Did either allele A or a disappear from the population you studied? Why or why not? Allele A disappeared for the most part because Allele a had an environmental advantage over Allele A. The population for Allele a appeared frequently, which leads me to believe that Allele a had a more dominant existence, thus leading to its survival over Allele A.
Did the effect of natural selection vary with different starting allele frequencies in identical environments? Why or why not? Yes, because the natural selection varied the number alleles that appeared more frequently. More frequent appearances lead to more population of that allele.
A population in which the frequency of alleles remains the same over generations is said to be in genetic equilibrium. Describe one mechanism by which a populations' genetic equilibrium can be disrupted and result in the process of evolution. If something happens to the environment that could drastically chance the landscape, the organisms in that environment may or may not survive, depending on the changes. Some organisms will adapt to the changes, and some will not.
In which of the simulated environments do individuals of the genotype Aa survive best? Urban and Grassland
In which of the simulated environments do individuals of the genotype aa survive best? Desert and Rocky
Which set of data represents a type of natural selection that stabilizes the allele frequencies of the population? The frequencies are pretty even around 50% for both allele A and a in the grassland. This is a good example of this dataset representing a type of natural selection that stabilizes allele frequencies in an environment.
...2 PAGES 305 – 310
Naturalselection: A process in which results in the characteristics of a population of organisms change over many generations. It occurs because individuals with certain inherited traits survive specific local environmental conditions and through reproduction, pass on their alleles to their offspring.
Selective Pressure: environmental conditions that select for certain characteristics of an individual and select against other characteristics
It may result from biotic factors as well, such as predators, parasites and competition for resources.
Example: population in Staphylococcus aureus, the individual members of the bacteria were selected by their environment.
They were able to survive the environmental change around them, and thus through reproduction passed on their genetic information against resistances to a particular antibiotic to their offspring’s.
NaturalSelection is Situational
IT HAS NO PURPOSE, WILL OR DIRECTION .
A trait that was once not used as an advantage for survival may be used in different times and situations for survival and reproduction
Fitness: the ability for an organism to survive and reproduce offspring’s that will live long enough to reproduce. The contribution to the gene pool of the next generation by producing offspring’s that survive long enough to reproduce
Described by the number of reproductively viable offspring’s that an organism produces in...
...relationship between structure and function in biology?
1. all kinds of organic matter
3. oxygen gas
Which statement about evolution is FALSE?
1. Naturalselection is about slow but steady progress. Through it, populations constantly get better-adapted. When this process is completed for all populations, evolution will come to a stop.
2. According to evolutionary theory, you are related to a bacterium, to a yeast cell, to a snake, and to a whale. In fact, you are related to every species now alive on Earth, and to fossil species like dinosaurs as well.
3. Naturalselection acts on genetic differences within a population to cause evolution. Individuals do not evolve.
4. Evolution occurs constantly, without end; there is no endpoint in evolution.
One organism gets larger as it passes through its life cycle. This is an example of __________.
Imagine you have a peanut butter sandwich in front of you. The sandwich is an example of _______.
You provide your gut bacteria with a warm place to live. They provide you with vitamins and other services. This most directly represents an example of...
2. shared ancestry of all life
4. interdependence of life
The ability or tendency of organisms and cells...
...UNIT 1 – LESSON 2 NOTES
NaturalSelection and Evidence for Evolution:
The mechanism for evolution is called NaturalSelection to distinguish it from Artificial Selection.
Evolution occurs at the population level because genetics don’t change. The frequencies of different genetic types (genotypes) within a population do change over time & can create new species.
There is genetic variation in all populations; some individuals are successful at surviving and finding resources & produce offspring sharing the same genotype as the parent.
Enough mutations are selected within the population to create new species.
Conditions needed for evolution to occur:
o Variation Within Population; differences in size, shape, physiology and reproductive abilities. Evolution requires variation within the population.
o Struggle for Existence (survival of the fittest); Darwin was influenced by Thomas Malthus—High birth rates and shortage of basic needs (food/shelter) forces organisms to compete for survival. The ability to survive in an environment is called fitness.
o Descent with Modification (ability of survivors to pass on their traits to the next generation); fitness traits must be heritable, species descended with changes from other species over time, appearing different from ancestors.
Naturalselection occurs without human intervention, bringing changes in the...
...concerned, nature selected the best adapted varieties to survive and to reproduce. This process has come to be known as naturalselection.
Darwin was correct in believing that the variation existed and that nature selected the most suitable beak shape against the less useful ones, not that the environment produced the variation, like some seemed to think. Darwin’s critics thought that he must have misinterpreted the Galapagos finch data. They seemed to believe that God had created the thirteen different species as they are and that there was no beak evolution as Darwin had suggested.
In 1798, Thomas Malthus, and English clergyman and pioneer economist, published Essay on the Principles of Population. In it he said that human populations would double every 25 years unless they were kept in check by food supply limits. After reading Malthus’ essay Darwin realized this idea also applied to all plant and animal populations. There is the opportunity for them to increase their numbers as high rate if there isn’t the constant threat of predators, diseases and limitations of food. Darwin then came to the conclusion that the most fit individuals in a population are the ones that are least likely to die of starvation and are most likely to pass on their traits to the next generation.
Another example of evolution resulting from naturalselection is the light and dark peppered moths. These were...
...Molluscs and NaturalSelection
The process of naturalselection is one of the most cited reasons for the evolution of a species, and it was made famous by Charles Darwin’s famous observations of finches in the Galapagos Islands. It is believed to work by way of random mutations; random mutations occur, as it indicates, randomly and spontaneously in a population for a multitude of genetic reasons. Mutations help to create variation of different traits within a species, and they can be expressed with different phenotypes. In times where a mutation has no negative effect on the individual organism, this trait could be advantageous in a new habitat or predatory situation, etc. With an advantage in survival, and thus reproduction, these organisms are often selected for over other members of the species, creating a change in variation of a species over generations.
Molluscs, although a very large and diverse group of animals, often share certain features: a mantle, radula, shell, and foot. The mantle is a thin and fleshy layer which secretes the hard shell of a mollusc. The radula is a grate-like structure in the mouth used to scrape surfaces and drill holes. The foot is a muscle which assists in locomotion and movement of the molluscs. It is hypothesized that all current-day molluscs share a common ancestor, called the hypothetical ancestral mollusc or HAM, because of the similar characteristics and body...
...Science NaturalSelection/Evolution Study Guide
- Charles Darwin developed the theory of evolution by naturalselection after collecting and studying many organisms on the voyage of the H.M.S. Beagle.
- Jean Baptiste Larmarck (1700s): he was a soldier and a biologist and an early proponent of the idea of evolution and natural laws.
- George Cuvier (1800s): Was in instrumental in establishing the field of comparative anatomy through his work in comparing living animals with fossils. He established extinction as a fact.
- Charles Lyell’s (1800s): his interests ranged from volcanoes to stratiography or basically Prehistoric Archaeology. He argues that earth was shaped by slow moving forces still in operation today.
- Alfred Wallace: best known for independently proposing a theory of evolution due to naturalselection. (This prompted Charles Darwin to publish his theory)
- Evolution: the development of new types of organisms from preexisting types of organisms over time.
- The theory of NaturalSelection: the process in which individuals that are better adapted to their environment survive and reproduce more successfully than less adapted individuals. Their environment selects the traits.
- Homologous Structures: anatomical structures that occur in different species...
...a chance you might have nothing to add to the conversation. And after hearing comments and arguments made by the rest of your company or family members, you would have wished you had a proposal to make. There are many breakthroughs that one could call upon, but there is one theory that has altered the way the human race thinks about how life had come about, and the changes millions of species around the world have made in the past to get to where they are today. The idea of simple organisms migrating, dying off, adapting, thriving and changing to fit their needs of survival was unheard of, or solely disregarded, for it was not supported by many or misunderstood. That is, until one man, Charles Darwin and his evolutionary theory of naturalselection was presented for the world to take into consideration. He provided mass amounts of evidence after traveling to the Galapagos Islands for research to support his ideas and eventually, his fundamental proposals would forever change the world of science, anthropology, philosophy, and faith.
To begin, Darwin tells us that every species (within populations) contains variation; they exhibit different physical features and/or behaviours from one another. Some examples include body size, voice properties, and numbers of offspring. These abbreviations can range from extreme shifts to minor alterations, and could also be beneficial or harmful. Changes in a species can occur due to environmental factors,...
...Darwin and NaturalSelection
1. Yes, this article is credible information. Daniel O’Neil, who is the Professor Emeritus of Anthropology Behavioral Sciences Department in Palomar College, wrote the article.
2. Based on the reading, we can infer that Darwin’s upbringing as a child was quite luxurious and opulent. We can interpret this from the facts that O’Neil tells us, such as his father, Robert, had the largest medical practice outside of London at the time and his mother, Susannah Wedgwood, was from a family of wealthy pottery manufacturers. The author also hints us by mentioning that Charles lived in a large house with many servants. We can also infer that he had a period of grief in his life, as the author tells us that his mother, Susannah, passed away, and he lived with his father and sisters.
3. This late 18th century theory of James Hutton states that the natural forces now changing the shape of the earth's surface have been operating in the past much in the same way. The most important implication is that the earth is very old and that the present is the key to understanding the past.
4. No, all people did not agree with uniformitarianism. An opposing theory to uniformitarianism is the theory of catastrophism. This theory states that the earth's geological landscape is the result of violent cataclysmic events. Advocates of this theory usually believe that there have been a number of wide-spread violent and...