Evolution

what are the different aspects encompassed by evolutionary biology

-identification and classification of species

-inferring relationships between species

-species adaptations

-genetic variation between species

-how species originated or went extinct

-INVESTIGATION OF THE UNDERLYING MECHANISMS THAT LED TO THE SPECIES OF TODAY

what is the best definition of evolution and who said it

Descent with modification -Darwin (changes in characteristics over generations)

what are the 2 things you need to know to understand how a species evolved

-It’s ancestor

-Modifications that have occurred

what are the mechanisms responsible for evolutionary change

-non-random mating

-mutation

-migration

-genetic drift

-natural selection

what is the definition of natural selection

beneficial alleles increase in frequency due to increased survival and reproductive success of individuals carrying those alleles

are any individuals identical

individuals posess genetic variation

how does the phenotype of an organism change

due to genetic mutations

what effect do genetic mutations have on an individuals fitness

they can increase, decreas or have no effect on fitness

what genetic mutations will increase in a population over time

those that improve an individuals fitness

how are new species, genera or families created

accumulation of advantageous genetic changes over long periods of time

what are the mechanisms that can drive evolution

natural selection, non-random mating, migration, genetic drift

why did the initial HIV drug not work

HIV evolved resistance since it had such a short generation time that a mutation resistant to the drug developed in a short amount of time

how did understanding evolution lead to the modern HIV treatment

the modern multi-drug treatment was developed after it was understood that HIV was evolving resistance to the first drug so the new strategy is just to throw a bunch of drugs at it

are HIV patients worse off taking no medications or only taking some of the treatment

they are worse off taking just some of the treatment since this allows the virus to survive and evolve unchecked

what is methodological naturalism

the strategy of explaining the way the world works using laws of nature

definition of evolution

descent with modification

what is uniformitarianism and who came up with it

charles lyell introduced uniformitarianism which is the school of thought that geological processes operate over long periods of time in a slow gradual manner

what is catastophism

the false school of thought that geological features arose from catastrophes

what was the belief on the origin of life before evolution

spontaneous generation: complex lifeforms arose from non-living matter

how was the theory of spontanepous generation disproven and by who

Francesco Redi with his experiment of raw meat and flies

Who was the first to describe evolutionary change

Erasmus Darwin

what did erasmus darwin describe

all life arose from a single living filament that was modified endlessly into the lifeforms of today and recognised the struggle for existence

who described the principle of progressive development

robert chambers

what was robert chambers recognised for

-new species arise from old species

-diversity of species changes over time

-populations evolve not individuals

-did not explain why diversity occurs

who described the inheritance of acquired characteristics

Jean-Baptiste Lamarck

what did Jean-baptiste lamarck say

new more complex species descend from old less comples species

but he also said that individuals pass down traits they acquired throughout their lives and this was untrue

who described circumstance adaptive law

patrick matthew

what did patrick matthew do

-individuals best suited to their environments will be selected over others

-had most of the idea of evolution but published it in a book about naval timber

who were the 4 predecessors to darwin and what were their theories called

(Charles Lyell (uniformitarianism) Francesco Redi (Disproving spntaneous generation))

Erasmus Darwin-Desribed evolutionary change

Robert Chambers-Progressive development

Jean-Baptiste Lamarck-Inheritance of acquired characteristics

Patrick Matthew-Circumstance adaptive law

What did Charles Darwin do

Published the origin of species which described evolution in a way that hadn’t been before, took a 5 year voyage around the earth’s souther hemisphere

who helped darwin publish his book

Russel Wallace

how did darwin first explain natural selection to his peers

he argued it was like artificial selection and used the dove reference about making a grey dove population int a white one

what are dawins 2 fundamental insights

1:The environment selects on variation in traits of individual organisms

-This answers why species are so well suited to their environments

2:All species descended from one or a few common ancestors

-This answers where species come from

what are the 3 observations that led to the struggle for existence

1:Organisms are very fertile

2:Natural populations remain fairly consistent in size

3:Ressources are limited

what are the 3 observations that led to the discovery of natural selection

1:there is a struggle for existence

2:Individuals within a population Vary

3:Variation is heritable

definition of evolution by natural selection

over many generations accumulation of beneficial traits allows a population to diverge from its original state

is evolution a variational or transformational process

variational

what is a transformational process

ensemble changes because each individual changes (pummeling of sand into dust)

what is a variational process

ensemble changes because something sorts among the variants in the original ensemble (sifting through sand to get dust)

would inheritance of acquired characteristics be a variational or transformational process

transformational

what are the 4pieces of evidence for evolution

1:species change through time (Microevolution)

2:Lineages split and diverge (Speciation)

3:New lifeforms arise from older lifeforms (Macroevolution)

4:All species have arisen from one or a few common ancestors

What is an example of microevolution

The artificial selection of grey pigeons into white pigeons

what is artificial selection

when humans select which individuals reproduce deliberately for a desired outcome

what is the difference between artificial selection and anthropogenic evolution

anthropogenic evolution is an all encompassing term that means evolutionary changes induced by humans whether intentional or not (Ex of unintentional, mountain goats horns getting shorter)

what is the biological species concept

a species consists of groups of actually or potentially interbreeding populations that are reproductively isolated from other groups

what ws the missing trnsitional piece between fish and tetrapods and what is this an example of

tiktaalik, macroevolution

what is homology

shared characteristics as a result of common ancestry

what is biogeography

study of the distribution of species in geographic space and geological time

are species in the same biomes seperated by geographic barriers more or less similar than species in different biomes closer together

less

what are the 3 components of natural selection

1:Variation

2:Inheritance

3:Differential reproductive success

when is a trait heritable

when variation is due to genetic variation

what do evolution researchers study

traits of organisms not the whole organism

do populations evolve or individuals

populations not individuals

when do mutations occur

randomly and independantly of whether they will be favoured by natural selection

how is phenotype determined

by genotype and also the environment

if difference in a trait is due to environmental factors is it heritable

no

what is differential reproductive success

differences in fitness

what is fitness

expected reproductive success of an individual relative to other members of the population

what happened to mice that didn’t match the environmental background compared to ones who did

they were captured more frequently than those that did

does natural selection sort on genotype or phenotype

phenotype

how does natural selection relate to individuals vs a population

it acts on individuals but it’s consequences occur on populations

how do natural selection and evolution interact with allele frequency

natural selection acts on the phenotype but evolution consists of changes in allele frequency

does natural selection lead to a perfect outcome

no, it faces many constraints so never leads to a perfect outcome

what is an adaptation

an inherited trait that increases an organisms fitness and is the result of natural selection for it’s primary function

what is an exaptation

a trait that has one function today but evolved from a trait that served a different function in the past

what is an example of an exaptation

feathers evolved before flight

are most complex traits adaptations or exaptations

most will have undergone many changes with a layering of adaptations and exaptations

what is gene duplication

an entire gene or gene package is duplicated

what is neofunctionalisation

a gene copy created through a copying mistake that acquires a brand new function while the old gene continues to do its old function

how do new hormones/receptors evolve

gene duplication/neofunctionalisation could allow a receptor to mutate and therefore bind to a new hormone

what is gene sharing

a protein recruited to serve a second function somewhere else

what are the 2 ways complex traits evolve

co-opted from previous organs

gradual intermediate steps, each step itself adaptive and serve the same function throughout

what are the constraints on natural selection

short term: lack of sufficient variation

Long term: physical constraints, co-evolution, lack of foresight

why is co-evolution a constraint on natural selection

-can’t optimize phenotype if the thing it’s being optimized for keeps changing

-evolutionary change in one species can effect selective conditions for a second species

-Evolutionary arms race: species invloves each evolve counter measures to the adaptations of the other species

why is lack of foresight a constraint on natural selection

selection can only favour traits that are immediately beneficial, not traits that may be useful in the future

what are the things you need to know to be able to prove a trait is adaptive

determine it’s function

demonstrate that individuls with the trait have a higher fitness than those without

why do mammals tolerate red billed oxpeckers

we think maybe because they serve as an early warning sign, not because they remove ticks, in fact they actually open wounds sometimes

what are the 3 methods of determining a trait’s function

controlled experiment

observational research

comparative methods

what is a controlled experiment

manipulate one component to assess it’s effects on the other components of a system

what is observational research

if a controlled experiment is impractical, careful observation could provide some answers instead

how do comparative methods of research work

look for trends and patterns in evolutionary history by comparing traits of many species, looking for similar traits and functions across multiple species to suggest that it is adaptive

are closely related species statistically independant or not

closely related species may not be statistically indipendant

why is classifying organisms important

helps understand how they’re related to each other

who developed the 8 taxonomic ranks and the binomial nomenclature systems

Carl Linnaeus

what are the 8 taxonomic ranks and in wat order are they organised

Domain→Kingdom→Phylum→Class→Order→Family→Genus→

Species

what are the 2 elements of binomial nomenclature

Genus and Species Epiphet

who is the creator of modern phylogenetic systematics

Willi Hennig

what is phylogenetic systematics and who created it

Invented by Willi Hennig

-Modern approach to classification using evolutionary relationships between organisms

what is the definition of phylogenetics

study of relationships among taxa based on evolutionary history

what is the definition of systematics

study of classification of organisms

what is the goal of phylogenetics

to reconstruct the evolutionary history of a study species and understand their pattern of descent

what are phylogenetic trees built using

traits of interest

what is a character

any observable characteristic or feature of an organism

what is a trait

the specific value of a character

what is the difference between a character and a trait

character is any observable characteristic or feature of an organism while a trait is the specific value of a character

what is the purpose of phylogenetic tree building

to generate a hypothesis

what is a taxon

group of related species placed at the tip of a branch

where are internal nodes on a phylogenetic tree and what do they represent

they are found at the points where branches meet and represent hypothetical common ancestor populations

what do outgroups help you with when creating a phylogenetic tree

they help you root the tree

what is an ancestral trait

a character present in a common ancestor