Bio 172 Exam #1 Material

notes from lecture including main topics and vocab

what are the four mechanisms that allow evolution to occur?

natural selection, sexual selection, gene flow, and random genetic drift

evolution

genetic change in a population, refers to the change in frequency or relative abundance of genes and alleles present

ecology

the study of factors which determine the distribution and abundance of organisms

natural selection

a mechanism for evolution which was first proposed by Alfred Wilson

what are the three prereqs or conditions which allow natural selection to occur?

1. character variation exists in the population

2. hertiability

3. character variation must lead to fitness variation

fitness

the number of fertile and viable offspring produced per individual per lifetime

components of survival ship and reproduction

age specific survivor ship, transitional survivor ship, and age specific fecundity

age specific survivorship

attempts to describe the likelihood of surviving to a different age, notated as L sub x, the chance of living birth / germination to the start of age x

transitional survivorship

probability of living from age x to age x+1, notated as p sub x

age specific fecundity

average number of offspring produced per individual of age x, notated as m sub x

r

population growth rate (individual/individual/time)

R sub knot

net productive rate (number of individuals)

Carolus Linnaeus

published Systema Naturae which organized plants with his orderly system and classification based on the number and position of sex features plants had (pistons&stamens)

The Great Chain of Being (Scala Naturae)

a list with the most important and complex beings at the top and the least important things at the bottom eg rock to plant to animal to man

Buffon

the director of a botanical garden with a zoo, questioned differences between species like dog and cat along with the little variation between breeds within the species, concluded the Earth was older than the Bible stated bc of 1) diameter of the earth 2) ambiance of crust 3) molten core

Cuvier

director of Nat Museum during Industrial Rev, a resident professor of vertebrae zoology who used comparative anatomy to determine what organisms looked and determined there were organisms that were being found that are extinct, theorized catastrophism was what caused the extinction

Smith

built canals for Industrial Rev and discovered fossils in this process, noted that there were distinct layers in the strata and the older ones contained organisms that were no longer alive and possibly extinct whereas the newer layers did not contain much evidence of past life, he concluded that because of this there was change through history

Hutton

Edinburgh geology professor who studied erosion as a method to explain the change in landscape / environment / natural features like rocks, proposed gradualism and that the Earth is dynamic with a constantly changing surface & environments change

Lyell

published geology encyclopedias with a gradualism emphasis, which he coined as uniformitarianism because the previous word was used by his mentor / teacher Hutton, he also mentions how the Bible chronology isn’t reasonable because of his findings to Mt. Edna

Rev TR Malthus

worked for the church of England as a demographer, he used data records from the 1760s to publish his 1798: Essay on the Principle of Population which had main ideas 1) how populations grow (exponentially not linearly) 2) with exponential growth of populations there is a struggle for existence with diminishing food resources (bc of social class differences the demographics were affected)

Alfred Russell Wallace

proposed that he might know why life forms had such wide variety of shape and sizes along with how they came to that point, used his field study of beetles on an island to provide evidence to his theory, wrote his first manuscript in June 1958

Charles Darwin

studied bird species on the Galapagos Islands, in Nov 1859 he published his ideas on natural selection but it was heavily edited since he didn’t include any details on concepts or ideas that were not thoroughly backed up by his field evidence

the five components of a natural selection study

- s>0, there is variation in the population

- heritability > 0, the character is heriable

- differential fitness among characteristics

- demonstrate change by using records or collecting data before the evolutionary event occurs

- selective agent (biotic / abiotic)

give the five components of a nat selection study for the Biston Betaine typica / carbonara moths example

1) variation existed - peppered / completely covered

2) Mendelian genetics proved that the typica was characterized by a dominant allele and the carbonara had the recessive allele

3) the differential fitness differed among individuals for survival or predation against birds

4) demonstrated change by previous records collected on these moths in unpolluted forest and polluted forest

5) selective agent ~ predation from birds, lower for typica in polluted woods but lower for carbonara in unpolluted

give the five components of a nat selection study for the medium ground finch at Daphne Island example

1) variety of beak depth with distribution among individuals

2) character of beak depth was proven heritable by the use of parent offspring correlations

3) differential fitness occurred when there were differences in survival rates during drought weather / rainstorm weather

4) collected records before the evolutionary change happened

5) selective agent ~ seed availability and seed size

give the five components of a nat selection study for the Dakota cliff swallows example

1) variation in body mass, tail and wing symmetry

2) from a storm that occurred, the researchers picked up perished birds and from that created a graph which warranted that the characteristics of body size is heritable because the offspring avg body size was the selection response

3) differential fitness occurred for survival during harsh weather for those in differences between body mass, and for those in larger differences in asymmetry in the tail and wings

4) demonstrated change by observing findings used in the second prereq and their records from before the storm

5) selection agent ~ weather (storms)

abiotic selective agent

nonalive things that cause differential fitness like weather and temperature

biotic selective agent

alive things that cause differential fitness like disease, predators, human intervention

adaptations

features that arise by natural selection to enhance fitness in a specific environment

to demonstrate an adaptation you must

1) the features are environment specific

2) maintained complex features are most likely adaptations

3) comparative method test

comparative method

looking for the presence or absence of a character across an environmental continuum

give two examples of the comparative method test

1) body mass relative to testes mass in gorillas depending on if they were a part of hookup culture or had lifelong mates, the environment where the behavior is tolerated had bigger balls

2) pine trees in fire frequent areas producing serotinous cones so when the forest fires happened, the cone could germinate with little comp and plenty nitrogen rich soil

the six reasons why adaptations are never perfect

1) natural selection

2) developmental pathways are a restriction

3) environments change

4) other evolutionary mechanisms

5) all adaptations are a compromise

6) adaptive landscape

things in nature that aren’t adaptations

1) pre-adaptations

pre-adaptation

secondary applications that inter perform to the original existence of a character and may provide a benefit