Speciation
What is speciation?
Speciation is the process by which one species splits into two or more distinct species.
What is natural selection?
A mechanism through which organisms that are better adapted to their environment have an increased chance of surviving and passing on their alleles
What is genetic drift caused by?
A random event, usually a natural diasaster
What is divergent evolution?
Divergent evolution occurs when species with a common ancestor evolve different traits due to different environmental pressures.
What is a phylogenetic tree, and what does it represent?
A phylogenetic tree is a diagram that shows the evolutionary relationships among species. It represents hypotheses about the common ancestors of species and how they diverged over time.
What is allopatric speciation, and how does it occur?
Allopatric speciation occurs when a population is geographically separated, leading to reproductive isolation. Over time, genetic differences accumulate, resulting in the formation of new species due to lack of gene flow between the populations.
What is the term used to describe when an organism is better adapted to their environment than others
They're at a selective advantage
Explain the concept of genetic drift
Genetic drift is the random fluctuation of allele frequencies in a population.
Define convergent evolution and provide an example.
Convergent evolution is the process where unrelated species evolve similar traits due to similar environmental pressures. An example is the wings of bats and birds, which evolved independently in response to the need for flight.
How is molecular homology used to determine relatedness between species?
Molecular homology involves comparing DNA, RNA, or protein sequences between species. The more similar the sequences, the more closely related the species are.
How does sympatric speciation differ from allopatric speciation?
Sympatric speciation occurs within a single geographic location where populations become reproductively isolated due to behavioural, ecological, or genetic differences, while allopatric speciation requires geographic separation.
What are the 4 steps of natural selection?
1- Variation
2- Selective Pressure
3- Selective Advantage
4- Heritability
What impact does genetic drift have on small populations?
In small populations, genetic drift can have a significant impact, potentially leading to the loss of genetic diversity as certain alleles may increase in frequency while others may disappear entirely, regardless of their advantage or disadvantage.
What role do mutations play in evolution?
Mutations introduce new genetic variation into a population. While most mutations are neutral or harmful, some may provide beneficial traits that increase an individual's fitness.
Explain the difference between homologous and analogous structures
Homologous structures are features that are similar due to shared ancestry, while analogous structures are similar due to convergent evolution, not because of a common ancestor.
What is an example of Sympatric speciation
Howea Palms
What is Miss Linnie's favourite example of Natural Selection
Giraffes :)
How does gene flow affect the genetic variation of populations?
Gene flow is the movement of alleles between populations through migration and increases genetic variation within a population by introducing new alleles. It can also reduce differences between populations, potentially preventing speciation by maintaining genetic similarities.
Which type of evolution can not be exhibited through phylogenetic trees?
Convergent evolution
Are amino acids or nucleotide sequences more reliable when investigating molecular homology?
Nucleotide sequences as there may be silent mutations not exhibited through amino acid sequences
What is required to define an organism as a new species?
Define the term "fitness" in the context of natural selection.
"fitness" refers to an individual's ability to survive and reproduce in a particular environment. Individuals with higher fitness are more likely to contribute their genes to future generations.
What is the bottleneck effect, and how is it related to genetic drift?
The bottleneck effect occurs when a population's size is drastically reduced due to an event, such as a natural disaster. This small surviving population may experience genetic drift, where allele frequencies change randomly, potentially leading to a loss of genetic diversity.
What is an example of a vestigial structure in humans?
Coccyx, wisdom teeth, appendix
Are opposable thumbs an example or convergent or divergent evolution?
Convergent