What is the process by which organisms that are better suited to their environment survive while others do not?

Every organism has a unique ecosystem within which it lives. This ecosystem is its natural habitat. This is where the basic needs of the organism to survive are met: food, water, shelter from the weather and place to breed its young. All organisms need to adapt to their habitat to be able to survive.

This means adapting to be able to survive the climatic conditions of the ecosystem, predators, and other species that compete for the same food and space. An adaptation is a modification or change in the organism's body or behaviour that helps it to survive. Explore the links given here to know more about habitats and how different plants and animals.

An animal may adapt to its habitat in different ways. It may be a physical or structural adaptation, just as the limbs of birds have modified into wings or the way the cheetah is shaped for running at a fast speed.

It may be in the way the body works in circulating and respiration, for instance the gills that fish have enable them to breathe in water. Or it may be the way the animal behaves whether it is hunting for food, or running fast to avoid predators or migrating to other places for food or survival. To know more about different types of adaptations visit the link.

An animal's environment consists of many different things. The climate, the kinds of food plants that grow in it, other animals that may be predators or competitors- the animal must learn to adapt to each of these factors in order to survive. With increasing population growth and human activity that disturbs the natural habitat, animals must learn to adapt to these kind of threats as well.

Animals in the wild can only live in places they are adapted to. They must have the right kind of habitat where they can find the food and space they need. Visit the link for a brief overview of how animals adapt to their habitat.

Did you know that animals camouflage themselves so they can adapt to their environment? Adaptation can protect animals from predators or from harsh weather. Many birds can hide in the tall grass and weeds and insects can change their colour to blend into the surroundings. This makes it difficult for predators to seek them out for food.

Some animals, like the apple snail, can survive in different ecosystems- from swamps, ditches and ponds to lakes and rivers. It has a lung/gills combination that reflects its adaptation to habitats with oxygen poor water. This is often the case in swamps and shallow waters. To know more about how the apple snail can survive in different habitats visit the link.

In the harsh cold climate of Alaska, the animals have learnt to adapt to the weather by storing food in their body and protecting themselves from the cold with thick furs. Human inhabitants in Alaska have also learnt to cope with the environment by building shelters that insulate and hold the heat, and yet do not allow the structure to melt. To know more about this go to this website.

Introduction to Evolution by Natural Selection

Without physically counting bacteria or viruses, scientists estimate that there are more than 8.7 million species of organisms living on Earth today. The origin and extinction of so many species has fascinated scientists for thousands of years, since the days of ancient Greece. The great diversity of living organisms on Earth is best explained by the evidence-based scientific concept of evolution by natural selection.

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Workshop: Natural Selection Introduction

Evolution is the change in inherited characteristics or traits in a population of organisms over many generations. The mechanism that best explains evolution is a phenomenon known as natural selection. Natural selection is the process by which certain inherited traits—such as the color of a fish, height of a person, or shape of a leaf—are favored within a population. A population is a group of organisms that mate and reproduce with one another. In general,

  • traits persist in a population because they contribute to the success of the organism, or
  • traits are eliminated because they detract from the success of the organism.

Thousands of years of selective pressures have determined the shapes, colors, sizes, and behaviors that optimize the survival and reproductive success of organisms in the environment in which they evolved. In fact, it is often possible to tell a lot about where something lives by how it looks and behaves.

Evolutionary fitness and success refers to surviving long enough to pass genetic material on to offspring. Traits that are passed on to offspring because they contribute to success are “selected for continuation.” Traits that are eliminated from the population because they detract from success are “selected against continuation.”

Any force in the environment that favors or disfavors traits is a selective agent. A force can be biological, like a predator, or physical, like temperature. Over time, populations subjected to different selective agents may become so different that they are no longer able to breed with one another. The biological definition of species is a group of organisms that can successfully breed with each other. Under this definition, when populations can no longer breed with each other, they are considered to be different species.

Activity

Activity: Modeling Evolution

Model natural selection in a population of bacteria.

History of Evolutionary Biology

In the 1800s, many people were trying determine why there were so many different kinds of plants and animals in the world. Charles Darwin wondered about the diversity of animals he saw while in the Galapagos Islands. This led him to develop the theory of natural selection, which is the best explanation we have for the diversity of life. Alfred Russell Wallace also hypothesized that the environment could help to shape the diversity of life by favoring certain traits over others. Wallace noticed that insects in the jungles of Africa and South America were very well adapted to unique environments. These two men, working independently of one another, developed the same basic explanation for the diversity of life: natural selection. These principles are supported by current scientific research.

Genetic Variation is Essential for Evolution by Natural Selection

For natural selection to occur, a population must have a wide variety of individuals with different traits. For example, natural selection would not influence fish body color if all individuals in a population were exactly the same color. The term phenotype is used to describe these physical traits. All phenotypes are the expression of genetic information in an individual’s DNA molecules. The term genotype describes the specific genetic code in the DNA molecular structure that produces a certain phenotype. Variations in genotypes can also produce variations in phenotypes.

New genotypes can be produced through the natural process of genetic mutation. A mutation is an error that is made during the DNA copying process. The mutation results in a change in the genetic code or genotype.

What is the process by which organisms that are better suited to their environment survive while others do not?

Sometimes mutations errors occur within the sections of the DNA strand that do not code for any phenotype or trait. Similarly, some mutations are minor and do not cause any significant change in the appearance, physiology, or behavior of the organism. Other times, mutations can cause changes in the phenotype (Fig. 1.7).

Over millions of generations of copying, even little errors in that influence phenotype can add up to big changes. Sometimes a single change in a regulating gene that controls other parts of an organism’s DNA can also have a big effect. To picture how this could work, think of the game “telephone.” In this game, one person whispers a phrase to their neighbor, who whispers it to their neighbor, and so on. The last person who receives the message compares the phase they think they heard to the original phrase. Often mistakes in repeating or understanding the sample phrase lead to changes in the meaning. The same thing happens when DNA is replicated again and again. The changes to the message in the game are similar to what happens when there are mutations. Changes in the meaning of the “message” of the DNA can cause changes in the appearance, physiology, or behavior of an organism.

A mutation can be an especially powerful force for change if it has a significant impact on the survival of an organism. Some mutations, for example, have provided resistance to antibiotics in bacteria. Because bacteria reproduce very rapidly, these mutations can quickly take effect in changing the population of bacteria.

It is also important to remember that mutations are random. An organism cannot pick or choose its mutation. For example, some species of animals that live their whole lives in caves without light have no pigment, or coloration. Because the caves are dark, there is no benefit to being camouflaged to avoid a predator or having coloration to attract a mate. However, not all animals that live in the dark lack color. In order for a species to lose its coloration, mutations must occur that allow the elimination of pigment. If the mutation never arises, the animals will stay pigmented.

Sexual reproduction can also increase genetic variation in a population. Many single-celled microorganisms reproduce simply by duplicating their genetic material (i.e., DNA) and dividing themselves in half. This process is called asexual reproduction. The new cells produced by asexual reproduction are genetically identical to the original parent cell unless some mutation occurs. Sexual reproduction is the production of offspring through the combination of specialized sex cells. These sex cells (also called gametes) contain only a half-copy of an individual organism’s genetic material. When the two halves—one from the male and one from the female—are combined, the offspring ends up with a brand new combination of genes.

What is the process by which organisms that are better suited to their environment survive while others do not?

Mutations and sexual reproduction increase genetic variation in a population. Individual organisms with unfavorable traits (e.g. malformed wings in fruit flies or bright white color patterning in male peacocks) are less likely to survive and reproduce. These individuals and the genes they carry are “selected against” or disfavored by natural selection (Fig. 1.8). In contrast, individuals with beneficial genes are more likely to survive and reproduce.


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Workshop: Natural Selection Wrap-up

In summary:

  1. Natural selection requires variation between individuals.
  2. Mutations and sexual reproduction increase genetic variation in a population.
  3. Natural selection occurs when environmental pressures favor certain traits that are passed on to offspring. The “big prize” in natural selection is passing on genetic information.
  4. Natural selection acts on populations. Individuals do not evolve in genetic evolutionary terms. Individuals may mutate, but natural selection acts by shifting the characteristics of the population as a whole.

Activity

Activity: Simulate Natural Selection

Model how variation in prey color and predator foraging affects survival and reproduction of a prey population.

What is the process by which organisms that are better suited to their environment survive and leave more offspring?

Natural selection is a mechanism of evolution. Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success. This process causes species to change and diverge over time.

What do you call the process that helps an organism survive in its environment?

“Adaptation is the physical or behavioural characteristic of an organism that helps an organism to survive better in the surrounding environment.” Living things are adapted to the habitat they live in.

What determines which organisms survive or do not survive in environment?

Every organism has a unique ecosystem within which it lives. This ecosystem is its natural habitat. This is where the basic needs of the organism to survive are met: food, water, shelter from the weather and place to breed its young. All organisms need to adapt to their habitat to be able to survive.

What is the name for the process in which the organisms best adapted to their environment survive apex?

Key terms.