Module 3 - Biological Diversity Flashcards
what is a selection pressure?
The selective pressure definition is an evolutionary force that causes a particular phenotype to be more favorable in certain environmental conditions. Selective pressures are considered forces that drive evolution via natural selection.
give an example of changes in a species due to selection pressures?
An example of selective pressure considering animals would be the ability to find a suitable mate. In peacocks, males with a longer plumage are more likely to mate and pass on their genes. It is less likely that females will agree to mate with shorter tailfeathers.
what is structural adaption?
Structural adaptations refer to the changes in the structure of a living organism that enables it to adapt better to its environment.
what is physiological adaptions?
Physiological adaptation is an internal body process to regulate and maintain homeostasis for an organism to survive in the environment in which it exists, examples include temperature regulation, release of toxins or poisons, subconscious emotional responses (guilt, fear, etc.).
What does natural selection rely on?
variations in the population
What is a result of natural selection?
Over time this can results in a population change where the desirable characteristic is selected for.
Convergent evolution:
The evolution through natural selection of similar features in unrelated groups of organisms
convergent example
Dolphins and sharks adaptions for swimming.
Divergent evolution:
Separated populations typically diverge (may be from genetic drift or natural selection) causing separated populations to gradually become different
Divergent example:
Galapagos finches
Compare spatial sorting and natural selection:
- They are both ways in which evolution occurs
- They both rely on variations in the population, inheritance of traits and time
- However, natural selection involves a selection pressure driving the survival of advantageous traits
- Whereas, spatial sorting involves traits leading to geographical dispersal with impacts on mating partner options.
define biodiversity
The range of organisms that makes up the living world and the ecosystems they live in.
what are two examples that support darwin’s theory
finches of the Galapagos islands (each species of finch found had differing forms of beaks. These were the traits altered by natural selection.
Each island of the Galapagos has different environmental conditions, including foods available, These provide selection pressures for birds to migrate to different islands.) + Australian flora and fauna (Darwin noticed that the platypus and english water rat occupied a similar ecological niche.
He concluded that animals that exist in similar conditions might have no resemblance to each other. This is because the water rat and platypus do not share a common ancestor.)
what is Darwin’s theory
Darwinism is a theory of biological evolution developed by the English naturalist Charles Darwin (1809–1882) and others, stating that all species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual’s ability to compete, survive, and reproduce
what is microevolutionary changes?
it is the changes in populations or species over a short period of evolutionary time. An accumulation of these changes can result in speciation.
what are the four main processes that drive microevolutionary changes
mutation, migration, genetic drift, natural selection
explain relative dating
relative dating compares the deep (old) layers of rock to the closer (young) layers.
what is natural selection?
Natural selection is the process through which populations of living organisms adapt and change.
what is speciation?
Speciation is how a new kind of plant or animal species is created. Speciation occurs when a group within a species separates from other members of its species and develops its own unique characteristics.
give an example of speciation.
Anole lizards
what is punctuated equilibrium?
Punctuated equilibrium is the idea that evolution occurs in spurts instead of following the slow, but steady path
what is gradualism?
the evolutionary changes in organisms must have been a gradual process, where the environment dictates which organisms survive and reproduce
is speciation and example of gradualism or punctuated equilibrium?
it can be both! In the gradual speciation model, species diverge gradually over time in small steps. In the punctuated equilibrium model, a new species changes quickly from the parent species and then remains largely unchanged for long periods of time afterward.
what are Vestigial structures?
features of an organism that are considered to have lost much or all of their original function through evolution. These structures can provide insight into the environment and behaviors of a species’ ancestors and how they have evolved through time.
