Unit 3 Flashcards
What is needed for evolution to occur?
The genetic material (that produce traits) in the population must change, resulting in in changes in the traits expressed by the population
What does evolution mean on a genetic level?
The frequencies of alleles of genotypes in the population must change.
Mutations
The ultimate source of new genes (alleles) and thus variation
What are something important to remember about mutations?
The can spread from one generation to the next, altering allele frequencies.
A specific mutation even it not influenced by natural selection?
What is gene flow?
an Individual with different alleles may disperse to a new population and affect the gene pool of the population, leading to hominization’s of said species.
What is non-random mating?
In some populations, individuals that tend to look alike mate more frequently that would be expected if mating was random.
What is sexual selection?
Selection of reproductive traits at the potential compromise of survival.
Genetic drift is…
A random process that is important in small populations
What 2 processes work under genetic drift?
The founder and bottle neck effects
What is the bottle neck effect?
A large population decreases into a smaller one, and then when it becomes a large population again, it can only have the traits of those who survived the bottle neck
What is the founder effect?
A small group of dispersers colonizes a area, which may or may not be representative of the parent population.
Evolution will not occur if all of these things are present
No mutations
no genes transferred to or from other sources
Random mating is occurring
The population size is so large, it offsets genetic drift
no natural selection occurs
What is genetic equalibrium?
Frequencies of genes or traits are the exact same year in year out.
What assumptions need to be made to mathematically equate evolution?
Random mating, no mutations, large population sizes, no gene flow in or out, and no natural selection. In other words, no evolution
Does evolution operate at the population or individual level?
Population
What is the Hardy-Weinberg equation?
It is the mathematical equation P^2 + 2pq + q^2 =1
What does p, q and 2pq represent?
P^2 is the frequencies of homozygous dominate individuals
2pq is the frequency of the hetrozygous genotype
q^2 is the frequency of homozygous recessive individuals.
Why isn’t the dominant allele also the most common?
Dominance doesn’t equate to commonality, and things like predation can contribute to that.
What is to be said about populations over time experiencing genetic equilibirum?
Over time, a populations will cease to exist in equilibrium because its darn near impossible to stop evolution.
What did early primates most likely look like?
They were small and arboral
What are the characteristics of primates?
Limber shoulder joints
Dexterous hands and opposable thumbs
Claws replaced by flat nails
Sensitive fingers for tactile perception
Good vision and hand eye coordination
Extensive parental care.
Why can’t we have definite answers on our primate ancestors?
There are still fossil gaps and degrees of relationships
What does it mean to be human?
Bi-pedal locomotion
Large brain to body size ratio
Culture or the transmission of accumulated knowledge over generations
Degree to which we manipulate our environment
Ability to acquire food.
What are some characteristics of Australopithocus afarensis?
They live in trees, are bi-pedal, climate change forces them to walk because of droughts, they walk upright to save energy in raising babies.
What are some of the characteristics of Paranthropus boisei
Gorilla Like, they are specialists, which was their demise. cannot build shelter, and loved termites
What are some of the characteristics of Homo Habilis
They were scavengers, struggled with dry weather, they were generalists, made stone tools, have more developed brains.
What are some of the characteristics of homo ergaster?
Long modern noses, sweat glands, they could do deductive reasoning, 1/6th size of our brain, the big brain was expensive but used for understanding other emotions, could make voices, roamers, White in eyes, monogamous between males and females. Left Africa.
Characteristics of Homo Erectus
No stone tools, lived in the eastern world, ate lots of foods,
Characteristics of Homo heidel bergensis
Larger brain yet, behave much like us, but abandon family and have no imagination.
Characteristics of Homo Neanderthals
Live in the north, smaller then us, short limbs, nose was bigger, still lack imagination. Thirved for the most part, but were also specialists.
Characteristics of homo sapiens
Like us, taller and slimer with dark skin. Lived in drought and almost went extinct, bottleneck effect, have an imagination from the bottleneck, thinking ahead, Used language, and spread across the globe
What was the movies important quote?
In evolution, you don’t have to fail, just succeed less often.
What is the proposed sequence of events during the origin of life
1.) Origin of simple monomeric compounds
2.) Assembly of monomers into polymers.
3.) Replication of nucleic acids
4.) Packaging-membranes and cells form into protobionts
5.) Production of complex molecules and processes
MIller and Urey’s experiment
Simulated primordial atmospheres, which gave the same reaction of what would have happened, producing simple monomers. Further testing could give you polymers
What did the miller urey experiment prove?
That it was possible to get theses simple monomers with the primordial conditions, proving the essentials for the abasis of life.
In extinction, there are some characteristics that make a species more vulnerable. What are they
Rarity, Dispersal ability, Degree of speculation, population variability, food chain position, life span, and reproductive ability.
Perturbation
A human caused disruption of the biota or the physical environment
2 major differences between disturbances and perturbation
1.) Human involvement
2.) Time frame and temporal scale.
What are the two types of ecological disrutions?
Pulse/Press
What is a pulse?
A discrete event that allows the system to recover
What is a press?
A more continuous disruption that does not allow the system to recover
What are natural distrubances?
Pulses
What are human disturbances?
Both pulses and presses
Are perturbations new or old and whats the result of that?
They are new, so biota are not adapted to them, they affect the resilience or resistance potentials of ecosystems.
