Macroevolution and Classification Vocab

Microevolution

Occurs on a small scale within a population

Macroevolution

Occurs on a large scale at and above species level over geologic time

Species

Organisms that are capable of interbreeding and producing fertile offspring in the same population at the same time

Habitat isolation

Physical isolation between a habitat

Temporal isolation

Two species are unable to breed because they breed at different times

Behavioral isolation

Different mating behaviors

Mechanical isolation

Physical incompatibilities in reproductive structures

Gametic isolation

Sperm and egg from different species are biochemically incompatible, preventing fertilization

Speciation

A population gets split into two reproductively and the differences eventually become too great and they become separate species

Descent with modification

Accumulation of differences among two groups of the same species. They can become so different that they can no longer interbreed, developing a new species. The common ancestor remains

Allopatric speciation

Always caused by geographic isolation

Sympatric speciation

NOT caused by geographic isolation - instead, driven by sexual selection, ecological specialization, and chromosomal arrangements

Evidence for Macroevolution

Fossil record, comparative anatomy, molecular evidence, biogeography, developmental biology

Patterns in macroevolution

Adaptive radiation vs stasis - Divergent vs. Convergent evolution - Coevolution - Directional changes over time – character change - Lineage splitting (speciation) - Extinction

Adaptive radiation

Rapid diversification, an event when many new species arise moderately quickly (can occur after a mass extinction)

Stasis

When a lineage doesn’t change much over a very long time

Divergent evolution

Species with a SHARED common ancestor evolve different traits

Convergent evolution

Unrelated species evolving without a common ancestor yet the animals have similar traits due to similar environmental pressures

Coevolution

The process where the evolution of two or more species is influenced by their interactions with one another. Ex. mutualism, predator-prey, parisitism

Directional selection

Environmental pressures favor a single phenotype, causing the allele frequency to continuously shift in one direction

Lineage splitting- speciation

Clades splitting to create new phylogenies

Extinction

The disappearance of a species from Earth

Clade

A group of organisms believed to compromise all the evolutionary descendants of a common ancestor

Taxonomy

The branch of biology that deals with the naming and classification of life forms. There are 8 different levels

Binomial nomenclature

Using 2 terms to indicate the genus and species of an organism

Monophyletic groups

Taxonomic groups that include a common ancestor and all of its descendants

Derived traits (synapomorphies)

A trait shared by two or more taxa that evolved from their most recent common ancestor

Molecular clock

A tool used in evolutionary biology to estimate the timing of evolutionary events by analyzing the mutation rates of DNA and proteins

Ingroups

A group of closely related taxa that share common traits

Outgroups

A more distantly related group that serves as a reference point for the ingroup

Bacteria

Single-celled, microorganisms, prokaryotic, no nucleus

Archaea

Single-celled, microorganisms, prokaryotic, no nucleus, different cell wall, DNA more similar to eukaryotes, can survive in extreme environments

Eukarya

Organisms that have a true nucleus and organelles - 5 kingdoms

Protista

Mostly single-celled - autotroph or heterotroph - some have cell walls

Fungi

Mostly multi-cellular heterotrophs - have cell walls made of chitin - yeast is a single-celled fungus

Plantae

Mostly multi-cellular autotrophs - have cell walls

Animalia

Mostly multi-cellular heterotrophs - invertebrates vs. vertebrates

Radial symmetry

Symmetry around a central axis. Ex: sea stars, jellyfish, sea anemones, corals

Bilateral symmetry

A single, imaginary line that can divide the body into two distinct right and left sides. Ex: mammals, birds, reptiles, amphibians, insects, spiders, worms

Sessile

This organism is permanently attached and not freely moving within its environment. Ex: trees, sea anemones, sponges, sea fans

Warm blooded

An organism that has a controlled body temperature that remains the same no matter what the temperature is in their surroundings. Ex: birds, mammals

Cold-blooded

An organism whose body temperature changes in response to its surroundings.

Exoskeleton

An organism whose skeleton is on the outside of its body. It is a hard, waterproof substance that provides protection from predators or drying out.

Examples of cold-blooded

Fish, amphibians, reptiles insects, spiders

Examples of exoskeleton

Spiders, insects

Invertebrates

Animals that do not have a spine or a backbone

Vertebrates

Animals that have a spine or backbone

Homologous structures

Anatomical features in different organisms that share a common ancestry, despite potentially serving different functions

Analogous structures

Features in different organisms that serve similar functions but have different evolutionary origins

Vestigial organs

Remnants of evolutionary history that have lost their original function over time, yet still exist in modern organisms

Vertebrates (Phylum Chordata) 5 classes

Mammals, fish, reptiles, birds, amphibians

Fish

Breathe with gills - live in water - cold blooded - skin is covered with scales and bony plates - lay eggs or have live birth

Amphibians

Breathe with lungs or gills - cold blooded - skin is smooth and moist - lay eggs

Reptiles

Breathe with lungs - cold blooded - bodies are covered with dry scales - lay eggs - sex is determined by temperature

Birds

Breathe with lungs - warm blooded - covered with feathers - lay eggs

Mammals

Breathe with lungs - warm blooded - have hair/fur - milk production - most give birth to live young