13 modern species are probably descended from species and communities.
A few seed-eating ancestors that blew to the islands from the South will consider the ways populations interact and the adaptation that America still has.
Evolution of species through natural selection is a corner stone of biology and its many subfields.
Many details have been filled in by subsequent discoveries.
The discovery of DNA in the 1950s allowed us to understand Charles Darwin.
Some of the ways 300(1): 38-43 will be looked at in this chapter.
The beneficial traits are passed on to diversity and their offspring.
The process of adaptation to the environment is central to the theory of evolution.
There are environmental tolerance limits for all species.
Taxonomy describes relationships.
We examine the theory of speciation by means of natural selec tion and adaptation, as well as the characteristics of species that make some of them weedy and others endanger, in this section.
Adaptability in a species happens over generations, as some die out and others persist.
If you move a houseplant from indoors to out doors, it may grow a thicker skin or denser pigments to tolerate the increased sunlight.
giraffes don't have long necks because they stretch to be not permanent, and the plant's offspring won't inherit those reach tree-top leaves, but those giraffes that happened to have longer necks got more food and had more offspring, so the trait became fixed
Random changes happen in any population.
Exposure to radiation and toxic mate rials are the main causes of mutations.
Changes in the genetic code can be passed on to offspring.
The majority of evolutionary change is brought about by a lot of mutations.
Body cell changes--cancers, for example--are not inherited.
The majority of the genes have no effect on fitness.
The result is a different species population.
The fitness of individuals and their offspring is influenced by environmental factors.
cacti are limited in where they can live Excellent example of distribution controlled by a critical environmental is one of the limiting factors.
Saguaros are sensitive to low temperatures because of their environmental factors, such as light, temperature, and pH, but they are also sensitive to competition with other species.
The organisms' behavior allows them to survive in certain environments.
The environmental factors that affect the growth of mussels and barnacles in the intertidal zone can be found in New England or the Pacific Northwest.
No one can decide if this pat isms will persist.
Justus von Liebig proposed tern in 1840.
The distribution of the hot Sonoran Desert of southern Arizona and northern Mexico is different for young and older people.
An example is offered by the desert pupfish.
The segulls live in small isolated populations in warm springs in heat and dry conditions, but the northern Sonoran Desert.
Adult pupfish are sensitive to freezing temperatures.
A high temperature for night with temperatures below freezing for 12 or more hours kills a fish and tolerates an equally wide range of salt concentrations.
The northern edge of the saguaro's range is killed by high salt levels and eggs and juvenile fish can only survive between 20 and 36 degrees.
A zone where freezing temperatures last less than half a day is called reproduction.
Lichens and eastern areas beyond which a species cannot survive or is unable to white pine are indicators of air pollution.
The critical factor that limits where a tively is the one factor that is close to these survivallim.
Bull thistle can live on disturbed organisms.
A vigorous population of unique factors limiting the growth of every plant and animal bull thistle or certain other plants in a pasture indicates it is being population.
We now know that there are many factors working together.
Even in a clear-cut case like the saguaro, the presence or absence of trout determines the distribution of trout.
The rocky coast is used as an indicator of water quality.
Distributions of species are affected by tolerance limits.
Abundance is high for every environmental factor because there is an optimal range within which a species lives or reproduces most easily.
The horizontal axis could represent a number of factors, such as temperature, rainfall, vegetation height, or the availability of a critical resource.
Specialists don't tolerate environmental change because their habitat was first defined in 1927.
Each species had a role in the community.
The niche defined its way of obtaining food, the relationships it had with other species, and the services it provided to its community.
The American limnologist proposed a more physical and biological definition of the niche.
He pointed out that every species exists in a range of physical and chemical conditions.
It can be found within a set of biological interactions, such as the presence of predator or prey.
Some species can exploit a wide range of resources.
Rats, roaches, and dandelions are some of the "weedy" species that thrive in a broad variety of environments.
Each of the species in the African savanna has its own grass.
pandas have to spend an ecological niche that determines where and how they live.
The ancestors lived on a diet of bamboo.
Generalists, such as the American black bear, tolerate Adaptions that include "thumbs" that help it grasp bamboo leaves, and teeth a wide range of environmental conditions.
Specialists help it chew the grass.
The giant panda is not in the competition.
The saguaro is endemic to the Sonoran Desert.
Some species have an ecological niche for a long time.
The species that is more efficient in social structures that help them expand the range of resources using available resources will exclude the other.
They can use the other species or environments.
Elephants, Chimpanzees, and Dol disappear or develop a new niche.
They expand their figure.
Different fish occur at different depths on a gradient from shallow to deep water in an ecological niche.
Two species compete for limited resources and eventually coexist in a single habitat.
A classic example of resource gaining the larger share is when the other finds a different habitat, or when Robert dies out or experiences a change in its behavior.
Competition causes resources to be divided.
People in this part of the niche have less success.
PDF to printer interbreeds with populations on other islands.
These isolated popu Tends to change in response to their individual environment outside of trees.
Some degree Yellow-rumped selection can happen in just a few years, but we usually assume evolution occurs slowly.
Several species of wood warblers occupy individuals in the finch population had better success opening the same forests in eastern North America.
The larger seeds were excluded from the competition.
The large-billed trait principle predicts that the warblers should partition the resources within two years.
In order to reduce competition, this shift toward one extreme of food has been made.
The warblers feed in a trait.
Moderate-size beaks aided exploitation of a wider range of seeds when the population shifted back toward them.
Environmental conditions can affect the levels of the forest canopy or inner and outer branches.
The two groups don't compete for the same insect prey.
As a population becomes more adapted to its ecological niche, it may develop specialized or distinctive traits that will eventually replace its biological cousins.
Disruptive selection of a new species is called speciation.
Evidence from body shape, behavior, and genetic simi Number of individuals suggest that the 13 current species of finch derive from an original seed-eating finch species that probably blew to the islands from the mainland.
Variation in ocean currents is rare.
We know this because of selection pressure.
A population with wide variation in beak shape.
Sometimes selection pressures advantage volcanic seamounts, the islands were never connected to a conti just one beak type.
In the Galapagos finches, speciation occurred largely because of moves to the extremes of the trait.
PDF to printer extremes.
Competition can cause disruptive selection, which can lead to better partitioning of a resource.
Directional selection can be seen in the emergence of antibiotic-resistantbacteria and pesticide- tolerant insects.
Chemical compounds create an environmental stressor.
A few indi viduals that have better-than-average tolerance of these compounds tend to live in a population.
A population with resistance to the antibiotic or the pesticide can be created by resistant survivors.
The loss of effectiveness of antibiotics and pesticides is a very common problem in public health and agriculture.
As in the case of the finch diversifi cation on the previously unoccupied Galapagos Islands, new environmental conditions often lead to speciation.
There are periods of tremendous diversification that have followed the sudden extinctions of species.
The end of the age of dinosaurs was followed by dramatic diversi fication of mammals, which expanded to fill newly available niches.
Despite several events that wiped out large proportions of species, the fossil record is one of increasing diversity.
The American alligator has existed unchanged for over 150 million years, but as we saw with Darwin's finches, some organisms evolve quickly.
Every sea son has a new flu virus.
In a few years, isolated populations can give rise to new species.
The last 10,000 years or so have seen the development of new traits in red squirrel populations in Arizona due to reproductive isolation.
Allopatric speciation can result from geographic barriers.
There were many examples from both laboratory experiments and from the time when Arizona was forest-covered.
Evolution is still going on as the climate warms.
The desert replaced the forest on the plains.
Squirrels were confined to many fruit fly properties, including body size, eye color, and growth cooler mountaintops, which acted as island refugia.
In tively isolated species began to evolve.
The flies with the most bristles were allowed to mate.
Sometimes evolution works in our favor.
In a similar way, we've spread a number of persistent organic pollutants, such as pesticides and industrial solvents, throughout oil content to plant and mate.
It is one of the best ways to get rid of them.
The best place to look for these species is in the culture and urban settings, which has led to the rapid evolution of resis most contaminated sites.
More than 500 insect species have tance in the presence of a new food source.
Artificial selection and genetic modification can be done in the laboratory if antibiotics are used in medicine and livestock operations.
These species are turned into useful bioremediation tools by the Centers for Disease.
A kind of arms race with germs is taking place.
The relation of organisms becomes impervious to them as quickly as new drugs are invented.
Vancomycin is a drug.
You can see how organisms have descended from last resort.
We may be related to common ancestors when resistance becomes widespread.
There is no protection from infections among taxonomic relationships.
One Hemagglutinin (H) Neuraminidase (N) 50 million people can't be made.
Bird virus doesn't kill pigs.
The flu has a mixed strain that seems to evolve more slowly than the ability to change quickly.
Suddenly pig viruses and build defenses against new viruses, have begun to evolve at a much Virus particle, while Viruses have evolved methods to bind to faster rate and move to humans with increasing Frequency.
Understanding the principles of evolution and genetics of pigs has made it possible to defend ourselves from the flu, provided we have the vac.
Many epidemiologists think about themselves.
They have to invade a cell and hijack the cell to make a new cell's biochemical systems.
A new re-assorted variety can be created when different strains of the flu virus mix.
To invade a cell, the virus has to bind to a susceptible virus on the cell surface.
Sometimes the best guess is wrong.
Once inside a cell, viral genes are called hemagglutin and can mix freely to create new, more virulent they also bind to antibodies in our blood.
The viruses have immunity and vaccines.
A bad flu was shown to have genes from at least five neuraminidases on their surface.
In 2009, there was an example of the surprises caused by the rapid flu evolution.
Two swine viruses are typically found in Asia.
There are 16 groups of H pro in the H1N1 family that emerged in Mexico.
It's thought that teins and 9 groups of N are related.
At least 1,000 people were killed by various strains of the H5N1 virus in pigs.
We don't know when or where that happened.
The H3N2 is based on their surface proteins.
For the time being, we must continue to get a new vaccine every year and hope for the best, as new strains sweep across the world, and because they change often, have some degree of immunity.
The immune system that protects us against the main flu strains isn't as strong as first thought, and it's likely to get worse in the next flu season.
The US Centers for Disease Control and Prevention had 50 million cases of the flu in November of 2009.
Also known as scien many common names.
Scientists use the scien Taxonomy to communicate about species and to organize subjects in tific names instead of common names.
Different organisms depend on each other for resources.
We will look at the interactions between species that affect their success.
There is a relationship between competition and a biological community.
Organisms compete for resources that are in limited supply: energy and matter in usable forms, living space, and specific sites to carry out life's activities.
Plants compete for space to grow root and shoot systems so that they can process sunlight, water, and nutrients.
Animals cell with nucleus compete for food and mates.
All life is represented by the six great kingdoms.
Common origins are indicated by the domains that the kingdoms are grouped in.
Six kingdoms are recognized by scientists: animals, plants, fungi, protists,bacteria, and archaebacteria.
You will learn about millions of different species in chapter 5 and chapter 11.
Explain how the pressure affects the species.
Competition leads to the allocation of resources.
Light and space are at a premium in the Indonesian rainforest.
Predation is a type of pressure.
Both species benefit from Symbiosis.
We have learned that adaptation to one's environment, deter and branches are epiphytes, that they find space and get closer to the sun by mination of the ecological niche, and that even speciation is affected perching above ground level.
Competition life in the dark jungle is just one of the ways in which bodily limits and behavior can be adapted.
Final PDF to a printer.
Competition causes individuals and species to shift their focus from one segment of a resource type to another.
Warblers compete with each other for insect food in New England, but they tend to specialize on different areas of the forest's trees, reducing or avoiding competition.
There have been hundreds of interspecific competition studies in natural populations.
Scientists assume that interspecific competition does occur, but not always, and that it has little effect in some groups.
There are several ways to reduce competition in a population.
Plants dispersal is done by wind, water, and animals moving to less crowded conditions away from the parent plants.
Many animals force their offspring out of their vicinity by showing strong territoriality.
Territorial species, which include bears, songbirds, ungulates, and even fish, minimize competition between individuals and generations.
Resources are divided between tigers and lions as much as they are between insect herbivores.
In the generations, insects consume most of the food.
These species occupy a world.
Fertient ecological niches have evolved from complex patterns of defense and predation.
monarch caterpillar eat between insect and plant prey.
Crabs do not compete with adult crabs.
Many animals don't fight, confront or look at animals on plants.
Predation is a powerful influence on species and many other ungulates.
It affects all stages of the life bat, with the weaker animal knowing instinctively when to back cycles of predator and prey species.
Evolutionary adjustments are about getting to food or habitat first, or being able to in behavior and body characteristics that help prey avoid being use it more efficiently.
Each species has to eat and help the predator catch their prey.
Studies show that dation interacts with competition.
Scientists remove predatory animals from communities of competing species to test the idea.
All organisms need food.
Other intertidal species are included in consumers.
Pest control in croplands is an application to human needs.
Figure 4.14 shows the damage to strawberry leaves.
Pesticide spraying decomposers are not.
Control of the cyclamen mite can increase the parasites because it also kills the beneficial predatory mites.
The PDF contains information about the predator and the position of the food web.
As individuals mature, the response of predator to prey can change.
Many pollinators and plants havemunity, and coevolu where they and hatchling larvae join the floating plankton com tion can be mutually beneficial.
Planktonic animals eat each other and benefit from each other.
It's a classic case for fish.
Fruit bats pollinate and distribute seeds of fruit-bearing predators as their prey species mature.
Barnacles are eaten by tropical plants.
The plants provide food for the bats, and get their by small fish, but as adults their hard shells protect them from dispersed seeds in exchange.
Different switch prey are displayed by many species with chemical defenses.
Adult frog patterns warn away enemies.
They begin their lives as tadpoles.
Certain species that are harmless look like switch prey when their original prey becomes rare or distasteful, gaining protection against other predators.
Many predator have bad experiences with toxic organisms.
A classic case of Batesian mimicry is the selection pressures that favor benign viceroy butterflies because of the distasteful monarch and predator relationships.
The ability to hide and nary speed are some of the strategies organisms benefit from.
The forms, colors, and patterns that species display help protect themselves.
Plants have thick bark and are less likely to be discovered.
Poison ivy is often used as camouflage by predator as they lie in wait for their next meal.
Other species leave arthropods, snakes, and mammals alone because of noxious odors.
Animals are good at hiding, fleeing or fighting back.
On the Serengeti Plain of East Africa, Thomson's gazelle and even swifter cheetah are engaged in an arms race of speed, endurance, and quick reac tions.
A large percentage of total striking patterns and brilliant colors are alert to potential predator to the world.
Many plankton have habitats that are very toxic on their skin.
Latin Amer's Indigenous people are feeding relationships very different from their adult forms.
The wasp has bright yellow and black bands.
The longhorn beetle has a similar color and pattern that helps it avoid being eaten by animals.
Some interactions mean survival of organisms that can live together.
Symbiotic relation was hurt.
Plants growing on ships enhance the survival of one or both partners.
Researchers estimate that each of us has about 90 tril, which will allow us to recover faster from a catastrophic event.
People in primi other organisms eat bodies.
Our fruits and vegetables are increased by the viruses inside those wide variety of whole grains, as well as by another order of meat or dairy products.
There are thousands of species liv diet full of simple sugars and highly ing in every orifice, glands, and processed foods, but the largest group has a much greater species 2 kilo worth.
The 10 trillion or so mammals, as well as chronic low levels of antimi cells, make up more than 95 per cent of the volume of your body.