Evolution
Skill 1: How do changes in a population over time occur?
Research classes - create an individual model of evolution
Research classes - create an individual model of evolution
*Class activity - Play "Draw the Dog" to show the accumulation of mutations. (Groups need to be exactly 6 people.)
*Class activity - Play "Draw the Dog" to show the accumulation of mutations. (Groups need to be exactly 6 people.)
Crossing over leads to variety in gametes, or sex cells.
Crossing over leads to variety in gametes, or sex cells.
Which two chromosomes above are 'recombinant?'
Which two chromosomes above are 'recombinant?'
Two gametes with vastly different genetic information combine to form a unique individual.
Two gametes with vastly different genetic information combine to form a unique individual.
Many unique individuals have different strengths and weaknesses. In a particular environment, one may be better suited to survive than the others which is called "survival of the fittest", or "natural selection."
Many unique individuals have different strengths and weaknesses. In a particular environment, one may be better suited to survive than the others which is called "survival of the fittest", or "natural selection."
This drives evolution, or the change in a species over time. Notice that the oldest ancestor of the Orca pictured lived on land. As the species spent more time in the water, the more streamlined individuals had higher survival rates, leading to the changes in the species over many generations.
This drives evolution, or the change in a species over time. Notice that the oldest ancestor of the Orca pictured lived on land. As the species spent more time in the water, the more streamlined individuals had higher survival rates, leading to the changes in the species over many generations.
Can you think of one other source of genetic diversity in a population?
Can you think of one other source of genetic diversity in a population?
What is an adaptation?
What is an adaptation?
What makes an individual more 'fit' to survive in a given environment? Adaptations do!
What makes an individual more 'fit' to survive in a given environment? Adaptations do!
This is one of those times where we use the word differently in English than in science. We say that a person adapts to things around him. For example, if school started earlier next year, you might hate it, but you would adapt...that is you would gradually get used to it and it would be fine.
This is one of those times where we use the word differently in English than in science. We say that a person adapts to things around him. For example, if school started earlier next year, you might hate it, but you would adapt...that is you would gradually get used to it and it would be fine.
In biology, an adaptation is a genetic variation that gives one individual a survival advantage over others of the same species. Remember that we are all different in our abilities. That makes some of us more fit for certain classes or sports. A deep thinker might do better at chess while a fast runner might run track or play soccer. Organisms DO NOT create adaptations for their environments, as they cannot change the DNA they were born with. Their behavior may change, or adapt, and that might be enough, but sometimes it is not. You are born as you are and your traits either help you survive or you die. With certain individuals surviving, they pass on the helpful trait (adaptation) more often and the species changes over time. If an individual does not have the adaptation, it will have less offspring and die younger, leading to less of the undesirable traits in a population over time.
In biology, an adaptation is a genetic variation that gives one individual a survival advantage over others of the same species. Remember that we are all different in our abilities. That makes some of us more fit for certain classes or sports. A deep thinker might do better at chess while a fast runner might run track or play soccer. Organisms DO NOT create adaptations for their environments, as they cannot change the DNA they were born with. Their behavior may change, or adapt, and that might be enough, but sometimes it is not. You are born as you are and your traits either help you survive or you die. With certain individuals surviving, they pass on the helpful trait (adaptation) more often and the species changes over time. If an individual does not have the adaptation, it will have less offspring and die younger, leading to less of the undesirable traits in a population over time.
Which species below would evolve the fastest? Justify your answer.
Which species below would evolve the fastest? Justify your answer.
1. Horses
1. Horses
2. Dogs
2. Dogs
3. Mice
3. Mice
4. Bacteria
4. Bacteria
