principles of natural selection
who proposed the theory of natural selection
The theory of natural selection was proposed by Charles Darwin in his book ‘On the Origin of Species’ in 1859.
What is Mutation
A change in the DNA sequence that is the ultimate source of new alleles.
What are homologous structures?
These are structures that have similar bone arrangements but different functions, like a human arm and a whale flipper, indicating a shared ancestor.
What is directional selection?
This mode of selection occurs when environmental changes favor individuals at one extreme end of the trait spectrum.
What is a node?
This point on a phylogenetic tree represents the most recent common ancestor where two lineages split.
what are the main four principles associated with evolution
Variation
Competition
Adaptation
Selection
What is Gene Flow?
The movement of alleles between populations, often via migration.
What are vestigial structures?
This term describes body parts that have lost their original function over time, such as the human appendix or tailbone.
What are peppered moths?
During the Industrial Revolution, these insects shifted from light-colored to dark-colored to blend in with soot-covered trees.
What are sister taxa?
This term refers to two lineages that are each other's closest relatives, arising from the same immediate node.
Individuals with adaptations that make them more likely to survive will reproduce.
What is a Genetic Bottleneck?
A random event, like a natural disaster, that drastically reduces population size.
What are analogous structures?
This type of structure describes parts that perform a similar function but evolved independently, like the wings of a bird and the wings of a butterfly.
What is shift
When looking at a population graph for directional selection, the "bell curve" appears to do this toward one side.
This part of the diagram represents an evolving lineage over time.
Traits being passed from parents to offspring through genetic information.
For natural selection to drive evolution, the advantageous traits must be heritable (transferable to the next generation
What is the Founder Effect?
When a few individuals leave a group to start a new colony, often losing genetic diversity.
What is divergent evolution?
Homologous structures are typically the result of this type of evolution, where two species become more different over time.
What is antibiotic resistance?
This modern medical problem is a classic example of directional selection, where bacteria evolve to survive exposure to drugs.
What is all organisms on the tree?
On a tree, the "root" represents the most recent common ancestor of
Individuals with traits best suited to their environment...
Fitness" in biology refers to reproductive success and how well an organism fits its environment.
What is Non-random Mating
This agent occurs when individuals choose mates based on specific traits.
What is convergent evolution?
Analogous structures are the result of this type of evolution, where unrelated species develop similar traits because they live in similar environments.
If a sudden drought leaves only large, hard seeds available, birds with this specific trait would likely undergo directional selection.
What is extinct?
If a branch on a tree does not reach the very top (the present day), it indicates that the species is _______.