Evolution Flashcards
What is law?
- Describing what happens. Facts observations
What is theory?
- Explaining an observation. Trying to come up with an idea based on facts
What is an adaptation?
- An adaption is a physical characteristic or behavior that makes a species able to survive better in a specific habitat
- Match the specific need of the organsim
What is a predator?
- A predator is an animal that only eats meat therefore only hunts prey
What is a prey?
- A prey is a herbivore animal that must run away from the predators to survive.
How do adaptations arise in species?
- Species develop over time through a process called evolution
Who wrote the origin of species?
- Charles Darwin
Pre zygotic?
- Before the gametes fertilize to create a zygote
What did Charles Darwin discover and how?
- He discovered natural selection
- By artificially selecting features, for example crossing birds with particular characteristics to create off springs.
What is natural selection?
- The process through which living organisms adapt and change.
What are some examples of natural selection?
- Evolving long necks has enabled giraffes to feed on leave other animals can’t reach
What is speciation?
- When a group of species separates from others in their species and develops its own unique characteristics.
Post zygotic?
- A change in an organisms genome that is acquired during its lifespan
The are the types of speciation?
- Allopatric : When a species splits into two separate groups
- Perapatric : When a smaller group is isolated usually from a very large group
- Sympatric : When there are no physical barriers preventing any members of a species mating with another
What are the 5 mechanisms of evolution?
- Mutation (Generates the genetic variation on which the evolutionary process depends)
- Genetic Drift (The change in frequency of an existing gene variant in the population due to random chance)
- Gene Flow (The movement of genes in or out of a population)
- Non Random Mating (A mating system in which at least some individuals are more or less likely to mate with individuals of a particular genotype than with individuals of other genotypes.)
- Natural Selection
What are the types of natural selection?
- Stabilizing selection (individuals with moderate or more average phenotypes are fit)
- Directional selection (individuals with traits on one side of the mean in their population survive or reproduce better)
- Disruptive selection (actively selects against the intermediate in a population, favoring both extremes of the spectrum)
Evidence of evolution?
- Consistency of the sequence of fossils from early to recent
What is hominid evolution?
- Modern humans and our evolutionary ancestors back to the separation of the human line from that leading to the living African apes
What is primate evolution?
- Apes are divided into lesser apes and greater apes
What are anthropoid traits?
- Relatively flat face
- Dry nose
- Small immobile ears
- Forward facing eyes
What are prosimian traits?
- Less inquisitive
- Less restive
- Less destructive
What are australopithecus traits?
- Large chewing teeth
- Thick enamel caps
- Slightly larger brains
What are homo halibis traits?
- Larger braincase
- Smaller face
- Smaller teeth
What are homo erectus traits?
- Human like body
- Elongated legs
- Short arms
What are homo sapien traits?
- large rounded brain case
- lack of brow ridge
- chin
- narrow pelvis
What are neanderthal traits?
- wide hips
- muscular bodies
- shoulders
- strong
What is a zygote?
- fertilized egg cell
Why do animals adapt?
- Animals adapt to improve their chance of survival in a less forgiving terrain
What does it mean when a species has similar DNA to others?
- They generally share a common ancestor
What is gene flow?
- It describes the movement of alleles from one population to another as a result of the migration of individuals
What is non random mating?
- Mating among individuals on the basis of a particular phenotype or due to inbreeding.
What is genetic drift?
- Is the change in frequencies of alleles due to random events in a small breeding population.
What best indicates that speciation has occurred?
- Two groups overlap geographically and do not interbreed
How is microevolution defined?
- changes in gene frequencies and phenotypic traits within populations and species
A community is founded by a small group of individuals, as a result there is a high incidence of dwarfism. This is an example of what?
- the founder effect
What is the founder effect?
- A migrant group of individuals that may carry genes in a different relative frequencies compared to the main population
Cross over, random assortment and mutation are some of the causes of what?
- Genetic diversity
A small number of individuals interbreed. These individuals have different genes than the original population. What is this?
- Genetic bottleneck
What is genetic bottleneck?
- Events that limit genetic variation in a population
Why do the galapagos islands have few large predators?
- They were unable to survive the trip from the mainland
What idea of uniforitarianism influenced charles darwin?
- Gradual geological changes that occurred in the past and present
What is sexual selection?
- The process by which animals compete for access to mate a fertilization opportunities
What is environmental selection pressures?
- A force that causes a particular phenotype to be more favorable in certain environmental conditions
What is temporal isolation?
- A difference in timing of critical reproductive events prevents members of closely related species from breeding
Which theory did Jean Baptiste suggest?
- Inheritance of acquired traits
What are vestigial structures?
- non functioning structures that serve no purpose to an organism anymore
How do you define the term gene pool?
- When there are different genes present in an interbreeding population
Define vestigial
- Something that either did not finish developing or through evolution become progressively more useless
Are chimpanzees considered hominids?
- No
What is convergent evolution?
- The process whereby distantly related organisms independently evolve similar traits to adapt to similar necessities
Which order did the older species of humans come in? 1 being the oldest.
- Australopithecus Afarensis
- Australopithecus Boisei
- Homo Habilis
- Homo Erectus
- Homo Neanderthals
- Homo Sapien
What are homologous structures?
- A similar physical feature in organisms that share a common ancestor, but the feature serves completely different functions
What are analogous structures?
features of different species that are similar in function but not necessarily in structure and which do not derive from a common ancestral feature
What is the temporal isolating mechanism?
a mechanism that prevents species from mating because they breed at different times
