17 terms

Biology: 3A


Terms in this set (...)

Common descent
All species living and extinct are descended from one ancient common ancestor.
Descent with modification
Passing traits from parents to offspring
Darwin's Tree Thinking Diagram
Lamarck's explanation of species over time and its flaws
Lamarck thought that traits could be picked up during an organisms lifetime and could be passed onto its offspring. For example, he would think that if a water bird had short legs, it could acquire long legs during its lifetime, so it could hunt for fish in deeper waters. However, Lamarck's ideas were flawed because traits acquired by individuals during their lifetime could not be passed onto offspring. For example, if a mother loses her hand in an accident, that doesn't mean her kids will be born without a hand.
What is artificial selection and how have humans used it?
Artificial selection is when plants or animals are picked to breeed with another. Humans have used artificial selection for dog breeding. For example, if a person desired a tiny lap dog, humans could breed tiny Chihuahuas that have a history of small ancestors to obtain this small lap dog.
How did the concepts of artificial selection influence Darwin's ideas of natural selection?
The concepts of artificial selection influenced Darwin's ideas of natural selection because he figured if humans could create variation in a few hundred generations, then nature could also create variation over a longer period of time that led to the very diverse lifeforms on this earth.
Homologous structures
Homologous structures have the same structure but different functions. For example, the front limbs of reptiles and birds. Shows evidence of common descent
Analogous structures
Analogous structures have different structures but same functions. For example, dolphin fins and penguin fins. Doesn't show evidence of common descent.
Vestigial structures
Vestigial structures have no function now, but once had a function in an organisms ancestors. For example, the tailbone in humans. Shows evidence of common descent.
Darwin's Theory of Natural Selection and the reason it is considered a scientific theory.
Darwin's Theory of Natural Selection says traits that help an organism survive and reproduce will be passed onto future generations.
Adaptation and Fitness and their roles in biological evolution
Adaptation and fitness are both related to the theory of evolution. Darwin developed a scientific theory of biological evolution that explains how modern organisms evolved over long periods of time through descent from common ancestors. Individuals with adaptations that are well suited to their environment can survive and reproduce and are said to have high fitness.

Fitness is the ability an organism has to survive its environment and create offspring, and eventually become the most dominant species. Being "fit" pertains to natural selection what is an animal's ability to survive and create offspring.

Adaptation is how organisms grow accustomed to a new environment; a physical characteristic that improves an individual's ability to survive and reproduce in a particular environment
Superbugs, their impact on human health, and how they relate to natural selection
Superbugs are bacteria that can't be killed using multiple antibiotics and it is very impactful on human health because people are dying of ordinary infections since the superbugs are resistant to existing drugs. Superbugs relate to natural selection because the bacteria with antibiotic resistant traits survived and reproduced.
Why it is important to not take antibiotics if they are not needed? (example-for a cold which is a virus)
Because when an antibiotic is being taken when it is not needed, they are giving more bacteria a chance to become resistance to antibiotics.
Why, if you do take antibiotics, it is important to take the entire dosage for the entire length of time?
To make sure the antibiotic resistant bacteria dies out. Since these bacteria usually are much harder to kill, the only possibility they have of being killed is if you take the prescribed antibiotics the full time.
Why an antibiotic that has worked several times in the past for a person, may not work anymore for that person?
Because now the body is filled with antibiotic resistant bacteria that can't be killed with the same antibiotics.
Desribe Darwin's Theory of Natural Selection using the rock pocket mice example. Identify and discuss each of the 5 components of Darwin's Theory of Natural Selection in the order they would occur.
- A variety of different traits
- Mice could be light or dark

- More offspring than the environment can support
- The mice will overproduce for higher chances for the species to survive.

- For food mates nesting sites escape predators
- Having dark fur on the lava rock or light fur on the sand

Differential survival:
- Successful traits = adaptations
- Traits that will help organism survival
- The dark colored mice can avoid being killed by predators on dark lava rock and light colored mice can avoid being killed by predators on the sand.

Differential reproduction:
- Adaptations become more common in population
- Overtime, dark lava rock will be more populated with darker mice and sand will be more populated with light mice.
3 pieces of evidence that show that modern whales evolved from a 4-legged land mammal
Comparative anatomy:

Whales breathe air with two fully developed lungs. They don't have noses like mammals do but they breath through their blowholes which is like a highly developed animal nose.

Through comparative anatomy, we can see that whales are like land mammals because they both breathe air with lungs. This is evidence of evolution because it shows how they have similar traits and an example of descent with modification.

Embryology and development:

In early fetus' of dolphins, they have nostril grooves just like in a puppy and human.

Through Embryology and development, we can see that puppies and whale's both have nostril grooves in their early fetus form. This is evidence of evolution because although the whale's nostril grooves eventually move together to form a blowhole, it shows how they have very similar structures in their developmental stages.

DNA comparisons:

Hippos and whales have very similar ankle bones and are missing a coat of fur.

Through DNA comparisons, we can see that whales come from a four legged land mammal because the closest genetic match of the whale is the hippo. This is significant because it shows how both the whale and the hippo came from one common ancestor since their DNA codes for similar ankle bones and are both missing a coat of fur.