DAT Biology - Evolution

Evolution

Gradual change of heritable traits over time over successive generations

Paleontolgy

the study of fossils

What are the two types of fossils

actual remains and ichnofossils

ichnofossils

Traces of animal like footprints and nests

Petrification

The body becomes buried under layers of sediment

how does petrification occur

minerals seep into the body and replace organic material to get a hardened corpse

What evidence of evolution do we get from fossils

anatomical changes and fossil timeline

What gives us evidence of anatomical changes and a timeline of fossils

Fossils

What Biogeography evidence explain in evolution

The spread of different species around the world

What is biogeography based on

the fact that pangea seperated into 7 different continents

What evidence of evolution does biogeography bring

The fact that geographical barriers made each organism specifically adapted to its surrooundings

What evidence proves that geographical barriers made each organism specifically adapted to its surrooundings

Biogeography

What evidence proves that embryological similarites observed during development stage in related organisms

Embryology

What is an example of embryology proving evolution

In phylum chordata, a gill slit is visible at some point in development

how does embryology prove evolution

embryological similarites observed during development stage in related organisms

Homologous structures

structures that may or may not perform the same function but are derived from a common ancestor

Analogous structures

structures that perform the same function but are not derived from a common ancestor

Are homologous structures derived from the same ancestors

yes

Are analogous structures derived from the same ancestors

no

Do analogous structures serve the same function

yes

Do homologous structures serve the same function

they might

What does comparative anatomy include

homologous, analogous, and vestigial structures

Vestigial structures

structures that exist but serve no purpose in the organism

Whats an example of a vesitigial structure

ostrich wings, they are homologs to eagle wings

What evidence brings forward the fact that as we compare different body parts from different animals, we start to see the possible connections between them

Comparative anatomy

What evidence of evolution does comparative anatomy bring

as we compare different body parts from different animals, we start to see the possible connections between them

Biochemical evidence of evolution

We see conserved DNA regions across species when comparing DNA sequences, as well as common observed pathways

What is an example of biochemical proof of evolution

Chimpanzees share 98% similarity in their DNA with humans

What evidence brings forward the fact that We are able to observe consered DNA regions and common pathways across related species

Biochemical

What does biochemical evidence bring forth

the fact that We are able to observe consered DNA regions and common pathways across related species

What does the ETC and the krebs cycle prove

That eukaryotes share common pathways and in turn share common pathways

what are the five evidence of evolution

1. Fossil record

2. Comparative anatomy

3. Comparative embryology

4. Molecular (biochemical) evidence

5. Biogeography

Who proposed catastrophism

Baron cuvier

What did baron cuvier propose

catastrophism

catastrophism

Proposed by baron cuvier, it proposed that sudden catastrophies shape the landscape and organism distribution to allow new organisms to populate the area

What two theories did jean baptiste lamarck propose

Use and disuse

and inheritance of aquired traites

Use and disuse theory

proposed by jean baptiste lamarck,

proposes the more used a body part is, the more it will develop, and the less used a body part is, the more it will weaken

IN ONE ORGANISM

Inheritance of aquired traits theory

proposed by jean baptiste lamarck

said that whatever characteristics an organism aquires throughout its life will be passed onto offspring

Which one of jean baptiste’s theories is wrong

Both of them

What did charles darwin propose

the theory of natural selection

What was charles darwin’s theory inspired by

The malthusian theory of population growth

What did thomas malthus propose

The malthusian theory of population growth

The malthusian theory of population growth

Unchecked populatuion groeth leads to a population that outgrows available resources, resulting in the malthusian catastrophe

What is the malthusian catastrophe

many members of the population die of starvation, and the remaining are froced to return to basic survival

What is evolution

the change in allele frequencies over time

What happens to organisms that are better adapted to survive and reproduce in an evolutionary viewpoint

Populations evolve over time to be more like that

Natural selection

the gradual, non random process where alleles become more or less common due to the individual’s interactions with the environment

What is fitness

the ability of an organsim to survive and produce viable and fertile offspring

What are the 4 requirements of natural selection

1. more demand than supply

2. difference in fitness

3. heritable traits

4. Variation of traits must be significant to reproduction and/or survival

What does the more demand than supply rule mean in natural selection

Natural selection occurs on the basis that there is an insufficient supply of recources to growing demand

Only the ones that are most fit can get the recourses, and in turn pass on their genes due to surviving

What does the Difference in level of fitness mean in natural selection

Organisms must have different fitness, not necessarily due to the trait (at least in the case of this rule)

is evolution random or non random

non random

What does Trait heritability mean in natural selection

Traits must be heritable or genetically influenced to be passed down

What does variation in traits being significant to reproduction/survival mean in natural selection

It means that genes that produce tratisSta that improve survival and/or reproductive suceess will be favored and increase in frequnecy as generations pass

stabilizing selection

mainstream is favored, and extremes are selected against

What is an example of stabilizing selection

average babies born are around 3.5 kg

Directional selection

one extreme is favored

What is an example of directional selection

black color moths where morefavorable than white colored moths in the industrial revolution

Disruptive selection

Extremes are favored, and maintream ones are not

What is an example of disruptive selection

Breeds of snails live both in low vegetation and high vegetation areas

How do males increase their fitness

by boosting the quantitiy of offspring

How do females increase their fitness

by boosting the quality of offspring

Sexual selection

non random mating between a male and a female

Why is sexual selection different from natural selection

evolutionary changes favorable to sexual selection could actually lead to less survival

Artificial selection

selection carried out by humans that selectivley breed for favorable traits

What is gene equilibrium

no change in allele frequencies, leading to no evolution

Alleles calculation in hardy weinberg equilibrium

p+q = 1

P = frequency of dominant

Q = frequency of recessive

Individals calculation in hardy weinberg equilibrium

p²+2pq+q² = 1

p² = frequency of homozygous dominant

pq =

q² = frequency of homozygous recessive

What if p²+2pq+q² = 1 and p+q = 1

There is no evolution, and the population is at hardy weinberg equilibrium

Memnemonic for a population to be in hardy weinberg equilibrium

Large random m&m

Large population

random mating

no mutation

no natural selection

no migration

How does large population help hardy weinberg equilibrium

it minimizes the effects of genetic drift

genetic drift

random increase or decrease of allele frequencies

How does random mating help hardy weinberg equilibrium

Individuals do not seek a particular type of individuals to mate with

How does no mutation help hardy weinberg equilibrium

Prevents new alleles in the population

How does no natural selection help hardy weinberg equilibrium

the environment is not impacting allele frequencies

How does no migration help hardy weinberg equilibrium

no gene flow

Gene flow

movement of genes in or out a population

allele frequencies

how often you find a certain allele

What is microevolution

the process in which allele frequencies change within a population from generation to generation

Will genes that result in traits best suited for the environment increase or decrease gene frequency

Increase

Will genes that result in traits not suited for the environment increase or decrease gene frequency

decrease

Mutations

source of genetic variation, as long as it is not fatal (it wont be passed on if so)

How does sexual reproduction lead to genetic variation

crossing over, independent assortment, random joining of gametes

Balanced polymorphism

where two or more different versions (alleles) of a gene are actively maintained in a population because each one gives some kind of advantage under certain conditions.

Heterozygote advantage

Type of Balanced polymorphism

heterozygote is better suited for the environment than both homozygote forms

What is an example of heterozygote advantage

Sickle cell anemia and malaria

AA - normal

Aa - slight sickle slight normal - malaria resistance

aa- full sickle, malaria resistance

Minority advantage

Type of Balanced polymorphism

the rare phenotype offers higher fitness than common phenotypes

Example of minority advantage

Type of Balanced polymorphism

predators usually develop a search image for prey based on the most common appearance, and the rare phenotype, in turn, can escape the predator

Hybrid advantage

Offspring of hybrids is usually superior due to combination of different genes

Hybrid

breeding between two different strains of organisms

Neutral variation

Type of Balanced polymorphism

Varitations passed down that do not cause benefit or harm to the organism

When is neutral variation useful

if the enviroment changes

Poly ploidy

form of genetic variation

Why is being diploid beneficial

the dominant allele can mask the harmful allele (ie, need two copies of the sickle cell gene to have the disease

Since some plants are polyploid, what does this mean fortheir genome

More variety and preservation of different alleles in the plants genome

What are the sources of genetic diversity

mutations,

sexual reproduction

balanced polymorphism

and polyploidy

What are the types of balanced polymorphism

Heterozygote advantage

minority advantage

hybrid advantage

neutral variations

Mnemonic for causes of microevolution

Oposite of large random m&m

Genetic drift

cause of microevoltuion

change in allele frequencies in a gene pool by chance

What populations does genetic drift have the highest effect on

small populations