Chapter 13-14 Biology

Malthus essay led Darwin to which of the following generalizations

evolution is most likely to occur when populations are subject to strong pressures such as famine and predication

macroevolution

evolution on a scale of separate gene pools. macroevolutionary studies focus on change that occurs at or above the level of species, in contrast with microevolution, which refers to smaller evolutionary changes within a species in a population

gemetic

for fertilization to occur, the sperm much reach the ovum. For this to happen they usually attract each other through chemical means, but the chemicals might vary from one specie to another. In this case gametes will not recognise each other and fertilization won't take place

sedimentary rock

formed by the deposition of material at the earth's surface within the bodies of water mix

microevolution

the change in allele frequencies that can occur over time within a population - this change is due to four different processes; mutation, selection (natural and artificial) gene flow, and genetic drift

lyell

the earth is formed by gradual forces - acts slowly to evolve

Lyell's book Principles of Geology, which Darwin read on board on the HMS Beagle, argued for which of the following concepts

the earth's surface is shaped mainly by forces that act gradually and are still acting

artificial selection

- controlled by humans - guided - does not necessarily select for genes that are adopted to the environment - has only occurred since humans began selectively breeding organisms

descent with modification

- evolution only occurs when there is a change in a gene frequency within a population over time - heritable and can be passed on to the next generation - long term change

natural selection

- occurs in nature without human intervention - selective pressures from the environment - promotes selection of genes that are best adapted to the environment - has been occurring since life itself

identify the four reasons natural selection cannot generate perfection?

- organisms are limited by historical constraints - chance variations - adaptations are compromises - selection can only edit existing variations

which of the following provides evidence that modern species have evolved from prior species

- the fossil record - comparative embryology - comparative anatomy - bio geography

how do fossils form

- the hard parts of animals that are rich in minerals, such as teeth and the shells of clams, may remain as fossils - insects and other small animals are preserved in amber or fossilized tree resin - actual organic material remains if an organism is buried in a medium that prevents bacteria and fungi from decomposing it - the remains of dead organism are sometimes turned into stone by perfection

factors that limit the degree of adaptations that can occur in a population

- the size of the gene pool - the speed at which the environment changes - population size - variation within the gene pool

identify and explain 5 sources of evidence that can show us how species have evolved

1. Comparative Anatomy 2. Comparative Embryology 3. Comparative Biochemistry 4. Biogeography 5. Fossil Record

5 conditions of the Hardy Weinberg Equalbrium

1. No mutations 2. No natural selection 3. Population sizes remain large 4. no individuals migrate into or out of the population 5. mating is random "Nate never prescribes people medicine"

in the 1700's _______ raised the possibility that certain fossil forms might be ancient versions of similar

Buffon

stabilizing selection

Stabilizing selection is the opposite of disruptive selection. Instead of favoring individuals with extreme phenotypes, it favors the intermediate variants - reduces the phenotypic variation. Ex: human birth weight

disruptive selection

disruptive selection describes the changes in population genetics in which the extreme values of a trait are favored over intermediate values - divided into two distinct groups. Ex: rattlesnakes blending into patchy environments

population

a group of organisms of one species that interbreed and live in the same place at the same time

postzygotic

a mutation that an organism acquires during its lifespan, rather than inheriting from its parents by the fusion of the haploid pronuclei in the sperm and egg

specification

an evolutionary process by which new biological species arise

genetic drift

chance changes in the gene pool of a small population

homologous

common origin or ancestry - modify for diverse jobs ex:a dolphins flipper, and a bird wing

how do we define what a biological species is?

defines a species as members of populations that are actually of potentially interbreed in nature; not according to similarity or appearance. Although appearance is helpful in identifying species, it does not define species

fitness

describes the ability to both survive and reproduce - equal to the average contribution to the gene pool of the next generation that is made by an average individual of the specified genotype or phenotype

mechanical

different species may have different sex organs which aren't compatible. It just won't fit haha

directional selection

directional selection is when the extreme phenotype is favored over the phenotypes, causing the allele frequency to shift over time in the direction of of that phenotype. Ex: moths shifted towards the darker variation when the environment changes

behavioural

during the selection of a possible mate, individuals from different species may discard each other as they don't have the same mating rituals

prezygotic

happens before fertilization - between gametes isolation keeps different species from sexually reproducing - if individuals cannot reproduce, they are considered to be different species and diverge on the tree of life

what term is used to refer to structures that have similar origin or ancestry even though they may be very different in appearance

homologous

punctuated equilibrium

hypothesis in evolutionary biology which proposes that most species will exhibit little net evolutionary change for most of their geological history, remaining in an extended state called stasis

the genetic variation among individuals in a sexually reproducing population of a plant that does not self-pollinate is the result of

independent assortment of chromosomes during meiosis

temporal

individuals from different species may be in season at different times in the year so they won't be interested in copulating at the same time

hybrid sterility

inhibition or suppression of the reproductive capacity of the F1 or later generation hybrids between genetically different strains or populations, usually belonging to different species

differential reproductive success

is the idea that those organisms best adapted to a given environment will be most likely to survive to reproductive age and have offspring of their own. Organisms that are successful in their environments will be more likely to be successful in reproduction, and therefore the better-adapted organisms will reproduce at a greater rate than the less well-adapted organisms

observations Darwin made on his rip to the Galapagos

kept a diary, extremely detailed notes and drawings and thoughts about species he found their

main difference between Lamarck and Darwin

lamarck identified that traits you get in your lifetime you can pass on. Darwin said you either have what you need when you're born, if you don't then you are less likely to survive.

habitat

living begins from different areas and cannot possibly meet either

bottleneck effect

loss of alleles due to unique populations - the sets of alleles are lost forever

the founder effect

loss of genetic variation - occurs when the new population is established by a very small individuals from a larger population

vestigial structures

lost much of its ancestral function ex: human appendix

lamarck

mechanism was flawed - there was some sort of change. Made it more easily identifiable to find the meaning of natural selection

a change in the relative frequencies of alleles in the gene pool of a population is called...

microevolution

nonrandom mating

people usually select mates non-randomly for traits that are easily observable (phenotypes). When mating is not done by chance, it is likely there has been human interference

mutations

permanent type of change of the nucleotide sequence of the genome of an organism, virus, or extrachromosomal DNA or other genetic elements

what is the smallest unit that can evolve

population

malthus

population - people die when their are too many people

when populations are hunted to near extinction and they are able to rebound, what are the long term concerns for the species? what happens to the genetic diversity in the gene pool?

population bottleneck; smaller population with a corresponding smaller genetic diversity remains to pass on genes to the future generations of offspring. genetic diversity remains lower.

hybrid inviability

postzygotic barrier which reduces a hybrid's capacity to mature into a healthy, fit adult. the relatively low health of these hybrids relative to pure-breed individuals prevents the gene flow between species

analogous

preforming a similar function but having a different evolutionary origin such as the wings of insects and birds ex: fins on a penguin and fins on a fish

adaptive radiation

process in which organisms diversify rapidly into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges and opens up environmental niches

sympatric speciation

process through which new species evolve from a single ancestral species while inhabiting the same geographic region- in the midst of population - new species occurs - same home -new species arises - caused by mutations

hybrid breakdown

produce fertile young, but over generations offspring become less fit and fewer in number

trace fossils

provide us with indirect evidence of life in the past

allopatric speciation

relating to or involving 2 populations of the same species which cannot interbreed because they are separated by as geographic barrier (mountain range, or wide river) - different environment - genes do not mix - eventually become different species

gradualism

the hypothesis the evolution proceeds chiefly by the accumulation of gradual changes

inheritance of acquired traits

the idea that an organism can pass on characteristics that it acquired during its lifetime and to its offspring

strata

the layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from the outer layers

gene flow

the movement of alleles within a population that alters the allele frequency

petrification

the process by which organic matter exposed to minerals over a long period of time turn into a stony substance

what are Darwin's theory of natural selection?

the strong will reproduce, weak die, resources are limited, inherited traits (favorable or not) overpopulation - lack of resources

what was Darwin's job on the Beagle?

to make maps of South America - he was the naturalist on the ship - job to understand the nature around him

wallace

younger, collaborated with Darwin - reached out to him