5. Evolution and Biodiversity Flashcards
What does the fossil record provide?
Provides evidence for evolution by revealing the features of an ancestor for comparison
What are heritable characteristics?
The characteristics that an organism processes due to its genetic makeup.
Evolution
The heritable characteristics of a species change over time
Dating
Allows the chronological ordering of organisms
Radioisotopes
Help date more accurately of the fossils
What is selective breeding?
A form of selection and another bit of evidence for evolution. It is man-made.
What is the role of humans in selective breeding?
Role: to choose which organisms breed and which does not
Explain the selective breeding of domesticated animals. Give examples to support your answer.
Most dog breeds today are artificial. Their original breeding is from wolves, they are tamed and bred for docile traits. This shows that evolution has occurred as they can differ a lot from wild ancestors.
What are 4 examples of selective breeding?
- Breeding race horses for speed
- Breeding egg-laying hens to lay lots of eggs
- Breeding cattle for increased meat or milk production
- Breeding dogs for herding, hunting or simply for specific physical features
What are homologous structures?
Same structure but not same functions.
It means that something came from the same ancestry or origin.
What is a pentadactyl limb?
A limb with five digits, characteristic of tetrapods vertebrates. It evolved from the paired fins of primitive fish as an adaptation to locomotion on land and is not found in modern fish.
What is a divergent evolution?
An accumulation of differences that led to the formation of new species
What does divergent evolution explain?
Explains the similarities in limb structure even if each of them has different methods to locomotion
What is an analogous structure?
Same function but not same structure. Eg. Butterfly and bat wings. It shows that they did not have a common ancestry
What is a convergent evolution?
Structures develop to resemble each other and same function but not of same origin.
What is speciation?
Process by which new species form
How do species form?
Physical separation of populations:
- due to landslides, changes in rivercourse
- the population remain isolated for a long time and they change, become genetically different.
What is adaptive radiation?
A process in which organisms diverge from orginal species to new species that allows them to adapt to their new environment
What is continuous variation?
Continuous variation is the idea of gradual divergence where organisms go through slow variation process to form new species
What is the role of industries in industrial melanism?
- Burn fossil fuels due to power machinery
- Produces large amounts of sulfur dioxide
- Produces vast quantities of soot that changed the color of tree barks
- light organisms can survive more in the light tree areas and dark in dark tree areas.
- this led to the decrease in light organisms in polluted areas and more dark organisms
What is variation?
The difference in physical features of organisms, this is a good measure for a healthy gene pool because it shows a range of alleles present in a species and this accounts for the variation in the population in the population.
List the three causes of variation with details.
- Mutations: any change to the DNA sequence, from a change in a single base or the whole segment of the chromosome
- Meiosis: produces gametes with alleles and increases genetic variation of the species
- Sexual reproduction : combination of the genes results in a zygote
What is an asexual reproduction?
producing a clone that is identical to itself
What is the only way a variation could be present in asexual species ?
mutations
What is natural selection?
Organisms that are better adapted to their environment tend to survive and produce more offspring.
How does the gene pool change overtime?
Number of offspring adapting to the environment increases, increasing the frequency and characteristics that help them adapt, and thus the gene pool changes overtime
What is natural selection based on?
Genetic variation within a species, the best adapted survive more, individuals that live longer produce more offspring passing on their adaptations to the next generation
What causes the adaptations of offspring?
- Overproduction of offspring: not everyone will survive, only the best adapted to the environment will
- Survival to an age where an organism can reproduce means that the individual is well adapted.
- Reproducing contributes passing genetic material to next generations
- Those that are not well adapted will die because of an accident or predation, and their genes alleles will be gone for good
List the 4 natural selection conditions by Darwin:
- Species are adapted to their environment
- Individuals survive because of the traits passed on by parents
- Individuals differ in a population
- Some individuals are more successful in reproducing and surviving
What does natural selection do to the frequency of characteristics?
Natural selection increases the frequency that helps the individuals adapt to the environment and decreases the frequency of other useless characteristics. So, overtime, the whole species will be able to adapt to the environment
How does the increase/decrease in beak length of Galapagos finches support the theory of evolution by natural selection?
Due to the food availability and other selectional pressures, the finches evolved to better fit their new environment. The finches have evolved to adapt to particular food sources available on the islands. This change is clearly visible in their beaks. Some beaks can crack larger seeds and some smaller beaks cope better with smaller seeds. This adaptive radiation has allowed the various finch populations to survive side by side, even on smaller islands, because of food specialisation.
List 4 reasons why antibiotic resistance has spread so widely and rapidly:
- Short bacterial life, quicker evolution
- People never finish using antibiotics, meaning there might be some left in the system which continue to spread
- Antibiotic resistance is often coded for a gene on plasmids. Plasmids are easily exchanged between bacteria.
- Hospitals inject antibiotics to big wounds
What is the binomial system?
Genus name starts with a capital letter. Always before the species name.
Species name starts with lowercase. Always after the genus name.
List the taxon.
Kings play chess on fine gold sets
Name the 3 domains.
Bacteria, Eukaryotes, Archaeans
What is one common thing between the 3 domains?
Their cell membrane is made up of glycerol-esters of lipids.
What is the cell wall of eukaryotes made up of?
peptidoglycan
Do eubacteria have histones and proteins?
No, because they do not have DNA
Where can you find archaea?
In extreme habitats such as hot springs
Classify eukaryota into 4 kingdoms:
- animalia
- plantae
- fungi
- protista
What is dichonomy?
The splitting into two or a division into two groups. This helps identify organisms and consists of a series of choices that lead the user to the correct name of a given item
What is a dichotomous key?
A series of paired statements that allows the classification of an organism. They rely on visible features.
What are the 4 phyla of the plantae kingdom?
- Bryophytes
- filicinophytes
- coniferophytes
- angiospermophytes
Explain the bryophytes in detail.
Bryophytes:
Mosses, liverworts
Non flowering plants
1-10 cm tall
Grow close together in shady, moist areas
No vascular tissues (no transport system)
Have rhizoids
No true leaves due to the lack in vascular system
Can carry out photosynthesis
Explain the filicinophytes in detail.
Filicinophytes: Ferns, horsetails Has vascular system Shallow roots Spores under leaves Small trees
Explain the coniferophytes in detail.
Coniferophytes: Gymnosperms Cone-bearing seeds with vascular tissue Wooden trees Narrow leaves with thick waxy cuticle Monoecious plants Reproduce sexually by releasing pollen from male cones to female cones to form seeds
Explain the angiospermophytes in detail.
Angiospermophytes: Any plants, clover to massive oak trees Flowering plants Has vascular tissue Woody stem Monocotyledons or dicotyledons Reproduction: transfer of pollen grains from anthers to the stigma of carpels Once fertilised, ovules form seeds and develop into fruits
List the 7 phyla of the animalia kingdom.
pcpamac: ponifera cnidaria platyhelminthas annelida mollusca arthropoda chordata
Ponifera
- organism full of spores and channels for water exchange
- random symmetry
- multicellular
- no mouth, anus, systems
Cnidaria
- Gelatinous umbrella-shaped bells with tentacles
- radial symmetry
- single mouth, surrounded by tentacles, used for capturing prey
List the 5 classes of the subphylum of chordata.
birds, mammals, reptiles, fish, amphibians
What are clades?
A group of organisms that share an ancestor
What are clades based on?
- based on anatomical characteristics
- based on similarity of dna or amino acid sequences
What are cladistics?
the study of the evolutionary relationship between species based on ancestry
What is a cladogram?
a tree diagram that shows the most probable sequence of divergence within a group that shares characteristics
What is a molecular clock?
A process that uses the mutation rate of biomolecules to deduce the time in prehistroy when two or more life forms diverged.
How does changes in DNA lead to speciation?
- DNA mutate
- can be seen in the protein level as well
- Changes gradually
- can be used to indicate how much time has passed after separation of the two species from their common ancestor
What happens if the species are being separated for a long time?
The longer the time period after the species being separated, the more differences there will be when the DNA of the two species is compared.
What is a node?
A node is a point of the cladogram where it shows the split of the species
What does it mean by more nodes?
more distant the relationship
What does the length of branches show?
It shows the time since divergence, long = longer time since divergence
What is a phylogenetic tree?
Phylogenetic tree is a diagram that represents evolutionary relationships among organisms based on physical and genetic similarities and differences.
True or false:
Figworts are of one clade and from the same ancestor.
False, they are of different ancestors but 5 different clades
Why was it impossible to distinguish between the five clades?
because their morphology was so similar due to convergent evolution.
What are the 5 clades?
Calceolariaceae, Orobanchaceae, Scrophulariaceae, Stilbaceae and Veronicaceae.
