Biology Chapter: Species and Genetics Concepts

The Biological Species Concept

• A species is defined as a group of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.

Pre-zygotic Isolation Mechanisms

• A pre-zygotic isolation mechanism prevents the formation of a zygote.

DNA

• The abbreviation for the molecule that carries genetic information in most life forms is DNA.

Nucleotides in DNA

• The nucleotide Uracil (U) is not part of the genetic alphabet in DNA.

Carboniferous Period

• The high levels of oxygen in the atmosphere during the Carboniferous period most contributed to the larger insect and amphibian sizes.

Transcription

• During transcription, the genetic information encoded in DNA is copied into a messenger RNA molecule (mRNA).

Protein Structure

• The primary level of protein organization consists of the unique sequence of amino acids.

Post-zygotic Isolation Mechanisms

• A post-zygotic isolation mechanism prevents the hybrid offspring from developing or reproducing.

Scientific Name

• The correct scientific name for Humans is Homo sapiens.

Species Name

• The species part of the scientific name is often not used alone because it can be ambiguous with other species in different genera.

Adaptations

• Adaptations are traits that increase an organism's fitness in a particular environment.

Speciation

• Two major types of speciation include allopatric speciation, where populations become geographically isolated, and sympatric speciation, where evolution occurs within the same geographic area.

Hybridization

• Hybridization between species occurs when two species interbreed, often resulting in a hybrid offspring.

Constraints on Adaptation

• One constraint that limits the ability of selection to produce adaptations is the lack of genetic variation within a population.

Snake Venom

• Snake venom genes likely evolved from genes with other functions through a process called gene duplication and subsequent mutation.

Lowest Taxon Level

• The lowest level of the hierarchical system used for classifying organisms is species.

Preferred Classification

• Modern biologists prefer to classify organisms based on clades, which are groups of organisms that share a common ancestor.

Branch in Phylogenetic Tree

• A branch in a phylogenetic tree represents a lineage splitting into two or more descendant lineages over time.

Polyphyletic Group

• A polyphyletic group is a group of organisms that does not include all of the descendants of a common ancestor.

Data for Testing Relationships

• Data useful for testing hypotheses about the relationships of taxa include morphological data, genetic data, and fossil data.

Sister Taxa

• Sister taxa in a phylogenetic tree are two lineages that share a common ancestor and are each other's closest relatives.

Hippos and Whales

• Modern biologists view the relationship between hippos and whales as close relatives, with whales originating from an aquatic ancestor of hippos.

Preferred Tree Structure

• The cladogram is the preferred phylogenetic tree structure for representing evolutionary relationships.

Paraphyletic Group

• A paraphyletic group in phylogenetic nomenclature is a group of organisms that includes some but not all of the descendants of a common ancestor.

Conservation Efforts

• Knowing the species names of turtles is crucial for conservation efforts because it allows researchers to identify and track specific populations for management and protection purposes.

Phylogenetic Diversity

• Phylogentic diversity encompasses the evolutionary history and relationships of organisms, while species diversity refers to the number and abundance of species in a given area.

International Organization for Endangered Species

• The IUCN (International Union for Conservation of Nature) maintains lists of endangered species.

Fauna of Hawaii

• The fauna of Hawaii, like the honeycreeper birds, is particularly special because its unique evolutionary history has resulted in a high degree of endemism, meaning a large number of species found only in that location.

Conservation of Turtles in Hawaii

• Conservation of turtles in Hawaii is complicated by various factors, including habitat loss, invasive species, and the impact of climate change.

Biological Evolution

• Subjects of the study of biological evolution include patterns of change over time, mechanisms of change, and the diversity of life on Earth.

Charles Darwin's Hypothesis

• The two main components of Charles Darwin's hypothesis regarding evolution include descent with modification and natural selection.

"Nothing in Biology Makes Sense..."

• The quote, "Nothing in biology makes sense except in light of evolution," is credited to Theodosius Dobzhansky.

Ship of Darwin's Voyage

• Charles Darwin traveled on the HMS Beagle during his influential voyage.

Evolution by Natural Selection

• For evolution by natural selection to occur, there must be variation within a population, heritability of traits, and differential reproductive success based on those traits.

"Descent with Modification"

• "Descent with modification" as proposed by Darwin signifies that species evolve from ancestral species, with modifications accumulating over time.

Theory, Hypothesis, and Guess

• A theory in science is a well-supported explanation for a phenomenon, a hypothesis is a testable prediction, and a guess is a speculation without evidence or testing.

Alfred Russel Wallace

• Alfred Russel Wallace is often not as famous as Charles Darwin because Darwin published his ideas first and had a more extensive body of work supporting his theory.