Darwin and Natural Selection Flashcards
There are 4 main points to the evolutionary theory of natural selection.
List all 4 points
- Members in one population vary from one another. Their varying traits are all inherited.
- There is always competition for natural resources. Because of this, the fittest individuals contribute more offspring than others.
- Natural selection acts on traits passed down generations.
- The process for change is slow and gradual.
What is natural selection?
It is the way in which the environment, or nature, favours reproductive success of certain individuals over others.
According to Darwins theory, evolution is the result of…?
Natural selection occurring over many generations.
What was Darwin’s key observation about the ratio between adults and offsprings in a population?
His observation was that in each generation, populations produce more offspring than there are adults.
What was Darwin’s observation on population size?
His observation was that it does not grow in size.
What was Darwin’s observations on the natural resources?
His observation was that food and other natural resources were limited.
If populations do not grow in size, has a higher ratio of offspring to adults, and that resources for these populations are limited, what might be the result in individual behaviour?
The result would be that individuals in a population will have to compete for these limited resources.
What was Darwins observations about individuals who vary within populations?
He observed that some individuals inherit other characteristics that give them a higher chance of survival and reproduction.
What does the theory of evolution predict?
It predicts that evolving species will respond to climate change because different environmental conditions will favour different traits.
Are native amphibians or large land animals found on remote oceanic islands?
No, this is because these species do not have the ability to fly/swim the distance to inhabit these islands.
Can some organisms have zero vestigial features?
All organisms that have been fully studied has shown that they all have many vestigial features.
What evidence from Darwin’s personal life suggests that he had developed his theory but was very hesitant to make it public? Why do you think Darwin might not have wanted to publish his ideas?
Evidence from Darwin’s personal life suggests that he had developed his theory but was very hesitant to make it public because he didn’t want to receive backlash because of people at the time’s religious values and he feared that it was controversial.
Use one or two examples to explain what Darwin meant by the term “selection.”
He meant that the environment favors reproductive success of certain individuals over others.
A male walrus lives to be 20 years old and mates with 18 females during its life. A second male lives to be 10 years old but mates with 44 females. Which male has natural selection “favored?” Explain your reasoning.
The second male walrus is favored by natural selection because in comparison to the first male walrus, he has more reproductive success. This will allow the more offsprings to survive in the environment and pass on the advantageous heritable characteristics onto more generations
Suggest a probable selective advantage for each of the following traits.
Clear wings of many flying insects
The selective advantage of clear wings in flying insects would be for camouflaging while in flight so birds and other larger prey will have a harder time locating them seeing as they dont stand out.
