Adaptations
What is an adaptive trait?
An adaptive trait is a characteristic that benefits an organisms ability to survive or increases chances of reproduction.
How much of an offspring's DNA comes from each parent during sexual reproduction?
50%
If a population has more births than deaths it will...
Increase
What is a selection pressure?
A biotic or abiotic factor that exists an an environment for a long period of time, resulting in a change in what traits are beneficial for organism that live there.
What process leads to changes in species after long periods of time (Thousands to millions of years)
Natural Selection.
Examples:
Feathers, Beak, Talons, Color
Showing feathers to potential mates,
What are the two types of reproduction?
Sexual and Asexual reproduction
A group of newts have variation among poison levels in their populations. A population of snakes now inhabits the area for the last 50 generations. Being poisonous is beneficial. How will this population change over time? Explain
The population will likely have more newts with higher poison levels due to those with low poison levels being eaten more frequently and reproducing less over many generations.
There are two variations of earthworm in a population, Diurnal and Nocturnal feeders. The species of bird in this environment only feed during the day. Over many generations this population of worm will likely be mostly nocturnal. What is the selection pressure?
The birds in the area feeding during the day
What is the name of the molecule that hold the genetic information for Humans
DNA Deoxyribonucleic acid
What determines what makes an adaptation beneficial?
The environment the organism lives in, and the selection pressures present.
How are the offspring of sexual reproduction different than the offspring of asexual reproduction
Sexual: Genetically diverse from their parents
Asexual: Genetically identical to parents
Populations of white oak trees have variations in thickness of bark. Thicker bark protects them from insects, and there is now an invasive species of ant in the area they grow. The ants and trees live alongside each other for many generations. How might they both change after 50 generations
The white oak trees will likely all have thicker bark due to those without thicker bark being eaten by ants and reproducing less. The ants may develop the trait to break through thicker bark.
Saber tooth tigers were a common apex predator in the Americas 10,000 years ago. There is evidence that Human have lived in the americas for at least 17,000 years. Human hunt wooly mammoths for food, and greatly decreased the populations of wooly mammoths in the americas over time. As a result the saber tooth tiger lost its main food source and went extinct. What is the selection pressure?
True or False: All organism have the same molecule to transfer their genetics. (All organisms use DNA to control all aspects of their live, and all share some portion of their DNA with all other living things)
True
What is the only way that an organism gets an adaptive trait?
They have to be born with it. They cannot change after birth.
Some traits are more likely to be passed down than others. Ones that are likely to be passed if present in a parent is called _________________. One that is only likely to be present in the offspring when both parents have the trait is called ________________.
Dominant
Recessive
Two populations of the same species become separated on two different islands. What would happen to them over thousands of generations?
As long as the islands have different environments, they would likely become two sperate species
Give an example of a selection pressure that could occur in Chicopee
Ex. Cutting down more wooded areas, pollution, invasive species
A whales closest lang ancestor is a hippo. About 55 million years ago the two families branched off. The whales ancestor lived on land and over millions of years changed into species after species who were better adapted for life in the water. Why did this change take so long?
Natural selection is a slow process that takes many generations to gradually change the population of a species.
How are behavioral adaptations passed down from parents to offspring?
Instinctive inheritance (DNA) or cultural transmission (They learn it from their community)
Why aren't all offspring between two parents identical?
They get a mix of DNA from their parents, while they receive 50% from each , they may not receive the same 50% each time.
A population of elk has variation on the amount of fur they have on their bodies. Almost all of the population has high levels of fur. In a ten year span the average temperature in the area they live in has increased by 10 degrees. What may happen to this population?
They would likely leave the area, however if there is no where to go they would die out due to the extreme selection pressure.
Why is global warming a selection pressure that has many ecologist worried?
It is a worldwide change to many ecosystems climate (More/less rain, frequent/infrequent rain, temperature change) that has occurred quickly. Due to the rate of this change populations are often unable to develop mutations (adaptations) quick enough, and therefore must already have the beneficial variation present in the population in order to survive.
There are organisms that live in almost every inch of the planet. Deep in the ocean depths, beneath the ground, in some levels of the air. Use what we know about natural selection how might this have occured?
Populations have variations, some variations were better at allowing organisms to survive in certain environments. This lets them spread out into different environments, and over time become adapted to different areas.