Exam 1 Flashcards
(47 cards)
Biological species concept
-The distinctiveness of species that occur together at a single locality
-The connection that exists among different populations belonging to the
same species
Phylogenetic species concept
Defines a species as a group of organisms that share a unique evolutionary history and are distinguished from other groups
Adaptive radiation
A process in evolutionary biology where a single species or small group of species rapidly diversify into many new species
Systematics
The distinctive characteristics of species and how they are related to other species through time
Phylogeny
The evolutionary history of a group of organisms, essentially depicting the relationships between different species based on their shared ancestry
Derived character
A trait that evolved in the most recent common ancestor of a lineage and was passed down to its descendants
Ancestral character
trait or feature that is inherited from a common ancestor and has remained largely unchanged since.
Clade
a group of organisms that includes a common ancestor and all of its descendants, both living and extinct
Cladogram
a branching diagram showing the cladistic relationship between a number of species.
Monophyletic
a group of organisms that includes a common ancestor and all of its descendants
Polyphyletic
a group of organisms that do not share a recent common ancestor
Paraphyletic
a group of organisms that includes a common ancestor and some, but not all, of its descendants
Sister group
group of organisms that are the closest relatives of another group of organisms, and are always the same age
Disruptive Selection
type of natural selection where extreme traits are favored over intermediate traits, giving those individuals a fitness advantage
Analogous Traits
characteristics that appear similar in function and form between different species, but have evolved independently from one another
2 categories of isolation mechanisms
prezygotic isolation mechanisms and postzygotic isolation mechanisms
Prezygotic (5 types)
Temporal isolation: Species breed at different times, such as different seasons or times of day
Habitat isolation: Species occupy different habitats within the same area
Behavioral isolation: Species have different mating rituals or signals
Mechanical isolation: Species have physical differences in reproductive structures
Gametic isolation: Differences in gamete cells prevent fertilization
Postzygotic (1 type)
Hybrid inviability:
In this scenario, the hybrid zygote might not develop properly, leading to the embryo dying before reaching maturity.
4 types of speciation
Allopatric-A population is split into two due to geographic isolation, such as by a river or mountain range
Peripatric-A smaller group of the main population becomes geographically isolated on the fringes of the larger population
Parapatric-A species is spread out over a large area, and individuals develop different characteristics and lifestyles despite being able to interbreed
Sympatric-A new species evolves from a single ancestral species without geographic isolation, but rather behavioral isolation.
Know the ways sympatric speciation can occur.
polyploidy (abnormal chromosome number), ecological niche differentiation (using different resources within the same area), and sexual selection (mating preferences based on specific traits
Homologous vs. analogous characters
Homologous structures exist in organisms that have a common ancestor, so they are monophyletic.
Analogous structures are found in organisms that do not have a common ancestor.
Analogous structures always have similar or identical functions, while homologous structures are not always the case
What is the Principle of Parsimony?
the scientific principle that things are usually connected or behave in the simplest or most economical way, especially with reference to alternative evolutionary pathways.
Taxonomic hierarchy
system for classifying organisms based on their characteristics
Domain
What are the domains of life?
Archaea, Bacteria, and Eukarya
