Unit 6 Biology Flashcards
What is the definition of Homologies
Features inherited from common ancestors
Evolution
Changes over time
Developmental homologies
Similarities in organisms that share a common ancestor
Molecular homologies
Similarities between species on the molecular level
Analogous structures
Similarities in organisms that don´t share a common ancestor
How can molecular homologies provide evidence for common ancestry?
2 species have the ¨same¨ gene because they inherited it from a common ancestor
How can Homologous structures provide evidence for common ancestry?
It can show traits that were passed down between two organisms from a common ancestor
What do the layers or strata of rock tell us about the age of fossils?
The oldest rock is on the bottom and the youngest rock is on the top.
Explain four factors that must be present for natural selection to take place
Variation, heritable, survival of the fittest, and adaptation
What is variation
Different traits and different organisms
Survival of the fittest
The ones who are best suited to the environment will survive
Adaptation
The ones who can gain traits
Heritable
If a trait is inherited or can be inherited
How does natural selection lead to an increase in fitness in a population?
Organisms without the best fitted traits survive and pass it on.
How does increased fitness lead to adaptations of populations over time?
Organisms with increased fitness will reproduce with offspring that have the best fitted trait.
