Charles Darwin Project
By: Mikayla & Malia
What is Evolution?
What is natural selection and how is it lead to new species or a change in species over time?
Homologous vs Analogous structures
What do each tell about evolution?
~Fossils: physical evidence of an organism that lived long ago that scientist's used to study the past; evidence may appear in rocks, amber, or ice.
~Embryology: earliest stage of growth and development of both plants and animals. ~Molecular Evidence: change in sequence compostion of cellular molecules such as DNA, RNA, and proteins over long periods of time.
~Anatomy: the branch of science concerned with bodily structure of human, animals, and other living organisms, especially, as revealed by dissection and the separation of parts.
What is "survival of the fittest"?
Meaning~ The idea that species adapt and change by natural selection with the best suited mutations becoming dominant.
Origin~ By 'fittest', of course, Spencer and Darwin didn't have in mind the commonly used meaning of the word now, that is, the most highly trained and physically energetic. The 'fittest' referred to here are those animals which are the most suited to their environment, that is, those which are best fitted to survive.
What causes genetic diversity/ variation in species over time?
~When a population interbreeds, nonrandom mating can sometimes occur because one organism chooses to mate with another based on certain traits. In this case, individuals in the population make specific behavioral choices, and these choices shape the genetic combinations that appear in successive generations. When this happens, the mating patterns of that population are no longer random
~Nonrandom mating can occur in two forms, with different consequences. One form is inbreeding, occurs when individuals with similar genotypes mate with each other rather than others with different genotypes. The second form is called outbreeding, where there's an increased probability that individuals with a particular genotype will mate with individuals of another particular genotype. Whereas inbreeding can lead to a reduction in genetic variation, outbreeding can lead to an increase.
What are adaptaions & why are they important?
~An adaptation is something about an animal that makes it possible for it to live in a particular place and in a particular way. It may be a physical adaptation, like the size or shape of the animal's body, or the way its body works. Or it may be the way the animal behaves. Each adaptation has been produced by evolution.
~As the environment changes, animals that cannot adapt die out, and only the adapted ones survive to produce babies. Because babies are usually more or less like their parents, the whole species soon contains only animals that are adapted to the new environment.
~Animals in the wild can only live in places they are adapted to. They must have the right kind of habitat where they can find the food and space they need.
What is geographic & reproductive isolation?
~ Geographic isolation refers to the separation of two populations by physical boundaries, such as rivers, mountains, etc. Ex: the polar bear and brown bear isolation due to the oceanic and glacier barriers.
~Reproductive isolation occurs when two populations no longer produce viable offspring. Ex: Rainbow trout spawn in the spring. Brook trout spawn in the fall. These two species are isolated reproductively by time.