffles the genes so offspring are different from each other (meiosis, crossing over of homologous chromosomes, independent assortment)

· How do the photic zone and aphotic zone in oceans differ? What about neritic and oceanic zones? Benthic?

- neritic zone: the ocean zone that is beyond the range of the lowest tidal level and extends to depths of 200m. This is where coral reefs are. - photic zone: the area of the neritic and oceanic zones that contains sufficient light for photosynthesis by algae - Aphotic zone - too deep for light to penetrate - Benthic: The benthic zone is the lowest ecological zone in a water body, and usually involves the sediments at the seafloor. These sediments play an important role in providing nutrients for the organisms that live in the benthic zone.

· Mating systems: polyandry, monogamy, polygyny, promiscuity and polygynandry.

- polyandry: Polyandry is when a female mates with two or more different males (the male equivalent, one male mating with multiple females, being called 'polygyny'). Monandry on the other hand is when a female only mates with a single male. A common example of polyandrous mating can be found in the field cricket (Gryllus bimaculatus) of the invertebrate order Orthoptera (containing crickets, grasshoppers, and groundhoppers). - Monogamy. Social monogamy is the behavioral pairing of a single male with a single female. It is most common in birds and rare in other animals (Figure 4). Theoretically, individuals in monogamous pairs will both contribute to the defense and parental care of offspring. - Polygyny is the association of one male with multiple females. This mating system is found in a few birds and insects, but is most common in mammals. Polygyny is a strategy used by males to increase their reproductive fitness. - promiscuity: A mating system where there are no pair bonds. In this case is seems that males and females mate randomly. - Polygynandry is a form of polygamy; in sexually reproducing animals, it is a multi-male and multi-female mating system. Polygynandry encapsulates both polygyny (males having multiple female mates) and polyandry (females having multiple male mates) within the same species.

Know examples of rapid microevolution - e.g. Galapagos finches (discussed in class), antibiotic resistance

- rapid microevolution: Rapid microevolution is usually associated with changes of genetic variation in a population, such as changes of allele frequency and generation of new alleles through mutations at functional genes - An example of this is Galapagos finches because beak size can vary in a population from generation to generation depending of weather conditions. If its a drought year more birds with smaller beaks will die because they can't access certain foods. Then the population will be compressed of mainly birds with larger beaks, because they can access food with their larger beak. This means more birds born that year will have larger beaks. Antibiotic resistance: The main cause of antibiotic resistance is antibiotic use. When we use antibiotics, some bacteria die but resistant bacteria can survive and even multiply. The overuse of antibiotics makes resistant bacteria more common. The more we use antibiotics, the more chances bacteria have to become resistant to them.

General characteristics of Savannas

- savannas are grasslands with scattered trees and are found in Africa, South America, and northern Australia (Figure 4 below). Savannas are hot, tropical areas with temperatures averaging from 24oC -29oC (75oF -84oF) and an annual rainfall of 51-127 cm (20-50 in). Savannas have an extensive dry season and consequent fires. As a result, there are relatively few trees scattered in the grasses and forbs (herbaceous flowering plants) that dominate the savanna. Because fire is an important source of disturbance in this biome, plants have evolved well-developed root systems that allow them to quickly re-sprout after a fire.

Why would you predict that the sex with the greatest variability in reproductive success would be more likely to show sexually selected traits?

- sexual dimorphism: species with M and F that look different. - sexual monomorphism: species with M and F that look the same. - Species where F and M look different cause one group of the population (this can be males or females) to become choosey about how they mate with or coipition between individuals for the right to mate. - Sexual selection- selection for traits that increase ability to obtain or successfully copulate with a mate Sexual selection can involve... Males competing with each other for access to females or territory that would attract females Males displaying to attract mates Females choosing their male mates based on visual traits, good territory, victory in competition with other males These are the typical patterns seen in many species, but there is variation - sometimes the males choose the mate and females show competitive behavior

Know differences between sexual and asexual reproduction.

- sexual reproduction: sexual reproduction, the production of new organisms by the combination of genetic information of two individuals of different sexes. In most species the genetic information is carried on chromosomes in the nucleus of reproductive cells called gametes, which then fuse to form a diploid zygote. SEXUAL REPRODUCTION: Benefits -offspring are variable. purge mutations. Costs: Have to look for a mate. Risky (disease, violence, no mates). Cost of Meiosis (parent only passes on 50% of their genes. - Asexual reproduction: Asexual reproduction is a mode of reproduction in which a new offspring is produced by a single parent. The new individuals produced are genetically and physically identical to each other, i.e., they are the clones of their parents. Asexual reproduction is observed in both multicellular and unicellular organisms. Aphids reproduce asexually. ASEXUAL REPRODUCTION: Benefits• Maximize your own genes in offspring• No need for mate (less risk and energy) Costs • Accumulation of mutations • Limited genetic variation - what if environment changes?

define , industrial melanism

- the change in the melanin-producing allele frequency from light to dark due to environmental changes brought on by industry pollution. - Ex: The peppered moth Biston betularia F.typica is a light-coloured species with dark patches, that help them to camouflage against the lichens on the barks of the trees. F.carbonaria which is a sub-species of F.typica had undergone some mutation and changed to a dark-coloured moth having light-coloured patches. In the polluted areas, the light-coloured species could not protect themselves from predators. This was because the lichen population had reduced due to pollution and the light-coloured species were easily visible on the tree barks. This replaced the F.typica species with the F.carbonaria species. Since Europe has started using environment-friendly modern technologies, the selection pressure from predation has reversed and the moth is returning to its typical variety. This process is slower than the initial change because the allele is recessive for light colour and copies from both the parents are required. This is called reverse industrial melanism. In Australia, one species of snakes living in water, with black and white stripes has become completely black due to urban pollution.

What is a bottleneck? Know examples. What is likely to happen to populations that have gone through bottleneck?

-A population bottleneck or genetic bottleneck is a sharp reduction in the size of a population due to environmental events such as famines, earthquakes, floods, fires, disease, and droughts; or human activities such as specicide, widespread violence or intentional culling, and human population planning. - Events like natural disasters (earthquakes, floods, fires) can decimate a population, killing most individuals and leaving behind a small, random assortment of survivors. - Because genetic drift acts more quickly to reduce genetic variation in small populations, undergoing a bottleneck can reduce a population's genetic variation by a lot, even if the bottleneck doesn't last for very many generations. This can lead to more negative traits to be expressed.

What are costs and benefits to asexual reproduction? What are costs and benefits to sexual reproduction?

ASEXUAL REPRODUCTION: Benefits• Maximize your own genes in offspring• No need for mate (less risk and energy) Costs • Accumulation of mutations • Limited genetic variation - what if environment changes? SEXUAL REPRODUCTION: Benefits -offspring are variable. purge mutations. Costs: Have to look for a mate. Risky (disease, violence, no mates). Cost of Meiosis (parent only passes on 50% of their genes.

Know definition and examples of adaptive radiation.

Adaptive radiation - speciation following expansion of one or a few forms into a new geographical area (usually happens rapidly) Occurs when one ancestor species rapidly evolves into many descendant species, each with own specializations Adaptive - implies natural selection at work, species become specialized for their unique environment/niche Radiation - refers to rapid diversification Darwin's finches provide lots of evidence for adaptive radiation in Galapagos Evidence for is also found on other islands • Hawaiian honeycreepers

· The video lecture then summarizes Ernst Mayr's framework for how straightforward it is to arrive at Evolution via Natural Selection to describe patterns of life on earth. You should be able understand the 6 facts and 3 inferences and understand how they structurally provide the pathway to the theory of evolution via natural selection.

Ernst Mayr's: Ernst Walter Mayr was one of the 20th century's leading evolutionary biologists. He was also a renowned taxonomist, tropical explorer, ornithologist, philosopher of biology, and historian of science. - 6 FACTS and 3 INFERENCES (Some facts:) 1. Populations have potential for exponential increase (Malthus) 2. Population size does not change dramatically over time (obvious) 3. Resources necessary for survival are limited (obvious) (inference #1): Individuals struggle to survive (Malthus) (Some facts) 4. variation exists among individuals in a species. 5. offspring resemble their parents. (inference #2): natural selection, individuals with more favorable variation will produce more offspring. (last fact) 6. the earth is very old. (inference #3): evolution, individuals with favorable variations will become more common in a population over time.

gene flow

Gene Flow • Movement of genes between populations • Can occur through movement of individuals (migration) • Example: pollen and/or seed dispersal allows for gene flow between populations • New genes introduced to a population provide source of variation on which natural selection can act

· We talked about other methods for estimating density - e.g. fecal counts, catch/unit effort, vocalization surveys, camera traps. You should be able to think about the positives and negatives associated with different techniques.

How can we find out the size of a population if the individuals in it are moving around? The technique we use to assess a population is important: depends on habitat, species, etc. Mark/recapture study Camera trapping: Camera traps provide data on species location, population sizes and how species are interacting. They also help us to understand how humans and livestock interact with each other and other forms of wildlife. However, camera traps are not without problems; the often large amounts of data generated by these devices can overwhelm users and lead to problems with storage, backup, sharing and image processing (Harris et al. 2010; Sundaresan et al Fecal sampling Hair sampling Vocalization surveys Regular trapping Pelt records Catch per unit effort (CPUE)

What is intrasexual selection? What does it result in?

Intrasexual selection - selection for traits that help in the competition of members of one sex (usually male) for access to other sex (usually female) • Increased body size, weaponry, mate guarding, sperm competition - Intrasexual selection is typically responsible for the evolution of male armaments such as deer antlers, beetle horns, and large body size, that provide individuals with an advantage when fighting off potential competitors.

· How is sex determined in different organisms? Mammals vs birds? Reptiles? Insects with XO, haplodiploid systems....Know what was covered in class and patterns in those organisms.

Mammals (and some other sp.) have sex determined by chromosomes they inherit • Have pairs of chromosomes (diploid organisms) • Mammalian males have XY, Females have XX. - Birds have different system • Male has pair of ZZ chromosomes • Female has one Z and smaller W chromosome - In organisms like crickets, grasshoppers, and some other insects, the female is XX and is the homogametic sex. The male is the heterogametic sex but only has one sex chromosome. The male in XX-XO systems produce gametes with (X) or without (O) a sex chromosome. - Haploid-diploid system seen in bees. Honeybees: female are diploid, males are haploid. The female queen is the only one how can produce gametes through meiosis. Queen will mate with males (drones) and can store sperm up to five years. If see needs more worker bees (female) she can fertilize her own eggs. If she needs more males, she can lay eggs without fertilizing and males will hatch. Reptiles: the temperature at which the eggs incubate and go through development will determine wether you'll get males of females.

· Mark-Recapture was one of the first methods used to estimate animal populations - You should be able to take data and calculate population size using mark recapture data.

Mark-recapture population estimate technique • Process has 2 stages: 1st pass - A subset of a population is captured and marked (tagged) in some way that doesn't harm or change the individual's behavior • After a relatively short amount of time (depends on species; a few hours, a day. Etc.), the same capture technique is carried out • In the 2nd pass, some of the individuals caught will already have been marked the previous day, some won't (it will be their 1st catch) • Formula used to calculate population estimate - The way you capture the animal the first time must not reduce the chance you'll catch them a 2nd time Individuals in the population must not be able to leave (or be unlikely to) and also new individuals must not be moving in during the mark- recapture period In order for this method to work, two assumptions must be met: 1) The likelihood of recapture is equal to first capture 2) No individuals are emigrating or immigrating from population during marking and recapturing

· You need to know the modern definition of Natural selection (organisms with favorable genetic traits produce more offspring thereby contributing more genes to future populations) and Evolution (a genetic change in a population)

Natural selection - organisms with favorable genetic traits produce more offspring thereby contributing more genes to future population Evolution - Genetic Change in a population - Was it natural selection? 1. Genetic variation within a population-there was variation in the alleles for beetle color (green & orange) 2. Variation in reproductive success of individuals within population -orange beetles reproduced more successfully than green beetles 3. A way for genetic info to be inherited by next generation-the mutation occurred on a gamete, so it was able to be passed on to offspring

How could the fact that parasites (bacteria and viruses in particular) evolve very rapidly act as a very strong selective force for sexual reproduction?

SEXUAL REPRODUCTION: One of the benefits• Offspring are variable • Increases genetic diversity that can help offspring deal with future environmental variation, including the existence of rapidly evolving parasites and pathogens • RED QUEEN HYPOTHESIS - Sexual reproduction results in variable offspring which allows some offspring to survive in world of rapidly evolving pathogens (viruses, bacteria, fungi, parasites) - Pathogens have a very short generation time, so they evolve so much more rapidly than most organisms Organisms need a way to increase variation in offspring to ensure that some of them may survive the constant attack from pathogens Sexual reproduction, meiosis, can add some variation quickly, within a single generation - Trematodes are worms that infect snails - need to live inside snails AND ducks in order to complete life cycle The worms can only mature to adults inside a duck'sintestines, where they reproduce and lay eggs When the duck defecates, the eggs are released into the lake Snails eat the worm eggs Eggs hatch and worm larva live inside snail - OBSERVATIONS: 1. Lakeswithhigh duck/trematode populations more likely to have some sexually reproducing snails 2. Snailsinshallowwater more likely to have some sexual reproduction than those in deep water SUGGESTS THAT SEXUAL REPRODUCTION IS FAVORED IF PARASITISM HIGH - supports the Red Queen Hypothesis

· If a female could determine the sex of her offspring could there be instances where producing one or the other sex could be advantageous?

yes. If the population had too few males then she could produce more males. If the population had too few female then she could produce more female.