Bio final 1002

What is scientific methodology

process used to establish facts through testing and experimentation objectively. It involves forming a question, forming a hypothesis, making a prediction, designing and running an experiment, analysing the results, and iterating using the results to make new hypotheses.

What are some experimental designs

Koch’s postulates, field and lab work

Which crisis is worse than threats from climate change

the biodiversity crisis

How many species are directly threatened by extinction

over 37,000 species. 1 in 4 species

What are the top 3 species most threatened by extinction

amphibians, conifers and sharks and rays

What are key threats to biological systems

Habitat Destruction, Invasive Species, Population, Pollution, and Over-harvesting & Bycatch. (HIPPO acronym)

What does evolutionary theory explain

explains how life changed after its origin, not the origin of life itself.

What is abiogenesis

process that gave rise to life on earth

What does the prevailing scientific hypothesis suggests

the transition from nonliving to living matter was not a single event. It involved a habitable Earth with a reducing atmosphere, prebiotic synthesis of small organic molecules, molecular self-replication, and self-assembly.

Does evolution favour organisms always getting better

no, reproductive fitness is linked to the environment, not progress

What is the role of natural selection

eliminates individuals less reproductively fit in a particular environment.

What is the oldest fossil

stromatolites 3.5 billion years ago

What is the ultimate source of genetic variations

random mutations

Does natural selection involve organisms trying to adapt

no, this is Lamark’s view

Lamarck's view

"Inheritance of acquired characteristics" and "Use and disuse".

What does "Use & Disuse" contradicts

vegistual structure

What are vestigial structures

traits that no longer provide a functional advantage.

What is the difference between use and disuse theory and vegistual structures

"Use & Disuse" implies rapid adaptation based on immediate circumstances, but vestigial structures are a long-term evolutionary process and preserves traits that no longer provide advantageous functions

Why was Lamark’s "Inheritance of acquired characteristics" theory rejected

traits are passed to next generation through genes not through acquires characteristics

Does natural selection give organisms what they need

no, it has no senses on what organisms need

Why is genetic diversity important in populations

If a population has genetic variation allowing some individuals to survive a particular stress, those individuals will have more offspring, and the population will evolve.

What happens if no genetic variation is present in a population

natural selection has noting to “select” on

What is a theory in science

explanation of some aspect of the natural world well-substantiated by multiple lines of independent evidence

What are the central premise of evolutionary theory

Life has existed for billions of years and has changed over time via descent through modification by natural selection.

What can specied adaptation lead to

Species adaptation can lead to reproductive isolation and new species

What was darwin’s proposal

• Individuals with better-suited traits are more likely to leave more offspring.

• Hereditary traits become more dominant in subsequent generations, leading to evolution by natural selection.

• Species adapt via natural selection or go extinct.

• Species adaptation can lead to reproductive isolation and new species.

What are some lines of evidence of natural selection

direct observation, homology and vistigial structures, fossil records, biogeography

What are homologous structures

similar physical features in species that share a common ancestor

What are analogous structures

features os species that are similar in function but not in structures; not derived from same ancestor

What are transitional species

organisms that has mix traits of ancestors and descendents - middle ground

What is biogeography

distribution of species/ ecosystems in geographic space and through geological time

What makes evolution possible

genetic variations

What are the types of mutations

neutral, deleterious, lethal and advantageous

What are sources of new genetic variations

Mutations in germ lines (leads to new alleles), Gene flow, Meiosis via recombination/crossing over in prophase I, Meiosis via independent assortment in metaphase I & anaphase I, Fertilization

What is heterozygosity

2pq, measure of population variation/diversity at a single locus

How is genotypic frequencies in a population calculated

p2+2pq+q2

What are mechanisms that alter allele frequency

mutation, gene flow, Genetic drift, Natural selection, nonrandom mating/inbreeding

What is needed to assess population heterozygosity

average heterozygosity over many loci

What does Hardy-Weinberg assume

there would be no evolution if there is no mutation, no immigration, large population size, genotypes equal fitness, random mating

What is the only mechanism that consistently causes adaptive evolution

natural selection

What is Evolution by natural selection

a blend of chance (creating new genetic variations) and sorting (natural selection favoring some alleles/traits over others).

How does natural selection lead to adaptive evolution

Natural selection increases allele frequencies that enhance reproduction or survival, leading to adaptive evolution.

How does natural selection increase allele frequency

Natural selection can increase these frequencies through directional selection, stabilizing selection, or disruptive selection.

What does genetic drift in small population lead to

genetic drift

What does genetic drift lead to

loss of genetic diversity and fixation of alleles

What are implications of genetic drift

the bottleneck effect and the founder effect

What is the inbreeding coefficient

measure of how fast you lose heteroszygosity

Define directional,stabilizing and disruptive selection

• Directional selection:Favors one extreme phenotype over others, leading to a shift in the population's traits.

• Stabilizing selection:favours average traits over extreme ones. maintaining the status quo

• Disruptive selection:Favors individuals with extreme traits at both ends of the spectrum over those with intermediate traits, potentially leading to speciation.

How does natural selection reduce unfavourable traits

through dipoidy and balancing selection

Define dipoity and balancing selection

• Diploidy:state of having 2 complete sets of chromosomes in a cell or organism

• Balancing selection: maintains genetic diversity in population and reduces likelihood of allele fixation through heterozygous advantage, habitat selection and frequency dependent selection

What are morphological species

distinct in form and structure from other groups, similarities can be misleading. Practical for fossil records and field guides

What are ecological species

share distinct resources and same niche. Relevant towards ecosystem modeling

What are biological species

potentially interbreed in nature and produce fertile offsprings

What is speciation

the bifurcation of an ancestral species into two species

What are androdioecies species

reproduce via self-fertilization

What are gynogenetic species

females produce 2N diploid eegs through internal fertiliazation and require sperm from different species to stimulate egg development

What are ring species

populations with geographic distributions that form a ring by interbreeding with neighbours… but not at extreme ends

What is the relationship between speciation and geographic separation

independent relationship; Speciation can occur with or without geographic separation.

What are the types of speciation

• all lead to reproduction isolation

• Allopatric speciation: 2 populations geographically separated preventing gene flow between them

• parapatric speciation:Population spread over discontinuity or strong gradient of enviromental conditions - natural selection may select different alleles on either sides

• Sympatric speciation: new species formed fro within range of a population, independent of geographic or enviromental gradient
  

What is the rate of speciation

Speciation rates can be very slow (millions of years) to rapid (one generation) and can involve many genes or just one gene.

Why do hybrids have lower fitness

reduced hybrid viability, reduced hybrid fertility, hybrid breakdown

What is macroeveolution

involves large-scale evolutionary changes above the species level over long periods. It includes novel adaptations leading to a new common ancestor and adaptive radiation.

What is adaptive radiation

rapid diversification from the common ancestor

What is paedomorphosis

when juvenile traits kept through to adulthood

Is evolution goal oriented

no.

What is the central goal of phylogeny

to organize and understand information around us from a biological perspective

Who invented the single nested binomial naming system

carolus linnaeus

What is taxonomy

identifying & naming species, placing species into hierarchical classifications that reflect their morphological similarity to each other (i.e., morphological species) does not imply evolutionary relatenedness

What is the order of the bionomial naming system

Kingdom, phylum. class, order, daily, genus and species

What is in class amphibia

amphibians like frogs, salamanders..

What is in class reptilia

reptiles like turtles, snakes, crocodiles

What is in class aves

birds

What is in class mammalia

mammals

What are paraphyletic

groups of organisms that includes a common ancestor and some (not all) of its descendants

Whats is in clade lissamphibia

amphibians (frogs, salamanders)

What is in clade sauropsida

reptiles and birds

What is clase synapsida

mammals

What is manophyletic

a common ancestor and all of its descendants

What are systematics

the discipline focused on classifying organisms according to their evolutionary relationship and their phylogeny

What is phylogenetic tree

a hypothesis of the evolutionary relationships of a species or group of species, inferred from morphological and/or molecular homologies.

What are cladistics

the building of a phylogenetic tree where common ancestry is the primary criterion, and species are placed into clades.

What is the difference between cladograms and phylograms

cladograms are time-independent and phylograms are time-dependent

What are the different domains

eukarya, archea and bacteria

What are the supergroups of eukarya

excavata, SAR, archaeplastida, unikonta

What are not protists

plants, fungi and animals

What is the kingdom of protists

protista

What do protists have in common with each other

they are Eukaryotic unicellular or Eukaryotic multicellular without specialised tissue

Do protists represent a single clade

no, they are included in the same clade as plants, fungi and animals - thus are paraphyletic

What happened in primary endosymbiosis of protists

1st autotrophic eukaryotic cell and beginning of the Archaeplastids

What are key characteristics of excavata

asymmetric body shape, excavated ‘feeding groove’, one or more flagella and modified mitochondria

What are key characteristics of Unikonta

single flagellum, actin filaments play role in cell movement, shape, and division, monophyletic

What is part of Excavata

• Diplomonads: bilateral symmetry, two nuclei, multiple flagella, mostly anaerobic parasites, and reduced mitochondria

• Parabasalids:flagella, undulating membrane, mitochondria reduced to hydrogenosomes
  

What is part of SAR

• Diatoms:unicellular, glass-like cell wall

• Brown Algae

• Oomycetes:water molds

• Dinoflagellates: unicellular, two flagella

• Apicomplexans: intracellular parasites, unique organelle apicoplast

What eukarya group are gungi a part of

unikonta

What subgroup of unikonta are fungi in

opisthokonts

What are jey characteristics of opisthokonts

single posterior flagellum, asexual & sexual reproduction

What is plasmogamy

fusion two haploid cells, but nuclei remain distinct

What is karyogamy

fusion of dikaryotic nuclei forming diploid zygote

What are the different groups of fungi

1. Cryptomycetes: recently discovered; possible symbiosis with pants or other invertebrates

2. Microsporidians:  classified as protists but now fungi based on genetic evidence - asexual reproduction, can only survive and reproduce inside host cell

3. Chrytrids: mostly unicellular, flagellated spores

4. Zoopagomycetes: spores sticky to adhere to body of healthy housefly, spores germinate to penetrate fly’s body through cuticle.  non-flagellated spores - host manipulation (zombie)

5. Mucoromycetes: asexual and sexual reproduction, 

6. Ascomycetes: asexual and sexual reproduction

7. Basidiomycetes: asexual and sexual reproduction contains septate hyphae, basidia

What is asci

specialized sac-like structures that contain haploid ascospores - in ascomycetes fungi