Term
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Definition
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Term
| Three biggest pieces of evidence for evolution? |
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Definition
| Universally shared features, Hierarchical classification, fossil record |
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Term
| Who was the first to understand survival of the fittest? |
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Definition
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Term
| Who destroyeed the "continuity of life"? |
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Definition
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Term
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Definition
Founder of paleontology but believed in catastrophism ……
But rejected the idea that their existence implied that evolution had occurred, dogmatically maintained the "fixity" of species.
Destroyed the Scala naturae
Animals grouped into phylum, no evidence of steady increase of complexity (vertebrates, molluscs, articulates (insects + crustaceans), and radiations). But man is different
He “proved” extinction since the extinct proboscidians (elephants) could not have remained unnoticed in some remote corners of the planet |
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Term
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Definition
Scottish geologist, writer and publisher
Vestiges of the Natural History of Creation (1844) (Anonymous)
Principle of Progressive Development
He hypothesized that new species arise from old ones based on the observation that: i) the composition of species has changed over time and
ii) this change is slow, gradual, and unlinked to catastrophes (Mayr, 1982). |
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Definition
Scottish landowner and fruit farmer
Anticipated Darwin and Wallace,in appendix to On Naval Timber and Arboriculture (1831)
was the first to elaborate the principle of natural selection, but was unknown to both of Darwin and Wallace. |
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Term
| Who first presented the idea of natural selection/ |
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Definition
| Alfred Wallace and Charles Darwin presented the idea of natural selection together |
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Term
| Evidence for epigenetic modification? |
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Definition
| A study shows that when mice are taught to fear an odor, both their offspring and the next generation are born fearing it. The gene for an olfactory receptor activated by the odor is specifically demethylated in the germ line and the olfactory circuits for detecting the odor are enhanced. |
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Term
| Why is the olfactor system uniquely positioned to address the question of nongenetic inheritance? |
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Definition
| Each olfactory receptor neuron, originating in the nasal epithelium, expresses only a single member of the olfactory receptor gene family, and the olfactory neurons that respond to a particular odor can be mapped and identified. |
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Term
| How did Dias and Ressler explore non genetic inheritance? |
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Definition
By pairing an odor with mild foot shocks.
Trained mice to fear the odor acetophenone, which is recognized by Olfr151, then measured the response to this odor in future generations. They also used a different odor without shocks, propanol, which acts on a different receptor, Olfr6. Mice trained with acetophenone, the F1 and F2 generations had a startle response to acetophenone, but propanol. This also works in reverse. This is transmitted though both sexes, and suggests epigenetic modifications. They found that there were demethylated sites in Olfr151, not Olfr6, when the mice feared acetophenone. There was no DNA methylation mark in the particular olfactory receptor genes in olfactory response neurons. This creates issues as it should be more complex and it is held that epigenetic modifications are removed in fertilisation. |
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Term
| How is studying genome evolution relevant to evolutionary biology of animals? |
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Definition
Tells us how fast and what changes can occur
Helps interpret patterns we see today |
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Term
| What kind of changes occur in the genome? |
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Definition
Single base pair changes
Insertions
Deletions
Chromosome breakages and fusions
Duplication of genes and entire genomes
Inversions
Pseudogene formation
Acquisition of horizontally transferred DNA
Plasmids
Transposons |
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Term
| What is the FLO1 gene used for? |
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Definition
| It encourages yeast to protect each other |
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Term
| Which genetic changes accumulate quicker? |
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Definition
| synonymous changes accumulate at a faster rate than non-synonymous changes because they are less likely to be removed by natural selection |
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Term
| Are mutations always independant? |
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Definition
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Term
| What is proposed to create rearrangements seen in primates? |
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Definition
| Chromosome fission and fusion events` |
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Term
| How have globin genes evolved and what is the result? |
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Definition
Evolution of globin genes has been through duplication. The result is multiple copies of globin genes. Some have lost their function (ie they have not been maintained by selection) and these become pseudogenes (non-functional copies)
Not all pseudogenes can have been formed in this way. For example, mitochondrial pseudogenes are sometimes found in the nucleus. We do not fully understand how they got there. |
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Term
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Definition
| two mating type alleles. Each individual has a ‘master copy’ of each allele, plus a working copy. The working copy can be removed and replaced with the other type by using one of the master copies as a template. Seen in yeast. |
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Term
| What causes homogenisation of alelles? |
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Definition
| Repair being biased towards one allele |
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Term
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Definition
| When one gene influences many traits -this limits the types of genetic changes that can occur |
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Term
| What do the macro and multiple micronuclei of the ciliates do? |
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Definition
| IT is thought to help the ciliates adapt, with certain sequences eliminated in varying micronuclei. The rates of mutation also vary from nuclei to nuclei. The genes that code for precursor proteins for toxins have a much higher rate of mutation than the rest. |
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Term
| In intrasexual competition... |
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Definition
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Term
| In Intersexual competition... |
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Definition
| females choose. (these two are gross oversimplifications and this module sucks) |
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Term
| What 5 things does Darwins theory predict|? |
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Definition
Populations changing over generations
Gradual change
Speciation
Natural selection
Common descent |
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Term
| Body mass is proportional to.. |
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Definition
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Term
| How can creatures with a large mass be tall? |
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Definition
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Term
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Definition
| The ability of an organism to survive |
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Term
| Components of natural selection... |
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Definition
| Variation, Inheritance and reproductive success |
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Term
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Definition
| represents average number of offspring produced by individuals of a particular genotype |
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Term
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Definition
| the average number of offspring produced by individuals of a particular genotype relative to other members of the population |
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Term
| Natural selection favours changes that are |
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Definition
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Term
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Definition
| 1- s (s = selection coefficient) |
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Term
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Definition
| s is a number from 0.02 to 0.40 (why?) and if it is 0, that means no selection, 0.02 is 2% reduction/increase in fitness, 0.40 is 40%, etc. etc. |
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Term
| A dominant allele will increase in frequency in each generation by: |
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Definition
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Term
| What does directional selection lead to? |
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Definition
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Term
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Definition
| (also known as balancing selection) occurs when the heterozygote has an advantage over either homozygote |
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Term
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Definition
| when the heterozygote is at a disadvantage, which normally leads to fixation of one allele and elimination of the other |
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Term
| What is positive frequency dependent selection? |
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Definition
the fitness associated with the trait (phenotype)
increases as the frequency of the trait (genotype) increases in the population, this may favour differentiation, and in the long term speciation |
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Term
| What is negative frequency dependent selection? |
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Definition
| The fitness associated with the trait (phenotype) increases as the frequency of the trait (genotype) decreases in the population - Balancing selection |
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Term
| What is Fisher's sex ratio model? |
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Definition
When female births are less common than male
A newborn female has better mating prospects than a newborn male, and therefore can expect to have more offspring (fitness increases when frequency decreases…).
Therefore parents genetically disposed to produce females tend to have more than average numbers of grandchildren born to them*.
Therefore the allele for female-producing tendencies spreads, and female births become more common.
More females then reduces the advantage for female producing tendancies |
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Term
| What is the neutralist - selectionist debate? |
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Definition
| it is a dispute about whether drift or selection is the primary driver of evolutionary changes. |
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Term
| What is the effect of genetic drift in a finite population? |
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Definition
| an advantageous allele may not be fixed, esp. if the population is small or selection is weak. Some alleles are fixed, other are lost and the fraction of heterozygotes in the population decreases over time. Separate populations diverge in term of allele frequencies and in term of which alleles are present = population structure |
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Term
| What does genetic drift reduce in a population? |
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Definition
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Term
| Where is genetic drift stronger? |
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Definition
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Term
| Why would rare morphs have an advantage over common morphs? |
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Definition
| Predators and parasites tend to favour common morphs, ironically leading to the morph becoming common and no longer favourable |
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Term
| What is the New World Monkey they taught us about's key feature, cos you know this is gonna be on the exam as its an almost worthless piece of individual knowledge which doesnt contribute much to the overall understanding of the module? |
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Definition
| Foraging groups need at least one dichromatic and trichromatic monkey |
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Term
| What are the three biggest forms of mimicry? |
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Definition
Batesian – e.g. Hoverflies mimicking a stinging wasp
Mullerian – e.g. unpalatable butterflies mimicking other non-palatable species
Cryptic mimicry – E.g. spider crabs on flowers |
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Term
| Why are species reproductively isolated? |
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Definition
– prezygotic (pre-mating) barriers e.g. mating call songs are incompatible
– postzygotic (post-mating) barriers e.g. failure of embryo to develop
– both occur in some species e.g. leopard frogs |
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Term
| What occurs during allopatric speciation? |
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Definition
Original population
Physical barrier develops
Reproductive isolation occurs
New range equilibrium develops |
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Term
| What occurs during sympatric speciation? |
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Definition
Original population
Reproductive isolation occurs in the absence of a physical barrier
New range equilibrium develops |
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Term
| What occurs during parapetric speciation? |
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Definition
Original population
Movement into adjacent (but connected) territory
Reproductive isolation occurs
New range equilibrium develops |
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Term
| What is Adaptive radiation? |
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Definition
| Rapid diversification and speciation to occupy ecological niches |
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Term
| Why does island dwarfism/gigantism occur? |
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Definition
| Increased competition and few opportunities lead to shortness to save energy, animals no longer limited by predators can lead to gigantism |
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Term
| What is the main advantage of sexual reproduction/ |
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Definition
| It allows the removal of deleterious homozygous recessive mutations |
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Term
| What is the main advantage of asexual reproduction? |
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Definition
| Allows exponential increase in population size |
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Term
| What factors limit rates of diversification? |
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Definition
Pleiotropy (one gene may affect >1 trait)
Genetic architecture (one gene physically linked to another so they are inherited together)
Trade-offs (trait may have >1 purpose)
Time-frame (there may not have been sufficient time to reach the optimum)
Past history (determines the starting point for adaptation) |
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Term
| What is a panmictic population? |
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Definition
| A population with no subdivision (what does this even mean) |
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Term
| What is genetic exchange mediated by? |
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Definition
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Term
| What is a metapopulation? |
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Definition
| a series of subdivided populations, connected by different migration rates |
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Term
| What is the Wahlund effect? |
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Definition
| In a structured population the number of heterozygotes is lower than you would expect |
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Term
| What is effective population size determined by and influenced by? |
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Definition
It is determined by the number of individuals contributing to the next generation
It is influenced by factors such as
population size and fluctuations in size -Ne is closer to the smallest population size value (the harmonic mean, not the actual mean)
unequal sex ratios
variance in reproductive success between individuals
population subdivision - There is a separate Ne for each of the populations - Overall Ne is influenced by factors such as migration rate between populations and the chances of extinction for any particular population |
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Term
| Why do endosymbionts promote aggregation and sibling mating? |
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Definition
| The chance of succesfully producing offspring is lower if both parents have different strains |
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Term
| What do endosymbionts in flour beetles cause? |
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Definition
| Infected males to be more fertile than uninfected |
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Term
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Definition
| Linked loci are inherited together |
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Term
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Definition
geographical distribution of genetic variants that reflects past events
usually found at broad geographical scales, but in some cases they are more local
they reflect past events – primarily colonisation history |
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Term
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Definition
| Slow growth, search cost - finding a mate, reduced relatedness between parent and progeny, risk of STI |
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Term
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Definition
| Faster evolution, clearance of deleterious mutations, generation of novel genotypes, combinations of beneficial mutations |
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Term
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Definition
| Production of different gamete sizes |
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Term
| What makes male reproductive success increase? |
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Definition
| As many matings as possible |
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Term
| What makes female reproductive success possible? |
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Definition
| As high quality matings as possible |
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Term
| What leads to exaggerated traits such as the peacocks tail? |
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Definition
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Term
| Sensory bias hypothesis: what is it? |
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Definition
| Females prefer a male trait not because of anything inherit about the trait but because they are evolutionarily predisposed to something like the trait, i.e. red berries predispose a preference for red colour |
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Term
| What is the good genes hypothesis? |
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Definition
| Good genes hypothesis predicts that females derive indirect benefits from choosing attractive males because elaborate or bright male ornaments will signal underlying genetic quality. |
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Term
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Definition
| Seperate sexes in animals |
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Term
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Definition
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Term
| Why would hermaphrodites develop seperate sexes? |
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Definition
| A mutant with only one sexual function is protected from inbreeding, or the reallocation of resources leads to an increase in fertility |
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Term
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Definition
• interdependent relationships between human and livestock
• a mutualistic relationship leading to a co-evolutionary process between human and their domesticates
• provides some of strongest evidence for evolution
• is not necessarily a slow process
• sometimes few genes involved, conveying large changes |
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Term
| What do ants farm and how? |
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Definition
| Aphids, by moving them around and milking it, Fungi, by protecting them from invading pathogenic fungi and bringing them food |
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Term
| What normally occured in early farming communities? |
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Definition
| more work, lower adult stature, worse nutritional condition and heavier disease burdens |
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Term
| What are the steps to domestication? |
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Definition
initial association with free breeding
• confinement
• confinement with breeding in captivity
• selective breeding and breed
• improvement |
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Term
| What are the three paths do domestication? |
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Definition
| Human directed, game management, commensalism |
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Term
| What are the selection pressures during domestication? |
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Definition
Human methodical choice
Human unconsious selection
natural selection |
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Term
| How have wild wheats and barley changed since domestication? |
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Definition
| Mutation that prevented seed stalks shattering was lethal in wild, but selected under humans because it was easier to collect seeds |
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Term
| Why do domestic animals have smaller brains and worse sensory organs? |
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Definition
| They are a waste of energy when they are protected by humans |
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Term
| Main changes in domesticated animals? |
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Definition
• Behavioural changes towards humans (e.g. imprinting behaviour) or compared to wild species (e.g. lack of broodiness)
• Morphological changes (smaller sizes, body size conformation (pigs, race horse),…etc.)
• Growth rate (e.g. broilers….)
• Fat (increase e.g. fat – tailed sheep, decreased fat in cattle meat… |
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Term
| How did agriculture spread? |
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Definition
| Conquest, spread of disease, outcompetition of neighbours - not multiple farming groups arising |
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Term
| Obstacles to domestication? |
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Definition
1. diet not easily supplied by humans
2. slow growth rates and long birth spacing
3. nasty disposition
4. reluctance to breed in captivity
5. lack of follow the leader dominance hierarchies,
6. tendency to panic in enclosure or when faced with predators |
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Term
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Definition
| inherited from both parents |
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Term
| Which genes differ between modern humans and Neandertals? |
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Definition
Repetin – protein expressed in skin, sweat glands, hair roots, and tongue papilli
– Melastatin - protein that helps maintain skin pigmentation –
Protein associated with type 2 diabetes in humans
and appearance and energy metabolism genes |
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Term
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Definition
| Evolution above the species level |
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Term
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Definition
| Changes in gene freqquencies |
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Term
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Definition
Fossils are formed by:
1) burial in sediment at the bottom of a water column or other sediment
2) then by one of the following: – compression before the organism decomposes- this leaves an impression of the organism’s shape
– mineralisation - where dissolved minerals precipitate in the cells, sometimes preserving details of internal structure
– cast formation - Infiltration of the decayed organism by substances that harden to form rock
– mold formation – the organism’s remains decay and the space remains unfilled
– unaltered remains (e.g. those frozen in ice) |
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Term
| What is the issue with fossil records? |
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Definition
| Fossilization is a rare event, terrestrial organisms were unlikely to be fossilized, and so are structures likely to be degraded |
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Term
| When was the first time we saw segmented body plans, notochords and exoskeletons? |
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Definition
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Term
| Homologous characters are features that: |
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Definition
| Come from a common ancestor |
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Term
| Analagous characters are features that: |
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Definition
| Are similar in function by evolved independantly |
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Term
| What are the three explanations for the sudden appearance of complete fossil forms? |
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Definition
• 1. We have no trace of earlier evolution (incomplete fossil record)
• 2. There was rapid diversification at this point in time
• 3. There was an entirely predictable exponential rate of increase in the number of organisms at this time due to an ecological ‘vacuum’ |
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