Phylogeny

the evolutionary history of a species or a group of related species

phylogeny

a population or a group of populations in which the members have the potential to interbreed in nature and produce viable fertile offspring, and do not produce viable fertile offspring with members from another group.

species

* biological species concept
* ecological species concept
* morphological species concept
* phylogenetic species concept

name the species concepts

* this concept defines species as a group of organisms that can interbreed and produce fertile offspring.
* According to this concept, individuals of the same species are reproductively compatible, whereas individuals of different species are reproductively isolated.

briefly explain the biological species concept

* this concept defines a species based on its ecological niche and interactions within the environment.
* it emphasizes the role and adaptations of an organism within its ecological community.
* It highlights the ecological factors that shape a species’ survival, reproduction, and coexistence with other organisms.

briefly explain the ecological species concept

* this concept defines a species based on observable physical characteristics.
* It suggests that individuals belonging to the same species share similar morphological traits and can be distinguished from other species based on these traits.

briefly explain the morphological species concept

* this concept defines a species based on its evolutionary history and genetic relationships
* it considers species as branches on the tree of life, with each species representing a distinct lineage of populations that share a common ancestor
* this concept utilises genetic data and analysis to determine species boundaries

briefly explain the phylogenetic species concept

the degree of variation of life forms within a given ecosystem, biome, or an entire planet

biodiversity

* ecological diversity
* genetic diversity
* organismal diversity

types of biodiversity

the variation of system level on a given location

what is ecological diversity?

the total amount of genetic characteristics / genes that are contained in the gene pool of a species / group of species

what is genetic diversity?

the number and distribution of species or other taxonomic groups in a given location

what is organismal diversity

it is a hypothesis about evolutionary relationships

what is the tree of life?

* it’s a diagram that represents evolutionary relationships among different species or a group of organisms

they show:

* patterns of descent (not based on phenotypes)
* the points where the branches intersect represent the common ancestor shared by the organisms
* insight on the pattern of speciation
* relationships between different taxonomic groups

what is a phylogenetic tree and its functions?

* it’s when the simplest explanations that are consistent with observations rank higher than more complex observations
* this means that the evolutionary tree that requires the lowest amount of evolutionary changes is the one that maximizes parsimony

principle of maximum parsimony (the simplest tree)

* it’s based on the basic assumptions about how genetic material change in the time it is possible to decide what evolutionary trees reflects the most probable sequence of evolutionary changes
* the assumption based on this principle is that DNA changes have occurred at equal rates at all branches from the common ancestor.

principle of maximum likelihood (the most likely tree)

the group consists of ancestral species and all descendants

monophyletic group

the group consists of ancestral species, but not all descendants

paraphyletic group

the group consists of taxa with different ancestors

polyphyletic group

when the traits are inherited by two different organisms from a common ancestor

homology

when there is a similarity between two species due to convergent evolution, not common ancestry

analogy